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HEALTH AND SAFETY ASSESSMENT OF
WASTE-PICKERS AT THE KPONE
LANDFILL SITE
BY
ARETHA MAKAFUI NUVIADENU
(ID: 10638074)
THIS THESIS IS SUBMITTED TO THE UNIVERSITY
OF GHANA, LEGON IN PARTIAL FULFILMENT OF
THE REQUIREMENT FOR THE AWARD OF MPHIL
NUCLEAR AND ENVIRONMENTAL PROTECTION
DEGREE
2019
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Declaration
This thesis is the result of research work undertaken by Aretha Makafui NUVI-
ADENU in the department of Nuclear Science and Application, College of Basic
and Applied Sciences, University of Ghana, under the supervision of Dr. Sampson
Atiemo (GAEC/SNAS, UG-Legon, Ghana) and Dr. Owiredu Gyampo (GAEC/S-
NAS, UG-Legon, Ghana).
Sign: ...........................................
Aretha Makafui NUVIADENU
(Student)
Sign: ............................................. Sign: ................................................
Dr. Sampson ATIEMO Dr. Owiredu GYAMPO
(Supervisor) (Co-Supervisor)
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Dedication
Dedicated to my husband (Christian) and children (Elikem, Nyuieko and De-
lanyo) . . .
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Acknowledgements
I praise God for the good health, strength and fortitude He blessed me with to
be able to go through this study.
I immensely thank my supervisors Dr. Sampson Atiemo and Dr. Owuredu
Gyampo for their time, guidance and support I greatly benefited from throughout
this work.
My heartfelt gratitude also gos to the Kpone landfill site supervisors, Ernest and
David Ameweh, for their warm reception and support anytime I visit the study
location.
I am most importantly thank the waste pickers and their leaders for the unreserved
cooperation throughout the field work.
I appreciate the support offered by Dr. Hyacinthe Ahiamadji for his assistance
during the sampling campaign.
I owe my family special a thank for their continued show of love and support.
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Abbreviations
Cdeg Degree of Contamination
CF Contamination Factor
EPA Environmental Protection Agency
HHW Hazardous Household Waste
HI Hazard Index
HQ Hazard Quotient
MMS Municipal Solid Waste
MSW Municipal solid waste
NO2 Nitrogen dioxide
SO2 Sulphur dioxide
UNEP United Nations Development Program
NO2 XRF X-ray Fluorescence
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Table of Contents
Declaration i
Dedication ii
Acknowledgements iii
Abbreviations iv
List of Figures ix
List of Tables xi
Abstract xii
1 Introduction 1
1.1 General background . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 The Kpone Landfills Site . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 Problem statement . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.4 Study objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.5 Scope of the study . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.6 Significance of the study . . . . . . . . . . . . . . . . . . . . . . . . 7
1.7 Study limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.8 Outline of Thesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2 Literature Review 9
2.1 Overview of municipal solid waste (MSW) . . . . . . . . . . . . . . 9
2.1.1 Management of municipal solid waste (MSW) . . . . . . . . 10
2.2 Recycling: A sustainable urban waste management . . . . . . . . . 11
2.3 Recycling processes . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.3.1 Stages in recycling . . . . . . . . . . . . . . . . . . . . . . . 12
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2.3.1.1 Collecting recyclables . . . . . . . . . . . . . . . . 12
2.3.1.2 Processing recyclables . . . . . . . . . . . . . . . . 12
2.3.1.3 Purchasing recycled product . . . . . . . . . . . . . 12
2.4 The Informal Recycling Sector . . . . . . . . . . . . . . . . . . . . . 13
2.5 Socioeconomic benefits of IWP . . . . . . . . . . . . . . . . . . . . 16
2.5.1 Provision of reusable materials . . . . . . . . . . . . . . . . . 16
2.5.1.1 Supply of materials to businesses . . . . . . . . . . 16
2.5.1.2 Employment and income generation . . . . . . . . 16
2.5.2 Conservation of natural resources . . . . . . . . . . . . . . . 17
2.5.3 Cheaper consumer product . . . . . . . . . . . . . . . . . . . 17
2.5.3.1 Reduction of greenhouse gas (GHG) emissions . . . 17
2.5.3.2 Reduced municipal cost and increased landfill span 17
2.5.3.3 Environmental stewards . . . . . . . . . . . . . . . 18
2.5.3.4 Improve sanitation and hygiene . . . . . . . . . . . 18
2.6 Working environment of waste pickers . . . . . . . . . . . . . . . . . 18
2.7 Occupational health and safety of waste pickers . . . . . . . . . . . 19
2.7.1 Chemical hazard . . . . . . . . . . . . . . . . . . . . . . . . 20
2.7.2 Biological hazard . . . . . . . . . . . . . . . . . . . . . . . . 21
2.7.3 Physical hazard . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.7.4 Health effects of exposure to chemicals in landfill . . . . . . 22
2.7.4.1 Health effects of lead . . . . . . . . . . . . . . . . . 23
2.7.4.2 Health effects of cadmium . . . . . . . . . . . . . . 23
2.7.4.3 Health effects of mercury . . . . . . . . . . . . . . 23
2.7.4.4 Health Effects of NO2 and SO2 . . . . . . . . . . . 23
2.8 XRF analysis in environmental monitoring . . . . . . . . . . . . . . 24
2.9 Previous studies on landfills in Ghana . . . . . . . . . . . . . . . . . 25
3 Methodology 26
3.1 The study area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.2 Study methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.3 Soil, dusts and gases sampling . . . . . . . . . . . . . . . . . . . . . 28
3.3.1 Sampling locations . . . . . . . . . . . . . . . . . . . . . . . 28
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3.3.2 Dust sampling . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.3.3 Soil sampling . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.3.4 SO2 and NO2 sampling . . . . . . . . . . . . . . . . . . . . . 32
3.3.4.1 The gas sampler . . . . . . . . . . . . . . . . . . . 32
3.3.4.2 SO2 and NO2 monitoring . . . . . . . . . . . . . . 32
3.4 Demographic data collection . . . . . . . . . . . . . . . . . . . . . . 33
3.5 Sample preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.6 Elemental analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.7 Data analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
3.7.1 Contamination factor . . . . . . . . . . . . . . . . . . . . . . 38
3.7.2 Degree of contamination . . . . . . . . . . . . . . . . . . . . 39
3.7.3 Human exposure to pollutants . . . . . . . . . . . . . . . . . 40
3.7.3.1 Ingestion of heavy metals . . . . . . . . . . . . . . 40
3.7.3.2 Dermal intake of heavy metals . . . . . . . . . . . 40
3.7.3.3 Inhalation of heavy metals . . . . . . . . . . . . . . 41
3.7.4 Health risk assessment . . . . . . . . . . . . . . . . . . . . . 41
3.7.4.1 Non-carcinogenic health risk . . . . . . . . . . . . . 41
3.7.4.2 Carcinogenic health risk . . . . . . . . . . . . . . . 42
3.8 Quality control/Quality assurance . . . . . . . . . . . . . . . . . . . 42
3.8.1 Field sampling precautions . . . . . . . . . . . . . . . . . . . 42
3.8.2 Laboratory precautions . . . . . . . . . . . . . . . . . . . . . 43
3.8.3 Results validation . . . . . . . . . . . . . . . . . . . . . . . . 43
4 Results and Discussions 44
4.1 Waste Pickers at Kpone Landfills site . . . . . . . . . . . . . . . . . 44
4.2 NO2 monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4.3 SO2 monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
4.4 XRF measurement validation . . . . . . . . . . . . . . . . . . . . . 54
4.5 Elemental composition of soil and dust . . . . . . . . . . . . . . . . 55
4.5.1 Heavy metals in dust samples . . . . . . . . . . . . . . . . . 58
4.5.2 Heavy metals in soil samples . . . . . . . . . . . . . . . . . . 60
4.6 Heavy metal contamination assessment . . . . . . . . . . . . . . . . 61
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4.7 Contamination factor . . . . . . . . . . . . . . . . . . . . . . . . . . 61
4.7.1 Degree of contamination . . . . . . . . . . . . . . . . . . . . 63
4.8 Heath risk assessment . . . . . . . . . . . . . . . . . . . . . . . . . 65
4.8.1 Non-carcinogenic health risk assessment . . . . . . . . . . . 71
4.8.2 Carcinogenic health risk assessment . . . . . . . . . . . . . . 73
5 Conclusions and Recommendations 75
5.1 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
5.2 Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
References 77
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List of Figures
1.1 Waste pile at the Kpone Landfills site (Picture from student’s field
work) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Waste pickers and their wares at the Kpone Landfills site (Picture
from student’s field work) . . . . . . . . . . . . . . . . . . . . . . . 4
1.3 Waste picking activity on a mixed waste pile (Picture from student’s
field work) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 Recycling Labour put in against Profit made from Recycling (Source:
WIEGO (2008)) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.1 The Kpone landfill site map (Source: Drawn by student) . . . . . . 26
3.2 Aerial view of the Kpone landfill site (source: Google Earth) . . . . 27
3.3 Traffic and waste volume to Kpone Landfill site (Source: Salifu, 2019) 28
3.4 Flowchart of the study methodology . . . . . . . . . . . . . . . . . . 29
3.5 Aeroqual 500 Series gas monitors being used for SO2 and NO2 mon-
itoring (Source: Aeroqual user manual) . . . . . . . . . . . . . . . . 33
3.6 Field monitoring of gases at one of the sampling locations at the
Kpone landfill site (Picture from student’s field work) . . . . . . . . 34
3.7 Equipment used for soil and dust samples preparation. A: Fritsch
Pulverisette-2; B: Metric Test Sieve BS 410 – WS Tyler; C: Manual
Press Pelletizer; D: Press-die set (Picture from student’s laboratory
work) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.8 The Amptek Experimental kit for XFR analysis used in this study
(Picture from student’s laboratory work) . . . . . . . . . . . . . . . 36
3.9 XRF measurement geometry with an aluminum filter placed in front
of the x-ray source to reduce spectrum background and improve
sensitivity (Source: Amptek user manual) . . . . . . . . . . . . . . 37
4.1 Measured average daily NO2 concentrations plotted alongside Ghana
EPA (for residential and industrial areas) and WHO guideline limits 48
4.2 Stack emission form adjacent ’Senteo Ceramic Factory’ with possi-
ble effect on ambient air quality (Picture from student’s field work) 49
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4.3 Measured average daily SO2 concentrations plotted alongside Ghana
EPA (for residential and industrial areas) and WHO guideline limits 52
4.4 Mean concentration for V, Cr, Ni and Cu in dust per sampling
location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
4.5 Mean concentration for Zn, Cd, Hg and Pb in dust per sampling
location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.6 Mean concentration for V, Cr, Ni and Cu in soil per sampling location 60
4.7 Mean concentration for Zn, Cd, Hg and Pb in soil per sampling
location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
4.8 Contamination factor for V, Cr, Ni and Cu per sampling location . 63
4.9 Contamination factor for Zn, Cd, Hg and Pb per sampling location 64
4.10 Degree of contamination of heavy metals from the Kpone Landfills . 64
4.11 Waste pickers at work at the Kpone landfill site (Picture from stu-
dent’s field work) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
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List of Tables
3.1 Description of sampling locations within the study area . . . . . . . 29
4.1 Summary of responses to the study questionnaire . . . . . . . . . . 44
4.2 NO2 concentration in µg/m3 recorded per sampling location during
the air quality monitoring . . . . . . . . . . . . . . . . . . . . . . . 46
4.3 SO2 concentration recorded per sampling location during the air
quality monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
4.4 XRF measured and certified values from BHVO-2, GSP-2 and IAEA
Soil-7 Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
4.5 Mean heavy metals concentrations (gm/kg) in dust sampled at the
Kpone landfill site . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
4.6 Mean heavy metals concentrations (gm/kg) in soil sampled at the
Kpone landfill site . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
4.7 Heavy metals contributions (contamination factor) to the degree of
contamination of soil and dust at each sampling location . . . . . . 62
4.8 Exposure parameters used for health risk assessment for different
pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
4.9 Heavy metal specific hazard quotients for different exposure pathways 67
4.10 Non-carcinogenic heavy metal specific hazard indexes per sampling
location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
4.11 Carcinogenic lifetime risk for inhalation of heavy metals . . . . . . . 73
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Abstract
Ambient sulphur dioxide (SO2) and nitrogen dioxide (NO2) were measured mea-
sured from seven (7) locations at the Kpone landfill site in the Kpone Municipality
of Greater Accra Region. Average 24-hour concentrations ranged 47 µg/m3 – 185
µg/m3 and 52µg/m3 – 164 µg/m3 were recorded for NO2 and SO2 respectively. All
the measured concentrations were above the WHO guideline limits.
Eight (8) heavy metals (Pb, Hg, V, Cr, Cu, Ni, Zn, and Cd) were detected and
quantified in the soil and dust sampled from ten (10) locations within the study
area using x-ray fluorescence analysis (XRF). Cu, Zn and Pb recorded the highest
concentrations that were all above their respective New Dutch List permissible
limits. The concentrations, at some sampling locations, were as high as: Cu (334
mg/kg), Zn (36585 mg/kg) and Pb (4808 mg/kg) which recorded high contami-
nation factors as well.
Contamination factors computed using elemental concentrations, as well as the
degree of contamination computed for each sampling location revealed locations
4, 5, 6 and 7 as highly contaminated. Health hazard index for carcinogenic and
non-carcinogenic health risk with respect to three exposure pathways (dermal, in-
gestion and inhalation) projected locations 4, 5, 6 and 7 as locations with high
health risks for waste pickers who ply their trade around these areas.
Waste pickers’awareness of health and safety risks was assessed as well. All of
them seem to be aware of the physical hazard while 23% are aware of the health
risks associated with their working conditions.
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Chapter 1
Introduction
1.1 General background
Human activities in general generate waste as byproducts. Decisions about waste
management are usually made by Government with the general public as stake-
holders. These decisions can have some impacts on public health and productivity,
and may also affect the environment. Poorly managed waste has the potential to
transmit diseases and pollute the environment (Kaza et al., 2018).
According to the World Bank report, authored by Kaza et al. (2018), management
of municipal solid waste (MSW) in developing counties is the sole responsibility
of local government with minimal public involvement. One of the most important
services a city provides is the management of MSW; and this absorbs 20–40 percent
of municipal operation budget in most developing countries (Coffey and Coad,
2010). This funding caters for collection and transporting of waste to the final
disposal site (landfill) without capturing recycling on the budget (Coffey and Coad,
2010). In spite of this funding, waste management is woefully inefficient leaving
local municipalities strained to address challenges associated with increased urban
waste generation (Kaza et al., 2018). Consequently, the large volume of waste
collected is exclusively dumped or sent to be landfilled since this is the cheapest
waste management option (Hoornweg et al., 2012).
The lapses in providing adequate waste management in most developing countries
have culminated in the provision of informal waste management services alongside
the formal waste services. Research has shown that the informal solid waste econ-
omy involves individuals or enterprises that deal with waste management and
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recycling; and whose activities are not supported or recognized by authorities or
perceived to be in violation of authorities (Made et al., 2017). Several researches
have recognized the contributions of the informal economy in waste management.
Recycling is one aspect of waste management that is capital intensive. Since
municipalities remain inadequately resourced to adopt modern technology to seg-
regate and recover recyclables in the mixed waste they do not realize the eco-
nomic value of MSW (Shankar and Sahni, 2018). Consequently, material retrieval
is therefore taken up by the informal waste pickers who identify this potential
resource and hence manually remove recyclables from the mixed waste stream.
Resource recovery in most developing countries is an economically vibrant activity
in most dump sites and landfills and relies heavily on informal work force, waste
pickers. They help to divert 15 to 20 per cent of waste from landfills to recycle
(Kaza et al., 2018). The process of recycling in most developing countries involves
recovery, processing and commercialising of recyclable materials.
Waste pickers are described as key stakeholders in sustainable urban waste man-
agement in developing countries. Apart from providing the main work force that
supply secondary materials to local industries, their contribution to the local econ-
omy and environmental sustainability is widely recognized (WIEGO, 2008). De-
spite their contribution, they face low social status, deplorable living and working
conditions and obtain little support from local government (WIEGO, 2008).
Handling municipal solid waste has the potential to cause adverse health impact
due to the toxic and hazardous material contained in it (Gutberlet and Uddin,
2017). According to Alam and Ahmade (2013), the USA Public Health Services
have identified 22 human diseases linked to improper MSW management; the
most vulnerable to MSW risk are waste pickers and waste workers. In the quest
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to retrieve reusable materials they encounter health and safety issues associated
with both occupational and environmental risks.
The hazardous nature of landfill environment is attributed to gaseous emissions
of volatile organic compounds (VOCs), air born particulate matter and leachate
which contain contaminants that has the potential to cause human illness (Slack
et al., 2005). Soils at landfill sites are also reported to be contaminated with heavy
metals such as Pb, Hg, Cr, Mn, Ni, Co, Cd, Zn and Cu with potential impact on
human health (Adamcová et al., 2017). Figure 1.1 shows parts of the waste pile
and emanating leachate at the Kpone Landfills site.
Figure 1.1: Waste pile at the Kpone Landfills site (Picture from student’s
field work)
1.2 The Kpone Landfills Site
As it is the practice in most developing countries, many dump sites and landfills
in Ghana witness waste picking activities due to the high recyclable content in the
large volume of waste deposited. The Kpone Landfills in the Kpone-Katamanso
Municipality is one of such sites. It is an engineered landfill built in 2013 and
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currently receives waste from all municipal assemblies in the Greater Accra region.
There is a significant presence of waste pickers (over 250) on site (Salifu, 2019).
Figures 1.2 and 1.3 show some waste pickers and their wares recovered from the
waste pile at the Kpone Landfills site.
Figure 1.2: Waste pickers and their wares at the Kpone Landfills site
(Picture from student’s field work)
As characteristic of waste pickers, they sift through the mixed MSW stream to re-
cover and collect recyclables (paper, metal, plastic, glass, e-waste) and add value to
it by sorting, cleaning, altering the shape of the materials, baling and compacting
before selling to middlemen (WIEGO, 2008). The municipal solid waste (MSW)
deposited at the Kpone landfill sites comprises residential, industrial, commercial,
institutional and construction and demolishing wastes (Owusu et al., 2012). This
co-disposed waste poses serious health and safety risks (Alam and Ahmade, 2013).
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Figure 1.3: Waste picking activity on a mixed waste pile (Picture from
student’s field work)
1.3 Problem statement
As the waste pickers handle waste daily they become exposed to toxic and haz-
ardous materials contained in the waste stream. They come into direct contact
with pathogenic bio-aerosols as well as decomposed highly mixed waste with or-
ganic material, fecal matter and chemicals contained in household hazardous waste
(HHW). This has the potential to cause adverse health effects and may lead to
the spread of various deceases (Gutberlet and Uddin, 2017).
There is also the risk of being injured by sharp objects and contracting infectious
diseases such as HIV AIDS and hepatitis C from contaminated health care waste.
Risks of injury or even death from heavy machinery and exposure to dust from
disposal operations exist as well (UNEP, 2013).
In spite of these apparent health and safety risks (or occupational health risk)
associated with working conditions of waste pickers at the Kpone Landfills site,
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characteristics and environmental quality at the landfills and their impact on qual-
ity of life is yet to be comprehensively established.
1.4 Study objectives
This study aims to examine the work environment at the Kpone Landfills site and
to assess the safety and health risks of waste pickers.
The specific objectives of the work are:
1. To determine environmental pollutants in ambient air, soil, and resuspended
dust at the Kpone landfill site.
2. Assess the pollution load index of the study location, and
3. To evaluate health effects associated with the contamination levels.
The output from this study will be a useful information for authorities responsible
for regulating activities of waste pickers.
1.5 Scope of the study
In this study, measurements of NO2 and SO2 gases in ambient air were carried out
using Aeroqual air quality monitors.
Soil and resuspended dust were also sampled and analysed by Energy Dispersive
X-ray Fluorescence (ED-XRF) spectrometry.
Based on the analytical results, environmental contamination levels at the study
location (Kpone landfill site) was assessed. Demographic data on waste pickers
was collected by means of questionnaires.
The carcinogenic and non-carcinogenic health risks were evaluated using the de-
mographic data and the analytical results.
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The measured NO2 and SO2 levels were also compared with EPA-Ghana regula-
tory guideline limits.
1.6 Significance of the study
Available data on environmental quality around landfills in Ghana and the related
health and safety impacts is scanty.
The findings of this study about pollutants concentration levels, site contamina-
tion levels and related health and safety impacts on waste pickers at the Kpone
Landfills site will constitute a very useful information for environmental pollution
mitigation decision-makers and researchers who are interested in the activities of
waste pickers.
For instance, the data obtained in this study can be beneficial to the ongoing
”Short-Lived Climate and Air Pollutants Reduction” project under the WHO’s
Urban Health Initiative (UHI) in Accra, in collaboration with the Ministry of
Health and the Accra Metropolitan Assembly (AMA).
Waste pickers will find the information useful as it will help them look out for or
use the most appropriate PPEs.
1.7 Study limitations
Atmospheric articulate matter PM2.5 and PM10 fractions as part of air quality
monitoring could not be carried out in this study due to unavailability of nec-
essary sampling tools (air sampler and filters). Nevertheless, resuspended dusts
were collected from window netting and workbenches at sampling locations. This
limitation has therefore been dealt with to produce an acceptable research output.
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1.8 Outline of Thesis
The general background of the study and the problems this study sought out to
address is presented in the first chapter (Chapter 1). This chapter explains the
significance of this research work and how its output could be useful data for
stakeholders in landfill management.
In chapter 2, concepts of municipal solid waste collection, its composition and
landfill operations are reviewed. Existing studies on environmental pollutants as-
sociated with landfill environments and their possible health impacts have also
been reviewed in order to make a contribution towards filling the gap in knowl-
edge.
In chapter 3, the study design is presented. The sampling site, sampling meth-
ods and laboratory analytical techniques as well as the experimental set-ups for
the different experiments carried out are described. These include soil, dust and
gas sampling (at Kpone Landfill); elemental analyses by energy dispersive x-ray
fluorescence (ED-XRF) spectroscopy at the National Nuclear Research Institute
(NNRI) of the Ghana Atomic Energy Commission (GAEC). Health risk assess-
ment is also presented. Quality assurance and quality control measures adopted
in this study were also outline.
Chapter 4 presents the experimental and data analysis results. The results’ sig-
nificance with respect to health and safety of waste pickers at study location are
discussed in this chapter.
In chapter 5, the concluding remarks and necessary recommendations are provided.
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Chapter 2
Literature Review
2.1 Overview of municipal solid waste (MSW)
Municipal solid waste (MSW), also called trash or garbage, is defined as wastes
consisting of everyday items such as product packaging, grass clippings, furniture,
clothing, bottles and cans, food scraps, newspapers, appliances, consumer elec-
tronics and batteries (U.S. Environmental Protection Agency, 2004). Municipali-
ties and government authorities are responsible for MSW management (Zurbrugg,
2003). MSW comprises wastes from public and private institutions, municipal
services, residential or household wastes, and construction and demolition debris
(UN-Habitat, 2010).
MSW generation has increased considerably over the past decades, attributed
mainly to rapid industrialization, technological advancement, modernization and
rapid rise in global human population. This has increased demand for food, shelter
and natural resources resulting in a commensurate increase in both quantity and
diversity of waste forms (Alam and Ahmade, 2013; Shankar and Sahni, 2018).
According to the World Bank Report (Kaza et al., 2018), 2.01 billion tons of
MSW is generated annually, of which 33% is not managed in an environmentally
safe manner. Improper management of solid waste is a cause of urban pollution
of air, soil, surface and underground water which adversely impact human health
and the environment (Alam and Ahmade, 2013). It poses the biggest challenge in
urban areas, small towns, and large villages (UN-Habitat, 2010).
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2.1.1 Management of municipal solid waste (MSW)
Options used for the management of municipal solid waste (MSW) are landfill
of untreated waste, mechanical biological treatment (MBT), incineration, com-
posting, anaerobic digesting and recycling (Smith et al., 2001). In most developed
countries, solid waste management practices that promote desirable activities such
as prevent, re-use, reduce and recycle at source is given the most priority. The sec-
ond priority is energy recovery with landfilling being the least favored (Lazarevic
et al., 2010; Pawels and Tom, 2013).
Solid waste management is expensive Kaza et al. (2018). Wealthier countries with
available resources are able to provide efficient collection and segregation services
which results in higher recovery and recycling rates of over 60% (Hoornweg et al.,
2012).
State of the art equipment and processing technology is available to process mixed
municipal waste, commingle and segregated recyclables and yard waste (Savage
and Diaz, 1990).
However, most developing countries resort to landfills as waste management option
(Zurbrugg, 2003). This is because urban waste management is expensive and it
absorbs 40 - 80/tonne of the municipal revenue in developing countries. This cost
is allocated to waste collection, transfer and disposal without considering material
recovery and recycling (Cointreau, 2006).
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2.2 Recycling: A sustainable urban waste man-
agement
Recycling involves the treatment or reprocessing of discarded waste to make it ad-
equate for reuse. At collection point and dump site, MSW can be seen to consist
of paper, metal, glass, plastic, leather, rubber, ash and fine earth, compostable
organics, and domestic hazardous materials (Pawels and Tom, 2013). These ma-
terials are recyclables that are considered a valuable resource that can be recycled
and transformed into new economic opportunities, while contributing to conserv-
ing natural resources and reduce greenhouse gas (GHG) emissions (Medina, 2007).
Recyclables are considerable commodity with higher profit returns and creating
millions of jobs. For instance the estimated value($ million) for paper is $90.1,
plastic is $33.2, metal $5.8 and organics $12.1 (Medina, 2007). Recycling a part of
solid waste management is capital intensive. Resource recovery in industrialized
countries is undertaken by the formal sector and regulated by law. It also involves
a public concern for the environment (Zurbrugg, 2003).
Recycling in most developing countries is an informal sector activity which re-
lies on waste pickers who divert more than 15% -20% of waste than is reported
(Gupta, 2012). Their activities are not regulated nor recognized or supported by
government agencies (Makhubele et al., 2019).
2.3 Recycling processes
The process of recycling involves three main stages: Collecting, Processing and
Commercialization of recycled materials (Makhubele et al., 2019). The informal
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waste picker is actively involved in the first stage where they retrieve materials of
economic value such as metals, glass, paper, plastic and sell.
2.3.1 Stages in recycling
Recycling involves three main steps: (1) Collecting (2) Processing (3) Purchasing
recycled products.
2.3.1.1 Collecting recyclables
This stage involves collection of recyclables. There are four main means of collec-
tion namely curbside, drop-off centers, buy-back centers and deposit or refund.
The collected materials are then sent to a materials-recovery facility to be sorted,
cleaned and prepared into marketable commodities to be sold to processing com-
panies. Items recycled by curbside are paper, cardboard, glass, cans, and plastics.
The informal waste pickers are involved in this stage of material recovery where
they remove items from mixed waste stream at collection points and dump sites.
2.3.1.2 Processing recyclables
In this stage the cleaned and sorted recyclables are sold to industries to be used in
manufacturing processes as secondary raw materials. The recyclables are broken
down, melted or liquefied into it basic units. It is then processed directly into new
products or mixed with virgin raw materials to make new products.
2.3.1.3 Purchasing recycled product
This step completes the recycling loop. Products made with total or partial recy-
clable materials is sold to consumers with recycled label on the product.
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2.4 The Informal Recycling Sector
In most developing countries, governments are unable to provide financial support
for the unemployed population. Since resources can be realised from waste, it is
common to find some of the people venture into informal recycling sector (Coffey
and Coad, 2010; UN-Habitat, 2010).
This sector exists and functions because of market forces and socio-economic fac-
tors such as poverty, unemployment, and the perception that waste generates
income (Ali, 1999). While driven by these financial benefits they have little knowl-
edge about environmental concerns and issues regarding the nature of their work
(Coffey and Coad, 2010; UN-Habitat, 2010).
The widespread of recycling materials and the focus of the Sustainable Develop-
ment Goals (MDGs) on poverty reduction and improving waste strategies through
recycling have drawn attention to the world’s informal recyclers UNEP (2013).
”Waste pickers”, this is a general term adopted by the first World Conference of
Waste Pickers in 2008 (Samson, 2009). They refer to people working on dumps
or rummage through garbage on the streets, and to informal private collectors
of recyclables who sell to middlemen or businesses or transform waste to new
products (WIEGO, 2008). Waste pickers recover reusable waste such as metals,
plastics and paper, since they are of higher economic value (Medina, 2007).
The occupational title of waste pickers is linguistically diverse; in Brazil - Cata-
dores, Argentina - Cirujas, Egypt - Zabbaleen, Cuba -Buzo, Mexico - Pependdores
(Hoornweg et al., 2012).
According to Wilson et al. (2006), depending on where and how material recovery
takes place, four main categories of informal recycling have been identified:
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1. Itinerant waste pickers: These are waste collectors who go from door to door
to buy sorted dry recyclable materials from households and then transport
to recycling shop.
2. Street waste pickers: They are workers who recover recyclable materials
from mixed waste in communal bins or waste thrown on the street before
collection.
3. Municipal waste collection crew: These are waste pickers who retrieve sec-
ondary raw materials from vehicles transporting MSW to disposal sites.
4. Waste picking from dumps: Waste pickers rummage through the mixed waste
deposited at dumps to recover secondary raw materials prior to covering.
Waste picking provide livelihood and employment opportunities to vulnerable
people especially to women, children, the elderly, migrants, people displaced by
massive conflicts, the unemployed and represents a large proportion of the world’s
working poor (Kaza et al., 2018).
Extensive study into their activities showed that their work is not regulated by
local city authorities and hence they do not pay taxes, have no trading license and
therefore they are not included in government insurance schemes or social security
benefits and they lack legal protection (UNEP, 2013; Wilson et al., 2006). Wilson
et al,.2006). They are generally noted to work in unsanitary conditions and they
lack educational and training opportunities, face social stigma and massive price
fluctuations of recyclable materials (Kaza et al., 2018; WIEGO, 2008). With low
technology employed in resource recovery, recycling of materials by waste pickers
is labor intensive with low returns.
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Waste pickers may not necessarily be the poorest in society although their income
is very low. This is primarily due to their low position in the trade hierarchy
for recycled materials. They are often badly exploited and paid low prices for
collected materials especially in markets where only one buyer exists and where
pickers bargain as individuals. Organized waste pickers form supportive network
which help to improve their income and legitimize their activities (Wilson et al.,
2006).
Figure 2.1: Recycling Labour put in against Profit made from Recycling
(Source: WIEGO (2008))
Despite their contribute to local economy, public health and safety and to envi-
ronmental sustainability their effort is often unnoticed.
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2.5 Socioeconomic benefits of IWP
2.5.1 Provision of reusable materials
2.5.1.1 Supply of materials to businesses
Informal Economy Monitory Study (IEMS) coordinated by WIEGO on 763 waste
pickers in five cities in Asia, Africa and Latin America showed that waste pickers
sell recyclables to both formal and informal business, private individuals and the
general public. For instance in Ghana scrap metal pickers supply scrap to Tema
Steel Company the largest producer of iron rod and fabricated metals. Plastics
and rubber are also supplied to Blow Plast limited a plastic recycling company
(Owusu-Sekyere et al., 2013). In Brazil 90 percent of materials recycled by industry
are recovered by Catadores (30,000 tons/day) (Medina, 2007). In Belo Horizonte,
Brazil and Nakuru in Kenya, waste pickers recover materials of artistic value and
sell them to artists and groups for re-imaging (WIEGO, 2008).
2.5.1.2 Employment and income generation
More than 15 million people earn living in the informal waste sector. For instance
in China 3.3 million to 5.6 million people in urban centers are engaged in informal
recycling, in Cairo 96 thousand people are involved, in Asia and Latin America
2 per cent of the urban population depend on waste picking for a living (Wilson
et al., 2006). In Ghana, scrap and plastic waste pickers earn Ghc 8,000 for 10 tons
of scrap metal and 20 Gp per kg of plastic waste (Owusu-Sekyere et al., 2013).
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2.5.2 Conservation of natural resources
Industries are supplied with secondary raw materials which is obtained from the
waste stream. This reduces demand for raw materials resulting in less energy
required to produce materials from recyclable items than using primary raw mate-
rials. This lowers cost of production and dependence on natural resources (Gupta,
2012).
2.5.3 Cheaper consumer product
Informal recycling provides cheaper materials than imported goods and virgin
materials. In this way product manufactured from recycled materials are more
affordable for low income consumers (d’Ambrières, 2019).
2.5.3.1 Reduction of greenhouse gas (GHG) emissions
Significant decrease in GHG emissions (Green House Emissions) experienced in
the waste sector from 1990 to 2015 (Kaza et al., 2018). For example in Pune,
India, Brazil and Egypt waste pickers collect organic matter for composting and
biogas (WIEGO, 2008).
2.5.3.2 Reduced municipal cost and increased landfill span
Significant quantities of materials that require land disposal are diverted from
landfills to be recycled. This create about 30 percent additional space to dispose
other wastes and also increase the life span of landfill at no cost to municipalities
(Coffey and Coad, 2010).
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2.5.3.3 Environmental stewards
Informal recyclers apart from collecting waste door-to-door also educate house-
holds about source separation and the significance of recycling to the environment
(Gutberlet and Uddin, 2017).
2.5.3.4 Improve sanitation and hygiene
50-100 percent of waste collection services are performed by waste pickers in most
cities in developing countries. This helps to improve sanitation in parts of the city
where formal waste collection services are not available (Wilson et al., 2006).
2.6 Working environment of waste pickers
In most developing countries, landfills being the final sites,receives large volumes of
MSW which is unsegregated and highly mixed. Many waste pickers are stationed
at the landfills because they readily have access to waste (Wilson et al., 2006).
In the course of work they handle large volumes of waste of diverse forms. The
composition of MSW they handle consists of organic and inorganic fractions. A
large proportion of these comes from residential sources which is noted to contain
household hazardous waste (HHW), of which about 4 percent poses environmental
and health risks when disposed in landfills (Binion and Gutberlet, 2012). HHW
contains corrosive, explosive, flammable, toxic, ignitable, or reactive ingredients
which is difficult to dispose and put human health and the environment at risk
because of its bio-chemical nature (Inglezakis and Moustakas, 2015).
Landfills and dump sites which are the working areas of waste pickers are noted
to be a dangerous environment. Extensive studies of landfills have attributed the
hazardous nature to the emissions from decomposed waste in the form of air borne
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particulate matter, gaseous emissions of volatile organic compounds (VOCs) and
leachate Guerrero et al. (2013); Mavropoulos (2015).
According to Slack et al. (2005), landfill gaseous emissions are volatilised from
leachate and hence can contain similar hazardous compounds found in leachate.
Leachate contains xenobiotic organic compounds (XOCs) and heavy metals which
are classified as hazardous and can be toxic, corrosive, flammable, reactive, car-
cinogenic, teratogenic, mutagenic and ecotoxic, bioaccumulative and can persist
in the environment. Consequently, environmental and human health risks are
associated with exposure to these hazardous substances (Brice et al., 2006).
2.7 Occupational health and safety of waste pick-
ers
Handling waste is associated with inherent risk due to the toxic and hazardous
substances contained in the waste stream which has the potential to adversely
affect human health and the environment (Gutberlet and Uddin, 2017). Where
hand sorting of inorganic materials is done, waste pickers come into close contact
with waste (Fewtrell, 2012). In their quest to retrieve articles of economic value
they become exposed to contaminants in the waste stream through body contact,
penetrating injuries, inhalation or ingestion (Ziraba et al., 2016).
Cointreau and Cravioto (2009) stated that throughout the world, workers and
waste pickers who handle solid waste are exposed to occupational health and
accidents hazards. These hazards are associated with the content of materials
(waste) being handled, emissions from the materials and the equipment used.
Waste pickers receive no protection or training regarding the highly risky nature
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of their work Binion and Gutberlet (2012). Their situation is further worsened by
lack of funds to purchase required personal protective equipment (PPE) such as
nose mask, safety boots, gloves, reflectors and also afford medical services when
the need arises.
They lack awareness on how to handle potentially risky materials contained in the
mixed waste stream (Gutberlet and Uddin, 2017), and also lack access to potable
running water and disinfectant to clean up after the day’s work (UNEP, 2013).
The three types of occupational hazards encountered by waste workers are physical,
chemical and biological (Fewtrell, 2012).
2.7.1 Chemical hazard
Chemical hazards at landfills may be due to exposure to industrial, pharmaceuti-
cal, hospital waste and household hazardous waste (Binion and Gutberlet, 2012).
Waste pickers may come into contact with paper saturated with toxic chemicals.
They are also likely to inhale residues of pesticides, solvents or chemicals in con-
tainers (Wilson et al., 2006). These chemicals may be toxic, corrosive and radioac-
tive resulting in cancers, sore and metabolic disorders (Parveen and Faisal, 2005).
Inhaling dust, smoke from burning waste and fumes from vehicle and heavy ma-
chinery emissions may cause eye problems and respiratory diseases (Parveen and
Faisal, 2005).
Exposure to dioxin and related compounds and heavy metals such as lead, cad-
mium and mercury are of great concern due to their health effect. For instance
after an investigation in Manila, Philippines, the blood of recyclers working in
landfills were found to contain high levels of lead (Suplido and Ong, 2000).
Also the breast milk of women recyclers in India, Cambodia, Vietnam, and the
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Philippine were found to contain higher levels of lead and dioxin related com-
pounds (Binion and Gutberlet, 2012; Kunisue et al., 2004).
High traces of polybrominated diphenyl ether (chemical flame retardant), heavy
metals and PBC were found in the blood of children between 11 to 15 years study
conducted in India (WIEGO, 2008). It is also assumed that waste pickers are at
risk of cancers after a lag period of 10 years due to exposure to cancer-inducing
agents, and lymphatic and hematopoietic cancers for working 5 years (Gogoi,
2005).
2.7.2 Biological hazard
This hazard refer to organisms or substances produced by organisms that are
harmful to human health. These hazards are caused by viruses, bacteria, parasites,
fungi and protein. The routes of transmission are inhalation, body contact(skin)
and contact with contaminated objects.
Waste pickers are at risk of inhaling contaminated particulate matter and dust
including fungus and endotoxins which has resulted in respiratory diseases such as
bronchitis, pneumonia, tuberculosis, allergy and asthma (Binion and Gutberlet,
2012). They may also suffer diarrhoea, intestinal protozoa and helminthes as result
of consuming contaminated food (Wilson et al., 2006). Many suffer injuries like
cuts from handling health care waste which exposed them to infections. They also
sustain cuts from sharp objects and glass which make them prone to infections
(Parveen and Faisal, 2005). They also risk contracting infection with hepatitis
C and HIV from handling hazardous health care waste waste-HHCW (UNEP,
2013). Waste pickers may also handle putrescible household waste such as animal
faeces,soiled disposable napkins and occasionally human excreta. They become
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exposed to pathogenic bioaerosols which can cause respiratory problems (Gogoi,
2005).
2.7.3 Physical hazard
This type of hazard refer to an agent,factor or circumstances that cause harm with
or without contact. They in include ergonomic hazards,radiation, heat and cold
stress,radiation,vibration hazards and noise hazards.
The work of waste pickers is labour intensive and physically taxing. They carry
their recycled materials and work for long hours in the sun,rain,smoke and dust
with little time to rest. This causes them to become to fatigue (Bopape et al., 2019;
Cardozo and Moreira, 2015; Gogoi, 2005). They are susceptible to stressed due
to the harsh conditions of work. The awkward positions(squatting,bending) and
carrying of heavy items cause stiffness of joints,pains in the arms and legs (Cardozo
and Moreira, 2015; Gogoi, 2005). The physical and mental stress suffered by waste
pickers stem from the fact that handle, see and smell ghastly mess in the waste
stream (WIEGO, 2008).
At the dump site, they risk sustaining severe injury or even being killed by heavy
moving equipments such as bulldozers or trucks especially when reversing (UNEP,
2013).
2.7.4 Health effects of exposure to chemicals in landfill
Heavy metals are used in industrial processes to make some products. These
products end up in MSW stream after material end of life phase (Järup, 2003).
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2.7.4.1 Health effects of lead
Lead can affect every organ and system in the body. Kidney and brain damage
can occur when exposed to high levels and in some cases cause death. High levels
of can cause miscarriage in pregnant women and affect sperm production organs in
men (Martin and Griswold, 2009). Children exposed to lead may suffer behavioral
disturbances as well as learning and concentration difficulties,respiratory problems
and cancer. Prolong exposure to lead may cause memory deterioration as well as
affect haemoglobin synthesis causing anaemia (Jomova and Valko, 2011).
2.7.4.2 Health effects of cadmium
Long term high exposure to cadmium by inhalation may affect bone functioning
resulting in skeletal damage and increase the rate of lung cancer (Macklin et al.,
2011). Cadmium is noted to be a human carcinogen(group 1)causing lung cancer
(Järup, 2003).
2.7.4.3 Health effects of mercury
The nervous system shows all forms of sensitivity. Lung damage,increased heart
rate or blood pressure, eye irritation and skin rashes is reported for short term
high exposure to mercury (Martin and Griswold, 2009). Long term high exposure
can damage vital organs like liver,kidney and brain. In pregnant women exposure
can cause cross placental barrier and damage developing fetuses
2.7.4.4 Health Effects of NO2 and SO2
Nitrogen dioxide (NO2), sulpur dioxide (SO2) and halides are acid gases emit-
ted from landfill gas (Macklin et al., 2011). Exposure to high concentration of
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nitrogen dioxide ((NO2)) irritates the airways. It causes inflammation and bron-
choconstriction (narrowing of the lung), affects immunity of the lung cells by
increasing susceptibility to respiratory infections (Macklin et al., 2011). Exposure
to sulphur dioxide ((SO2)) irritates the airways and cause narrowing of the lungs.
At high concentrations the gas can trigger asthma attacks(most vulnerable are
children and the elderly). It can also cause chronic heart diseases,acute respira-
tory infections in children and in adults cause bronchitis (Kampa and Castanas,
2008).
2.8 XRF analysis in environmental monitoring
X-ray fluorescence (XRF) spectroscopy is a multi-elements analytical method with
widespread use in science and industry. Key strengths of XRF spectroscopy in-
clude: easy sample preparation, high sensitivity and reproducibility, non-destructive
and rapid analysis(Injuk and Van Grieken, 2003).
The operating principle is that energy from an external source excite individual
atoms in a sample or material. The excited atoms emit x-ray photons of a char-
acteristic energy or wavelength. The number of photons of each energy emitted
from the sample is counted and the elements present are identified and quantified
(Guthrie and Ferguson, 2012).
XRF method has been widely used for environmental applications, mainly for
trace-elements measurement in soil and sediments (Parsons et al., 2013; Rouil-
lon and Taylor, 2016; Weindorf et al., 2012) and atmospheric particulate matter
characterisation (Calzolai et al., 2008; Marcazzan et al., 2001; Watson et al., 1999).
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2.9 Previous studies on landfills in Ghana
There have been some previous research works on selected landfill sites in Ghana.
In investigating the impacts of the Oblogo landfill site in Accra on surrounding
environment, Osei et al. (2011) evaluted the extent of contamination of the landfill
leachate to water and soil using atomic absorption spectrometer (AAS). The study
established that although there is accumulation of metals in the sediments and
water, the concentration has not reached toxic levels to humans.
Annorbah (2014) measured heavy metals in total suspended particulate (PST),
PM10, soil, leachate and groundwater at the Pantang and Mallam Landfill Sites
in Accra using atomic absorption spectrometer (AAS). The study evaluated the
leachate pollution index (LPI) as well as air quality index (AQI) for both landfill
sites.
A few other studies focused on municipal solid waste management systems, their
socio-economic prospects and related challenges at some landfill sites in Accra
and Kumasi (Asase et al., 2009; Boadi and Kuitunen, 2003; Owusu et al., 2012;
Owusu-Sekyere et al., 2013).
Majority of the existing studies have been carried out at landfill sites most of
which have now been decommissioned. While a few of these studies focused on
environmental impacts of municipal solid waste, none however dealt with safety
and health risks assessment of waste pickers at landfill sites. This is the gap in
knowledge that this study seeks to bridge.
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Chapter 3
Methodology
3.1 The study area
The kpone landfill site is located (5◦42’14.76”N; 0◦1’43.68”E) in the Tema metropo-
lis, about 5 km northeast of the city centre, in the Greater Accra Region of Ghana.
Figure 3.1: The Kpone landfill site map (Source: Drawn by student)
The site is situated about 2 km off the Tema–Aflao highway along the road leading
to Kpone. The landfill covers an area of 38 ha and shares its western boundary with
’Senteo Ceramic Company’, a tile and ceramic factory. The facility management
offices and the mechanical workshop are located at eastern end of the site, whilst
waste pickers’ sitting and storage areas are located along its northern, western and
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southern borders. The northeastern boundary is a dumping ground of waste from
a nearby metallurgy company where waste pickers extend their activities. The
Kpone landfill site map is shown Figure 3.1 whilst Figure 3.2 give an aerial view
of the site and its surroundings with sampling locations indicated with orange
pins.
Figure 3.2: Aerial view of the Kpone landfill site (source: Google Earth)
Hundreds of solid waste carting trucks and tricycles dump their loads (about
3000 tonnes) at site on daily basis (Figure 3.3). The road network within the
landfill site is unpaved. The site is a scene for elevated dust storms as a result of
the high volume of vehicular traffic. Stack emissions from the adjacent tile and
ceramic factory also contribute significantly to resuspended dust in the ambient air.
The combined effects of the resuspended dusts and the smell from the putrefying
organic wastes make the Kpone landfill an environment worth studying for its
potential health and safety risks to the large number of waste pickers who work
daily, for long hours, on site.
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Figure 3.3: Traffic and waste volume to Kpone Landfill site (Source: Salifu,
2019)
3.2 Study methodology
Soil and dust samples were collected at the Kpone landfill site and analysed by
X-ray fluorescence (XRF) spectrometry. Real-time measurements of sulfur dioxide
(SO2) and nitrogen dioxide (NO2) were also carried out. The experimental results
were used for health and safety risks assessment. The methodology used in this
study illustrates with a flowchart in Figure 3.4.
3.3 Soil, dusts and gases sampling
3.3.1 Sampling locations
Dusts were sampled from window netting at the administration office block, the
mechanical workshop and the plastic crushing unit, and on benches and tables
in waste pickers compounds and sitting areas. SO2 and NO2 gases were sampled
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Figure 3.4: Flowchart of the study methodology
at these same locations. The selected sampling locations are ’camps’ around the
waste pile where waste pickers spend most of their time sorting out and packing
the scavenged materials. There were eight (8) locations in all. Sampling locations
are indicated in figures 3.1 and 3.2. Samples were collected at all the selected
locations during the dry season (March 2019).
Table 3.1: Description of sampling locations within the study area
GPS coordinates
Location Location description
Latitude Longitude
Loc-1 Administration Block lo- 5◦ 42’ 16”N 0◦ 1’ 51”E
cated at the entrance of
the landfill site, adjacent
(northern side) to the axle-
load/Toll Station.
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Loc-2 The recovered waste crush- 5◦ 42’ 15”N 0◦ 1’ 52”E
ing unit adjacent (southern
side) to the axle-load/Toll
Station. Serves as sitting
area for landfill staff.
Loc-3 The landfill’s Mechanical 5◦ 42’ 14”N 0◦ 1’ 50”E
Workshop located very
close to the dumpsite
Loc-4 Southeastern side of the 5◦ 42’ 24” 0◦ 1’ 39”E
smelting waste dumpsite lo-
cated in a valley behind the
Leachate Ponds
Loc-5 Northern side of the smelt- 5◦ 42’ 21”N 0◦ 1’ 36”E
ing waste dumpsite located
in a valley behind the
Leachate Ponds
Loc-6 Northwestern side of the 5◦ 42’ 18”N 0◦ 1’ 35’E
smelting waste dumpsite lo-
cated in a valley behind the
Leachate Ponds
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Loc-7 Resting/eating area (tem- 5◦ 42’ 12”N 0◦ 1’ 33”E
porary structure) for waste
pickers, located around the
recovered waste sorting
camps.
Loc-8 Waste pickers’ sorting camp 5◦ 42’ 4”N 0◦ 1’ 41”E
located between the dump-
site and an adjacent ce-
ramic factory
Loc-9 Temporary dwelling/sort- 5◦ 42’ 7”N 0◦ 1’ 45”E
ing camp
Loc-10 Resting/waste-sorting 5◦ 42’ 10”N 0◦ 1’ 50”E
camp with temporary
structures
3.3.2 Dust sampling
Composite dust samples of about 400 g were collected from window netting and
other flat surfaces at a height of about 1.5 m above the ground. The collection was
done by gently sweeping dust into disposable plastic cups using paint brushes. The
samples were transferred into Ziploc polyethylene bags and stored for subsequent
laboratory analysis. A total of forty (40) composite dust samples (5 samples per
location) collected.
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3.3.3 Soil sampling
The soil sampling was done at three of the eight locations, including the metallurgic
dumping site. Composite soil samples of about 500 g each were collected at five
(5) different points within these locations at about 6 cm depth using a hand
auger. The samples were poured into Zipper-lock polyethylene bags for laboratory
analysis. The soil sampling was done from disturbed grounds within the three
locations. A total of fifteen (15) soil samples were collected.
3.3.4 SO2 and NO2 sampling
3.3.4.1 The gas sampler
The sampler used for sulfur dioxide (SO2) and nitrogen dioxide (NO2) measure-
ments is the Aeroqual 500 Series portable air quality monitor, which is designed
to accurately measure multiple target gases at different concentrations in both
indoor and outdoor environments. The Aeroqual monitor is fitted with an inter-
changeable sensor head that can be swapped with another sensor head depending
on the type of gas one wants to measure (Figure 3.5).
The Aeroqual monitor draws ambient air into the sensor head. The gas sensitive
electrochemical (GSE) sensors detect the gases and generate nano-amp currents
proportional to the gas concentration which can be read out from the digital
display. The low noise electronics system of the monitor makes it possible to
measure gases with low detection levels.
3.3.4.2 SO2 and NO2 monitoring
Two Aeroqual monitors were used to simultaneously measure SO2 and NO2 at
the sampling locations. Measurement was done at each sampling location over
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Figure 3.5: Aeroqual 500 Series gas monitors being used for SO2 and NO2
monitoring (Source: Aeroqual user manual)
the operational period (between 8:00AM and 5:00PM) of the landfill site with
data logging (recording) every 5 minutes. Sampling was done with the monitors
placed at a height of about 1.5 m above ground level. After the field monitoring,
the logged data was downloaded from the Aeroqual monitors onto a personal
computer for analysis and interpretation.
3.4 Demographic data collection
A questionnaire was administered to the waste pickers in order to collect the
following information:
• their age and gender,
• their body mass,
• number of working hours per day and numbers of years spent on site,
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Figure 3.6: Field monitoring of gases at one of the sampling locations at
the Kpone landfill site (Picture from student’s field work)
• general awareness about safety and occupational hazards,
• their health conditions, etc.
The data was used for safety and health risks assessment.
3.5 Sample preparation
The dust and soil samples collected from the Kpone landfill site were sent to the
X-ray Fluorescence (XRF) Laboratory of the National Nuclear Research Insti-
tute (NNRI) at the Ghana Atomic Energy Commission (GAEC) and prepared for
elemental composition analysis.
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• The soil samples collected at different points within the same sampling loca-
tion were aggregated to form one representative sample. The same was done
with the dust samples.
• First, the soil samples were air-dried for 72 hours to remove any moisture
contents. The dry soil was then pulverised for 25 min, using the “Fritsch
Pulverisette-2”, to obtain a homogenised fine powder.
• In order to avoid particle size effect, the pulverised soil and dust samples
were sieved using two meshes (Metric Test Sieve BS 410 – WS Tyler) with
pore geometric diameters of 112 µm and 55 µm respectively.
• 100 g of the homogenous fine powder was scoop into a press die set and placed
in a Manual Pellet Press with built-in hydraulic pump with a maximum
pressure 30 metric tons to make pellets for XRF analysis.
• Pellets were also prepared from standard reference materials (SRMs): IAEA-
Soil7 and IAEA-Soil3 for comparative quantitative analysis of the samples
and data validation.
The equipment used in soil and dust sample preparation is shown in Figure 3.7.
3.6 Elemental analysis
The pellets prepared from the soil and dust samples were analysed by x-ray fluo-
rescence (XRF) spectrometry using the portable Amptek Experimental Kit shown
in Figure 3.8.
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Figure 3.7: Equipment used for soil and dust samples preparation. A:
Fritsch Pulverisette-2; B: Metric Test Sieve BS 410 – WS Tyler; C: Manual
Press Pelletizer; D: Press-die set (Picture from student’s laboratory work)
Figure 3.8: The Amptek Experimental kit for XFR analysis used in this
study (Picture from student’s laboratory work)
The XRF measurement geometry for the Amptek spectrometer is given in figure
3.9:
The main components of this XRF system are:
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Figure 3.9: XRF measurement geometry with an aluminum filter placed
in front of the x-ray source to reduce spectrum background and improve
sensitivity (Source: Amptek user manual)
• Mini-X x-ray tube of a voltage up to 50kV with a silver (Ag) anode.
• X-123 silicon drift detector (SDD) with energy resolution of 70 keV.
• Radiation shielded sample analysis chamber and
• Amptek multichannel analyser data acquisition software (dppADMCA) in-
stalled on a personal computer.
The samples and certified reference materials (IAEA Soil-7 and GSP-2) were
irradiated and data acquired under the following conditions:
• X-ray tube voltage of 45 kV,
• X-ray tube current of 5 µA
• Duration of irradiation was 3 min per sample
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• Spectrum analysis and elemental concentrations calculations were performed
with the bAxil quantification software.
Prior to sample analysis, a background measurement in the analytical chamber
was carried out with the x-ray tube switched-on with no sample in the chamber.
The bAxil’s elemental concentration computation is based on the fundamental
XRF analysis equation 3.1 (Sitko and Zawisza, 2012):
· · · · · · 1 − exp [−µs (E0, Ei) · ξ]Ia (Ei) = I0 G σi (E0) fab (Ei) d Ca (3.1)
µs (Ei)
Where, I0: incident x-ray intensity; Ia(Ei): characteristic x-ray intensity; G: ge-
ometric factor; σi(E0): cross section of element i; fab(Ei): attenuation in air ;
d: detector efficiency; Ca: element of interest concentration; µs(E0, Ei): self-
attenuation coefficient, ξ: sample thickness.
3.7 Data analysis
Results from elemental analysis of soil and dust samples were analysed to deter-
mine the contamination levels in the samples.
3.7.1 Contamination factor
The contamination factor is a measure of pollution of the environment relative to
the individual pollutants (heavy metals) measured in the study. The contamina-
tion factor is evaluated as follows:
Ci
CF = measuredi (3.2)
Cibackground
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where, CFi is the contamination factor; Ci is the concentration of pollutantmeasured
’i’ (heavy metal i) measured in this study; Ci is the background literaturebackground
value for the metal ’i’ in the earth crustal (Aktaruzzaman et al., 2014).
The criteria for contamination factor interpretation are given as follows:
• CF < 1: low contamination
• 1 < CF ≤ 3: moderate contamination
• 3 < CF ≤ 6: considerable contamination
• CF > 6: very high contamination
3.7.2 Degree of contamination
The degree of contamination Cdeg is used to evaluate the combined effect of all the
pollutants measured in this study. It is hence the sum of all contamination factors
determined in section 3.7.1: ∑n
Cdeg = CFi (3.3)
i=1
where CFi is the contamination factor of heavy metal ’i’ ; n is the number of heavy
metals detected and measured in this study.
The degree of contamination Cdeg is assessed using the following criteria:
• Cdeg < 8:low degree of contamination
• 8 ≤ Cdeg < 16: as moderate degree of contamination
• 16 ≤ Cdeg < 32: considerable degree of contamination
• Cdeg ≥ 32: as very high degree of contamination
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3.7.3 Human exposure to pollutants
Human exposure to the pollution levels determined in this study was evaluated for
three (3) different pathways, namely ingestion (drinking and eating), inhalation
(breathing) and dermal (skin contact) intakes. The associated health risks were
also assessed.
3.7.3.1 Ingestion of heavy metals
The average daily dosage for the ingestion pathway (AvDD) is computed using
equation 3.4:
× IngR× EF × EDAvDDing = C −6(mg/kg) × 10 (3.4)
BW × AT
where C(mg/kg): measured concentration of heavy metal, IngR: ingestion rate
(value: 200 mg day−1), EF : frequency of exposure (350 day year−1), ED : du-
ration of exposure (6 years), BW : average body weight (70 kg) and AT : averaging
time (ED×365 days for non-carcinogens and 25 550 days i.e. 70×365 days for
carcinogens) (Nickel, 1995b; Tuyen et al., 2016).
3.7.3.2 Dermal intake of heavy metals
The average daily dosage for the dermal pathway (AvDD) is computed using
equation 3.5:
SA× SL× ABS × EF × ED
AvDDderm = C
−6
(mg/kg) × × 10 (3.5)
BW × AT
where SA is exposed skin area (2800 cm2), SL: skin adherence factor (0.2 mg
cm−2h−1) and ABS is the dermal absorption factor (value: 0.001).
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3.7.3.3 Inhalation of heavy metals
The average daily dosage through inhalation (AvDD) is computed using equation
3.6:
InhR× EF × ED
AvDDinh = C(mg/kg) × × 10−6 (3.6)
PEF ×BW × AT
where InhR is the inhalation rate (7.6 m3day−1) and PEF is particle emission
factor (1.36 × 109m3kg−1).
3.7.4 Health risk assessment
The health risks of waste pickers exposure to pollution were assessed for the non-
carcinogenic and the carcinogenic.
3.7.4.1 Non-carcinogenic health risk
For the non-carcinogenic health risk, the health Hazard Quotient (HQ) is first
evaluated for each exposure pathway relative to the heavy metal of interest as
follows:
AvDDpathway
HQpathway = (3.7)
RfD
where AvDDpathway is the average daily dose per pathway; RfD is the reference
dose, which is the maximum acceptable daily intake of the heavy metal of interest.
The health risk index is then determined using equation 3.8 (Kyere et al., 2018):
HI = HQing +HQinh +HQderm (3.8)
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3.7.4.2 Carcinogenic health risk
For the carcinogenic health assessment, the lifetime average daily intake was first
computed as expressed in equation 3.9:
[( ) ( )]
C(mg/kg) × EF · InhRchild × EDchild InhRadult × EDadultLiAvDD = +
AT × PEF BWchild BWadult
(3.9)
The cancer risk was then evaluated as follows:
Cancer risk = LiAvDD × inhalation slope factor (3.10)
3.8 Quality control/Quality assurance
The procedures for field and laboratory analyses may introduce some sources of
error that could potentially influence the results obtained in this study. Error
sources include cross-contamination of samples from different sampling location,
sample storage, equipment calibration and laboratory measurement conditions.
Precautions were however taken to minimise the impact of these sources of errors
on the final experimental results.
3.8.1 Field sampling precautions
The following steps were taken to minimise errors associated with field sampling
procedures:
• In order to prevent cross-contamination between soil and dust samples col-
lected at different locations, a new set of tools (paint brush, disposable cups,
ziploc bags and hand gloves) were used for each sampling point.
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• The samples were clearly labeled according to the location description and
the same records entered in the log book.
• samples were collected at five (5) different points within each sampling lo-
cation in order to have a composite sample that is representative of the
location.
• The Aeroqual air monitors (for SO2 and NO2) were co-located at each sam-
pling point and the location ID and sampling periods (start and end) were
synchronised in the monitor settings to ensure simultaneous measurement of
all pollution events.
3.8.2 Laboratory precautions
In the laboratory some QA/QC procedures were followed:
• The samples were covered with micrometre pore size sieves during air drying
to avoid dust and soil particles flying from one sample to another.
• Sample preparation tools (pulveriser, sieves, pelletiser dies) were thoroughly
cleaned with acetone after each sample to avoid cross-contamination.
• The XRF spectrometer was calibrated and a background measurement was
performed without a sample placed in front of the x-ray tube and detector.
This was to remove background effects from experimental results.
3.8.3 Results validation
Certified reference material (IAEA Soil-7) was analysed under the same experi-
mental conditions as the samples in order to validate the method.
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Chapter 4
Results and Discussions
Results from ambient air monitoring, elemental composition analysis of soil and
dust, as well as the outcome of administered questionnaires are presented and
discussed in this chapter. The implications of these results for health and safety
of the waste pickers at the Kpone landfill site are also assessed.
4.1 Waste Pickers at Kpone Landfills site
After randomly interacting with 110 waste pickers, seventy five (75) of them (43
male, 32 female), aged between 18–70 years, agreed to participate in the study.
They were hence sampled to provide some personal and general work-related in-
formation with respect to their trade. The outcome of the questionnaire is sum-
marised in Table 4.1.
Table 4.1: Summary of responses to the study questionnaire
Sampled population Sample size Percentage (%)
Female subjects 32 43
Male subjects 43 57
Total 75 100
Range Mean
Age distribution (years) 18 - 70 35
Body mass (Kg) 58 - 95 73
Working experience (Years) 5 - 12 8
Daily working hours 5 - 12 9
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Risk/Hazard awareness Aware (%) Not aware (%)
Physical risk 100 0
Chemical risk 23 77
The waste pickers are self-employed. Each waste picker is engaged in his/her own
waste collection, sorting and selling of the retrieved materials to middlemen.
From observations made, waste pickers scavenge materials from the dumpsite us-
ing a stick, an iron rod or directly pick the target items with their hands. Their
footwear are not safety/wellington boots and their hand-gloves are not safety
gloves; hence cannot prevent dermal contacts with liquid substances. They do
not wear nose-mask as they say it hinders breathing. Due to excessive heat at the
dumpsite the waste pickers usually put on light clothing.
All the respondents (waste pickers) said they were aware of the physical risks,
while 23% of them say they appreciate the chemical risks associated with their
trade. However, this assertion did not reflect in their dressing during work. They
may be exposed to toxic substances from the waste pile through inhalation and
dermal contact.
4.2 NO2 monitoring
The ambient nitrogen dioxide (NO2) concentrations (in µgm−3) measured at the
sampling locations 1, 2, 3, 7, 8, 9 and 10 within the study area are presented in
Table 4.2. Ambient air monitoring was not carried out at locations 4, 5 and 6
which are situated at the metallurgic dumpsite where it was not possible to mount
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a support stand for the Aeroqual air monitors. The data presented include some
statistics (minimum, maximum and average) of the results.
Table 4.2: NO2 concentration in µg/m3 recorded per sampling location
during the air quality monitoring
NO2 concentration (µg/m3)
Time Loc-1 Loc-2 Loc-3 Loc-7 Loc-8 Loc-9 Loc-10
9:00 41 49 69 31 84 62 31
9:15 45 52 70 46 175 60 31
9:30 47 31 69 41 86 64 10
9:45 43 38 67 52 154 56 27
10:00 41 42 69 71 187 63 40
10:15 48 73 67 63 183 68 39
10:30 44 64 68 59 110 60 34
10:45 45 73 69 41 100 64 29
11:00 51 65 71 32 59 42 39
11:15 43 56 70 25 257 44 40
11:30 61 47 70 31 202 46 39
11:45 71 41 67 34 195 35 29
12:00 56 40 68 35 266 45 39
12:15 46 37 67 54 290 43 49
12:30 51 44 66 60 219 43 61
12:45 40 40 66 40 343 38 32
13:00 43 48 69 38 263 53 38
13:15 60 44 69 41 263 54 30
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13:30 63 40 69 32 191 55 56
13:45 53 53 68 48 183 51 57
14:00 66 45 67 61 164 53 52
14:15 62 47 66 55 163 56 49
14:30 64 63 65 58 163 54 61
14:45 77 66 67 66 191 54 64
15:00 61 67 70 63 173 55 60
15:15 66 68 70 55 164 55 63
15:30 66 68 63 124 194 53 66
15:45 65 69 50 124 164 56 65
16:00 65 67 50 78 174 52 67
16:15 64 68 50 78 163 55 63
16:30 63 66 55 194 183 53 64
16:45 64 66 55 205 162 54 64
17:00 61 66 57 110 172 54 64
Statistics
Minimum 40 31 50 25 59 35 10
Maximum 77 73 71 205 343 68 67
Average 55.6 54.6 65.2 65.0 183.0 53.0 47.0
The average daily concentrations (in µgm−3) computed from the logged data
(Table 4.2) are presented in Figure 4.1. The measured NO2 are plotted together
with the Ghana Environmental Protection Agency (EPA) and the World Health
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Organisation (WHO) air quality guidelines.
Figure 4.1: Measured average daily NO2 concentrations plotted alongside
Ghana EPA (for residential and industrial areas) and WHO guideline limits
The highest average NO2 concentration of 183 µgm−3 was recorded at location-8
while the lowest average concentration of 47 µgm−3 was measured at Location-10
.
Nitrogen dioxide NO2 which is one of the gaseous air pollutants is mainly produced
by anthropogenic activities such as fossil fuel combustion, decomposing organic
matter and processing of mineral ores (Follett and Hatfield, 2001; Stavrakou et al.,
2008). The high ambient levels of NO2 observed at the Kpone landfill site could
be emanating from the following sources: exhaust emissions from diesel fueled
waste carting trucks and tricycles’ two stroke engines, stack emissions from an
adjacent Senteo Ceramic factory (Figure 4.2), the putrefying organic waste from
the dumpsite as well as the leachate ponds.
The measured ambient NO2 concentrations for locations 3, 7 and 8 were above
the set EPA guideline limit of 60 µgm−3 for residential. Location-8 recorded an
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average concentration of 183 µgm−3, which is higher than both the residential and
industrial (150 µgm−3) limits.
The sampling location-8 which recorded a very high average NO2 concentration of
185 µgm−3 is located between the landfill and the adjacent Senteo Ceramic factory
with constant stack emissions during the sampling period. Figure 4.2 shows the
Senteo Ceramic factory with the sack emissions into the ambient air. This may
contribute to the high ambient NO2 level observed at this location as well as the
concentrations above EPA limits recorded at the other locations within the Kpone
landfill site.
Figure 4.2: Stack emission form adjacent ’Senteo Ceramic Factory’ with
possible effect on ambient air quality (Picture from student’s field work)
The ambient NO2 levels recorded at all the sampling locations, in this study, were
above the WHO air quality guideline limit of 40 µgm−3 (WHO, 2006).
Elsewhere, NO2 concentration levels far less than what were recorded at the Kpone
landfill were found to have some negative impacts on human health. For exam-
ple, exposure to 2.3 ppm ambient NO2, which is less than the levels measured in
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this study, was found to have some delayed effects on alveolar permeability and
glutathione peroxidase in healthy humans (Pénard-Morand et al., 2005). An in-
creased prevalence of respiratory conditions were also recorded by Pénard-Morand
et al. (2005) for moderate increase in exposure to ambient NO2 concentrations.
The sampling locations 7, 8, 9 and 10 are venues where waste pickers spend a lot of
time, sorting their recovered items. These are also their resting and eating places.
In view of this, waste pickers at the kpone landfill site may experience long-term
occupational health effects, with those working around location-8being likely the
most vulnerable.
4.3 SO2 monitoring
Results from ambient SO2 monitored at the Kpone landfill site are presented in
Table 4.3. These concentrations were measured at the same locations as the NO2
monitoring.
Table 4.3: SO2 concentration recorded per sampling location during the
air quality monitoring
SO2 concentration (µg/m3)
Time Loc-1 Loc-2 Loc-3 Loc-7 Loc-8 Loc-9 Loc-10
9:00 70 50 60 20 70 330 80
9:15 60 30 70 40 110 210 70
9:30 50 20 40 40 110 190 60
9:45 40 30 90 30 140 200 80
10:00 40 40 80 40 130 170 90
10:15 50 30 80 30 130 190 90
10:30 50 30 50 30 110 220 110
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10:45 40 40 60 50 140 150 100
11:00 60 30 50 50 110 100 90
11:15 60 30 90 50 100 90 80
11:30 50 30 90 50 170 120 80
11:45 70 50 80 50 190 80 90
12:00 50 50 80 50 250 110 90
12:15 50 60 40 40 230 130 100
12:30 50 60 50 40 160 150 100
12:45 50 60 40 40 190 130 70
13:00 50 60 30 50 150 170 60
13:15 40 70 30 40 170 180 70
13:30 80 70 50 30 180 170 90
13:45 70 70 50 40 160 170 90
14:00 60 70 40 40 160 160 80
14:15 50 70 40 40 160 160 110
14:30 50 60 40 40 160 170 110
14:45 40 60 50 30 150 170 110
15:00 60 50 40 130 160 170 100
15:15 70 50 50 120 170 160 100
15:30 70 50 60 140 160 170 100
15:45 60 50 60 110 150 170 100
16:00 60 50 60 90 160 170 110
16:15 50 60 50 100 160 170 110
16:30 40 60 60 160 160 160 100
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16:45 40 70 50 180 180 170 100
17:00 50 90 90 150 180 160 110
Statistics
Minimum 40 20 30 20 70 80 60
Maximum 80 90 90 180 250 330 110
Average 53.9 51.5 57.6 64.8 154.8 164.2 91.8
The average daily ambient SO2 concentrations are plotted in Figure 4.3 in com-
parison with the Ghana EPA and WHO guideline limits. The ambient SO2 concen-
Figure 4.3: Measured average daily SO2 concentrations plotted alongside
Ghana EPA (for residential and industrial areas) and WHO guideline limits
trations per location ranked as follows: location-9 with 164 µgm−3 is the highest,
location-8: 156 µgm−3, location-10: 92 µgm−3, location-7: 65µgm−3. Locations 3,
1 and 2 recorded 58 µgm−3, 54 µgm−3 and 52 µgm−3 respectively as the lowest
concentrations. Locations 1, 2 and 3 are not environments where waste pickers
spent their time.
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The average SO2 concentrations measured during the air monitoring campaign
were all below the EPA air quality guideline limit of 100 µgm−3 for residential
areas, except those recorded at locations 8 and 9. Location-8 and Location-9
recorded 155 and 164 of SO2 respectively, which were above the EPA guideline
limits for both residential and industrial areas.
However, the average SO2 concentration levels recorded at all the locations were
above the WHO air quality guidelines (AQG).
Sulphur dioxide (SO2) is among the compounds the WHO has classified as “gaseous
pollutants” (World Health Organization, 2006). They have similar anthropogenic
sources as those enumerated for NO2: fossil fuel combustion, industrial processes,
organic matter decomposition, and sea salt.
Pandey et al. (2005) also linked concentrations of suspended particulate matter
(SPM), nitrogen dioxide (NO2) and sulfur dioxide (SO2), below WHO guideline
values, in Delhi City in India and the occupancy of the exposed individuals to the
high health risks. This indicates that a long-term exposure of waste pickers to the
ambient SO2 concentration levels recorded at the Kpone landfill site could also lead
to some adverse health effects. This should be of concern especially when studies
have linked pollutants associated with landfill and open dump site environments,
including SO2, with human health problems Karthikeyan et al. (2011); Muttamara
and Leong (1997).
The total daily exposure is the product of ambient pollutant concentrations and the
time spent in that environment (WHO, 2006). Hence, the waste pickers working
at the Kpone landfill on average 8 hours a day without suitable personal protective
equipment are at risk of adverse health effects from exposure to high concentrations
of SO2 and and other pollutants measured in this study.
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4.4 XRF measurement validation
The results for soil and dust analysis by x-ray fluorescence (XRF) were first vali-
dated by XRF analysis of BHVO-2, GSP-2 and IAEA Soil-7 standards under the
same conditions as the samples collected at the Kpone landfill site. Table 4.4
shows the validation results.
Table 4.4: XRF measured and certified values from BHVO-2, GSP-2 and
IAEA Soil-7 Standards
Measured (mg/kg) Certified (mg/kg) Meas−Cert (%)
Cert
BHVO-2
Cr 275.9±14.77 280±19 -1.5
Ni 122.05±7.27 119±7 2.6
Cu 123.06±15.03 127±7 -3.1
Zn 97.05±25.53 103±6 -5.8
GSP-2
Sc 5.54±0.82 6.3±0.7 -12.1
V 47.4±5.15 52±4 -8.8
Cr 17.31±1.01 20±6 -13.5
Ni 15.42±0.61 17±2 -9.3
Cu 38.85±3 43±4 -9.7
Zn 114.42±14.56 120±10 -4.7
Pb 38.04±8.7 42±3 -9.4
IAEA Soil-7
Sc 7.55±0.22 8.3 -9
V 60.04±7.14 66 -9
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Cr 54.39±4.35 60 -9.4
Ni 23.41±1.41 26 -10
Cu 9.87±1.5 11 -10.3
Zn 100.38±13.98 104 -3.5
Cd 1.18±0.15 1.3 -9.2
Hg 0.05±0.02 0.04 2.5
Pb 55.37±7.21 60 -7.7
Comparing the measured and certified values for the standards, it was observed
that the two set of values closely matched. The uncertainty was generally below
±10%. And if one takes into consideration the certified uncertainty margins for
each element, the uncertainty associated with the measured values will be around
5%.
The XRF analytical results obtained in this study can therefore be confidently
used for the objectives of this thesis work.
4.5 Elemental composition of soil and dust
Dust and Soil elemental analysis results are presented in Tables 4.5 and 4.6 re-
spectively.
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Table 4.5: Mean heavy metals concentrations (gm/kg) in dust sampled at the Kpone landfill site
Location V Cr Ni Cu Zn Cd Hg Pb
Loc1 82.52±7.69 82±4.56 25.36±1.53 398.91±26.33 214.63±24.92 1.06±0.15 0.06±0.02 292.03±16.72
Loc2 66.43±6.65 85.14±4.71 27.93±1.53 413.82±27.52 219.29±20.68 1.18±0.16 0.03±0.01 268.34±23.18
Loc3 58.04±6.11 95.52±5.17 28.75±1.49 601.22±31.46 343.57±31.41 1.56±0.19 0.02±0.01 222.16±18.22
Loc7 68.57±7.21 95.55±5.27 19.01±0.95 1910.55±45.32 1064.54±120.49 1.73±0.22 0.06±0.02 753.66±28.53
Loc8 43.68±4.82 62.16±3.57 24.39±1.15 291.28±22.16 692.58±78.64 1.03±0.12 0.01±0.01 12.46±1.33
Loc9 63.96±6.4 70.34±3.98 26.67±1.33 412.91±26.93 117.44±13.91 1.24±0.15 0.01±0.01 83.4±5.22
Loc10 55.78±5.97 78.73±4.41 27.28±1.4 494.54±29.4 368.33±19.07 1.22±0.15 0.03±0.01 161.79±16.98
MPA1 50 100 75 100 300 50
1 Alert Value of the New Dutch List (Crommentuijn and Polder, 1997)
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Table 4.6: Mean heavy metals concentrations (gm/kg) in soil sampled at the Kpone landfill site
Location V Cr Ni Cu Zn Cd Hg Pb
Loc4 18.66±5.61 76.03±4.99 46.12±2.45 142.91±21.61 36585.06±414.47 2.35±0.42 0.17±0.24 4808.18±152.81
Loc5 35.94±5.73 130.27±7.02 40.28±2.32 333.69±28.36 14402.61±314.16 2.54±0.34 0.17±0.09 4678.52±128.95
Loc6 40.71±5.66 123.61±6.65 37.57±2.16 328.34±27.36 11054.63±125.1 2.93±0.36 0.18±0.08 2595.33±105.34
MPA1 250 380 210 190 720 12 10 530
1 Alert Value of the New Dutch List (Crommentuijn and Polder, 1997)
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4.5.1 Heavy metals in dust samples
Eight (8) heavy metals (vanadium (V), chromium (Cr), Nickel (Ni), copper (Cu),
zinc (Zn), cadmium (Cd), mercury (Hg) and lead (Pb)) were detected and quan-
tified in the dust samples using XRF analysis. Their mean concentrations are
plotted in Figures 4.4 and 4.5
Figure 4.4: Mean concentration for V, Cr, Ni and Cu in dust per sampling
location
Location-1 recorded the highest concentration for vanadium (82.5 mg/kg) in dust,
while the mean V concentrations recorded at all the sampling locations, except
location-8, were above their New Dutch List ”alert value” of 50 mg/kg. The ”alert
value” is the limit concentration permissible for an elemental concentration beyond
which a remediation action will be taken (Crommentuijn and Polder, 1997).
Location-7 had the highest mean chromium concentration of 96.5 mg/kg; all con-
centrations measured at all the sampling locations were below their alert value of
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Figure 4.5: Mean concentration for Zn, Cd, Hg and Pb in dust per sam-
pling location
100 mg/kg.
All sampling locations recorded mean concentrations above their alert values for
Cu, Zn, Cd and Pb. The following elements recorded the highest concentrations:
Cu (1911 mg/kg) for location-7, alert limit of 100 mg/kg; Zn (3685 mg/kg) for
location-10; Cd (1.73 mg/kg) for location-7; Pb (783 mg/kg) for location-7. Shi
et al. (2004) analysed dust collected in Chengdu, China, at a height of 1.5 m (as
was done in this work) and obtained the following concentrations in mg/kg: Cr:
112 mg/kg, Cu: 240 mg/kg, Zn: 1078 mg/kg, Cd: 4.33 mg/kg, Hg: 0.54 mg/kg
and Pb:372 mg/kg.
Location-7 which is one of the main camps for the waste pickers appeared to have
recorded the highest concentrations for almost all the heavy metals measured in
dust samples. This requires further site contamination analysis for health risk
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assessment.
Locations 1, 2, 3 are not waste picker camps; nevertheless, the health risk assess-
ment will cover these locations as well, though with less emphasis.
4.5.2 Heavy metals in soil samples
Figure 4.6: Mean concentration for V, Cr, Ni and Cu in soil per sampling
location
The following heavy metals were detected and quantified in dust samples as well:
vanadium (V), chromium (Cr), Nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd),
mercury (Hg) and lead (Pb). Their mean concentrations are plotted in Figures
4.6 and 4.7.
Copper (Cu), Zinc (Zn) and lead (Pb) concentration levels were generally above
their respective ”alert values”. Their highest mean concentrations were as follows:
Cu (334 mg/kg) measured at location-5 against the alert value of 190 mg/kg; Zn
(36585 mg/kg) for location-4 with 720 mg/kg as alert value; and Pb (4808 mg/kg)
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Figure 4.7: Mean concentration for Zn, Cd, Hg and Pb in soil per sampling
location
for location-4 with alert value as low as 530 mg/kg.
High concentration levels measured at locations 4, 5 and 6 especially for Cu, Zn
and Pb should be of concern as waste pickers extend their activities to these
locations. Location-7 a major waste pickers’ camp is also not too far from these
locations.
4.6 Heavy metal contamination assessment
4.7 Contamination factor
Contamination factors (CF) were computed for the heavy metals quantified in soil
and dust samples in order to evaluate the element specific contributions to the
toxic units. The results are presented in Table 4.7.
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Table 4.7: Heavy metals contributions (contamination factor) to the degree
of contamination of soil and dust at each sampling location
Element V Cr Ni Cu Zn Cd Hg Pb
Loc-1 1.38 1.54 42.27 14.43 22.83 1.51 0.06 6.90
Loc-2 1.11 1.60 46.55 14.97 23.39 1.69 0.03 6.34
Loc-3 0.97 1.80 47.92 21.74 36.67 2.23 0.02 5.25
Loc-41 0.31 1.43 76.87 5.17 390.03 3.36 0.17 113.67
Loc-51 0.60 2.45 67.13 12.07 153.55 3.63 0.17 110.60
Loc-61 0.68 2.32 62.62 11.87 117.85 4.19 0.18 61.36
Loc-7 1.14 1.80 31.68 69.10 113.46 2.47 0.06 17.82
Loc-8 0.73 1.17 40.65 10.53 73.84 1.47 0.01 0.29
Loc-9 1.07 1.32 44.45 14.93 12.53 1.77 0.01 1.97
Loc-10 0.93 1.48 45.47 17.89 39.29 1.74 0.03 3.82
1 Contamination factor computed for soil samples
A graphical representation of the contamination factor for each element per sam-
pling location is given in Figures 4.8 and 4.9.
From the results, Ni, Cu, Zn and Pb showed ’very high contamination’ (CF >>
6) for all sampling locations; while V, Cr and Cd showed ’moderate contamina-
tion’ (3 < CF < 6) with Hg showing ’low contamination’ (CF < 1). Location-7
recorded the highest contamination factors from V, Cr, Cu, Zn, Cd and Pd; this
culminated in this location having the highest degree of contamination, followed
by Location-8, Location-3, Location-10, Location-2, Location-1 and Location-9.
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Figure 4.8: Contamination factor for V, Cr, Ni and Cu per sampling loca-
tion
4.7.1 Degree of contamination
The degree of contamination (Cdeg) computed as the sum of contamination factors
is shown in Figure 4.10.
All the sampling locations recorded “very high degree of contamination” (i.e.
Cdeg >> 32). Locations 4, 5, and 6 where soil was sampled recorded the highest
degree of contamination. Location-7 which is one of the main meeting points of
waste pickers recorded the highest degree of contamination for dust. These obser-
vations were further probed by conducting an assessment of health risks associated
with the degree of contamination obtained.
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Figure 4.9: Contamination factor for Zn, Cd, Hg and Pb per sampling
location
Figure 4.10: Degree of contamination of heavy metals from the Kpone
Landfills
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4.8 Heath risk assessment
Daily intake dose for ingestion, dermal and inhalation pathways were computed
using the measured heavy metal concentrations and the some parameters from
literature (Table 4.8). The daily dose intakes were used to evaluate the heavy
metal specific non-carcinogenic hazard quotients (HQ) and the carcinogenic life-
time average daily dose (LiAvDD) for different exposure pathways for each sam-
pling location (Table 4.9). The average daily dose intakes were calculated only for
adults since there is no child-waste picker at the Kpone Landfill site.
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Table 4.8: Exposure parameters used for health risk assessment for different pathways
Parameter Unit Child Adult References
Body weight (BW) kg 15 70 (Tuyen et al., 2016)
Exposure frequency (EF) days/year 350 350 (Tuyen et al., 2016)
Exposure duration (ED)1 years 6 8 (Tuyen et al., 2016)
Ingestion rate (IR) mg/day 200 100 (Tuyen et al., 2016)
Inhalation rate (IRair) m3/day 10 20 (Tuyen et al., 2016)
Skin surface area (SA) cm2 2100 5800 (Tuyen et al., 2016)
Soil adherence factor (AF) mg/cm2 0.2 0.07 (Tuyen et al., 2016)
Dermal Absorption factor (ABS) 0.1 0.07 (Tuyen et al., 2016)
Dermal exposure ratio (FE) 0.61 0.61 (Tuyen et al., 2016)
Particulate emission factor (PEF) m3/kg 1.3×109 1.3×109 (Tuyen et al., 2016)
Conversion factor (CF) kg/mg 10−5 10−5 (Tuyen et al., 2016)
Average time (AT)
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For carcinogens days 365x70 365x70 (Nickel, 1995a)
For non-carcinogens days 365xED 365xED (Nickel, 1995a)
1 Exposure duration is specific to this study.
Table 4.9: Heavy metal specific hazard quotients for different exposure pathways
Cr Ni Cu Zn Cd Hg Pb
Location-1
HQing 7.18E-02 3.33E-03 2.83E-02 1.88E-02 5.57E-03 5.25E-04 2.13E-01
HQderm 6.46E-02 2.14E-04 7.86E-04 1.35E-03 1.00E-04 9.46E-06 2.63E-02
HQinh 5.28E-10 3.43E-10 1.93E-12 3.59E-12 1.35E-13
LiAvDD 1.81E-09 5.60E-10 8.81E-09 4.73E-08 2.34E-11 1.32E-12 6.45E-09
Location-2
HQing 7.46E-02 3.67E-03 2.94E-02 1.92E-02 6.20E-03 2.63E-04 1.96E-01
HQderm 6.71E-02 2.36E-04 8.15E-04 1.38E-03 1.12E-04 4.73E-06 2.42E-02
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HQinh 5.48E-10 3.77E-10 2.00E-12 4.00E-12 6.74E-14
LiAvDD 1.88E-09 6.17E-10 9.14E-09 4.84E-08 2.61E-11 6.62E-13 5.92E-09
Location-3
HQing 8.36E-02 3.78E-03 4.27E-02 3.01E-02 8.20E-03 1.75E-04 1.62E-01
HQderm 7.53E-02 2.43E-04 1.18E-03 2.17E-03 1.48E-04 3.15E-06 2.00E-02
HQinh 6.15E-10 3.88E-10 2.90E-12 5.29E-12 4.49E-14
LiAvDD 2.11E-09 6.35E-10 1.33E-08 7.59E-08 3.44E-11 4.42E-13 4.90E-09
Location-4
HQing 6.66E-02 6.06E-03 1.01E-02 3.20E-01 1.23E-02 1.49E-03 3.51E+00
HQderm 5.99E-02 3.89E-04 2.82E-04 2.31E-02 2.22E-04 2.68E-05 4.33E-01
HQinh 4.90E-10 6.23E-10 6.90E-13 7.96E-12 3.82E-13
LiAvDD 1.68E-09 1.02E-09 3.15E-09 8.08E-07 5.19E-11 3.75E-12 1.06E-07
Location-5
HQing 1.14E-01 5.29E-03 2.37E-02 1.26E-01 1.33E-02 1.49E-03 3.41E+00
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HQderm 1.03E-01 3.40E-04 6.57E-04 9.08E-03 2.40E-04 2.68E-05 4.21E-01
HQinh 8.39E-10 5.44E-10 1.61E-12 8.61E-12 3.82E-13
LiAvDD 2.88E-09 8.89E-10 7.37E-09 3.18E-07 5.61E-11 3.75E-12 1.03E-07
Location-6
HQing 1.08E-01 4.94E-03 2.33E-02 9.68E-02 1.54E-02 1.58E-03 1.89E+00
HQderm 9.74E-02 3.17E-04 6.47E-04 6.97E-03 2.77E-04 2.84E-05 2.34E-01
HQinh 7.96E-10 5.08E-10 1.59E-12 9.93E-12 4.04E-13
LiAvDD 2.73E-09 8.29E-10 7.25E-09 2.44E-07 6.47E-11 3.97E-12 5.73E-08
Location-7
HQing 8.37E-02 2.50E-03 1.36E-01 9.32E-03 9.09E-03 5.25E-04 5.50E-01
HQderm 7.53E-02 1.61E-04 3.76E-03 6.71E-04 1.64E-04 9.46E-06 6.79E-02
HQinh 6.15E-10 2.57E-10 9.23E-12 5.86E-12 1.35E-13
LiAvDD 2.11E-09 4.20E-10 4.22E-08 2.35E-08 3.82E-11 1.32E-12 1.66E-08
Location-8
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HQing 5.44E-02 3.20E-03 2.07E-02 6.07E-03 5.41E-03 8.76E-05 9.09E-03
HQderm 4.90E-02 2.06E-04 5.74E-04 4.37E-04 9.74E-05 1.58E-06 1.12E-03
HQinh 4.00E-10 3.29E-10 1.41E-12 3.49E-12 2.25E-14
LiAvDD 1.37E-09 5.38E-10 6.43E-09 1.53E-08 2.27E-11 2.21E-13 2.75E-10
Location-9
HQing 6.16E-02 3.50E-03 2.93E-02 1.03E-02 6.52E-03 8.76E-05 6.09E-02
HQderm 5.54E-02 2.25E-04 8.14E-04 7.41E-04 1.17E-04 1.58E-06 7.51E-03
HQinh 4.53E-10 3.60E-10 1.99E-12 4.20E-12 2.25E-14
LiAvDD 1.55E-09 5.89E-10 9.12E-09 2.59E-08 2.74E-11 2.21E-13 1.84E-09
Location-10
HQing 6.89E-02 3.58E-03 3.51E-02 3.23E-02 6.41E-03 2.63E-04 1.18E-01
HQderm 6.21E-02 2.30E-04 9.74E-04 2.32E-03 1.15E-04 4.73E-06 1.46E-02
HQinh 5.07E-10 3.69E-10 2.39E-12 4.13E-12 6.74E-14
LiAvDD 1.74E-09 6.02E-10 1.09E-08 8.14E-08 2.69E-11 6.62E-13 3.57E-09
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4.8.1 Non-carcinogenic health risk assessment
Table 4.10: Non-carcinogenic heavy metal specific hazard indexes per sampling location
Location LC1 LC2 LC3 LC4 LC5 LC6 LC7 LC8 LC9 LC10
Cr 0.1364 0.1417 0.1589 0.1265 0.2167 0.2057 0.1590 0.1034 0.1170 0.1310
Ni 0.0035 0.0039 0.0040 0.0064 0.0056 0.0053 0.0027 0.0034 0.0037 0.0038
Cu 0.0291 0.0302 0.0439 0.0104 0.0244 0.0240 0.1394 0.0213 0.0301 0.0361
Zn 0.0201 0.0206 0.0323 0.3434 0.1352 0.1038 0.0100 0.0065 0.0110 0.0346
Cd 0.0057 0.0063 0.0083 0.0126 0.0136 0.0157 0.0093 0.0055 0.0066 0.0065
Hg 0.0005 0.0003 0.0002 0.0015 0.0015 0.0016 0.0005 0.0001 0.0001 0.0003
Pb 0.2394 0.2200 0.1821 3.9419 3.8356 2.1277 0.6179 0.0102 0.0684 0.1326
HI 0.4347 0.4230 0.4297 4.4427 4.2326 2.4838 0.9388 0.1504 0.2369 0.3449
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For the non-carcinogenic health risk assessment, the hazard indexes were com-
puted as the sum of hazard quotients for all exposure pathways shown in Table
4.9. The hazard indexes are presented in Table 4.10.
For the non-carcinogenic health risk assessment, the hazard indexes were com-
puted as the sum of hazard quotients for all exposure pathways shown in Table
4.9. The hazard indexes are presented in Table 4.10.
Location-4 (HI: 4.4427), location-5 (HI: 4.2326) and location-6 (HI: 2.4838) had
hazard indexes greater than 1, the reference limit (US-EPA, 2004). Location-7
had a hazard index of HI =0.9388 which ≈ 1. This location appeared to be a sink
(receptor) for contaminants due to its location with respect to the municipal and
metallurgic dumpsites.
For hazard quotient (HQ) and hazard index (HI) values less than 1, there has not
been any reported obvious risk to the population. However, if HQ and HI val-
ues exceed 1, there may be potential non-carcinogenic health concern (US-EPA,
2004). The overall hazard index for the study are was HITotal = 14.12, over 1400%
higher than the reference value. The high HI value was driven by lead (Pb) which
recorded high HI for the sampling locations 4, 5 and 6, situated around the in-
dustrial dump site. The ingestion and dermal exposure pathways were found to
be the highest contributors to the non-carcinogenic hazard index followed by the
inhalation route. In view of the working conditions and the general awareness of
waste pickers about health and safety issues, this population may be at risk of
non-carcinogenic effects.
Although 23% of the waste pickers said they were aware of of health risk associated
with their trade, it was observed that this assertion does not reflect in the type of
dresses and footwear they put on during working hours as shown in Figure 4.11.
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Figure 4.11: Waste pickers at work at the Kpone landfill site (Picture from
student’s field work)
4.8.2 Carcinogenic health risk assessment
The carcinogenic health risk was computed based on Cr and Cd with the following
slope factors (SF) for the inhalation pathway, Inhalation SF: Cd = 6.3, Cr = 4.2.
The health risk indexes are presented in Table 4.11.
Table 4.11: Carcinogenic lifetime risk for inhalation of heavy metals
LC1 LC2 LC3 LC4 LC5
Cr 7.60E-09 7.89E-09 8.86E-09 7.05E-09 1.21E-08
Cd 1.47E-10 1.64E-10 2.17E-10 3.27E-10 3.53E-10
RI1 7.75E-09 8.06E-09 9.07E-09 7.38E-09 1.24E-08
LC6 LC7 LC8 LC9 LC10
Cr 1.15E-08 8.86E-09 5.76E-09 6.52E-09 7.30E-09
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Cd 4.08E-10 2.41E-10 1.43E-10 1.72E-10 1.70E-10
RI1 1.19E-08 9.10E-09 5.91E-09 6.69E-09 7.47E-09
1 Cancer risk index
The acceptable regulatory range for cancer risk index according to the United
States Environmental Protection Agency (US-EPA, 2004) is: 1 × 10−6–10−4.
From the two heavy metals used in the cancer risk assessment in this study,
chromium (Cr) had higher risk index than cadmium (Cd) (Cr > Cd) at all the
sampling locations. The sampling locations with the highest cancer risk indexes
ranked as follows: location-5 (1.24E-08) > location-6 (1.19E-08) > location-7.
Overall, the carcinogenic risk indexes ranged 1.43 × 10−10 – 1.21 × 10−8, which
were all below the regulatory range . However, the waste pickers may still be at
risk for an extended exposure to environmental contaminants at the Kpone Land-
fill site, especially when majority of them neither wear suitable protective clothing
nor put on nose masks.
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Chapter 5
Conclusions and Recommendations
5.1 Conclusions
Field reconnaissance visits to the Kpone landfill site led to the study design that
included demographic information gathering through a questionnaire administered
to waste pickers, the collection and analysis of soil and dust samples and ambient
nitrogen dioxide (NO2) and sulphur dioxide (SO2) monitoring to aid health risk
and safety assessment.
Although majority of the respondents (waste pickers) were aware of the physical
hazards associated with their scavenging activities, quite a few (23%) were aware
of the related health risks.
The ambient air quality monitoring was carried out at locations within the Kpone
landfill site, which are mainly areas with temporary structures where waste pickers
spend time sorting and selling their recovered items or take rest. Average NO2 and
SO2 concentration levels recorded were mostly within the Ghana Environmental
Protection Agency (EPA) regulatory limits of 150 µg/m3 for industrial areas for
both pollutants. However, these measured concentrations were above the World
Health Organisation (WHO) guideline limits of 40 µg/m3 and 20 µg/m3 for NO2
and SO2 respectively for all sampling locations, which is indicative of possible
health risks.
Eight (8) heavy metals (vanadium (V), chromium (Cr), Nickel (Ni), copper (Cu),
zinc (Zn), cadmium (Cd), mercury (Hg) and lead (Pb)) were detected and quan-
tified in the soil and dust samples collected from the study locations using X-ray
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fluorescence analysis (XRF). The results were first validated using reference stan-
dards and were found to be valid for this study with less than ±10% error margin.
Locations 4, 5, 6, 7 and 8, which are located around the metallurgic waste dump-
site and the adjacent Senteo Ceramic factory, recorded the highest concentrations
of heavy metals as was confirmed by their respective degree of contamination.
The non-carcinogenic health risk assessment projected locations 4, 5, 6 and 7 as
areas with high hazard indexes, making waste pickers who spend long hours at
these locations vulnerable to potential long-term health effects.
Carcinogenic lifetime risk for inhalation of heavy metals assessment revealed risk
indexes below the US-EPA regulatory range of 1×10−6 – 10−4. Here again locations
4, 5, 6, and 7 recorded the highest cancer risk indexes.
5.2 Recommendations
This study did not include atmospheric particulate matter collection and analysis
due to logistic constrains. For the same reason, the duration of the sampling
campaign was shortened. For an environment such as the Kpone landfill site, an
extended sampling campaign that included measurement of other pollutants for
pollution source identification and apportionment is recommended.
The waste pickers are major stakeholders in municipal solid waste management in
view of the socioeconomic import of their activities. Hence, considering the degree
of contamination and the health hazard indexes at the Kpone landfill side and
the waste pickers level of health and safety awareness, there should be increased
education and sensitisation campaign which will benefit them.
They should also be supported through provision of appropriate PPEs and other
work implements.
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References
Adamcová, D., Radziemska, M., Ridošková, A., Bartoň, S., Pelcová, P., Elbl,
J., Kynickỳ, J., Brtnickỳ, M., and Vaverková, M. D. (2017). Environmental
assessment of the effects of a municipal landfill on the content and distribution
of heavy metals in Tanacetum vulgare L. Chemosphere, 185:1011–1018.
Aktaruzzaman, M., Chowdhury, M. A. Z., Fardous, Z., Alam, M. K., Hossain,
M., and Fakhruddin, A. N. M. (2014). Ecological risk posed by heavy metals
contamination of ship breaking yards in Bangladesh. International Journal of
Environmental Research, 8(2):469–478.
Alam, P. and Ahmade, K. (2013). Impact of solid waste on health and the environ-
ment. International Journal of Sustainable Development and Green Economics
(IJSDGE), 2(1):165–168.
Ali, M. (1999). The informal sector: What is it worth? Waterlines, 17(3):10–11.
Annorbah, R. (2014). Environmental Impacts of Active and Decommissioned Land-
fill Sites in the Accra Metropolis: A Case Study of the Pantang and Mallam
Landfill Sites. PhD thesis, University Of Ghana.
Asase, M., Yanful, E. K., Mensah, M., Stanford, J., and Amponsah, S. (2009).
Comparison of municipal solid waste management systems in Canada and
Ghana: A case study of the cities of London, Ontario, and Kumasi, Ghana.
Waste Management, 29(10):2779–2786.
Binion, E. and Gutberlet, J. (2012). The effects of handling solid waste on the
wellbeing of informal and organized recyclers: A review of the literature. Inter-
national journal of occupational and environmental health, 18(1):43–52.
Boadi, K. O. and Kuitunen, M. (2003). Municipal solid waste management in the
Accra Metropolitan Area, Ghana. Environmentalist, 23(3):211–218.
Bopape, M., Mothiba, T., Mutambudzi, M., Wens, J., and Bastiaens, H. (2019).
Baseline Assessment of Knowledge of Home Based Carers for People with Di-
abetes in a Rural Village in South Africa: A Quantitative Study. The Open
Public Health Journal, 12(1).
77
University of Ghana http://ugspace.ug.edu.gh
Brice, J., Sevitz, J., and Cornelius, J. (2006). Guidance for the classification, rating
and disposal of common hazardous waste streams. Water Research Commission.
Calzolai, G., Chiari, M., Lucarelli, F., Mazzei, F., Nava, S., Prati, P., Valli, G.,
and Vecchi, R. (2008). PIXE and XRF analysis of particulate matter samples:
an inter-laboratory comparison. Nucl. Instr. and Meth. in Physics Research
Section B: Beam Interactions with Materials and Atoms, 266(10):2401–2404.
Cardozo, M. C. and Moreira, R. M. (2015). Potential health risks of waste pickers.
O Mundo da Saúde, 39(3):370–376.
Coffey, M. and Coad, A. (2010). Collection of municipal solid waste in developing
countries. UN-Habitat, United Nations Human Settlements Programme.
Cointreau, S. (2006). Occupational and environmental health issues of solid waste
management: special emphasis on middle-and lower-income countries. Urban
Papers, 2.
Cointreau, S. and Cravioto, F. G. (2009). Finance for solid waste system in
developing countries.
Crommentuijn, T. and Polder, M. D. (1997). Maximum permissible concentra-
tions and negligible concentrations for metals, taking background concentrations
into account. Rijksinstituut voor Volksgezondheid en Milieu RIVM, Bilthoven,
Netherlands.
d’Ambrières, W. (2019). Plastics recycling worldwide: current overview and de-
sirable changes. Field Actions Science Reports. The journal of field actions,
19:12–21.
Fewtrell, L. (2012). Municipal Solid Waste and Health. Technical report, Research
Report for Regional Visions of Integrated Sustainable Development.
Follett, R. F. and Hatfield, J. L. (2001). Nitrogen in the environment: sources,
problems, and management. The Scientific World Journal, 1:920–926.
Gogoi, L. (2005). Occupational Health Hazard of Waste Pickers in the Vicinity of
Dumping Ground: a Case Study of West Boragaon Dumpsite, Guwahati, India.
78
University of Ghana http://ugspace.ug.edu.gh
Guerrero, L. A., Maas, G., and Hogland, W. (2013). Solid waste management
challenges for cities in developing countries. Waste management, 33(1):220–
232.
Gupta, S. K. (2012). Integrating the informal sector for improved waste manage-
ment. Private Sector and Development, 15:12–17.
Gutberlet, J. and Uddin, S. M. N. (2017). Household waste and health risks
affecting waste pickers and the environment in low-and middle-income countries.
International journal of occupational and environmental health, 23(4):299–310.
Guthrie, J. M. and Ferguson, J. R. (2012). Overview of X-ray Fluorescence.
Archaeometry Laboratory at the University of Missouri Research Reactor.
http://archaeometry. missouri. edu/xrf overview. html.
Hoornweg, D., Bhada-Tata, P., et al. (2012). What a waste: A global review of
solid waste management, volume 15. World Bank, Washington, DC.
Inglezakis, V. J. and Moustakas, K. (2015). Household hazardous waste manage-
ment: A review. Journal of environmental management, 150:310–321.
Injuk, J. and Van Grieken, R. (2003). Literature trends in x-ray emission spectrom-
etry in the period 1990–2000: A review. X-Ray Spectrometry: An International
Journal, 32(1):35–39.
Järup, L. (2003). Hazards of heavy metal contamination. British medical bulletin,
68(1):167–182.
Jomova, K. and Valko, M. (2011). Advances in metal-induced oxidative stress and
human disease. Toxicology, 283(2-3):65–87.
Kampa, M. and Castanas, E. (2008). Human health effects of air pollution. En-
vironmental Pollution, 151(2):362–367.
Karthikeyan, O. P., Murugesan, S., Joseph, K., and Philip, L. (2011). Character-
ization of particulate matters and volatile organic compounds in the ambient
environment of open dump sites. Universal Journal of Environmental Research
& Technology, 1(2).
79
University of Ghana http://ugspace.ug.edu.gh
Kaza, S., Yao, L., Bhada-Tata, P., and Van Woerden, F. (2018). What a waste 2.0:
A global snapshot of solid waste management to 2050. World Bank Publications.
Kunisue, T., Watanabe, M., Iwata, H., Subramanian, A., Monirith, I., Minh, T.,
Baburajendran, R., Tana, T., Viet, P., Prudente, M., et al. (2004). Dioxins and
related compounds in human breast milk collected around open dumping sites
in Asian developing countries: bovine milk as a potential source. Archives of
environmental contamination and toxicology, 47(3):414–426.
Kyere, V. N., Greve, K., Atiemo, S. M., Amoako, D., Aboh, I. K., and Cheabu,
B. S. (2018). Contamination and Health Risk Assessment of Exposure to Heavy
Metals in Soils from Informal E-Waste Recycling Site in Ghana. Emerging
Science Journal, 2(6):428–436.
Lazarevic, D., Buclet, N., and Brandt, N. (2010). The influence of the waste
hierarchy in shaping European waste management: the case of plastic waste.
Regional Development Dialogue, 31(2):124–148.
Macklin, Y., Kibble, A., and Pollitt, F. (2011). Impact on health of emissions
from landfill sites: advice from the Health Protection Agency. Health Protection
Agency.
Made, F., Wilson, K., Jina, R., Tlotleng, N., Jack, S., Ntlebi, V., and Kootbodien,
T. (2017). Distribution of cancer mortality rates by province in South Africa.
Cancer Epidemiology, 51:56–61.
Makhubele, M., Ravhuhali, K., Kuonza, L., Mathee, A., Kgalamono, S., Made,
F., Tlotleng, N., Kootbodien, T., Ntlebi, V., and Wilson, K. (2019). Common
Mental Health Disorders among Informal Waste Pickers in Johannesburg, South
Africa 2018 – A Cross-Sectional Study. International Journal of Environmental
Research and Public Health, 16(14):2618.
Marcazzan, G. M., Vaccaro, S., Valli, G., and Vecchi, R. (2001). Characterisa-
tion of PM10 and PM2.5 particulate matter in the ambient air of Milan (Italy).
Atmospheric Environment, 35(27):4639–4650.
Martin, S. and Griswold, W. (2009). Human health effects of heavy metals. En-
vironmental Science and Technology briefs for citizens, 15:1–6.
80
University of Ghana http://ugspace.ug.edu.gh
Mavropoulos, A. (2015). Wasted health, the tragic case of dumpsites. Technical
report, ISWAs Scientific and Technical Committee Work-Program 2014-2015.
Medina, M. (2007). Waste picker cooperatives in developing countries. In Mem-
bership based organizations of the poor, pages 125–141. Routledge.
Muttamara, S. and Leong, S. T. (1997). Environmental monitoring and impact
assessment of a solid waste disposal site. Environmental Monitoring and As-
sessment, 48(1):1–24.
Nickel, E. (1995a). The definition of a mineral. Mineral J, 17(7):46–349.
Nickel, E. H. (1995b). Definition of a mineral. Mineralogical Journal, 17(7):346–
349.
Osei, J., Osae, S., Fianko, J., Adomako, D., Laar, C., Anim, A., Ganyaglo, S.,
Nyarku, M., and Nyarko, E. (2011). The impact of Oblogo landfill site in Accra-
Ghana on the surrounding environment. Research Journal of Environmental and
Earth Sciences, 3(6):633–636.
Owusu, G., Oteng-Ababio, M., and Afutu-Kotey, R. L. (2012). Conflicts and
governance of landfills in a developing country city, Accra. Landscape and Urban
Planning, 104(1):105–113.
Owusu-Sekyere, E., Osumanu, I. K., and Yaro, J. A. (2013). Dompoase Landfill
in the Kumasi Metropolitan Area of Ghana: A ’Blessing’or a ’Curs’? Int. J.
Cur. Tr. Res, 2(1).
Pandey, J. S., Kumar, R., and Devotta, S. (2005). Health risks of no˜ 2, spm and
so˜ 2 in delhi (india). Atmospheric Environment, 39(36):6868–6874.
Parsons, C., Grabulosa, E. M., Pili, E., Floor, G. H., Roman-Ross, G., and Charlet,
L. (2013). Quantification of trace arsenic in soils by field-portable X-ray fluo-
rescence spectrometry: considerations for sample preparation and measurement
conditions. Journal of Hazardous Materials, 262:1213–1222.
Parveen, S. and Faisal, I. M. (2005). Occupational health impacts on the child
waste-pickers of Dhaka City. WIT Transactions on Biomedicine and Health, 9.
81
University of Ghana http://ugspace.ug.edu.gh
Pawels, R. and Tom, A. P. (2013). Assessment of Technological Options for Solid
Waste Treatment in Kerala. Hospitals (Non-infectious), 2(4.22):3–6.
Pénard-Morand, C., Charpin, D., Raherison, C., Kopferschmitt, C., Caillaud, D.,
Lavaud, F., and Annesi-Maesano, I. (2005). Long-term exposure to background
air pollution related to respiratory and allergic health in schoolchildren. Clinical
& Experimental Allergy, 35(10):1279–1287.
Rouillon, M. and Taylor, M. P. (2016). Can field portable X-ray fluorescence
(pXRF) produce high quality data for application in environmental contamina-
tion research? Environmental Pollution, 214:255–264.
Salifu, L. Y. (2019). Environmental and social audit of Kpone landfill. Ministry
of Works and Housing P. O. Box M 43 Accra, Ghana.
Samson, M. (2009). Refusing to be cast aside: Waste pickers organising around the
world. Women in Informal Employment: Globalizing and Organizing (WIEGO).
Savage, G. M. and Diaz, L. F. (1990). Processing of solid waste for material
recovery. In American Society of Mechanical Engineers 14th National Waste
Processing Conference, Long Beach, California, USA.
Shankar, V. K. and Sahni, R. (2018). Waste Pickers and the Right to Wastein an
Indian City. Economic and Political Weekly.
Shi, Z.-m., NI, S.-j., and Zhang, C.-J. (2004). The geochemical characteristics of
air dust near the ground in Chengdu. Earth and Environment, 32(53):3–4.
Sitko, R. and Zawisza, B. (2012). Quantification in X-Ray fluorescence spectrom-
etry. X-Ray Spectroscopy, pages 137–162.
Slack, R. J., Gronow, J. R., and Voulvoulis, N. (2005). Household hazardous
waste in municipal landfills: Contaminants in leachate. Science of the total
environment, 337(1-3):119–137.
Smith, A., Brown, K., Ogilvie, S., Rushton, K., Bates, J., et al. (2001). Waste
management options and climate change: Final report to the European Com-
mission. In Waste management options and climate change: final report to the
European Commission. European Commission.
82
University of Ghana http://ugspace.ug.edu.gh
Stavrakou, T., Müller, J.-F., Boersma, K., De Smedt, I., and Van Der A, R.
(2008). Assessing the distribution and growth rates of NOx emission sources
by inverting a 10-year record of NO2 satellite columns. Geophysical Research
Letters, 35(10).
Suplido, M. L. and Ong, C. N. (2000). Lead exposure among small-scale bat-
tery recyclers, automobile radiator mechanics, and their children in Manila, the
Philippines. Environmental research, 82(3):231–238.
Tuyen, L. D., Hien, V. T. T., Binh, P. T., and Yamamoto, S. (2016). Calcium
and vitamin D deficiency in vietnamese: recommendations for an intervention
strategy. Journal of Nutritional Science and Vitaminology, 62(1):1–5.
UN-Habitat (2010). Solid waste management in the worlds cities. United Nations
Human Settlements Programme, Washington, DC 20036, USA.
UNEP (2013). Health and safety guidelines for waste pickers in South Sudan.
Technical report, United Nations Development Program, South Sudan, South
Sudan.
U.S. Environmental Protection Agency (2004). Risk Assessment Guidance for
Superfund Volume I: Human Health Evaluation Manual (Part E, Supplemental
Guidance for Dermal Risk Assessment). USEPA:Washington, DC, USA.
Watson, J., Chow, J., and Frazier, C. (1999). X-ray fluorescence analysis of am-
bient air samples. Elemental Analysis of Airborne Particles, 1:67–96.
Weindorf, D. C., Zhu, Y., Chakraborty, S., Bakr, N., and Huang, B. (2012). Use
of portable X-ray fluorescence spectrometry for environmental quality assess-
ment of peri-urban agriculture. Environmental Monitoring and Assessment,
184(1):217–227.
WIEGO (2008). Waste Pickers without Frontiers. In First International and
Third Latin American Conference of Waste-Pickers, Bogota, Colombia. Women
in Informal Employment: Globalizing and Organizing (WIEGO).
83
University of Ghana http://ugspace.ug.edu.gh
Wilson, D. C., Velis, C., and Cheeseman, C. (2006). Role of informal sector
recycling in waste management in developing countries. Habitat international,
30(4):797–808.
World Health Organization (2006). WHO Air quality guidelines for particulate
matter, ozone, nitrogen dioxide and sulfur dioxide: global update 2005: sum-
mary of risk assessment. Technical report, Geneva: World Health Organization.
Ziraba, A. K., Haregu, T. N., and Mberu, B. (2016). A review and framework for
understanding the potential impact of poor solid waste management on health
in developing countries. Archives of Public Health, 74(1):55.
Zurbrugg, C. (2003). Solid waste management in developing countries. SWM
introductory text on www. sanicon. net, 5.
84