Browsing by Author "Obiri, S."
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Item Anthropogenic sources and environmentally relevant concentrations of heavy metals in surface water of a mining district in Ghana: A multivariate statistical approach(Journal of Environmental Science and Health - Part A Toxic/Hazardous Substances and Environmental Engineering, 2010-11) Armah, F.A.; Obiri, S.; Yawson, D.O.; Onumah, E.E.; Yengoh, G.T.; Afrifa, E.K.A.; Odoi, J.O.The levels of heavy metals in surface water and their potential origin (natural and anthropogenic) were respectively determined and analysed for the Obuasi mining area in Ghana. Using Hawth's tool an extension in ArcGIS 9.2 software, a total of 48 water sample points in Obuasi and its environs were randomly selected for study. The magnitude of As, Cu, Mn, Fe, Pb, Hg, Zn and Cd in surface water from the sampling sites were measured by flame Atomic Absorption Spectrophotometry (AAS). Water quality parameters including conductivity, pH, total dissolved solids and turbidity were also evaluated. Principal component analysis and cluster analysis, coupled with correlation coefficient analysis, were used to identify possible sources of these heavy metals. Pearson correlation coefficients among total metal concentrations and selected water properties showed a number of strong associations. The results indicate that apart from tap water, surface water in Obuasi has elevated heavy metal concentrations, especially Hg, Pb, As, Cu and Cd, which are above the Ghana Environmental Protection Agency (GEPA) and World Health Organisation (WHO) permissible levels; clearly demonstrating anthropogenic impact. The mean heavy metal concentrations in surface water divided by the corresponding background values of surface water in Obuasi decrease in the order of Cd > Cu > As > Pb > Hg > Zn > Mn > Fe. The results also showed that Cu, Mn, Cd and Fe are largely responsible for the variations in the data, explaining 72% of total variance; while Pb, As and Hg explain only 18.7% of total variance. Three main sources of these heavy metals were identified. As originates from nature (oxidation of sulphide minerals particularly arsenopyrite-FeAsS). Pb derives from water carrying drainage from towns and mine machinery maintenance yards. Cd, Zn, Fe and Mn mainly emanate from industry sources. Hg mainly originates from artisanal small-scale mining. It cannot be said that the difference in concentration of heavy metals might be attributed to difference in proximity to mining-related activities because this is inconsistent with the cluster analysis. Based on cluster analysis SN32, SN42 and SN43 all belong to group one and are spatially similar. But the maximum Cu concentration was found in SN32 while the minimum Cu concentration was found in SN42 and SN43. Copyright © Taylor & Francis Group, LLC.Item Association of Arsenic and Adverse Pregnancy Outcomes/Infant Mortality: A Systematic Review and Meta-analysis.(Open Access, 2015-05) Quansah, R.; Armah, F.A.; Essumang, D.K.; Luginaah, I.; Clarke, E.; Marfoh, K.; Cobbina, S.J.; Nketiah-Amponsah, E.; Namujju, P.B.; Obiri, S.; Dzodzomenyo, M.Background Exposure to arsenic is one of the major global health problems, affecting > 300 million people worldwide, but arsenic’s effects on human reproduction are uncertain. Objectives We conducted a systematic review and meta-analysis to examine the association between arsenic and adverse pregnancy outcomes/infant mortality. Methods We searched PubMed and Ovid MEDLINE (from 1946 through July 2013) and EMBASE (from 1988 through July 2013) databases and the reference lists of reviews and relevant articles. Studies satisfying our a priori eligibility criteria were evaluated independently by two authors. Results Our systematic search yielded 888 articles; of these, 23 were included in the systematic review. Sixteen provided sufficient data for our quantitative analysis. Arsenic in groundwater (≥ 50 μg/L) was associated with increased risk of spontaneous abortion (6 studies: OR = 1.98; 95% CI: 1.27, 3.10), stillbirth (9 studies: OR = 1.77; 95% CI: 1.32, 2.36), moderate risk of neonatal mortality (5 studies: OR = 1.51; 95% CI: 1.28, 1.78), and infant mortality (7 studies: OR = 1.35; 95% CI: 1.12, 1.62). Exposure to environmental arsenic was associated with a significant reduction in birth weight (4 studies: β = –53.2 g; 95% CI: –94.9, –11.4). There was paucity of evidence for low-to-moderate arsenic dose. Conclusions Arsenic is associated with adverse pregnancy outcomes and infant mortality. The interpretation of the causal association is hampered by methodological challenges and limited number of studies on dose response. Exposure to arsenic continues to be a major global health issue, and we therefore advocate for high-quality prospective studies that include individual-level data to quantify the impact of arsenic on adverse pregnancy outcomes/infant mortality.Item Comparative Assessment of Heavy Metals in Drinking Water Sources in Two Small-Scale Mining Communities in Northern Ghana.(International Journal of Environmental Research and Public Health, 2015-08) Cobbina, S.J.; Duwiejuah, A.B.; Quansah, R.; Obiri, S.; Bakobie, N.The study assessed levels of heavy metals in drinking water sources in two small-scale mining communities (Nangodi and Tinga) in northern Ghana. Seventy-two (72) water samples were collected from boreholes, hand dug wells, dug-out, and a stream in the two mining communities. The levels of mercury (Hg), arsenic (As), lead (Pb), zinc (Zn), and cadmium (Cd) were determined using an atomic absorption spectrophotometer (AAS). Mean levels (mg/l) of heavy metals in water samples from Nangodi and Tinga communities were 0.038 and 0.064 (Hg), 0.031 and 0.002 (As), 0.250 and 0.031 (Pb), 0.034 and 0.002 (Zn), and 0.534 and 0.023 (Cd), respectively, for each community. Generally, levels of Hg, As, Pb, Zn, and Cd in water from Nangodi exceeded the World Health Organisation (WHO) stipulated limits of 0.010 for Hg, As, and Pb, 3.0 for Zn and 0.003 for Cd for drinking water, and levels of Hg, Pb, and Cd recorded in Tinga, exceeded the stipulated WHO limits. Ingestion of water, containing elevated levels of Hg, As, and Cd by residents in these mining communities may pose significant health risks. Continuous monitoring of the quality of drinking water sources in these two communities is recommendedItem Human Health Risk Assessment of Exposure to Heavy Metals in Selected Mining Communities in Ghana.(University Of Ghana, 2018-01) Obiri, S.Gold mining is an important economic activity in Ghana. However, processing and extraction of gold from its ores generate a lot of wastes. Studies conducted in different countries have established that long-term exposure to As, Cd, Pb and Hg in the wastes could cause cancer and other non-cancerous diseases such as cardiovascular diseases. It is within this context that, this thesis assessed cancer and non-cancer human health risk associated with exposure to As, Cd, Hg and Pb in water and sediment via oral and dermal contact by receptors such as adults workers in mining companies or artisanal small-scale mines (ASM), resident adults (i.e., who do not work in either mining companies or ASM) and resident children in selected mining communities in Ghana. The study further evaluated the health risk associated with ingestion of food crops such as cassava grown in soils the study areas as well as the determination of levels of As, Cd, Pb and Hg in human such as whole blood and serum among resident adults (non-mine workers i.e., workers of mining companies or ASM), and resident children in selected mining and non-mining communities in Ghana in line with USEPA risk assessment guidelines as there exist limited information on this subject in Ghana. The study protocol was approved by the Ghana Health Service Ethical Review Committee. Random sampling techniques were adopted in selecting the sampling sites as well as recruitment of respondents who donated their blood samples as well as provided information about their personal health in relation to cardiovascular diseases. The collected water, sediment and cassava samples were stored under 4ºC and conveyed to the CSIR-Water Research Institute laboratory for analysis. The blood samples were collected by laboratory staff of Tarkwa Nsuaem Municipal Hospital, Cape Coast metropolitan Hospital, Health Centre at Bole and Nangodi respectively. The blood samples were separated into whole blood and serum by the laboratory staff and conveyed to Ghana Atomic Energy Commission for analysis of As, Cd and Hg using the NAA at Ghana Reactor 3 under -4ºC; while the Pb levels in the blood samples were determined using GFAAS at Heavy Metals Laboratory of CSIR-Water Research Institute. The mean concentrations for As, Hg, Cd and Pb in whole blood of resident adults from mining communities in Tarkwa Nsuaem Municipality were; 38 ± 0.20 μgL-1, 63 ± 0.23 μgL-1, 303 ± 117 μgL-1 and 28 ± 14 μgL-1 respectively; while the levels of As, Hg, Cd and Pb measured in serum of resident adults from mining communities were; 65 ± 14 μgL-1, 358 ±22 μgL-1, 134 ± 12 μg/L, 58 ±5.8 μgL-1 respectively for As, Hg, Cd and Pb. These were found to have exceeded the permissible WHO guideline values. The mean concentrations of As, Cd, Hg and Pb in water samples ranged from 15 μg/L to 325 μg/L (As), 0.17 μg/L to 340 μg/L (Cd), 0.17 μg/L to 122 μg/L (Pb) and 132 μg/L to 866 μg/L (Hg) respectively. These measured concentrations of arsenic (As), mercury (Hg), cadmium (Cd) and lead (Pb) were used as input parameters to calculate the cancer and non–cancer health risks from exposure to these metals in surface water bodies and sediments based on an occupational exposure scenario using Central Tendency Exposure (CTE) and Reasonable Maximum Exposure (RME) parameters. The results of the non-cancer human health risk assessment for small-scale miners working around river Anikoko were expressed in terms of hazard quotients based on CTE parameters are as follows: 0.04 (Cd), 1.45 (Pb), 4.60 (Hg) and 1.98 (As); while cancer health risk faced by ASGM miners in Dumase exposed to As in River Mansi via oral ingestion of water is 3.1 × 10−3. The hazard quotient results obtained from this study in most cases were above the HQ guidance value of 1.0. Furthermore the cancer health risk results were found to be higher than the USEPA guidance value of 1 × 10−4 to 1 × 10−6. The findings from case-control epidemiological studies established a strong relationship between exposure to As in drinking water and incidence of cardiovascular diseases among residents in the study areas. The results from this study calls for strong policy interventions to address the issue of health and safety of both mine workers and residents of mining communities in Ghana.Item Integrated Assessment of Artisanal and Small-Scale Gold Mining in Ghana-Part 1: Human Health Review(International Journal of Environmental Research and Public Health, 2015-05) Basu, N.; Clarke, E.; Green, A.; Calys-Tagoe, B.; Chan, L.; Dzodzomenyo, M.; Fobil, J.; Long, R.N.; Neitzel, R.L.; Obiri, S.; Odei, E.; Ovadje, L.; Quansah, R.; Rajaee, M.; Wilson, M.L.This report is one of three synthesis documents produced via an integrated assessment (IA) that aims to increase understanding of artisanal and small-scale gold mining (ASGM) in Ghana. Given the complexities surrounding ASGM, an IA framework was utilized to analyze economic, social, health, and environmental data, and co-develop evidence-based responses with pertinent stakeholders. The current analysis focuses on the health of ASGM miners and community members, and synthesizes extant data from the literature as well as co-authors’ recent findings regarding the causes, status, trends, and consequences of ASGM in Ghana. The results provide evidence from across multiple Ghanaian ASGM sites that document relatively high exposures to mercury and other heavy metals, occupational injuries and noise exposure. The work also reviews limited data on psychosocial health, nutrition, cardiovascular and respiratory health, sexual health, and water and sanitation. Taken together, the findings provide a thorough overview of human health issues in Ghanaian ASGM communities. Though more research is needed to further elucidate the relationships between ASGM and health outcomes, the existing research on plausible health consequences of ASGM should guide policies and actions to better address the unique challenges of ASGM in Ghana and potentially elsewhere. © 2015 by the authors; licensee MDPI, Basel, Switzerland.Item Integrated Assessment of Artisanal and Small-Scale Gold Mining in Ghana-Part 2: Natural Sciences Review.(International Journal of Environmental Research and Public Health, 2015-07) Rajaee, M.; Obiri, S.; Green, A.; Long, R.; Cobbina, S.J.; Nartey, V.; Buck, D.; Antwi, E.; Basu, N.This report is one of three synthesis documents produced via an integrated assessment (IA) that aims to increase understanding of artisanal and small-scale gold mining (ASGM) in Ghana. Given the complexities surrounding ASGM, an IA framework was utilized to analyze economic, social, health, and environmental data, and co-develop evidence-based responses with pertinent stakeholders. The current analysis focuses on the health of ASGM miners and community members, and synthesizes extant data from the literature as well as co-authors’ recent findings regarding the causes, status, trends, and consequences of ASGM in Ghana. The results provide evidence from across multiple Ghanaian ASGM sites that document relatively high exposures to mercury and other heavy metals, occupational injuries and noise exposure. The work also reviews limited data on psychosocial health, nutrition, cardiovascular and respiratory health, sexual health, and water and sanitation. Taken together, the findings provide a thorough overview of human health issues in Ghanaian ASGM communities. Though more research is needed to further elucidate the relationships between ASGM and health outcomes, the existing research on plausible health consequences of ASGM should guide policies and actions to better address the unique challenges of ASGM in Ghana and potentially elsewhere. (PDF) Integrated Assessment of Artisanal and Small-Scale Gold Mining in Ghana—Part 1: Human Health Review. Available from: https://www.researchgate.net/publication/277349673_Integrated_Assessment_of_Artisanal_and_Small-Scale_Gold_Mining_in_Ghana-Part_1_Human_Health_Review [accessed Sep 13 2018].