Browsing by Author "Dankyi, E."
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Item Application of the QuEChERS procedure and LC–MS/MS for the assessment of neonicotinoid insecticide residues in cocoa beans and shells Journal of Food Composition and Analysis(Elsevier - Journal of Food Composition and Analysis, 2015-09) Dankyi, E.; Carboo, D.; Gordon, C.; Fomsgaard, I.S.The Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) procedure was applied and validated for the analysis of neonicotinoid insecticide residues in cocoa bean matrix with high fat and high pigments. Samples employed in the study were fermented and dried beans obtained from major cocoa producing regions in Ghana where neonicotinoids are extensively used. Shells covering the beans were removed and analyzed separately to examine insecticide distribution. Analytes in both matrices were extracted in acetonitrile with sodium acetate and magnesium sulfate salts, cleaned up using a sorbent mixture of primary secondary amine (PSA), C18 and graphitized carbon black (GCB), and quantified using liquid chromatography tandem mass spectrometry (LC–MS/MS). Average recoveries at four levels of fortification ranged from 92 to 111% with relative standard deviation of 16% for all analytes. Limits of quantification ranged from 3 to 10 mg/kg for all neonicotinoids. Imidacloprid was the most frequently encountered neonicotinoid and was quantified in more than 10% of deshelled bean and 30% of cocoa shell samples, with concentrations ranging from 11.5 to 35.6 mg/kg and 11.8 to 214 mg/kg in cocoa beans and shells, respectively. The findings from this study suggest a need for greater efficiency in neonicotinoid application, to avoid the build-up of these insecticides to unsafe levels in cocoa beans.Item Assessing groundwater quality in peri-urban Accra, Ghana: Implications for drinking and irrigation purposes(Groundwater for Sustainable Development, 2022) Hagan, G.B.; Minkah, R.; Yiran, G.A.B.; Dankyi, E.In many developing countries, cities are faced with rising water demand due to rapidly increasing population. inadequate municipal water supply and growing sanitation pressure. Consequently, groundwater resources are being heavily relied on to meet the demand. However, the long-term supply and quality of groundwater are threatened by multiple anthropogenic pressures. This study assessed the quality and suitability of groundwater available to more than 600,000 inhabitants in several peri-urban communities in Accra, the capital city of Ghana. Thirty-six (36) borehole samples were analysed for their suitability for domestic and irrigation purposes based on relevant physicochemical parameters. In addition, water quality index (WQI), sodium absorption ratio, and relevant statistical plots were employed to assess the groundwater’s quality and suitability for domestic and irrigation purposes. The results indicate that almost all parameters measured were within the WHO recommended limits for drinking water for most samples. This is reflected in the classification of 92% of water samples as good or excellent quality for domestic purposes using WQI. The abundance of ions in groundwater followed the trend: Na+ > Ca2+ > Mg2+ > K+ for cations, and Cl− > SO4 2 > HCO3 − > F > NO3 − for anions. By using principal component and hierarchical cluster analyses, the study identified mineral dissolution and anthropogenic activities as the main factors influencing groundwater chemistry in the study area. These factors resulted in mixed water types, viz., Na-Ca-Mg–Cl and Na-Ca-Mg–SO4, with Na-Cl as the dominant water type. Classifications based on the Wilcox and USSL diagrams, it appears that groundwater in the study area is generally suitable for irrigation. Given that these boreholes are new, the results from this study represent background levels and have important implications for groundwater development and management in the rapidly developing capital of Ghana.Item Exposure and Fate of Neonicotinoid Insecticides in Cocoa plantations in Ghana(University of Ghana, 2015-07) Dankyi, E.; Carboo, D.; Gordon, C.; Fomsgaard, I. S; University Of Ghana, College of Basic and Applied Sciences ,School of Physical and Mathematical Sciences, Department of ChemistryNeonicotinoids belong to the most important class of insecticides currently used in crop production and account for about a fourth of the insecticide market. They are considered highly effective against insect pests, safe to mammals, and possess multiple means of application for convenience and widespread usage in diverse crop protection. Neonicotinoids are systemic insecticides - they are absorbed into plants, travel through the vascular tissue, and help protect the plant from piercing and sucking insects. Their mode of action is through agonist activity at the postsynaptic nicotinic acetylcholine receptor (nAChRs) sites in the nervous system. In recent years, reports have emerged on possible harmful effects of neonicotinoid insecticides on bee health. Across Europe, America and Australia, there has been calls for ban and reevaluation of the use of neonicotinoid insecticides. In Europe, a ban has been in place for almost two years following a scientific report by the European Food Safety Authority (EFSA) which identified “high acute risks” for bees. However, the availability of conflicting reports on the effects of neonicotinoids on bees has prompted intense research on these class of insecticides. Quite clearly, understanding the effects of neonicotinoids on organisms in the ecosystem will rely on accurate knowledge of their exposure in the environment. In Ghana, neonicotinoids are one of the most widely used class of insecticides particularly in cocoa production, where they are important for the control of mirids. Insect pests are a major concern in crop production in tropical conditions, due to the prevailing conducive environment for their growth. In cocoa production, insect pests such as mirids contribute to significant loses in yield. To address this concern, the government of Ghana introduced a free mass application policy on insecticides in cocoa farming, which has contributed to substantial improvements in yields of cocoa beans. Under the program, neonicotinoids are the major class of insecticides used. In spite of the remarkable contribution of neonicotinoids to cocoa production, concerns about the environment and food safety have arisen due to widespread and intensive use of these chemicals in cocoa farms. Addressing these concerns requires accurate knowledge of the behavior and fate of these class of insecticides in the Ghanaian environment. The primary goal of this work was to assess the extent of exposure, behavior and fate of neonicotinoids in the Ghanaian environment, particularly in cocoa plantations where they are extensively used. To achieve this, concentrations of neonicotinoid residues in soils across all the cocoa producing regions of the country were studied to examine their environmental exposure. Their fate in soils was studied by investigating their dissipation and sorption behavior using established kinetic models and isotherms. Finally, the exposure to cocoa beans (food) was studied to ascertain concerns for food safety. Analytical methods and instrumentation was an important aspect of this work to ensure accurate and reliable data. To this end, the Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) procedure was optimised and used for the diverse matrixes understudy. Quantification of analytes involved the use of liquid chromatography- tandem mass spectrometry (LC-MS/MS) for high sensitivity and low detection limits in the complex soil and cocoa matrixes used. The findings from the study suggest that, neonicotinoids are persistent in the Ghanaian soils studied and may be found in soils several months to years after application. Sorption studies revealed that, sorption coefficients of neonicotinoids are generally low, with a high potential for leaching into surface and underground water systems. Due perhaps to their systemic nature and high application rates, neonicotinoids may accumulate to high levels in cocoa beans, particularly in cocoa shells. The findings from this study has implications for pesticide application and current policy on pesticide usage, and reveal that, efficient application regimes are needed in cocoa production to ensure food and environmental safety.Item Farmers’ knowledge and practices on pollination and insecticide use in cocoa farming in Ghana(INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY, 2022) Umeh, B.C.; Avicor, S.W.; Dankyi, E.; Kyerematen, R.ABSTRACT Although evidence of the limiting role of pollination in cocoa production is mounting, concern about the potential harm of insecticides to pollinators is also increasing. However, effort at examining farmer knowledge and practices on pollination and insecticide use aimed at promoting cocoa pollination is limited. This study assessed farmers’ knowledge and practices on pollination and insecticide usage in four cocoa-growing communities (two organic and two conventional) in the Eastern region of Ghana. Data from interviewing cocoa farmers (200) with a structured questionnaire were analysed using various statistical techniques. Less than 50% of the farmers had knowledge of pollination and its influence on yield. Only 1% of the respondents identified midges as pollinators of cocoa, while 11% and 19.5% identified honey bees and ants as pollinator agents, respectively. Less than 50% of respondents believed insecticide application might impact on beneficial insects, including pollinators. Farmers’ responses were highly influenced by farming system, educational background, farmer groups and extension officers. Our findings show that educating smallholder farmers on pollination and judicious insecticide use is crucial in improving long-term cocoa yields. These findings have implications for pest management policies and farmer sensitization on the impact of indiscriminate insecticide application on the environment and pollinators.Item In search of new leads: A closer look at the therapeutic potential of the constituents of millettia thonningii, Millettia pachycarpa and their structural analogues(International Journal of Pharmacy and Pharmaceutical Sciences, 2011-01) Harrison, J.J.E.K.; Dankyi, E.; Kingsford-Adaboh, R.; Ishida, H.This review discusses the potential applications of isoflavonoids from Millettia thonningii and M. pachycarpa in developing new pharmaceutical agents based on folkloric anecdotes and evidences from pharmacological and biochemical assays and to encourage further research into their pharmacological applications. Millettia thonningii is a deciduous plant indigenous to tropical West Africa, M. pachycarpa, is a climbing shrub indigenous to South-East Asia and other species have been used in folk-medicine for the treatment of inflammatory diseases, chronic diseases and several pathogenic diseases. Scientific research has implicated several prenylated isoflavonoids as being useful antioxidants and used in the management of radical-mediated diseases such as cancer, diabetes, ischemic heart diseases, Alzheimer's and Parkinson's diseases etc. Chemical investigations into these plants have revealed that they contain several isoflavonoids which bear structural resemblance to some of the isoflavonoids already in allopathic medical usage. Plants continue to maintain their historical stead as a store house of important drug candidates and source of new "leads" for synthetic modifications to improve activity through optimization of pharmacodynamic and pharmacokinetic properties. Natural products have also been found useful in specific pharmacological probes, a potential which is grossly underestimated. The alpinumisoflavones which have been isolated from the Millettia thonningii have shown high toxicities to the brine shrimp while isolates from M. pachycarpa have also shown anti-estrogenic and anticancer properties. Information obtained from crystal structural studies of these alpinumisoflavonoids coupled with their molecular and electronic distribution properties can further our understanding of their therapeutic potential and their observed bioactivities. The alpinumisoflavones are characterized by a fused tricyclic ring system which contains nearly coplanar benzopyrone ring fragments and a puckered six membered pyran ring that adopts a half-chair conformation with inter and intra molecular O-H....O and C-H...O contacts. A phenyl ring attached to the benzopyrone moiety shows out of plane twist with various degrees of torsion depending on the substitution on the phenyl ring.Item Iron and silver nanostructures: Biosynthesis, characterization and their catalytic properties(Nano-Structures & Nano-Objects, 2020-04-20) Ohemeng, P.O.; Dankyi, E.; Darko, S.; Yaya, A.; Salifu, A.A.; Ahenkorah, C.; Apalangya, V.A.Finding suitable plant extracts that exert precise control over both the shape and size of nanoparticles remains a challenge in the synthesis of metal nanoparticles. In this study, iron (Fe) nanoparticles with uniform sizes and shapes, and silver (Ag) nanoparticles with unique morphology and phases were synthesized from aqueous plantain peel extracts. The effect of temperature and concentration of the starting metal salts on the size and shape of the synthesized nanoparticles were investigated. The catalytic effectiveness of the metal nanoparticles was also assessed based on their ability to mediate the degradation of methylene blue dye in the presence of sodium borohydride (NaBH4) as the reducing agent. Phytochemical analysis of the plantain peel extract revealed the presence of polyhydroxy compounds: tannins, flavonoids, glycosides, saponins, and terpenoids. The presence of these compounds in the extract was confirmed by Fourier transform infra-red analysis. Microstructural analysis showed that the Fe nanoparticles had uniform cylindrical shapes with 70.0 ± 0.4 nm diameters, whereas the Ag nanoparticles exhibited multi-shaped, single and polycrystalline phases with a varying size range. UV–Vis spectroscopic analysis indicated that Ag nanoparticles exhibited maximum plasmon absorbance at 440 nm typical of nanoscale silver while X-ray diffraction studies showed that the Fe and Ag nanoparticles were highly crystalline. The study indicated that Ag can be synthesized at all temperatures, whereas the Fe nanoparticles formed only above room temperature with plantain peel extract. Both Fe and Ag nanoparticles exhibited dose-dependent degradation of methylene blue dye, suggesting their potential use as bio-catalysts, although the Fe nanoparticles showed a better catalytic efficiency. This study demonstrates an eco-friendly approach to synthesizing uniformly shaped and sized Fe and Ag bio-catalysts for potential use in effluent waste treatment in cosmetics, food, pharmaceuticals, plastics, paper industries, and in general environmental remediation.Item Knowledge, perception, and pesticide application practices among smallholder cocoa farmers in four Ghanaian cocoa-growing regions(Toxicology Reports, 2023) Boateng, K.O.; Dankyi, E.; Amponsah, I.K.; Awudzi, G.K.; Amponsah, E.; Darko, G.Pesticides are widely used in Ghana, especially in cocoa farming. However, the practice is suboptimal and un supervised. Incorrect use of these chemicals can seriously harm human health, the environment, and economies that rely on these farmers’ output. The study assessed cocoa farmers’ pesticide knowledge, practices, and risk perception. Four hundred and four cocoa farmers were chosen randomly from 26 communities in four cocoa growing regions of Ghana to answer questions about their risk knowledge, awareness, and practices, including personal protective equipment, storage and disposal of leftover pesticides, and used containers. The study revealed that 87% of the respondents belonged to cooperatives and certification groups. There was a significant positive relationship between group membership and benefits derived from inputs and training in pesticide use. About 70% of insecticides used were approved by the Ghana Cocoa Board, with neonicotinoids and pyrethroids being the most highly used insecticide classes in cocoa farms. Although farmers claimed adequate pesticide knowledge, this did not translate into practice, with the majority exhibiting improper pesticide storage, application, and disposal practices. Farmers appeared to know a lot but lacked the skills and attitude to put their knowledge to use. The improper practices appear to manifest in a variety of health symptoms experienced by farmers as a result of chemical exposure. The findings from this study suggest that cocoa farmers in Ghana require adequate practical training and support on pesticide use to reduce their associated health risks, protect the environment and ensure sustainable cocoa production in the world’s second-largest cocoa bean exporter.Item Parental Wellbeing, Parenting and Child Development in Ghanaian Families with Young Children(Child Psychiatry and Human Development, 2018-09) Huang, K.Y.; Bornheimer, L.A.; Dankyi, E.; De-Graft Aikins, A.Approximately one-third of early childhood pupils in Ghana are struggling with meeting basic behavioral and developmental milestones, but little is known about mechanisms or factors that contribute to poor early childhood development. With a lack of developmental research to guide intervention or education program and policy planning, this study aimed to address these research gaps by examining a developmental mechanism for early childhood development. We tested a mediational mechanism model that examined the influence of parental wellbeing on parenting and children's development. Two hundred and sixty-two Ghanaian parents whose children attended early childhood classes (nursery to 3rd grade) were recruited. Data were gathered through parent interviews and Structural Equation Modeling was utilized to examine pathways of the model. Results support the mediational model that Ghanaian parents' depression was associated with less optimal parenting, and in turn greater child externalizing behavioral problems. This study adds new evidence of cross cultural consistency in early childhood development.Item Quantification of neonicotinoid insecticide residues in soils from cocoa plantations using a QuEChERS extraction procedure and LC-MS/MS(Science of the Total Environment, 2014-11) Dankyi, E.; Gordon, C.; Carboo, D.; Fomsgaard, I.S.The use of neonicotinoids as an insecticide group in Ghana has been quite significant particularly in cocoa production. The high usage has been mainly as a result of a government policy of free insecticide spraying on cocoa farms, in an effort to curb declining yields caused by pests and diseases and to prevent the use of unapproved or banned insecticides on cocoa farms. However the scale of cocoa farming, the frequency and intensity of usage coupled with the mode of application may result in large physical volumes of insecticides in the environment. This makes the knowledge of the concentration and fate of neonicotinoids in the environment extremely important. The present study was aimed at assessing the levels of five major neonicotinoids in soils from cocoa farmlands in Ghana. Extraction and cleanup of analytes were performed by use of a method based on the original QuEChERS procedure after optimizing salts, sorbents and instrumental conditions. Analyte extraction with NaCl and MgSO4 in acidified acetonitrile followed by cleanup with primary secondary amine (PSA) presented the optimum conditions for extraction. Quantification was performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI). Validation of the procedure showed average recoveries ranging from 72.0 to 104.8% for all analytes at all fortification levels with relative standard deviation (RSD)≤15.0. Limits of quantitation were<10μgkg-1 for all neonicotinoids studied. The results obtained from the analysis of 52 samples from cocoa farms revealed imidacloprid as the predominant neonicotinoid with concentrations ranging from 4.3 to 251.4μgkg-1 in>50% of samples analyzed. © 2014 Elsevier B.V.Item Rapid microwave synthesis of needle-liked hydroxyapatite nanoparticles via template directing ball-milled spindle-shaped eggshell particles(Elsevier Ltd, 2018-04) Apalangya, V.; Rangari, V.; Jeelani, S.; Dankyi, E.; Yaya, A.; Darko, S.Needle-like hydroxyapatite nanoparticles were synthesized by fast microwave irradiation of partially acid etched ball-milled eggshell particles which were guided milled using two sets of stainless steel balls. The milled eggshell samples were irradiated for 7.5, 15 and 30 min while reagent concentration, the temperature (50 °C), and argon purge pressure of 60 psi were kept constant using a CEU microwave. The Scanning Electron Micrographs showed that the precursor milled eggshell particles which were prepared using a combination of 12 of 6 mm and 6 of 3 mm balls displayed spindle-shaped morphology whereas eggshells milled with 12 of 3 mm and 6 of 6 mm stainless steel balls did not show distinct morphology. The XRD patterns of the nano-hydroxyapatite prepared using spindled-shaped eggshells as synthetic precursors are in preferential crystalline orientations in the [211] and [300] directions. The XRD patterns and TEM images of partially acid etched spindle-shaped CaCO3 particles and (NH4)2HPO4 irradiated for 7.5 min produced a mixture of hydroxyapatite and CaCO3 particles but produced only pure needle-liked hydroxyapatite particles when the microwave irradiation was extended to 30 min. The irradiation of eggshell particles with no clear shape (milled using 12 of 3 mm and 6 of 6 mm stainless steel balls) and (NH4)2HPO4 produced agglomerated hydroxyapatite particles with indistinct morphology. The absence of modulating functional groups in the FTIR chromatograms showed that etched spindle-shaped CaCO3 served as templates which directed the growth of the needle-liked hydroxyapatite particles. This material could be a useful biomaterial as there are no concerns due to surfactant contamination. © 2018 Elsevier Ltd and Techna Group S.r.l.Item Reciprocity in global social protection: providing care for migrants’ children(Taylor & Francis, 2017) Dankyi, E.; Mazzucato, V.; Manuh, T.Migration research tends to conceptualize migrants as providers of social protection for people back home. Yet the care conducted within transnational families and the way it is organized is an integral part of a global social protection system which is based on reciprocity between migrants and their families in their home countries. This system relies on the work of people back home just as much as on the remittances of migrants overseas. Drawing on ethnographic data from 34 caregivers, we provide a detailed description of the work conducted by people in Ghana to care for migrants’ children and analyze what caregivers do to make this work possible. We find that caregivers have small networks of support they can rely on and identify the strategies they develop when remittances are not forthcoming or enough to cater for the material needs of migrants’ children.Item The role of primary caregivers in Ghana's child protection system: Lessons from transnational caregivers(University of Ghana, 2015-04-17) Dankyi, E.Children constitute the single largest sub-group of the population of many countries. They are born into societies of distinct values and cultures and deserve optimum protection regardless of where they find themselves. Thus, there has been the formulation of different legal and policy instruments at various levels to ensure the protection of children, chief among them being the UN Convention on the Rights of the Child (UNCRC) which has been ratified by many nations, Ghana being the first. Ghana has made many strides in line with her commitment to child protection. What is largely missing in the child protection efforts in Ghana is the place of primary caregivers of children (biological parents, foster parents and or caregivers of children in institutions). The subject of primary caregivers is even more crucial in the face of changing traditional familial roles and relationships and the evidence of deficits of care. The near omission of the subject of care and primary providers of care in much theoretical thinking, academic enquiry and practical planning efforts have some implications for social policy. Drawing on findings of a research on caregivers of children left behind by migrants in Ghana, this paper discusses the place of primary caregivers in the child protection system and its implications for social policyItem Sorption and degradation of neonicotinoid insecticides in tropical soils(Northeast Forestry University, 2018-04) Dankyi, E.; Gordon, C.; Carboo, D.; Apalangya, V.A.; Fomsgaard, I.S.The purpose of this study was to evaluate the effects of Broussonetia papyrifera (paper mulberry) invasion and land use on the floristic composition of a dry semi-deciduous forest in Ghana. Forty-five plots (25 m × 25 m each), distributed among three land uses—selectively logged (SL); abandoned farmlands (AF); and an undisturbed reference (RF)—were surveyed. Results showed lower tree species richness (S), diversity (H′), evenness (S) and basal area (BA) in the SL (46, 0.78, 0.32 and 269.12 m2 ha−1, respectively) and AF (40, 0.53, 0.45, and 131.16 m2 ha−1) sites compared to the RF site (79, 2.66, 0.87, 963.72 m2 ha−1). Similar patterns were found at the shrub layer, but no differences were observed at the herb layer. Non-metric multidimensional scaling ordination revealed distinct species composition among the land uses. The two disturbed habitats, SL and AF, were associated with increased B. papyrifera invasion particularly in the overstory, with importance value index and mean relative density of 45 and 65.03%, and 42 and 53.29%, correspondingly. However, the species was only sparsely represented in the RF site. Tree density of B. papyrifera correlated negatively with H′, S, E, BA, and native tree density and richness. These findings highlight the strong link between human land use (i.e., logging and slash-and-burn farming), invasion, and vegetation characteristics, and suggest the need to limit these disturbances to conserve biodiversity within tropical forest ecosystems. © 2018 Northeast Forestry University and Springer-Verlag GmbH Germany, part of Springer NatureItem Stigma and Forgiveness in Ghanaian Mothers of Children with Autism Spectrum Disorders (ASD)(Journal of Autism and Developmental Disorders, 2020-01-22) Oti-Boadi, M; Dankyi, E.; Kwakye-Nuako, C.O.This study explored stigma experiences of mothers of children with ASD and forgiveness as their coping response. Semi-structured interviews were conducted with 6 mothers of children with ASD. Results of this study found several noteworthy themes including, feelings of mother, family/societal reactions, forgiveness factors, and impact of forgiveness. Mothers reported significant stigmatization from families and society. Some expressed their feelings towards themselves, others and God, and finally recounted the use of forgiveness as a coping resource which contributed significantly to their well-being. Findings from this study contribute to the emerging literature on forgiveness as a coping resource for persons who are offended. Implications for clinical practice, intervention and policy are discussed.Item Street Children in Ghana’s Golden Triangle Cities: Mental Health Needs and Associated Risks(Springer, 2021) Dankyi, E.; Huang, K.More than 61,000 persons below the age of 18 are living on the streets in the Greater Accra region in Ghana. Street children is a hidden vulnerable population and a global public health issue in the world, but little is known about their mental health and health needs, and mechanisms that contribute to their poor health. With a lack of mental health research to guide intervention or psychoeducation programme and policy planning, this study aimed to address these research gaps by examining prevalence of mental health problems and a set of associated risk factors (i.e. Perceived quality of life, and social connection). In addition, we examined whether the associations between risk factors and mental health problems were moderated by demographic and contextual factors (i.e., gender, age, work status, reason for living on street, number of years in street). Two hundred and seven children between age 12 and 18 who lived on the street in three cities (Accra, Sekondi Takoradi, and Kumasi) were recruited. Data were gathered through adolescent survey/interviews. Multiple regression was utilized to examine risk factors and moderation efects. Results support high mental health needs among street children. Approximately 73% street children experienced moderate to severe mental health problems, and 90% experienced poor quality of life. Perceived quality/happiness of life was the strongest predictor for street children’s mental health. Social connection was associated with children’s mental health only in certain subgroups and contexts. This study adds new epidemiological evidence for street children, an extremely vulnerable population, in Ghana and global child and adolescent mental health.