Assessment of concentration of polycyclic aromatic hydrocarbons (PAHs) in vegetables from farms in Accra, Ghana.

Ingestion of leafy vegetables is an important dietary component of most Africans due to its health benefits. High levels of polycyclic aromatic hydrocarbons (PAHs) in the leafy vegetables may pose a significant health hazard to the consumers. Rose/Hibiscus, Chinese cabbage, lettuce, and garden egg leaves from farms along the Nima Creek, Accra, were selected. At each sampling site, the vegetable was uprooted and cut into leaves, stem, and root and analyzed differently. The GC-MS method was employed in the identification and quantification of 16 PAHs in the samples. The analysis was done at CSIR - Water Research Institute Organic Laboratory. The results obtained show concentrations of acenapththylene, acenapthene, benzo[a]anthracene, benzo[b]fluoranthene, and benzo[a]pyrene (except chrysene and pyrene which were found in garden egg leaves and Chinese cabbage respectively), while naphthalene was detected in all the vegetables. The mean concentration of phenanthrene in leaves, stem, and roots of Chinese cabbage vegetable varies according to the following order: roots (0.744 ± 0.16 µg/kg) ≥ leaves (0.598 ± 1.21 µg/kg) ≥ stem (0.327 ± 1.01 µg/kg). From the results of the isomeric ratios, the source of the PAHs in the leafy vegetables are from mixed sources, i.e., either pyrogenic and petrogenic origins. This calls for the formulation of stringent policies on the importation of over-age vehicles into the countries as well as on the indiscriminate burning of materials containing PAHs.

Complex Mixtures of Brominated/Chlorinated Diphenyl Ethers and Dibenzofurans in Soils from the Agbogbloshie e-Waste Site (Ghana): Occurrence, Formation, and Exposure Implications.

The distribution and toxic equivalents (TEQs) of brominated and chlorinated dibenzo- p-dioxins/dibenzofurans (PBDD/Fs and PCDD/Fs) in soils from Agbogbloshie e-waste site (Ghana) were investigated. The composition of brominated/chlorinated dibenzofurans (PXDFs) and diphenyl ethers (PBDEs, PCDEs, and PXDEs) was examined using two-dimensional gas chromatography-time-of-flight mass spectrometry to elucidate possible formation pathways of dioxins from e-waste recycling. The highest concentrations of PCDD/Fs and PBDD/Fs were found, respectively, in the open burning (1.3-380 ng/g dry weight) and dismantling areas (11-1000 ng/g dry weight) and were comparable to the highest reported for informal e-waste sites. PXDFs and PXDEs were detected at up to the range of hundreds of nanograms per gram. The homologue profiles suggest that PXDFs were formed mainly from PBDFs through successive Br-to-Cl exchange. However, monobromo-PCDFs were also derived from de-novo-generated PCDFs in open burning areas. PBDFs contributed similar or higher TEQs (7.9-5400 pg/g dry weight) compared with PCDD/Fs (6.8-5200 pg/g dry weight), whereas PXDFs were also substantial TEQ contributors in open burning areas. The high TEQs of PBDFs in the dismantling area (120-5200 pg/g dry weight) indicate the need to consider brominated dioxins besides chlorinated dioxins in future studies on health implications for e-waste workers and local residents.

Levels of arsenic, mercury, cadmium, copper, lead, zinc and manganese in serum and whole blood of resident adults from mining and non-mining communities in Ghana.

Human beings working or living near an industrial site where toxic chemicals such as As, Hg, Cd, Cu, Mn, Pb, Zn and or their compounds are used or indiscriminately discharged into the environment, are constantly exposed to such chemicals via ingestion (drinking or eating), dermal contact or inhalation (breathing). However, in developing countries such as Ghana, limited data on levels of the aforementioned chemicals in whole blood and serum of human beings as a result of exposure to the aforementioned chemicals from mining communities and non-mining communities is preventing effective policy formulation to protect human health. Hence, this study was undertaken to measure the levels of the aforementioned toxic chemicals in whole blood and serum of 300 resident adults from mining (Tarkwa Nsuaem Municipality Assembly (TNMA) and Prestea Huni Valley District (PHVD)) and non-mining (Cape Coast Metropolis) communities in Ghana, using neutron activation analysis (NAA). Blood samples were taken from 200 resident adults (105 males and 95 females) from mining and 100 resident adults (60 males and 40 males) from non-mining communities in the study area following the completion of an informed consent and the issuance of ethical clearance by the Ghana Health Service Ethical Committee. The mean concentrations for As, Hg, Cd, Cu, Mn, Pb and Zn in whole blood of residents from mining communities were as follows: 38 ± 320 µg/L, 63 ± 0.23 µg/L, 303 ± 117 µg/L, 3300 ± 953, 195 ± 90 µg/L, 28 ± 14 µg/L and 1405 ± 458 µg/L, respectively; while the levels of measured toxic chemicals in the serum of resident adults from mining communities were as follows: 65 ± 14 µg/L, 358 ± 22 µg/l, 134 ± 12 µg/L, 3590 ± 254 µg/L, 401 ± 113 µg/L, 58 ± 5.8 µg/L and 49 ± 31 µg/L, respectively, for As, Hg, Cd, Cu, Mn, Pb and Zn and were found to have exceeded the permissible WHO guideline values.

Assessing the Environmental and Socio-Economic Impacts of Artisanal Gold Mining on the Livelihoods of Communities in the Tarkwa Nsuaem Municipality in Ghana.

Gold mining has played an important role in Ghana's economy, however the negative environmental and socio-economic effects on the host communities associated with gold mining have overshadowed these economic gains. It is within this context that this paper assessed in an integrated manner the environmental and socio-economic impacts of artisanal gold mining in the Tarkwa Nsuaem Municipality from a natural and social science perspective. The natural science group collected 200 random samples on bi-weekly basis between January to October 2013 from water bodies in the study area for analysis in line with methods outlined by the American Water Works Association, while the social science team interviewed 250 residents randomly selected for interviews on socio-economic issues associated with mining. Data from the socio-economic survey was analyzed using logistic regression with SPSS version 17. The results of the natural science investigation revealed that the levels of heavy metals in water samples from the study area in most cases exceeded GS 175-1/WHO permissible guideline values, which are in tandem with the results of inhabitants' perceptions of water quality survey (as 83% of the respondents are of the view that water bodies in the study area are polluted). This calls for cost-benefits analysis of mining before new mining leases are granted by the relevant authorities.

Human Health Risk Assessment of Artisanal Miners Exposed to Toxic Chemicals in Water and Sediments in the Prestea Huni Valley District of Ghana.

A human health risk assessment of artisanal miners exposed to toxic metals in water bodies and sediments in the PresteaHuni Valley District of Ghana was carried out in this study, in line with US EPA risk assessment guidelines. A total of 70 water and 30 sediment samples were collected from surface water bodies in areas impacted by the operations of artisanal small-scale gold mines in the study area and analyzed for physico-chemical parameters such as pH, TDS, conductivity, turbidity as well as metals and metalloids such as As, Cd, Hg and Pb at CSIR-Water Research Institute using standard methods for the examination of wastewater as outlined by American Water Works Association (AWWA). 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 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). These findings call for case-control epidemiological studies to establish the relationship between exposure to the aforementioned toxic chemicals and diseases associated with them as identified in other studies conducted in different countries as basis for developing policy interventions to address the issue of ASGM mine workers safety in Ghana.

Comparative Assessment of Heavy Metals in Drinking Water Sources in Two Small-Scale Mining Communities in Northern Ghana.

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 recommended.

Integrated Assessment of Artisanal and Small-Scale Gold Mining in Ghana-Part 2: Natural Sciences Review.

This paper 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 integrated assessment (IA) framework was utilized to analyze socio-economic, health, and environmental data, and co-develop evidence-based responses with stakeholders. This paper focuses on the causes, status, trends, and consequences of ecological issues related to ASGM activity in Ghana. It reviews dozens of studies and thousands of samples to document evidence of heavy metals contamination in ecological media across Ghana. Soil and water mercury concentrations were generally lower than guideline values, but sediment mercury concentrations surpassed guideline values in 64% of samples. Arsenic, cadmium, and lead exceeded guideline values in 67%, 17%, and 24% of water samples, respectively. Other water quality parameters near ASGM sites show impairment, with some samples exceeding guidelines for acidity, turbidity, and nitrates. Additional ASGM-related stressors on environmental quality and ecosystem services include deforestation, land degradation, biodiversity loss, legacy contamination, and potential linkages to climate change. Though more research is needed to further elucidate the long-term impacts of ASGM on the environment, the plausible consequences of ecological damages should guide policies and actions to address the unique challenges posed by ASGM.

Integrated assessment of artisanal and small-scale gold mining in Ghana--part 1: human health review.

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.

Association of arsenic with adverse pregnancy outcomes/infant mortality: a systematic review and meta-analysis.

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: ß = -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.

Assessment of cancer and noncancer health risks from exposure to PAHs in street dust in the Tamale Metropolis, Ghana.

This study is part of a broader initiative to characterize, quantify and assess the human health risk associated with exposure to polycyclic aromatic hydrocarbons (PAHs) in street dust along the Trans-ECOWAS highway in West Africa. In the first part, PAHs were characterized and quantified in low- and high-traffic zones. In this study, cancer and noncancer human health risks from exposure to (PAHs) in street dust in the Tamale metropolis, Ghana were assessed in accordance with the USEPA risk assessment guidelines. The results of the study as obtained from inhalation of benzo [a] anthracene (BaA), benzo [a] pyrene (BaP), benzo [k] fluoranthene (BkF) and chrysene via central tendency exposure parameters (CTE) by trespassers (street hawkers including children and adults) in street dust within low traffic zones in the Tamale metropolis are 1.6E-02, 4.7E-02, 1.8E-03, and 1.6E-04 respectively. For reasonable maximum exposure parameters (RME), risk values of 1.2E-01, 3.5E-01, 1.3E-02 and 1.2E-03 respectively were obtained for benzo [a] anthracene, benzo [a] pyrene, benzo [k] fluoranthene and chrysene. Hazard index for acenaphthene, anthracene, fluoranthene, fluorine, naphthalene and pyrene in the CTE and RME scenarios were 2.2, 3.E-01, 2.6, 2.6, 100, 38 and 12, 1.7,15, 14, 550, 210 respectively. Generally, the cancer health risk associated with inhalation of benzo [a] anthracene, benzo [a] pyrene, benzo [k] fluoranthene and chrysene revealed that resident adults and children in the Tamale metropolis are at risk from exposure to these chemicals. The results of this preliminary assessment that quantified PAH related health risks along this part of the Trans-ECOWAS highway revealed that, there is the need for regulatory agencies to put in comprehensive measures to mitigate the risks posed to these categories of human receptors.

Quantification and characterization of vehicle-based polycyclic aromatic hydrocarbons (PAHs) in street dust from the Tamale metropolis, Ghana.

OBJECTIVE: Concentrations of polycyclic aromatic hydrocarbons (PAHs) in street dust in the Tamale metropolis, Ghana, have been measured in this study. RESULTS: The concentrations of the various types of PAHs identified in street dust samples from high vehicular traffic density in the metropolis are as follows: naphthalene, 10,000 µg/kg; acenaphthylene, 13,000 µg/kg; acenaphthene, 76,000 µg/kg; fluorene, 18,900 µg/kg; phenanthrene, 40,000 µg/kg; anthracene, 21,000 µg/kg; fluoranthene, 35,200 µg/kg; pyrene, 119,000 µg/kg; benzo[a]anthracene, 17,700 µg/kg; chrysene, 10,600 µg/kg; benzo[k]fluoranthene, 18,700 µg/kg; benzo[a]pyrene, 10,900 µg/kg and benzo[g, h, i]perylene, 21,000 µg/kg. Calculation of the phenanthrene/anthracene ratio indicated that the PAHs identified in this study were from vehicular fallout as the ratio was less than 10. CONCLUSION: It is clear from the results of the study that road users in the Tamale metropolis, especially hawkers, are exposed to the harmful effects of PAHs, and this suggests the need for the establishment of mitigation measures by the regulatory agencies.

Anthropogenic sources and environmentally relevant concentrations of heavy metals in surface water of a mining district in Ghana: a multivariate statistical approach.

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.

Determination of heavy metals in water from boreholes in Dumasi in the Wassa West District of western region of Republic of Ghana.

Concentrations of heavy metals in the borehole at Dumasi in the Wassa West District of the Republic of Ghana have been measured in this study. The concentrations of the following metals in the ground water from Dumasi borehole are: Iron (Fe) - 7.52 ppm, Manganese (Mn) - 1.11 ppm, Arsenic (As) - 4.52 ppm, Chromium (Cr) - 0.026 ppm, Cobalt (Co) - 0.01 ppm, Zinc (Zn) - 0.007 ppm, Cadmium (Cd) - 0.002 ppm and Lead (Pb) - 0.005 ppm. The results of the study show that resident adults and children who use water from the boreholes are at serious risk from exposure to health hazards associated with exposure to the above metals in the boreholes in Dumasi. If the results of this study are applied to other mining communities, which lie on the Birimian and Tarkwaian rock system, then the residents are at serious risk from exposure to toxic metals from drinking water from the boreholes dag for them by mining companies operating in their communities.