Samuel Obiri

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: 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. Citation Quansah R, Armah FA, Essumang DK, Luginaah I, Clarke E, Marfoh K, Cobbina SJ, Nketiah-Amponsah E, Namujju PB, Obiri S, Dzodzomenyo M. 2015. Association of arsenic with adverse pregnancy outcomes/infant mortality: a systematic review and meta-analysis. Environ Health Perspect 123:412–421; http://dx.doi.org/10.1289/ehp.1307894

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 Hawths 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.

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.

Cancer and Non-Cancer Risk Assessment from Exposure to Arsenic, Copper, and Cadmium in Borehole, Tap, and Surface Water in the Obuasi Municipality, Ghana

ABSTRACT Cancer and non-cancer risk assessment from exposure to As, Cd, and Cu by resident adults and children from different water sources in Obuasi Municipality, Ghana, were measured in this study in accordance with the U.S. Environmental Protection Agencys (USEPAs) Human Health Risk Assessment guidelines. The results of cancer health risk for resident adults in Obuasi exposed to As in their tap water for both Central Tendency Exposure (CTE) and Reasonable Maximum Exposure (RME) parameters, respectively, are 6.6 × 10−4 and 5.5 × 10−6. For resident children in Odumasi, we obtained 4.7 × 10−1 (CTE) and 6.7 × 10−1 (RME). The results of the study obtained in most cases were found to exceed the USEPAs acceptable cancer risk range of 1 × 10−6 to 1 × 10−4 (i.e., 1 case of cancer out of 1,000,000 people to 1 case of cancer out of 10,000 people). Similarly, the results of the non-cancer human health risk for both resident adults and children were also found in most cases to be greater than the USEPAs acceptable non-cancer human health hazard index of 1.

Evaluation of lead and mercury neurotoxic health risk by resident children in the Obuasi municipality, Ghana.

This study assesses neurotoxic effects associated with exposure to lead and mercury in borehole, tap and surface water by resident children in the Obuasi municipality in accordance with USEPA risk assessment guidelines. From the results of the study, the hazard quotient for oral ingestion of mercury in tap water in Obuasi is 7.4 and 15 respectively via both central tendency exposure (CTE) and reasonable maximum exposure (RME) parameters, respectively. This means that approximately 7 and 15 (by both CTE and RME parameters, respectively) resident children in Obuasi are likely to show neurologic effects associated with exposure to mercury and lead such as increased nervousness, loss of memory and/or decrease in concentration, impaired writing ability and tremor.

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.

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.

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.

Assessing environmental exposure and health impacts of gold mining in Ghana

Understanding the extent to which people are being exposed to environmental contaminants helps to identify those populations which may be disproportionately exposed to the contaminants of potential public health concern. This study represents the first report of a comparison of heavy metal arsenic (As), mercury (Hg), cadmium (Cd), cobalt (Co), copper (Cu), lead (Pb), platinum (Pt), zinc (Zn), and manganese (Mn) concentrations in the blood of residents of mining and non-mining communities in Ghana. Blood sampling, health records, and interviews were used in this study to establish the links between the levels of contaminants and health effects in humans within a mining and non-mining community in Ghana. Results of this study show that mean concentration of As in blood in Tarkwa Nsuaem Municipality/Prestea-Huni Valley District (TNMA/PHVD) (mining communities) and Cape Coast Metropolis (CCMA) (non-mining community) was 18- and 2-fold higher, respectively, than the WHO guideline value of 0.002 mg L−1. The mean concentrations of As, Cd, Pb, Hg, and Mn were elevated up to 20-fold higher in the blood of resident adults and children in TNMA/PHVD than in CCMA. The risk of acute respiratory infections in the exposed populations of TNMA and PHVD were approximately 41- and 12-fold greater than the unexposed group. The risk of diabetes mellitus in the exposed populations of TNMA and PHVD were also approximately 20- and 4-fold higher than the unexposed group. In TNMA and PHVD, 40 blood donors were suffering from hyperkeratosis or pigmentation unlike their CCMA counterparts. Data suggest a potential association between mining activities and the levels of these heavy metals. However, the proportion of anthropogenic contribution to the levels of these metals in the blood remains uncertain. This uncertainty seems to be the umbrella under which both government and mining companies continue to hide, leading to inaction.

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.