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

Rajaee M, Obiri S, Green A, Long R, Cobbina SJ, Nartey V, Buck D, Antwi E, Basu N - Int J Environ Res Public Health (2015)

Bottom Line: This paper focuses on the causes, status, trends, and consequences of ecological issues related to ASGM activity in Ghana.Soil and water mercury concentrations were generally lower than guideline values, but sediment mercury concentrations surpassed guideline values in 64% of samples.Additional ASGM-related stressors on environmental quality and ecosystem services include deforestation, land degradation, biodiversity loss, legacy contamination, and potential linkages to climate change.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA. mrajae@umich.edu.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus

Mercury in marine (A) and freshwater (B) fish in Ghana. Bars represent range and dots represent means for fish at each trophic level (n = number of studies) across Ghana. For values below detection limit, standard protocol of dividing the detection limit by  was followed. Where minimum and maximum measurements were not available for a study, the mean value is included in the overall mean for the trophic level, but no minimum or maximum was included in calculations. WHO/FAO (0.5 µg/g) and U.S. EPA (0.3 µg/g) guideline values are indicated as horizontal lines [37,38]. All studies except for two sampled in districts or regions with ASGM, but only one explicitly sampled at or close to an ASGM site.
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ijerph-12-08971-f009: Mercury in marine (A) and freshwater (B) fish in Ghana. Bars represent range and dots represent means for fish at each trophic level (n = number of studies) across Ghana. For values below detection limit, standard protocol of dividing the detection limit by was followed. Where minimum and maximum measurements were not available for a study, the mean value is included in the overall mean for the trophic level, but no minimum or maximum was included in calculations. WHO/FAO (0.5 µg/g) and U.S. EPA (0.3 µg/g) guideline values are indicated as horizontal lines [37,38]. All studies except for two sampled in districts or regions with ASGM, but only one explicitly sampled at or close to an ASGM site.

Mentions: Below we provide a brief review of these studies with key results emphasized. International guideline values were used to evaluate mercury concentrations in various media when available, otherwise selected U.S. guidelines were used (Table 1). Figure 5, Figure 6, Figure 7, Figure 8 and Figure 9 show results synthesized from all relevant peer-reviewed data we could find. Table 2 summarizes the number of studies and samples reviewed for mercury and other heavy metals in various media, as well as reported mean concentration ranges. District boundaries have changed significantly in the past five years, but since boundary maps are not yet available and many studies reviewed refer to older districts, we have used the district names referred to in each respective study or older districts where geographic boundaries are available. Study sites referred to as “reference” sites in each respective study were designated as “non-mining” in this review. Since ASGM often occurs in areas with large-scale gold mining (LSGM), many sites reviewed include areas with ASGM and LSGM, and in areas near LSGM. These sites were designated as “mining” areas in this review. When detection limits were provided, a standard protocol of dividing the detection limit by was followed for values below the detection limit. Values were reported as provided in each respective study when detection limits were not provided (i.e., as zero or not detectable [ND]).


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

Rajaee M, Obiri S, Green A, Long R, Cobbina SJ, Nartey V, Buck D, Antwi E, Basu N - Int J Environ Res Public Health (2015)

Mercury in marine (A) and freshwater (B) fish in Ghana. Bars represent range and dots represent means for fish at each trophic level (n = number of studies) across Ghana. For values below detection limit, standard protocol of dividing the detection limit by  was followed. Where minimum and maximum measurements were not available for a study, the mean value is included in the overall mean for the trophic level, but no minimum or maximum was included in calculations. WHO/FAO (0.5 µg/g) and U.S. EPA (0.3 µg/g) guideline values are indicated as horizontal lines [37,38]. All studies except for two sampled in districts or regions with ASGM, but only one explicitly sampled at or close to an ASGM site.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555259&req=5

ijerph-12-08971-f009: Mercury in marine (A) and freshwater (B) fish in Ghana. Bars represent range and dots represent means for fish at each trophic level (n = number of studies) across Ghana. For values below detection limit, standard protocol of dividing the detection limit by was followed. Where minimum and maximum measurements were not available for a study, the mean value is included in the overall mean for the trophic level, but no minimum or maximum was included in calculations. WHO/FAO (0.5 µg/g) and U.S. EPA (0.3 µg/g) guideline values are indicated as horizontal lines [37,38]. All studies except for two sampled in districts or regions with ASGM, but only one explicitly sampled at or close to an ASGM site.
Mentions: Below we provide a brief review of these studies with key results emphasized. International guideline values were used to evaluate mercury concentrations in various media when available, otherwise selected U.S. guidelines were used (Table 1). Figure 5, Figure 6, Figure 7, Figure 8 and Figure 9 show results synthesized from all relevant peer-reviewed data we could find. Table 2 summarizes the number of studies and samples reviewed for mercury and other heavy metals in various media, as well as reported mean concentration ranges. District boundaries have changed significantly in the past five years, but since boundary maps are not yet available and many studies reviewed refer to older districts, we have used the district names referred to in each respective study or older districts where geographic boundaries are available. Study sites referred to as “reference” sites in each respective study were designated as “non-mining” in this review. Since ASGM often occurs in areas with large-scale gold mining (LSGM), many sites reviewed include areas with ASGM and LSGM, and in areas near LSGM. These sites were designated as “mining” areas in this review. When detection limits were provided, a standard protocol of dividing the detection limit by was followed for values below the detection limit. Values were reported as provided in each respective study when detection limits were not provided (i.e., as zero or not detectable [ND]).

Bottom Line: This paper focuses on the causes, status, trends, and consequences of ecological issues related to ASGM activity in Ghana.Soil and water mercury concentrations were generally lower than guideline values, but sediment mercury concentrations surpassed guideline values in 64% of samples.Additional ASGM-related stressors on environmental quality and ecosystem services include deforestation, land degradation, biodiversity loss, legacy contamination, and potential linkages to climate change.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA. mrajae@umich.edu.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus