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

Abstract

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.

Keywords: Ghana; Minamata Convention; gold; heavy metals; mercury; mining; noise; occupational injuries; research; water.

Figure 1

Framework linking key drivers and impacted human/natural systems. Principal domains of inquiry are highlighted. Framework is adapted from the Millennium Ecosystem Assessment [9].

Figure 2

Key occupational (top panel) and community (bottom panel) human health hazards in the Ghanaian artisanal and small-scale gold mining (ASGM) sector. Silhouettes adapted from UNEP Mercury: Time to Act (2013) [22].

Figure 3

Map of sampling sites of studies on mercury in human hair and urine in Ghana. Maps produced using data provided by the United Nations Secondary Administrative Boundaries Dataset (UNSALB), by Rachel Long, July 2013.

Figure 4

Urinary mercury levels (µg/L) from miners and non-miners across Ghana. For a given population (see key below), the bars represent the measured range while the circles represent the mean. Lines represent the WHO guideline value of 50 μg/L for occupational exposure [37], and 0.5 μg/L, the average mercury concentration in urine for the U.S. population [38]. The population numbers refer to various studies as follows. Study Population 1—Southwest Ghana in large-scale and small-scale gold mining area, [36]: 1a. Non-miners 10 km from mines (n = 12); 1b. permanent large-scale miners (n = 12); 1c. Casual large-scale miners (n = 12); 1d. Large-scale miners 0.5 km from mines (n = 12); 1e. Large-scale miners 2 km from mines (n = 12). Study Population 2—Tarkwa, Western Region [35]: 2a. Non-miners in mining area (n = 15); 2b. Non-miners in non-mining area (n = 4); 2c. Miners in mining area (n = 17). Study Population 3—Dunkwa-on-Offin, Central Region [34]: 3a. Farmers (n = 54); 3b. Small-scale miners (n = 40). Study Population 4—Ankroba and Tano River Basins, Western Region [39]:4a–4d. Mining area residents, possibly involved in mining (n = 50, 50, 51, 66, respectively). Study Population 5—Talensi-Nabdam District, Upper East Region [33]: 5a-c. Small-scale miners in mining areas (n = 13, 92, 15, respectively).

Figure 5

Mercury levels (µg/g) in hair samples of miners and non-miners from across Ghana. For a given population (see key below), the bars represent the measured range while the circles represent the mean. Lines represent the WHO guideline value of 10 μg/g for mercury in hair [40], and 0.5 μg/g, the average mercury concentration in hair for the U.S. population [38]. Study Population 1—Ankroba and Tano River Basins, Western Region [39]: 1a–d. Mining area residents, possibly involved in mining (n = 50, 50, 51, 66, respectively). Study Population 2—Accra, Greater Accra Region, and Kumasi, Ashanti Region [43]: 2a. Students from Accra; 2b. Students from Kumasi (n = 19, 18, respectively). Study Population 3—Pra River Basin (in Western, Central, and Ashanti Regions) [41]: 3a. Non-miners in mining area (n = 24); 3b. Small-scale miners (n = 38). Study Population 4—Dunkwa-on-Offin, Central Region [34]: 4a. Farmers (n = 54); 3b. Small-scale miners (n = 40). Study Population 5—Throughout Ghana [42]: 5a. General population (n = 123). Study Population 6—Talensi-Nabdam District, Upper East Region [33]: 6a–c. Small-scale miners (n = 11, 77, 12, respectively).

Figure 6

Percentage of injury types recorded in a review of newspaper articles between 9 February 2007 and 11 October 2012 on injuries in small-scale gold mining in Ghana.