Evaluation of pollution indices in Gold Mining communities in the Central Region of Ghana


  • Dominic Akwasi Bonah ATU
  • Ebenezer J. D. Belford KNUST




Artisanal small-scale gold minig, contamination degree, geoaccumulation index, ecological risk factor, pollution load index


The impact of artisanal small-scale gold mining (galamsey) is of global concern due to its threat to soil, water resources, food production and human health. For this reason, pollution indices of heavy metals in soils at the mining communities of Twifu Ati-Mokwaa District in the Central Region of Ghana where illegal mining is gaining notoriety were evaluated. An agricultural soil auger was used to collect 27 samples to a depth of 20 cm. Physicochemical properties including soil organic matter, moisture, pH, soluble salts, electrical conductivity and ash were determined. The concentrations of As, Cd, Hg and Pb were determined with Agilent AA 240 and AF 70 Atomic Absorption Spectrophotometer. Cadmium was not detected in any of the soils. Concentrations of Pb (0.62 - 12.7mg/kg) were all below pre-industrial values and FAO/WHO guidelines. Levels of As (3.64 - 39.84mg/kg) varied greatly with nine sites recording concentrations above the FAO/WHO permissible limit. Concentrations of Hg (0.02 – 6.47 mg/kg) were also high with eighteen of the twenty-seven site levels above FAO/WHO permissible limit. The observed differences in means from each site were statistically significant (p < 0.05) in all three communities. Degree of contamination, geoaccumulation and ecological risk indices were high for Hg and As but low for Pb. The PINemerow and PLI values however signalled slight pollution to severe pollution at 85.2% of the sample sites. The implication of these findings is that artisanal gold mining should be discouraged and lands should be thoroughly remediated before cultivated for agricultural production.


ADOMBIRE I. M. (2013) Business as usual (BAU) scenario information and analysis covering the Pra and Kakum river basins, Ghana.

AFRIYIE K., GANLE J. K., AFUA J., ADOMAKO A. (2016) The good in evil : A discourse analysis of the galamsey industry in Ghana, 0818, 0–16. doi: 10.1080/13600818.2016.1217984

ALFARO M. R., MONTERO A., UGARTE O. M., WILLIAMS C., MARIA A., ACCIOLY D. A., BEZERRA, A. (2015) Background concentrations and reference values for heavy metals in soils of Cuba. doi: 10.1007/s10661-014-4198-3

ALMEIDA I. L. S., OLIVEIR M. D. R., SILVA J. B. B., COELHO N. M. M. (2016) Suitable extraction of soils and sediments for mercury species and determination combined with the cold vapor generation atomic absorption spectrometry technique. Microchemical Journal, 124, 326–330. doi: 10.1016/j.microc.2015.09.007

APPLEYARD S., WONG S., ANGELONI J., WATKINS R. (2004) Groundwater acidification caused by urban development in Perth , Western Australia : Source, distribution and implications for management, 579–585.

ARYEE B. N. A., NTIBERY B. K., ATORKUI E. (2003) Trends in the small-scale mining of precious minerals in Ghana : A perspective on its environmental impact, 11, 131–140.

BEATA J., RYSZARD K., MICHAŁ M. (2018) Pollution indices as useful tools for the comprehensive evaluation of the degree of soil contamination – A review, 0123456789, 2395–2420. doi: 10.1007/s10653-018-0106-z

BOATENG D. O., NANA F., CODJOE Y., OFORI J. (2014) Impact of illegal small scale mining (Galamsey) on cocoa production in Atiwa district of Ghana, 2, 89–99.

DAILY GRAPHIC (Apr 26, 2017) Government begins reclamation of 1.5 % of Ghana's land destroyed by Galamsey, Daily Graphic News Paper, Ghana

DONKOR, A. K., BONZONGO, J. J. AND NARTEY, V. K. (2007). Heavy metals in sediments of the gold mining impacted Pra river basin, Ghana, West Africa Heavy Metals in Sediments of the Gold Mining, 0383. doi: 10.1080/15320380500263675

DONKOR A. K., BONZONGO J. J., NARTEY V. K., LACERDA D., (2004) Mercury pollution in Ghana : A case study of environmental impads of artisanal gold mining in Sub-Saharan Africa.

FAO/WHO (2011) JOINT FAO / WHO food standards programme codex committee on contaminants in foods, Fifth Session, The Hague, The Netherlands, 21 - 25.

FAO/WHO (2016) Alimentarius, Rep16/cf joint FAO/WHO food standards programme codex alimentarius commission 39

FAO/WHO (2018) Rep18/cf joint FAO/WHO food standards programme codex alimentarius commission 41

FAO/WHO (2017) Rep17/ Joint FAO/WHO food standards programme, codex alimentarius commission 40.

FAO (2006) Guidelines for soil description, 4th Edition, Rome.

FOSU-MENSAH B. Y., ADDAE E., YIRENYA-TAWIAH D., NYAME F. (2017) Heavy metals concentration and distribution in soils and vegetation at Korle Lagoon area in Accra ,. Cogent Environmental Science, 1–14. doi: 10.1080/23311843.2017.1405887

GEMET (2019) General multilingual environmental thesaurus (retrieved from http://www.eionet.europa.eu/gemet/concept/6422)

GIS (2014) Ghana Statistical Service, 2010 Population and Housing Census, District Analytical Report, Twifu Ati-Mokwaa, Ghana.

QUINJIE G., DENG J., QINGFEI W., YANG L. (2008) Calculating pollution indices by heavy metals in ecological geochemistry assessment and a case study in Parks of Beijing, 0705. doi: 10.1016/S1002-0705(08)60042-4

HE E. Z., SHENTU J., YANG X. BALIGAR V. C., ZHANG T., STOFFELLA P. J. (2015) Heavy metal contamination of soils: Sources, Indicators and Assessment, Journal of Environmental Indicators, 9:17-18.

HILSON G., BANCHIRIGAH S. M. (2010) Are alternative livelihoods alleviating poverty in mining communities? Experiences from Ghana.

HILSON G., HILSON C. J., PARDIE S. (2007) Improving awareness of mercury pollution in small-scale gold mining communities : Challenges and ways forward in rural Ghana, 103, 275–287.

doi: 10.1016/j.envres.2006.09.010

HILSON G., YAKOVLEVA N. (2007) Strained relations : A critical analysis of the mining conflict in Prestea , Ghana, 26, 98–119. doi: 10.1016/j.polgeo.2006.09.001

JONES R. D., ATFSTROM C. (1997) Closed-ampule digestion procedure for the determination of mercury in soil and tissue using cold vapor atomic fluorescence spectrometry, 29–34.

COBBINA S. J., MYILLA M., MICHAEL K. (2013) Small scale gold mining and heavy metal pollution : Assessment of drinking water sources in Datuku in the Talensi-Nabdam District , IJSTR, 2(1), 96–100.

KPAN J. D. A., OPOKU B. K., GLORIA A. (2014) Heavy metal pollution in soil and water in some selected towns in Dunkwa-on-Offin District in the Central Region of Ghana as a result of small scale gold mining, 40–47.

LEGG E. D., OUBOTER P. E., WRIGHT M. A. P. (2015) Small-scale gold mining related mercury contamination in the Guianas : A review, 1–49. doi: 10.13140/RG.2.1.1399.9204

MADELLA N. R. (2017) Soil physicochemical properties, 5–10. doi: 10.1007/978-3-319-42655-6

MANTEY J., NYARKO K. B., AUBYNN A. (2018) Spatial distribution patterns of illegal artisanal small scale gold mining ( Galamsey ) operations in Ghana : A focus on the Western Region. doi: 10.1016/j.heliyon.2018.e00534

MISHRA, M. K., KESHARWANI L. (2018) Analysis of heavy metal in soil through atomic absorption spectroscopy for forensic

MOE-Japan (2018). Environmental quality standards for soil pollution, 4–5.

MUCHE M., KOKEB A., MOLLA E. (2015) Environmental and analytical toxicology assessing the physicochemical properties of soil under different land use types, 5(5). doi: 10.4172/2161-0525.1000309

OFORI A., OFOSUHENE M., NUNOO F. K. E., DARKO G., TUFFOUR I. (2018) Assessment of heavy metal contamination and distribution in surface soils and plants along the West Coast of Ghana, 26, 167–178.

OPPONG S. O. B., VOEGBORLO R. B., AGORKU S. E., ADIMADO A. A. (2010) Total mercury in fish, sediments and soil from the River Pra Basin , Southwestern Ghana, 324–329. doi: 10.1007/s00128-010-0059-0

OWUSU-DONKOR Y. (2011) Heavy metal contents of soil and citrus grown in selected districts of Ashanti Region, Ghana.

OFOSU-MENSAH E. A. (2011) Historical overview of traditional and modern gold mining in Ghana, University of Ghana, IRJLIAS, Vol1, pp 6-22

QINGJIE G., JUN D. (2008) Calculating pollution indices by heavy metals in ecological geochemistry assessment and a case study in parks of Beijing, 19(3), 230–241.

QUARTEY P. (2000) Finance and development research programme environment for small and medium-sized industries, (15), 1–30.

RAJAEE M., LONG R. N., RENNE E. P., BASU N. (2015) Mercury exposure assessment and spatial distribution in a Ghanaian small-scale gold mining community, 10755–10782. https://doi.org/10.3390/ijerph120910755

RAJAEE M., OBIRI S., GREEN A., LONG R., COBBINA S. J., NARTEY V., BASU N. (2015) Integrated assessment of artisanal and small-scale gold mining in Ghana — Part 2 : Natural Sciences Review, 8971–9011. doi: 10.3390/ijerph120808971

ROBINSON B., MORRIS C. (2018) These five technologies will shake up the mining industry (https://www.mining.com/web/five-technologies-will-shake-mining-industry-2018.html)

SEY E., BELFORD E. J. D. (2019) Levels of heavy metals and contamination status of a decommissioned tailings dam in Ghana, EQA, 35, 33–50. doi: 10.6092/issn.2281-4485/9060

SIKABUOR (2011). History of gold mining in Ghana, Sikabour crystal mining, Ghana.

CSIR (2013). Council for Scientific and Industrial Research annual report, Ghana

SME (2015), Access to credit in Ghana : Determinants and Challenges, University of Ghana

UNDP (2016) Final report, Social analysis of Ghana’s artisanal and small-scale mining sector.

YASH P. K. (1995) Determination of pH of soils by different methods: Collaborative study, 78(2)

TAIB M. (2015) Minerals yearbook: Morocco. U.S. Geological Survey


TAMBE E., GOTMARE S. (2017) Assessment of metal contamination using single and integrated pollution indices in soil samples of Nashik District , India, 07, 15016–15024.

TCHAM B. G. D. (2013) Studies of heavy metal contamination associated with gold mining in the Twifo Atti Mokwa District, Ghana, Department of Nuclear Science and Applications, School of Nuclear and Allied Sciences, University of Ghana, Legon (Ghana).

TETTEH E. N. (2010) Evaluation of land reclamation practices at Anglogold Ashanti, Iduapriem Mine Ltd, Tarkwa. (http://hdl.handle.net/123456789/2086)

TESCHNER B. A. (2012) Small-scale mining in Ghana : The government and the galamsey, 37, 308–310.

TILLER K. G. (1989) Heavy metals in soils and their environmental significance, 9, 9–10.

TUZEN M. (2003) Determination of heavy metals in soil, mushroom and plant samples by atomic absorption spectrometry, 74(03), 289–297. doi: 10.1016/S0026-265X(03)00035-3

VIEIRA R. (2000) Mercury-free gold mining technologies : Possibilities for adoption in the Guianas

WHO (2007) Public health and environment, Exposure to mercury. DP services, Geneva, Switzerland.

WHO (2004) Guidelines for drinking-water quality. 3rd Edition. Geneva (http://www.who.int/water_sanitation_health/dwq/ GDWQ2004web.pdf)

WHO (2011) Arsenic in drinking water, Background document on developing guidelines for drinking water quality.

WUANA R. A., OKIEIMEN F. E. (2011) Heavy metals in contaminated soils : A review of sources , Chemistry, risks and best available strategies for remediation. doi:10.5402/2011/402647




How to Cite

Bonah, D., & Belford, E. (2022). Evaluation of pollution indices in Gold Mining communities in the Central Region of Ghana. EQA - International Journal of Environmental Quality, 48(1), 10–26. https://doi.org/10.6092/issn.2281-4485/14016