Background
There is increasing global concern over the health effects of heavy metals arising from various anthropogenic activities, especially mining. Mining activities in developing countries are often carried out at an artisanal level using a variety of extraction
Discussion
Cancer risk and non-cancer risk (hazard index) assessment showed that arsenic poses a higher risk in adults and children compared to other metals through the dermal exposure route.
Methods
Samples were collected from 28 active mine pits and sequentially extracted using standard methods. Extracts were analyzed for metals using inductively coupled plasma optical emission spectrometer (ICP/OES), while health risk was assessed using United States Environmental Protection Agency (USEPA) and Dutch methods. Chemical speciation of heavy metals and health risk assessment was calculated using mobile phase fraction summation.
Results
Metals were exclusively present in the residual fractions, indicating that these metals are strongly bound to the resistant components of the soil matrix. The percentage in the residual fraction ranged from 9.41% (tin) to 99.42% (aluminium). The heavy metals geoaccumulation index for the site ranged from 0 (no contamination) to 6 (extremely contaminated). The cancer risk ranged from 6.17E-13 to 7.77E-05 and 2.73E-12 to 4.64E-04 for adults and children, respectively.