Ecotoxicological status and health risks implication of heavy metals in urban soils of the A’koon and Brahabobom communities, Tarkwa – Ghana

Abstract Heavy metal contamination of urban soils and it possible detrimental effects to both environmental quality and humans have gained significant attention for decades. However, data on the ecotoxicological status and health implication of heavy metal pollution of soils in Tarkwa remains vague. Herein, nine heavy metals (Cd, Co, Cu, Cr, Fe, Mn, Pb, Ni, and Zn) were analyzed in 20 urban soils, of typical artisanal mining communities in Tarkwa, using Flame Atomic Absorption Spectrophotometer (AAS VARIAN AA240FS). Multivariate statistical analysis as well as ecotoxicological indexes were employed to identify pollution sources of metals and possible ecotoxicological effects, respectively. In addition, non-carcinogenic and carcinogenic risks for residents’ exposure through oral, dermal, and inhalation were estimated. The mean concentrations (mg/kg) of the nine metals followed a decreasing order: Fe > Mn > Zn > Cr > Pb > Cu > Co > Ni > Cd. Results on principal component analysis (PCA) and hierarchical cluster analysis (HCA) were in concomitant revealing that Pb and Cd inputs may be due to anthropogenic influenced whiles the occurrences of Cr, Fe, Co in the soil could be attributed to similar geochemical processes. Noteworthily, 45% of soils samples from the study sites had the total toxic unit (TTU) greater than 4, an indication that the heavy metals may pose deleterious effects on soil-dwelling organisms. For all the exposure routes, the estimated hazard quotients (HQs) for the children, youth, and adult populations were < 1, for all metals. However, hazard index (HI) estimations showed a considerable non-cancer risk to children residents of the A’Koon community via dermal exposure (HI = 1.5). The potential cancer risks associated with daily exposures revealed that children resident of the two communities may be susceptible to Cr via inhalation (> 1 × 10− 4), at a cancer risks of 5.7 × 10− 4 and 4.13 × 10− 4 for the Brahabobom and A’koon communities, respectively.