Trace elements determination and health risk assessment of groundwater sources in Kumasi Metropolis, Ghana

Trace element (TEs) contamination in groundwater is a key factor for health risk assessment and one of the environmental challenges linked with Ghana's sustainable development. This study aims to investigate TE concentrations in groundwater used for drinking and domestic purposes and their potential health risk in the Kumasi Metropolis using multivariate statistics. In the study, 23 groundwater samples were analyzed for 32 TEs using Perkin Elmer Nexion 2000 Inductively Coupled Plasma Mass Spectrometer (ICP-MS). Levels of TEs recorded in the study were in order of Na > Si > Ca > K > Mg > S > Ba > Cu > Zn > Al > Sr > Li > Mn > P > Fe > B > Pb > Ni > Co > Bi > Se > Sb > Cr > As > Ti > Be > V > U > C d > T l > Mo > Hg. The study revealed that the concentration of trace and toxic elements like Al, Cu, and Pb exceeded their corresponding WHO permissible standards. Hazard index (HI) values and total likely cancer risk (TLCR) values for non-carcinogenic and carcinogenic health risks indicate that 91.3% of the total sampling sites presented health concerns to adults and children. The mean TLCR values associated with exposure to carcinogenic metals via ingestion of groundwater samples were estimated to be 2.09 × 10^-4 and 4.44 × 10^-4 for adults and children respectively. Exposure through the ingestion pathway was found to be more risky compared to dermal contacts. Children are particularly vulnerable to these health hazards. Pearson correlation (PC) matrix, principal component analysis (PCA), and hierarchical cluster analysis (HCA) suggested that sources of TEs in the groundwater are attributed to both anthropogenic and geogenic factors.