Occurrence and Exposure Assessment of Antibiotics, Parabens and Potentially Toxic Elements in Groundwater Sources from Two Rural Communities in Nigeria.

Abstract

The presence of emerging organic contaminants (EOCs) and Potentially Toxic Elements (PTEs) in groundwater is a global concern. In Nigeria, however, monitoring and risk assessment data for EOCs such as Methylparaben (MeP), Ethylparaben (EtP), Propylparaben (PrP), Butylparaben (BuP), and antibiotics like ampicillin (AMP), chloramphenicol (CLP), ciprofloxacin (CIP), and metronidazole (MET) are scarce, especially in rural areas. This study quantified EOCs and metals in groundwater from two rural Nigerian communities using HPLC-UV and ICP-OES, with validation through recovery (99.6-101%) and linearity (R2 > 0.999). Health risks were assessed via Target Hazard Quotient (THQ), Target Carcinogenic Risk (TCR), and risk quotient (RQH). The groundwater samples followed the decreasing order: Ca > Mg > Na > K > Co > Al > Fe > Cr > Mn > Zn > Cd > Ni > Pb > B > Cu > Se for metals and MET > CIP > BuP > MeP > PrP > EtP for EOCs. Groundwater EOC concentrations were as high as 7846 (MET), 1137 (CIP), 342 (MeP), 295 (EtP), 299 (PrP), and 400 μg L - 1 (BuP) while Fe, Zn, Al, Cr, Ni, and Pb in all groundwater samples investigated were higher than the permissible limit recommended by WHO. The human risk assessment revealed both non-carcinogenic and carcinogenic hazards from Cd, Cr, Ni, and Pb, with Cr contributing ∼90% of the cumulative THQ and TCR. Additionally, CIP exhibited high RQH (>1) across all age groups, ranging from 1.142 to 49.174. Findings from this study indicate that groundwater consumption in these communities poses significant health risks.