Health Risk Assessment of Heavy Metals in the Water of the LoutétéRiver, Mfouati District, Southeast Congo

The overall objective of this study was to assess the health risk of water in the Loutété River contaminated with heavy metals. Six surface water samples were collected during the dry season (October 2014). The physico-chemical parameters (pH, electrical conductivity, total dissolved salts) were measured using a HANNA brand device. The values of these physico-chemical parameters are below the WHO standards. The concentrations of heavy metals Cr, Cu, Fe, Pb, Zn and Mn were determined by ICP-OES. These obtained in (μg/L) are in the range: Cr (0.08 - 5.8);Cu (0.6 - 14.5);Fe (0.2 - 386.05);Pb (1.02 - 370.09);Zn (8.02 - 248.7) and Mn (37.1 - 328.08). These concentrations are below the WHO drinking water guideline value in all samples for Cr, Cu, Mn and Zn, 50, 2000, 400 and 3000 μg/L respectively. Concentrations of As, Fe and Pb exceeded the WHO guideline value for drinking water at the following stations: S1 for arsenic, S4 for iron, and for Pb at all stations except S5. The health risk assessment for adults due to ingestion exposure gave HQing. values < 1 for the following heavy metals: Cr, Cu, Fe, Mn, Zn, except for Arsenic and Lead. The hazard quotient calculated by dermal contact (HQ derm) in the waters of the river Loutété, showed that HQ derm < 1 for all heavy metals in all stations. For children, the dermal contact hazard quotient HQ derm < 1 for all heavy metals As, Fe, Cu, Zn, Mn, Cr and Pb. With the exception of station S4, we observed that HQ > 1 for lead. In the case of ingestion, HQing. < 1 for the heavy metals Cr, Cu, Zn, Mn, with the exception of the following metals Arsenic, Lead and Iron.