Health risk assessment linked to consumption of water contaminated by lead in the cotton area of Kerou (BENIN) in the watershed of Niger

Abstract

This survey is an assessment of risks associated with consumption of contaminated drinking water by lead in the cotton zone of Kerou. Lead (Pb) was measured by atomic absorption spectrophotometer and risk assessment was made following a standardized method. The results obtained showed that 22% (7/18) of studied boreholes have been contaminated by lead. In addition, boreholes of Ganbore and Korigourou showed relatively high values of lead levels: 0.061, 0.098 and 0.604 mg/L compared to the accepted value,that is 0.04 mg/L. Risk assessment revealed that Daily Exposure Dose (DED)of lead due to consumption of drinking water in these three regions are thesame, namely 12.54 ƒÊg/kg/day for children and 3.85 ƒÊg/kg/day for adultscompared to the daily allowed dose defined by WHO that is 3.6ƒÊg/kg/day.Kerou in Benin is a good reference of a site to test the hypothesis of the connection between groundwater and river contamination with heavy metals(Pb in the present investigation) and the intensity of farming activities andcotton cultivation in the zone.These high values can be attributed to infiltration of residues of pesticides. Also, they can be attributed to contamination of groundwater by the Mekrou River containing wastewater rich in organic matter. This contamination and exposure are serious risks for human health and especially for children and needs serious attentions of public health authorities and policy makers.