Residues of organochlorine pesticides in cellar water and their health risk in south mountainous areas of Ningxia

ObjectiveTo examine residues of organochlorine pesticides in cellar water and their potential health hazards of in south mountainous areas of Ningxia.MethodsIn September 2012,the samples of cellar water were collected at 12 points in the south mountainous areas of Ningxia.Six L cellar water was collected at each site.The residual levels of hexachloro-cyclohexane(HCH),dichloro-diphenyl-trichloroethane(DDT)and their isomers were determined.Health risks of HCHs and DDTs in drinking cellar water were assessed.ResultsThe detection rates of HCH and DDT in the drinking cellar water samples was 100%.The HCHs content ranged from not detectable to 5.20 ng/L,and the main residue was γ-HCHs.The DDTs content ranged from not detectable to 73.50 ng/L,and the only residue detected was p,p'-DDT.The DDTs' content was higher than HCHs.The health risk of HCHs and DDTs of the residues in cellar water for an individual were 1.74×10^-12 and 3.96×10^-11,respectively.The total health risk caused by the organochlorine pesticides was 4.14×10^-11 per year.ConclusionThe residues of organochlorine pesticide in cellar drinking water in the south mountainous areas of Ningxia were detected but the contents are lower than the surface water quality standard limits and the potential hazards to human health is weak.