宁夏窖水有机氯农药残留现状与健康风险评价

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

目的了解宁厦南部山区饮用窖水中有机氯农药的残留状况及对人体健康产生的潜在危害。方法于2012年9月初，在宁夏南部仍以窖水作为饮用水的山区设置12个采样点，每个采样点采集窖水6L，测定其中六六六类（HCHs）和滴滴涕类（DDTs）各异构体残留量；评价饮用窖水中HCHs、DDTs所引起的健康风险。结果宁夏南部山区饮用窖水中检出HCHs和DDTs，HCHs含量范围在0—5．20ng／L，主要残留物为γ-HCHs，DDTs含量范围在0—73．50ng／L，只检测到P，p＇-DDE，DDTs残留量高于HCHs；HCHs、DDTs所引起健康危害的个人年风险分别为1．74×10-12／a、3．96×10-11／a；2种有机氯农药对人体健康危害的年风险为4．14×10-11／a。结论宁夏南部山区饮用窖水中仍有HCHs和DDTs残留，但低于地表水质量标准限值，对人体潜在危害很小。

Objective To examine residues of organochlorine pesticides in cellar water and their potential health hazards of in south mountainous areas of Ningxia. Methods In 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. Results The 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 pes- ticides was 4. 14 × 10-11 per year. Conclusion The 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.