荆江航道河段表层水中有机氯农药残留量对健康影响研究

Assessment of the potential health risk of organochlorine pesticideresidues in shallow water of Jingjiang waterway in Yangtzi River

目的调查长江航道工程河段表层水中有机氯农药滴滴涕(dichlorodiphenyltrichloroethanes,DDTs)、六六六(hexachlorocyclohexanes,HCHs)的残留及其对健康的影响。方法2013-2014年枯水期、丰水期采集长江中游荆江航道河段表层水样。利用气相色谱法(GC-MS)检测水中DDTs、HCHs浓度,采用健康风险评价法,估算经饮水途径DDTs、HCHs的健康风险性。结果丰水期水中o,p′-DDT、p,p′-DDT未检出,其他DDTs(p,p′-DDT、o,p′-DDT、p,p′-DDD、p,p′-DDE)及HCHs(α-HCH、β-HCH、γ-HCH、δ-HCH)的检出率23.26%~45.12%,但∑DDTs、∑HCHs浓度低于国家地表水水质标准(GB3838-2002);经两样本率的检验,丰水期α-HCH含量高于枯水期(χ~2=8.153,P<0.05),其他DDTs、HCHs浓度差异无统计学意义(P>0.05);枯水期、丰水期DDTs、HCHs经水途径的致癌及非致癌风险处于可接受水平。结论本研究河段可检出DDTs、HCHs,目前处于水质安全状况。但需要加强监测和防控,以保证长江航道工程水环境健康及饮水安全性。

Objective To assess the potential health risk of organochlorine pesticide residues in the shallow water of Jingjiang waterway in Yangtze River.Methods The water samples were collected from Jingjiang waterway in the middle reaches of the Yangtze River during the dry season and the wet season between 2013and 2014.The contents of dichlorodiphenyltrichloroethanes(DDTs)and hexachlorocyclohexanes(HCHs)in water were determined by GC-MS.The potential health risk of DDTs and HCHs residules in water was estimated using health risk assessment(HRA)method.Results O,p′-DDT and p,p′-DDT were underdetermined in samples collected during the wet season,while the detection rates of other DDTs(p,p′-DDT,o,p′-DDT,p,p′-DDD,p,p′-DDE)and HCHs(α-HCH,β-HCH,γ-HCH,δ-HCH)ranged from 23.26%to 45.12%,and the contents ofΣDDTs andΣHCHs,were both below the national quality standard(GB3838-2002).The chi-square test showed thatα-HCH level was significantly higher in the wet season than that in the dry season(χ2=8.153,P<0.05),however,there were no significant differences in the contents of other DDTs and HCHs(P>0.05).HRA analysis revealed that carcinogenic and non-carcinogenic risks of DDTs and HCHs in water were very low and acceptable both in dry season and in wet season specified by the EPA.Conclusions Although some DDTs and HCHs are detectable in water of Jingjinag waterway,they are at low levels,and water is still safe.However,continuous monitoring should be strengthened to ensure that the water is safe all the time for drinking.