宁波市郊农业土壤中持久性毒害污染物的残留现状及健康风险评估

调查了宁波市郊农业土壤中持久性毒害污染物的残留现状,采用美国能源部风险评估信息系统的暴露量化方法和美国环保局健康风险评估手册的风险表征方法,评估了市郊农业土壤中持久性毒害污染物对户外劳作者的健康风险。结果表明:宁波市郊的农业土壤样本中有机氯农药仍能检出,其中HCHs、DDTs的检出率最高,七类OCPs的总浓度范围为Nd～41.3μg/kg;市郊农业表层土壤中多环芳烃含量范围为4.09～3491μg/kg,平均含量为501μg/kg,荧蒽、苯并(a)芘的含量相对较高,平均浓度分别为72.5μg/kg、71.7μg/kg;Pb、Cd、Cu、Zn、Cr、Hg、As 7种重金属检出率为100%,其中铅、锌、总铬的平均浓度相对较高,分别为59.6 mg/kg、89.0 mg/kg、58.8 mg/kg;宁波户外劳作者由于市郊农业土壤中持久性毒害污染物引起的综合非致癌危害指数为5.18×10-4,综合致癌风险值为9.92×10-7,可判定对目标人群的健康危害较小。由于综合致癌风险值已接近一般可接受致癌风险值(10-6),故应注意其PTS浓度值水平,以便及时采取土壤治理措施,降低风险。

Health Risk Assessment of Persistent Toxic Substances in Agricultural Soils of Ningbo

The health impact of organ chlorine pesticides in agricultural soil sample was evaluated based on the investigation of persistent toxic substances in soils of Ningbo Area according to exposure assessment of Risk Assessment Information System(RAIS) from USA Energy Department and Risk Equation of Human Health Evaluation Manual of USEPA.In the research,the total concentration of seven kinds of OCPs ranged from detection limits to 41.3ug/kg.HCHs and DDTs had the higher detection rates.The concentration range of PAHs in surface soil was from 4.09 to 3491ug/kg and the average was 501ug/kg.Fluoranthene and BaP had the higher concentrations than other PAHs which were 74.5ug/ kg and 71.7ug/kg.Seven heavy metals for Pb,Cd,Cu,Zn,Cr,Hg,As in polluted soils could been detected.The average concentrations of Pb,Zn and Cr were 59.6mg/kg,89.0mg/kg and 58.8mg/kg which were higher than others.This results showed that PTS in the soils had little risk on human health with the average non-carcinogen hazard index and the average cancer risk for outdoor workers being 5.18×10-4and 9.92×10-7.Considering the cancer risk approached to the acceptable cancer risk leval(10-6),people should pay much attention to PTS pollution of agricultural soils.