Study On The Association Between Concentration Of Organic Chlorine Compound In Vitro And In Vivo Exposure In Zhoushan Area

ObjectivesThe study was conducted to find out the contents of organic chlorine compound in soil of Zhoushan area;to find out the contents of organic chlorine compound in rice of Zhoushan area;to find out the contents of organic chlorine compound in the residents of Zhoushan area;to probe the difference of area distributes among the contents of organic chlorine compound in soil,rice and the residents;to probe the association between the contents of organic chlorine compound in soil and rice;to probe the association between the contents of organic chlorine compound in rice and the residents.MethodsThe study was conducted in rural area in Dinghai district of Zhoushan city.Ten towns were sampled for three parts from east,central and west regions in Dinghai district.Seven families were sampled by random sampling technology in each town One kilogram of soil,five hundred gram of rice and 5 milliliters peripheral venous blood of each reproductive woman were sampled from each family.Isomeric of HCH, DDT and PCBs in samples were detected by gas chromatograph according to method of GB/T5009.19-1996.The amount of total HCH was calculated by summing the Isomeric compounds.total DDT and PCBs were calculated according to the same method.The descriptive analysis was used to describe the distribution of these organic chlorine compound in east,central and west regions in soil,rice and the residents; then Spearman correlation analysis was used to analyze the association between the contents of organic chlorine compound in soil and rice,by the same method,a correlation analysis was used to analyze the association between the contents of organic chlorine compound in rice and the serum of the residents.Results78 soil samples were detected.The positive rate of total HCH in soil samples was 89.74%.The median was 3.46×10^-3mg/kg;The positive rate of total DDT was 96.15%.The median was 11.68×10^-3mg/kg;The positive rate of total PCBs was 46.15%.The 75 quartile was 6.37×10^-4mg/kg.78 rice samples were detected.The positive rate of total HCH in rice samples was 100%.The median was 2.64×10^-3mg/kg;The positive rate of total DDT was 70.51%.The median was 1.74×10^-4mg/kg;The positive rate of total PCBs was 35.90%.The 75 quartile was 4.01×10^-4mg/kg.66 serum samples of the residents were detected.The positive rate of total HCH in blood samples was 100%.The median was 0.28ng/ml;The positive rate of total DDT was100%.The median was 0.11 ng/ml;The positive rate of total PCBs was 100%.The 75 quartile was 1.43 ng/ml.By comparison of different regions,the contents of total PCBs in soil samples decreased from east to west region(X²=26.79,P=0.000);the contents of total DDT in soil samples of central region was higher than east and west regions(X²=6.85,P=0.032). The proportion ofγ-HCH in soil samples in each region was high(east:57.83%;central:66.62%;west:55.55%).The contents of total PCBs in rice samples also decreased from east to west region(X²=18.93,P=0.000).,The contents of total DDT in rice samples also decreased from east to west region(X²=9.00,P=0.011). There was no statistics difference in the contents of three organic chlorine compounds in the residents of each region.Finally,Spearman correlation analysis was used to analyze the association among the contents of total HCH,total DDT and total PCBs in soil and rice.The contents of total HCH,DDT PCBs,in rice samples remains positively associated with those in soil samples(Correlation coefficients:total HCH is 0.005;total DDT is 0.048;total PCBs is 0.000).Spearman correlation analysis did not demonstrate that contents of organic chlorine compound in rice samples associated with blood samples of the residents; Only the contents of PCB28 in rice was associated with blood samples of the residents(Correlation coefficients:-0.284).ConclusionsHCH,DDT and PCBs exist in soil and rice in Zhoushan area,but the contents of HCH,DDT and PCBs have declined down to the safety level.In contrast with west region,the level of organic chlorine compound pollution in east and central region seems relatively higher.Since the proportion ofγ-HCH in soil samples was high in each region,it point out that lindane may uesd in Zhoushan area.The contents of organic chlorine compound in rice samples remains positively associated with those in soil samples.Correlation analysis did not demonstrate that contents-of organic Chlorine compound in rice samples remain associated with serum samples of the residents. HCH,DDT and PCBs were all found in serum samples of the residents,it seems that the dangerous of organic chlorine compound exposure in the residents in Zhoushan area is still exist.