Residues And Risk Identification Of Pesticides In Soil In Northeast Agricultural Region Of China

Pesticides are widely used to control diseases,pests and weeds,increasing food production.Because utility ratio of pesticides is between 20% and 30%,most of the pesticides that are applied to farmland enter into the soil.Some pesticides are carcinogenic,endocrine disruptive and bioaccumulative.The pesticides could threat the safety of human and ecological environment.As Northeast Agricultural Region of China is one of the important grain production bases in China.The total grain output exceeds 115 million ton,and the application amount of pesticides exceeds 200 thousand ton.However,residue and risk of pesticides in agricultural soil in Northeast Agricultural Region of China are not clear.Northeast Agricultural Region of China was the research region of this project.Pesticides residue concentration in agricultural soil was obtained by the way of combination of field sampling and laboratory analysis.Pesticides residue in Northeast Agricultural Region of China was identified by principle component analysis.According to risk assessment method recommended by United States Environmental Protection Agency,risk of human health and ecological environment of pesticides in Agricultural Soil in Northeast Agricultural Region of China were identified.A method was established for the determination of 110 pesticides in soil using high performance liquid chromatography tandem mass spectrometry(HPLC-MS/MS)and gas chromatography tandem mass spectrometry(GC-MS)with modified QuEChERS.The method could be used to determine the concentration of 110 pesticides in soil after the optimization of pretreatment and instrument conditions.The r2 of standard curves of 110 pesticides ranged from 0.9652 to 0.9996.The average recoveries of the 43 pesticides analyzed by HPLC-MS/MS at three spike levels(10,20,and 50 ?g/kg)ranged from 59.1% to 129.4% with relative standard deviations(RSDs)between 0.3% and 15%,and the average recoveries of the 67 compounds analyzed using GC-MS ranged from 44.9% to 168.1% with RSDs of 0.5%~20%.The detection limits of the method ranged from 0.01 to 5.00 ?g/kg.Overall,the method is simple,efficient,and sensitive,which could be used for the simultaneous determination of pesticide residues in soil.One hundred and seventy-nine soil samples in Northeast Agricultural Region of China were collected and analyzed.The results showed that total residue concentration of pesticides ranged from 80.7 ?g/kg to 2799.1 ?g/kg.Residue concentration of Panjin,Liaoyang,north of Anshan,south of Shenyang was higher than other regions(>1200 ?g/kg).The number of pesticides detected in soil samples ranged from 17 to 82,which included atrazine,simazine,acetochlor,butachlor,HCHs,DDTs,ethion,parathion and phosalone.Three percent of pesticide residue in soil samples in Northeast Agricultural Region of China was beyond the National Soil Environmental Quality Standards.According to principal component analysis,a large number of pesticides were transformed to 20 principal components.Because some pesticides have similar structures,have similar effects in corn field or rice field,and are mixed to use,the pesticides were classified and reduced to 13 residue sources.The results showed pesticides residue in soil in Northeast Agricultural Region of China had the region difference.The general distribution of residue sources that have higher residue concentration distributed in Dashiqiao of Yingkou,Dawa and Panshan of Panjin,Dengta and Gongchangling of Liaoyang,Taian and Haicheng of Anshan,Liaozhong of Shenyang in Liaoning province,Harqin Banner,Hexigten Banner and Linxi and Ongniud Banner of Chifeng.Total carcinogenic risk of pesticides(for adult)in agricultural soil in Northeast Agricultural Region of China ranged from 4.29×10-7 to 1.48×10-5,and for the child ranged from 2.64×10-6 to 9.14×10-5.Generally,total carcinogenic risk of pesticide residues in Northeast Agricultural Region of China is lower than 1×10-4,and it couldn't affect human health.Total non-carcinogenic risk of pesticides(for adult)in agricultural soil in Northeast Agricultural Region of China ranged from 6.19×10-5 to 4.98×10-2,and for the child ranged from 3.82×10-4 to 3.07×10-1.Total non-carcinogenic risk of pesticide residues in agricultural soil in Northeast Agricultural Region of China is far lower than 1,which could be ignored.Total ecological risk of pesticides in soil toward earthworm ranged from 1 to 344,showing ecological environment of all regions could be threatened.Ecological risk of Panjin,Anshan,Yingkou in Liaoning province where the maximum value could reach 344 was higher than other regions.According to principal component analysis,the ecological risk of residue sources in Northeast Agricultural Region of China had the region difference.The general distribution of residue sources that have higher ecological risk is similar to the distribution of pesticides residue.Generally,residue of a variety of pesticides were ubiquitous in agricultural soil in Northeast Agricultural Region of China.The concentration and kind of pesticides residue in soil varied from place to place.The health risk of pesticide in agricultural soil in Northeast Agricultural Region of China could be ignored.However,multiple pesticide residues in soil could pose a major threat to the ecological environment.The research results could provide scientific basis for the protection of human health and ecological environment.