Study On Dietary Exposure And Residual Characteristics Of 9 Chiral Pesticides In Human Body

Broad application of chiral pesticides results in ubiquitous occurrence of these pesticides.Chiral pesticides can enter and accumulate in human bodies through daily diets and pose health risks to humans.In this study,a method was developed to detect nine common chiral pesticides including bitertanol,benalaxyl,hexaconazole,tebuconazole,flutriafol,triadimefon,bonzi,myclobutanil and metalaxyl in various kinds of diets(foods and drinking water)and human urine through UPLC-MS/MS.The residual characteristics of these chiral pesticides were then investigated in diets and human urine in Eastern China.Besides,the exposure doses and health risks of the chiral pesticides were evaluated and compared in different populations.The main results are listed as follows:Neither bitertanol nor benalaxyl was detected in foods and drinking water.The concentration of metalaxyl was the highest(median 1.0 μg·kg-1 fresh weight in foods and 0.99 ng·L-1 in drinking water)among the other seven detected chiral pesticides The same tendency but different degree of enantioselectivity was observed for each chiral pesticide in all kinds of foods as the same as drinking water.All of the chiral pesticides except triadimefon were detected in human urine.The highest residual concentration was found for metalaxyl with a median 59.4 ng·mg-1 creatinine.The level of the detected eight chiral pesticides showed a trend:women higher than men and adults higher than children.Significant differences in gender and age were observed in the residues of bitertanol,benalaxyl,hexaconazole and tebuconazole.While similar differences were not found for bonzi.The enantioselectivity was observed for all of the chiral pesticides with different degree except benalaxyl in the urine.External exposure assessment revealed that average daily doses(ADDs)of the seven chiral pesticides were 14.1,13.6,3.5,3.2,0.4 ng/kg bw/day through uptake of vegetables,cereals,eggs and milk,livestock and soy products,respectively.The ADDs were 60.6,20.7,18.9 pg/kg bw/day for tap water,bottled water and barreled water.Vegetables and cereals were the main sources of dietary exposure matrices of these chiral pesticides.Exposure to the chiral pesticides through diets was gender and age-specific.The ADDs of the seven detected chiral pesticides were in the order of girls>boys>women>men.The hazard quotient(HQ)of the seven detected chiral pesticides ranged from 10-8 to 10-2 in the foods,and 10-8 to 10-5 in the drinking water.Cereals and vegetables showed the highest risks and soy products showed the lowest.The non-carcinogenic health risks of these chiral pesticides were at very low in human bodies through uptake of drinking water.The risks of hexaconazole and metalaxyl were the highest ones,which were three orders of magnitude far away from the safety threshold.