Distribution of chlorpyrifos in rice paddy environment and its potential dietary risk.
Chlorpyrifos is one of the most extensively used insecticides in China. The distribution and residues of chlorpyrifos in a paddy environment were characterized under field and laboratory conditions. The half-lives of chlorpyrifos in the two conditions were 0.9-3.8days (field) and 2.8-10.3days (laboratory), respectively. The initial distribution of chlorpyrifos followed the increasing order of water<straw<soil, and soil was characterized as the major absorber. The ultimate residues in rice grain were below the maximum residue limit (MRL) with a harvest interval of 14days. The chronic exposure for chlorpyrifos was rather low compared to the acceptable daily intake (ADI=0.01mg/kg bw) due to rice consumption. The chronic exposure risk from chlorpyrifos in rice grain was 5.90% and 1.30% ADI from field and laboratory results respectively. Concerning the acute dietary exposure, intake estimated for the highest chlorpyrifos level did not exceed the acute reference dose (ARfD=0.1mg/kg bw). The estimated short-term intakes (ESTIs) were 0.78% and 0.25% of the ARfD for chlorpyrifos. The results showed that the use of chlorpyrifos in rice paddies was fairly safe for consumption of rice grain by consumers.
Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310000, China. Electronic address: fuyan0571@163.com.
Yan
Y
Fu
Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310000, China.
Feifei
F
Liu
Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310000, China.
Chenglin
C
Zhao
Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310000, China.
Ying
Y
Zhao
Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Fuyang 311400, China.
Yihua
Y
Liu
Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310000, China. Electronic address: zhugn@zju.edu.cn.
Guonian
G
Zhu
D000383:Agriculture; D002681:China; D004390:Chlorpyrifos / Q000032:analysis*; D004781:Environmental Exposure; D004784:Environmental Monitoring; D006801:Humans; D007306:Insecticides / Q000032:analysis*; D012275:Oryza / Q000254:growth & development; D010573:Pesticide Residues / Q000032:analysis*; D018570:Risk Assessment; D012989:Soil Pollutants / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
D007306:Insecticides; D010573:Pesticide Residues; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D004390:Chlorpyrifos
Chlorpyrifos; Dietary risk assessment; Distribution; Paddy environment