Risk assessment of dietary intake of pesticide residues in kiwifruit

Abstract: 【Obiective】Risk assessment of dietary exposure to pesticide residues in kiwifruit and quantifiction of the dietary risk levels of commonly used pesticides provide references for safe production and guidance for consumption of the fruit, food safety supervision, and revision of the Maximum Residue Limits(MRLs) of kiwifruit.【Methods】Based on detection of the residues of 66 pesticides in 61 kiwifruit samples from a major producing area, chronic dietary intake risk(%ADI) and acute dietary intake risk(%ARfD) of pesticide residues in these samples were assessed. Based on the veterinary drug residue risk ranking matrix constructed by the British Veterinary Drug Residues Committee, the risk of th epesticides and samples was ranked by integrating kiwifruit consumption and pesticide toxicity, frequency of use and residue level, and maximum residue limit estimates(eMRL) were calculated using allowable daily intake(ADI) values, large portion consumed(LP), and body weight(bw). The study will provide a reference for the regulation of the maximum residue limit(MRL) for the corresponding pesticides.【Results】(1)Among the 62 pesticides, a total of 21 pesticides were detected, and they were lowtoxic pesticides except for chlorpyrifos, deltamethrin, cypermethrin and cyhalothrin, which were moderately toxic;(2) Using the pesticide toxicology data, acceptable daily intake(ADI) and acute reference does(ARfD), residual data and kiwifruit consumption data, the risk assessment of the 21 pestcides detected showed that the chronic dietary intake(%ADI) of each pesticide in kiwifruit ranged from 0.000 01%to 0.016 04%. All the 21 pesticides detected but acetamiprid and chlorpyrifos without ARfD information had an acute dietary intake(%ARfD) ranging from 0.01% to 26.20%. The acute dietary intake risk difference between different pesticides was significantly.(3) According to the residual risk score, the 21 pesticides detected were medium-to low-risk pesticides. The risk scores for deltamethrin and chlorpyrifos were 16.5 and 16.1 ie(15≤S<20), respectively, which were in the medium-risk range. The risk scores of cypermethrin, pyrimidine, buprofezin, cyhalothrin and difenoconazole were between 12.1 and 12.4,and the risk scores of 14 pesticides including procymidone and chlorpyrifos ranged from 8.0 to 9.3(S<15). All of them were low-risk pesticides. Among the 61 kiwifruit samples, 45.9% of the samples were in a very low risk area with a pesticide residue risk index(RI) below 5; 34.4% of the samples were in a low risk range with a pesticide residue RI between 5 and 10; and 18.0% of the samples were in a medium risk range with a pesticide residue RI of 10 and 15;(4) At present, there were few standard pesticides in kiwifruit. Among the 21 pesticides detected, only carbendazim, acetamiprid, chlorpyrifos, deltamethrin, and cyhalothrin had maximum residue limit(MRL) in kiwifruit or berries and other small fruits in GB 2763—2016, while 76.2% the pesticides had not a limit value. Compared with eMRL, the MRL values of the five pesticides was a more strict parameter related to limitation of quantities. For example, the eMRL of carbendazim was 6.6 times that of MRL; the eMRL of acetamiprid was 3.8 times that of MRL; the eMRL of cyhalothrin was 10.9 times that of MRL; the eMRL of deltamethrin 21.9 times that of MRL; and the eMRL of chlorfenuron was 153 times that of MRL. Among the 21 pesticides detected, carbendazim, acetamiprid, cyhalothrin, deltamethrin and chlorpyrifos had MRLs, and azoxystrobin, chlorfenapyr, malathion, and procymidone had no necessecity to formulate MRL. 12 pesticides including thiamethoxam, imidacloprid, thiophanate-methyl, tebuconazole, propiconazole, prochloraz, difenoconazole, buprofezin, trifloxystrobin, chlorpyrifos, cypermethrin and chlorothalonil had no MRLs.【Conclusion】The pesticides detected were all middle-risk or low-risk pesticides, and the acute and chronic dietary risks of the 21 pesticides were acceptable. At the same time, 98.4% of the 61 samples were at medium, low or very low risk. Therefore, the kiwifruit in the major producing area was relatively safe. It was recommended to develope the MRLs of 12 pesticides including thiamethoxam and imidacloprid for in kiwifruit.