关键词: 苹果, 农药残留, 膳食暴露, 非参数概率评估模型, 风险评估

Abstract: 【Objective】 The objectives of this study are to detect pesticide (carbendazim, thiophanate-methyl, imidacloprid and chlorbenzuron) residues in apples from China and evaluate their dietary exposure, identify and quantify the risk levels of dietary intake of the 4 commonly used pesticides in China, and to provide evidence for safe production, consumption, and safety supervision of apple. 【Method】 Based on the 282 apple samples from two main apple producing areas, including the Bohai bay (Liaoning, Shandong and Hebei) and the Northwest loess plateau (Shaanxi, Shanxi and Henan), professional risk assessment software @Risk was used to evaluate the dietary intake (exposure) risk of apple with the 4 pesticides by building a nonparametric probabilistic evaluation model. First, data on the 4 pesticides residual content in 282 apple samples were collected for distribution fitting, which were checked by three statistical test methods: the Chi-Squared test, the Anderson-Darling test and the Kolmogorov-Smirnov test, and the optimum fitting distribution was selected from the results. The supervised trials median residue (STMR) and highest residue (HR) values were superseded by the values of optimum distribution fitting. %ADI and %ARfD indicate the chronic dietary intake risk and acute dietary intake risk, respectively. 【Result】 Of the 282 apple samples tested, 90.4% of apple samples (255) had detectable residues. Of the 4 common used pesticides, the detectable rate of carbendazim (CA) was 81.9%, which was the most frequently detectable pesticide, followed by thiophanate-methyl (TH) (52.1%), imidacloprid (IM) (39.0%), and chlorbenzuron (CH) (31.2%). The vast majority of samples pesticide residues were at lower levels, and the highest concentration was 0.9251 mg·kg^-1 (CA), which was still lower than the MRL (3.0 mg·kg^-1). The mean residual concentrations of the 4 pesticides in samples were in the following order: CA (0.1042 mg·kg^-1) ＞CH (0.0182 mg·kg^-1) ＞TH (0.0082 mg·kg^-1) ＞IM (0.0050 mg·kg^-1). There were differences in residual concentrations’ dispersion degree, and the variance coefficient was up to 136.4% (CA), 232.8% (TH), 214.8% (IM) and 174.1% (CH), respectively. The distribution law of the residual concentration of the 282 apple samples was obvious, the proportion of samples was reduced gradually in a trend with the increase of residual concentration. Twenty-seven samples (9.6% of all tested samples) were residue-free of the 4 pesticides, 198 samples (70.2%) had more than two residues, and 19 samples (6.7%) even had 4 kinds of pesticide residues. The chronic dietary intake risks for different age groups consuming apples with these 4 pesticides were 0.2120%-35.1100% (CA), 0.0051%-0.8240% (IM), 0.0049%-0.1710% (TH) and 0.0004%-0.0152% (CH), respectively. The acute dietary intake risks were 0.1940%-16.0500% (CA) and 0.0122%-0.9400% (IM), respectively. The infants (aged 2 to 6) and children (aged 7 to 13) were significantly higher than that of other groups, because of higher apple intake and lower body weight, so that they were the vital monitoring objects. The pesticide intake risks were declined gradually with the age growth, and the risks were higher with the larger percentile values selected.【Conclusion】CA, TH, IM and CH residues in Chinese apples had a relatively high detectable rate. Nevertheless, the residual concentrations of all the samples tested were under MRLs. Both chronic and acute dietary intake risks for the general population consuming apples with the selected 4 pesticides were low. The infants and children were significantly higher than that of other groups and should be paid more attention.

Key words: apple, pesticide residue, dietary exposure, nonparametric probabilistic evaluation model, risk assessment