Analysis Of Pesticide Residues In Vegetables And Dietary Exposure Risk Assessment In Qiandongnan Prefecture

Vegetables are one of the most important foods in people's daily lives,and their quality and safety are particularly important.In recent years,the problem of pesticide residue pollution in vegetables is not uncommon.It is of great significance to study whether pesticide residues have exposure risks to the health of residents.In this study,864 vegetable samples from 16 counties/cities in Qiandongnan Prefecture were used as test materials.According to the national standard "7-2021 National Food Safety Standard Maximum Residue Limits of Pesticides in Foods",the test samples were divided into Brassica species,There are five types of vegetables including leafy vegetables,solanaceous fruits,melons,and beans.Establish Qu ECh ERS-gas chromatography method to detect 25 kinds of organophosphorus,pyrethroids and organochlorine pesticides in vegetable samples,evaluate the pesticide residues in vegetable samples based on the results of the test,evaluate the dietary exposure risk and rank the risks for supervision The department reasonably allocates supervision resources and provides reference for systematically carrying out vegetable risk assessment in the future.The results are as follows:The vegetable samples collected included 21 kinds of vegetables including cabbage,broccoli,cauliflower,cauliflower,Chinese cabbage,pakchoi,Shanghai green,lettuce,tomato,eggplant,pepper,winter melon,gourd,cucumber,bitter gourd,pumpkin,loofah,lentil,cowpea and green bean.Samples were collected from vegetable planting enterprises,cooperatives and large planting bases,distributed in 16counties/cities of Qiandongnan Prefecture.1.This study established a method for the determination of 25 pesticide residues in vegetables by Qu ECh ERS pretreatment and gas chromatography.The concentrations of 25 pesticides were in the linear range of 0.01?g/mL?1?g/mL,and the linearity of all pesticides was good,with the correlation coefficients between0.992 and 0.9998.The detection limit of 25 pesticides was 0.0001?0.0208mg/kg,the recoveries were 82.2%?112.9%,and the precision of all pesticides was less than 10%.The method could meet the requirements of pesticide residue analysis in vegetables.2.14 pesticides were detected in 864 vegetable samples,including triazolone,propyl,cyhalothrin,fenprothrin,chlorothalonil,biphenthrin,cyhalothrin,cypermethrin,permethrin,cyvalerate,cyvalerate,deltamethrin,dichlorvos and malathion,with detection rates ranging from 0.12% to 11.34%.All did not exceed the standard of limit set by the state.3.5 The detection rates of pesticides in vegetables from high to low were melon > cigar > leaf vegetable > Brassica > legume,the detection rates were 41.12%,37.34%,34.39%,19.01% and 15.27%,respectively.The detection rate of multiple residues from high to low was solarized vegetables(23.65%)> melon vegetables(14.49%)> leaf vegetables(9.55%)> Brassica(5.79%)> legumes(2.29%).Among them,the detection rate of pesticide residues in 5 kinds of vegetables was the highest in the second and third quarters,and the detection rate of pesticide residues in the first and fourth quarters was relatively low.The reason for this phenomenon is that the climatic environment in the second and third quarter is suitable for the growth of vegetables and the reproduction of diseases and insect pests,which leads to the increase of pesticide application and the corresponding higher detection rate of pesticide residue.4.The detection rate of organochlorine pesticides in vegetable samples was the highest,followed by pyrethroids,and organophosphorus pesticides was the lowest.The average detection rate of organochlorine pesticides in 864 vegetable samples was20.83% and the average detection rate was 3.87%.The detection rates of organochlorine pesticides in brassica,leafy vegetables,jackets,melons and beans were 12.4%,19.75%,24.07%,30.37% and 8.40%,respectively,and the detection rates were 1.89%,3.28%,6.05%,5.01% and 1.09%,respectively.The average detection rate of pyrethroid pesticides in 864 vegetable samples was 18.87% and the average detection rate was 3.15%.The detection rates of pyrethroid pesticides in Brassica,leaf vegetables,cigars,melons and beans were 8.26%,16.56%,30.71%,19.16% and 9.16%,respectively.The detection rate was 1.38%,2.48%,5.86%,2.75%and 1.27%,respectively.The average detection rate of organophosphorus pesticides in864 vegetable samples was 0.46%,and the average detection rate was 0.05%.No organophosphorus pesticides were detected in brassica,jackets,melons and beans.5.Among the 14 pesticides detected,the chronic dietary exposure risk(%ADI)of single pesticide residue was less than 100%,and the chronic dietary exposure risk(%ADI)of compound pesticide residue was less than 100%.No matter the single risk of pesticide residue in vegetables,Or compound risks are acceptable.In the assessment of acute dietary exposure risk,the acute dietary exposure risk(%ARfD)of children(<6 years old)ranged from 0.01% to 51.24%,and that of the general population ranged from 0.01% to 27.25%.The risk of acute dietary exposure(%ARfD)was less than 100% for children(<6 years old)and the general population,which was within the acceptable range.In children(<6 years old),the acute dietary exposure risks of biphenthrin,cyhalothrin and cyhalothrin in Chinese cabbage were51.24%,39.61 and 46.22%,respectively,although they did not exceed the national maximum residue limits.Therefore,attention should be paid to the high risk.6.According to the ranking of risks,14 pesticides detected in vegetables were divided into high risk and low risk.The high risk pesticide was dichlorvos,but the residue level of dichlorvos in vegetables was low,resulting in less risk.Most of the864 vegetable samples were very low and low risk,accounting for 98.38% of the total samples.Medium and high risk samples accounted for only 1.62%.