| Objectives:This thesis aimed to provide direct evidence of internal pesticide exposure to local residents and assess the health risks associated with pesticide occupational exposure.The pesticide exposure was based on the determination of pesticide residues in rural residents’ urine,local water and soil samples in some county of Yunnan Province.The relationship was explored between urine pesticide residues and concerned conditions including pesticide using,individual self-protective equipment taking,preventive measures,related symptoms with pesticide using,as well as the pesticide residues in the environment.Methods:Questionnaire survey and laboratory determination were carried out in this research.Two hundred and thirty local residents were surveyed by using a questionnaire to collect data on pesticide usage,the situation of wearing individual self-protectiveequipment when using pesticide,and the symptoms related to pesticide use.The urine samples of the 230 residents were collected from the 5 villages where those live,as well 29 soil and 28 water samples.Ultra high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)was applied to detect the residues of 17 commonly used pesticides in local agricultural production,qualitatively and quantitatively.The urine samples were solid-phase extracted by Waters Oasis MCX cartridge(3 cc)after eluted with methanol and methanol solution of 5%aqueous ammonia,centrifugated and concentrated.Water samples were lyophilized.Soil samples were extracted by methanol,filtered and concentrated.After solving in 1 mL acetonitrile respectively,filtered(0.22μm,the samples were separated on Cosmosil packed column(4.6 mm×150 mm)column with acetonitrile solution of 0.01%formic acid and aqueous solution of 0.01%formic acid as mobile phase in gradient elution.UHPLC-MS/MS analysis was conducted with electrospray ionization source and detected in positive ion mode.Analyst(?)Instrument Control Processing Software Version 1.6.2 was employed to analyze total ion chromatogram and mass spectra.The statistic analysis was investigated using EpiData 3.1 entry questionnaire and statistical testing with SPSS 17.Results:The analytical method shows a satisfied linear relationship in the scope of 0.01-1.00μg/mL,with the correlation coefficients of the method greater than 0.990.In the 230 urine samples,7 kinds of pesticides including carbendazim,iprodione,chlorothalonil,thiram,fenpropathrin,lambda-cyhalothrin and chlorpyrifos were detected and 150 urine samples contained at least one pesticide residue and the positive rate was 65.2%.Among the 7 pesticides detected,iprodione was identified in 102 urine samples and the positive rate was 44.4%.No statistically significant difference was found in the positive rates of different gender and age groups.However,the positive rates of pesticide residues in the urine samples from two townships were significantly different(χ2 =7.29,P<0.05).The positive rates and the concentration of iprodione residues in the urine samples from 5 villages were also different(χ2 =10.91,χ2=11.49,P<0.05;F=3.60,P<0.01).The positive rate of pesticide residues of residents who did not use pesticides in the last month prior to the survey were lower than those who used pesticides(χ2=10.59,P<0.05);among the residents whose urine samples were detected with iprodione residues,those who did not use pesticide in the last month had lower iprodione concentration than who used pesticides(t=5.78,P<0.05).Wearing masks,rubber gloves,protective clothing and boots decreased positive rate of pesticide residues(Z=-4.969,Z=-5.359,Z=-5.180,Z=-2.783,P<0.01).The positive rate and residual concentration of iprodione were lower in those who had higher frequency of taking self-protection(χ2 =24.74,F=3.35,尸<0.05).The positive rate of pesticide residues of residents who had no experience of pesticide accidently spilled in their skin was lower than those who had spilled pesticides accidently in their skin(χ2 =6.115 P<0.05),those who immediately washed and cleared after accident pesticide skin exposure had lower positive rate of pesticide residues than those who did not clear timely(x2 ＝10.45,P<0.05).Those who were detected with pesticide residues also reported symptoms such as dizziness,headache,nausea,and itchy skin more frequently than those whose pesticide residues were negative(χ2=4.41,χ2=3.86,χ2=7.10,χ2 =6.25,P<0.05).Three pesticides including carbendazim,iprodione and chlorpyrifos were detected in soil samples with the residue concentration 0.05-0.76μg/mL.Twelve soil samples were detected with pesticide residues and the positive rate was 41.38%,of which the positive rate of farming field soil was 53.33%and the household land soil was 28.57%.Among the 3 pesticides detected,iprodione was identified in 8 samples with the detection rate of 27.58%.Two pesticides including carbendazim and fenpropathrin were detected in water samples with a residue concentration 0.04-0.89μg/mL in total.Seven water samples were detected with pesticide residues and the positive rate was 25.00%,the positive rate of irrigation water was 35.71%and the drinking water was 14.29%.Among the 2 pesticides detected,carbendazim was identified in 5 water samples with the detection rate of 17.85%.Conclusion:Pesticide residues were detected in urine,water and soil samples in this county,and all of them had iprodione residues.The positive rates of pesticide residues were high in the urine samples of local residents in this county,which provides direct evidence of internal pesticide exposure to local residents.The research provided a basis for the health risk assessment associated with occupational pesticide exposure.Wearing individual self-protection measures can effectively decrease the pesticides exposure to human body and reduce pesticides entry into the human body.Therefore,residents should be prompted to use pesticides rationaly and take self-protective measures in order to reduce the health hazards associated with pesticide exposure. |
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