摘要
摘要:为探究杀虫剂联苯菊酯、溴氰菊酯和虫螨腈的常用剂量和减施剂量对绿茶品种‘丰绿’（Camellia sinensis Yutakmitor）的鲜叶和茶园土壤及降雨径流的影响以及可能产生的膳食摄入风险，选择联苯菊酯、溴氰菊酯和虫螨腈的当地常用剂量和减量30%剂量作为处理组，在浙江绍兴富盛镇御茶村茶园进行田间试验，喷药后1 d、3 d、7 d、10 d分别采集试验小区的鲜叶和土壤，喷药后4 d、8 d采集降雨径流，检测样品中的杀虫剂残留并评估3种杀虫剂的膳食暴露风险。试验结果表明：同种杀虫剂常用剂量处理的茶鲜叶中残留虽然高于减施剂量处理，但二者差异不显著，杀虫剂减量30%对减少鲜叶中的残留并无明显效果。经过常用剂量与减施剂量处理的茶鲜叶中联苯菊酯的半衰期分别为5.89 d和4.61 d，溴氰菊酯的半衰期分别为5.75 d和2.55 d，虫螨腈的半衰期分别为3.72 d和2.70 d。3种杀虫剂在土壤中的残留均低于《土壤环境质量标准（GB 15618-1995）》中有机氯杀虫剂六六六的一级标准值（≤ 0.05 mg·kg^-1）。联苯菊酯和虫螨腈在降雨径流中的残留均低于《生活饮用水卫生标准（GB5749-2006）》中有机氯杀虫剂六六六的限值（0.005 mg·L^-1），溴氰菊酯在降雨径流中的残留低于《生活饮用水卫生标准（GB5749-2006）》中溴氰菊酯的限值（≤ 0.02 mg·L^-1）。3种杀虫剂在茶叶中的膳食暴露风险评估结果表明，联苯菊酯、溴氰菊酯和虫螨腈的最大暴露量分别为0.5×10^-4~1.7×10^-4 mg·kg^-1（bw）·d^-1、1.0×10^-6~7.3×10^-6 mg·kg^-1（bw）·d^-1、1.0×10^-5~8.3×10^-5 mg·kg^-1（bw）·d^-1，风险商分别为0.005~0.017、0.000 2~0.001和0.000 2~0.003，使用联苯菊酯、溴氰菊酯和虫螨腈防治茶树虫害，对消费者的膳食暴露的风险均可以接受。与常用剂量相比，减施剂量处理对减少茶叶和环境中的杀虫剂残留的效果不明显。
关键词:杀虫剂残留/
茶/
土壤/
降雨径流/
杀虫剂减量使用
Abstract:Insecticide residues in tea have attracted much attention, and the means to reduce the level of residues in tea and the surrounding environment is a serious issue. Reducing the usage or dose of insecticide may be a viable option to address this problem. We analyzed the possible dietary intake risks and the effects of regular dose versus reduced dose of bifenthrin, deltamethrin, and chlorfenapyr on their residues in fresh tea leaves, soil, and rainwater runoff in tea plantations of the green tea variety 'Fenglv' (Camellia sinensis Yutakmitor). Field trials using bifenthrin, deltamethrin, and chlorfenapyr were conducted in the tea plantations of Yucha Village, Shaoxing City, Zhejiang Province in China. The local regular dose and 30% dose reduction of bifenthrin, deltamethrin, and chlorfenapyr were considered as the experimental treatments group, which included dosages of bifenthrin at 150 mL·hm^-2 and 105 mL·hm^-2, deltamethrin at 750 mL·hm^-2 and 525 mL·hm^-2, and chlorfenapyr at 750 mL·hm^-2 and 525 mL·hm^-2, respectively. Samples of tea leaves and soil were collected on the 1^st, 3^rd, 7^th, and 10^th day after spraying, and rainwater runoff was similarly collected on the 4^th and 8^th day after spraying. The data related to insecticide residues in all the collected samples were used to evaluate the behavioral pattern of residue and risk assessment of the three insecticides. The results indicated that no significantly different residues present in fresh tea leaves was observed sprayed with regular dosage and 30%-reduced dose. The half-lives of bifenthrin in fresh tea leaves sprayed with regular dosage and reduced dosage were 5.89 d and 4.61 d, respectively, and the half-lives of deltamethrin with regular dosage and reduced dosage were 5.75 d and 2.55 d, respectively; and those of chlorfenapyr with regular dosage and reduced dosage were 3.72 d and 2.70 d, respectively. The residue levels of bifenthrin, deltamethrin, and chlorfenapyr in soil were lower than the primary standard value (≤ 0.05 mg·kg^-1) of organochlorine insecticide, hexachlorocyclohexane, as stated in Environmental Quality Standard for Soils (GB15618-1995). The residue levels of bifenthrin and chlorfenapyr in rainwater runoff were lower than the value (≤ 0.005 mg·L^-1) of organochlorine insecticide hexachlorocyclohexane as stated in Standards for Drinking Water Quality (GB5749-2006). The residue levels of deltamethrin in rainwater runoff were lower than the value (≤ 0.02 mg·L^-1) of deltamethrin as stated in Standards for Drinking Water Quality (GB5749-2006). Dietary exposure risk assessment referred to the risk assessment of exposure to insecticides and other harmful substances ingested through food. The results related to the assessment of risk of dietary exposure to the three insecticides in tea indicated that the maximum exposures of bifenthrin, deltamethrin and chlorfenapyr were 0.5×10^-4-1.7×10^-4, 1.0×10^-6-7.3×10^-6, 1.0×10^-5-8.3×10^-5 mg·kg^-1(bw)·d^-1. Risk quotient was expressed as the ratio of maximum exposure to acceptable daily intake. The risk quotients of bifenthrin, deltamethrin and carbonitrile were 0.005-0.017, 0.000 2-0.001, 0.000 2-0.003, respectively, which meant the risk to consumers was within an acceptable range. Reducing sprayed dosages of the above three insecticides in the tea plantations made no significant differences to the residues in tea and the environment.
Key words:Insecticide residues/
Tea/
Soil/
Rainfall-runoff/
Insecticide reduction



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