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简述农药残留的主要来源。

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正确答案:

1、施用农药对农作物的直接污染,这与农药的性质、剂型、浓度、施用的时间、次数、气象条件、种类、食用部位有关

2、农作物从污染的环境中吸收农药:这与施用农药的种类、植物根系情况、土壤状况有关

3、通过食物链(生物富集作用)污染食品:某些比较稳定的农药、与特殊组织器官有高度亲和力的农药、或可长期贮存于脂肪组织的农药(如有机氯、有机汞、有机锡等), .通过食物链的作用可逐级浓缩,称之为生物富集作用。

4、其他,如仓库熏蒸、对畜禽使用、食品的贮存加工或事故也可引起农药污染食品。

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