Does Waterborne Exposure Explain Effects Caused by Neonicotinoid-Contaminated Plant Material in Aquatic Systems?
Does Waterborne Exposure Explain Effects Caused by Neonicotinoid-Contaminated Plant Material in Aquatic Systems?
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DOI：
10.1021/acs.est.7b00827
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发表时间：
2017-05-16
影响因子：
11.4
通讯作者：
Bundschuh, Mirco
中科院分区：
文献类型：
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作者：
Englert, Dominic;Zubrod, Jochen P.;Bundschuh, Mirco
新烟碱类杀虫剂作为一种防治害虫的措施，在树木上的应用越来越广泛。因此，新烟碱不可避免地通过喷雾漂移或地表径流或（由于新烟碱的系统性）通过衰老的叶子转移到水生环境中。在那里，特别是撕碎叶子的无脊椎动物可能通过水阶段和食用受污染的叶子而暴露于新烟碱。在为期7天的生物试验中（n = 30），我们以摄食率为反应变量，研究了两种暴露情景对片足类动物和昆虫若虫的生态毒理学差异。生物体要么只接触水性新烟碱（即吡虫啉、噻虫啉和啶虫啉），要么通过食用受污染的叶子和从叶子中滤出的新烟碱进入水中而同时接触（水性和食源性）。片足类昆虫（7 d EC(50)s为0.3 ~ 8.4 μ g/L）比昆虫若虫（7 d EC(50)s为7.0 ~ 19.4 μ g/L）更敏感。此外，对于这两个物种，由水浓度得出的浓度响应模型表明，在联合暴露下，影响更大。结合观察到的碎纸机无法避免被新烟碱污染的叶子，我们的研究结果强调了饮食暴露（例如通过叶子）与系统性杀虫剂的相关性。因此，为了保护生态系统的完整性，在系统性杀虫剂登记期间考虑饮食暴露是谨慎的。
Neonicotinoids are increasingly applied on trees as protection measure against insect pests. Consequently, neonicotinoids are inevitably transferred into aquatic environments either via spray drift or surface runoff or (due to neonicotinoids' systemic nature) via senescent leaves. There particularly leaf-shredding invertebrates may be exposed to neonicotinoids through both the water phase and the consumption of contaminated leaves. In 7 day bioassays (n = 30), we examined ecotoxicological differences between these two exposure scenarios for an amphipod and an insect nymph with their feeding rate as the response variable. Organisms either experienced waterborne neonicotinoid (i.e., imidacloprid, thiacloprid, and acetamiprid) exposure only or a combined exposure (waterborne and dietary) through both the consumption of contaminated leaves and neonicotinoids leaching from leaves into water. The amphipod (7 day EC(50)s from 0.3 to 8.4/mu g/L) was more sensitive than the insect nymph (7 day EC(50)s from 7.0 to 19.4 mu g/L ). Moreover, for both species, concentration response models derived from water concentrations indicated higher effects under the combined exposure. Together with the observed inability of shredders to avoid neonicotinoid-contaminated leaves, our results emphasize the relevance of dietary exposure (e.g., via leaves) for systemic insecticides. Thus, it would be prudent to consider dietary exposure during the registration of systemic insecticides to safeguard ecosystem integrity.