Leistra Minze, Zweers Anton J, Warinton Jacqui S, Crum Steven J H, Hand Laurence H, Beltman Wim H J, Maund Stephen J
Alterra Green World Research, Wageningen University and Research Centre, PO Box 47, 6700 AA Wageningen, The Netherlands.
Pest Manag Sci. 2004 Jan;60(1):75-84. doi: 10.1002/ps.780.
Use of the insecticide lambda-cyhalothrin in agriculture may result in the contamination of water bodies, for example by spray drift. Therefore, the possible exposure of aquatic organisms to this insecticide needs to be evaluated. The exposure of the organisms may be reduced by the strong sorption of the insecticide to organic materials and its susceptibility to hydrolysis at the high pH values in the natural range. In experiments done in May and August, formulated lambda-cyhalothrin was mixed with the water body of enclosures in experimental ditches containing a bottom layer and macrophytes (at different densities) or phytoplankton. Concentrations of lambda-cyhalothrin in the water body and in the sediment layer, and contents in the plant compartment, were measured by gas-liquid chromatography at various times up to 1 week after application. Various water quality parameters were also measured. Concentrations of lambda-cyhalothrin decreased rapidly in the water column: 1 day after application, 24-40% of the dose remained in the water, and by 3 days it had declined to 1.8-6.5%. At the highest plant density, lambda-cyhalothrin residue in the plant compartment reached a maximum of 50% of the dose after 1 day; at intermediate and low plant densities, this maximum was only 3-11% of the dose (after 1-2 days). The percentage of the insecticide in the ditch sediment was 12% or less of the dose and tended to be lower at higher plant densities. Alkaline hydrolysis in the water near the surface of macrophytes and phytoplankton is considered to be the main dissipation process for lambda-cyhalothrin.
农业中使用氯氟氰菊酯这种杀虫剂可能会导致水体污染，例如通过喷雾漂移。因此，需要评估水生生物接触这种杀虫剂的可能性。由于该杀虫剂对有机材料有强烈吸附作用，且在自然范围内的高pH值条件下易水解，水生生物接触该杀虫剂的可能性可能会降低。在五月和八月进行的实验中，将配制好的氯氟氰菊酯与装有底层以及大型植物（密度不同）或浮游植物的实验沟渠围隔水体混合。在施用后长达1周的不同时间，通过气液色谱法测量水体和沉积层中氯氟氰菊酯的浓度以及植物部分中的含量。还测量了各种水质参数。氯氟氰菊酯在水柱中的浓度迅速下降：施用后1天，24 - 40%的剂量残留在水中，到3天时已降至1.8 - 6.5%。在最高植物密度下，施用1天后植物部分中的氯氟氰菊酯残留量最高达到剂量的50%；在中等和低植物密度下，这一最高值仅为剂量的3 - 11%（1 - 2天后）。沟渠沉积物中杀虫剂的百分比为剂量的12%或更低，且在较高植物密度下往往更低。大型植物和浮游植物表面附近水体中的碱性水解被认为是氯氟氰菊酯的主要消散过程。
