School of Geography, Earth and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK.
School of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK.
Sci Total Environ. 2016 Feb 1;543(Pt A):37-43. doi: 10.1016/j.scitotenv.2015.11.040. Epub 2015 Nov 12.
Metaldehyde is a widely used molluscicide in countries where damage to crops from slugs and snails is a major problem associated with warm and wet winters. In the UK it is estimated that over 8% of the area covered by arable crops is treated with formulated granular bait pellets containing metaldehyde as the main active ingredient. Metaldehyde is hydrophilic (log Kow=0.12), water soluble (200 mg·L(-1) at 17 °C) and has been detected in UK surface waters in the concentration range of typically 0.2-0.6 μg·L(-1) (maximum 2.7 μg·L(-1)) during 2008-2011. In the absence of chronic data on potential hazards to non-target freshwater molluscs, a laboratory study was conducted to investigate the impact of metaldehyde on embryo development in the gastropod Lymnaea stagnalis (RENILYS strain) and using zinc as a positive control. L. stagnalis embryos were exposed to metaldehyde under semi-static conditions at 20±1 °C and hatching success and growth (measured as shell height and intraocular distance) examined after 21 d. Exposure concentrations were verified using HPLC and gave 21 d (hatching)NOEC and (hatching)LOEC mean measured values of 36 and 116 mg MET·L(-1), respectively (equal to the 21 d (shell height)NOEC and (shell height)LOEC values). For basic research purposes, a second group of L. stagnalis embryos was co-exposed to metaldehyde and the pesticide synergist piperonyl butoxide (PBO). Co-exposure to the PBO (measured concentrations between 0.47-0.56 mg·L(-1)) reduced hatching success from 100% to 47% and resulted in a 30% reduction in embryo growth (shell height) in snail embryos co-exposed to metaldehyde at 34-36 mg·L(-1) over 21 d. In conclusion, these data suggest mollusc embryos may have some metabolic detoxication capacity for metaldehyde and further work is warranted to explore this aspect in order to support the recent initiative to include molluscs in the OECD test guideline programme.
聚乙醛是一种在温暖潮湿的冬季，因鼻涕虫和蜗牛对农作物造成损害而导致问题严重的国家广泛使用的杀螺剂。在英国，据估计，有超过 8%的耕地作物采用含有聚乙醛作为主要活性成分的颗粒状诱饵进行处理。聚乙醛亲水性强（log Kow=0.12），水溶性高（17°C 时为 200mg·L(-1)），并且在 2008 年至 2011 年期间，在英国地表水的浓度范围通常为 0.2-0.6μg·L(-1)（最高 2.7μg·L(-1)）。在缺乏有关非目标淡水软体动物潜在危害的慢性数据的情况下，进行了一项实验室研究，以调查聚乙醛对圆田螺（RENILYS 品系）胚胎发育的影响，并使用锌作为阳性对照。在 20±1°C 的半静态条件下，圆田螺胚胎暴露于聚乙醛下，21 天后检查孵化成功率和生长（用壳高和眼内距离衡量）。使用 HPLC 验证暴露浓度，得出 21 天（孵化）NOEC 和（孵化）LOEC 的平均实测值分别为 36 和 116mg MET·L(-1)，分别相当于 21 天（壳高）NOEC 和（壳高）LOEC 值。出于基础研究目的，第二组圆田螺胚胎与聚乙醛和杀虫剂增效剂胡椒基丁醚（PBO）共同暴露。PBO（实测浓度在 0.47-0.56mg·L(-1)）的共同暴露将孵化成功率从 100%降低到 47%，并导致暴露于 34-36mg·L(-1)聚乙醛的蜗牛胚胎的胚胎生长（壳高）降低 30%，在 21 天内。总之，这些数据表明，软体动物胚胎可能对聚乙醛具有一定的代谢解毒能力，需要进一步研究以探索这一方面，以支持最近将软体动物纳入经合组织测试指南计划的倡议。
