School of Life and Environmental Sciences, The University of Sydney, City, NSW 2015, Australia.
ETS Nederland BV, Frankensteeg 4, Zutphen, The Netherlands.
Int J Environ Res Public Health. 2020 Mar 3;17(5):1629. doi: 10.3390/ijerph17051629.
Our mechanistic understanding of the toxicity of chemicals that target biochemical and/or physiological pathways, such as pesticides and medical drugs is that they do so by binding to specific molecules. The nature of the latter molecules (e.g., enzymes, receptors, DNA, proteins, etc.) and the strength of the binding to such chemicals elicit a toxic effect in organisms, which magnitude depends on the doses exposed in a given timeframe. While dose and time of exposure are critical factors determining the toxicity of pesticides, different types of chemicals behave differently. Experimental evidence demonstrates that the toxicity of neonicotinoids increases with exposure time as much as with the dose, and therefore it has been described as time-cumulative toxicity. Examples for aquatic and terrestrial organisms are shown here. This pattern of toxicity, also found among carcinogenic compounds and other toxicants, has been ignored in ecotoxicology and risk assessments for a long time. The implications of the time-cumulative toxicity of neonicotinoids on non-target organisms of aquatic and terrestrial environments are far reaching. Firstly, neonicotinoids are incompatible with integrated pest management (IPM) approaches and secondly regulatory assessments for this class of compounds cannot be based solely on exposure doses but need also to take into consideration the time factor.
我们对靶向生化和/或生理途径的化学物质（如农药和药物）毒性的机制理解是，它们通过与特定分子结合来实现这一点。这些分子的性质（例如酶、受体、DNA、蛋白质等）以及与这些化学物质的结合强度会在生物体中引起毒性效应，其程度取决于在给定时间内暴露的剂量。虽然剂量和暴露时间是决定农药毒性的关键因素，但不同类型的化学物质表现不同。实验证据表明，新烟碱类杀虫剂的毒性随暴露时间的增加与剂量一样大，因此它被描述为时间累积毒性。这里显示了水生和陆地生物的例子。这种致癌化合物和其他有毒物质的毒性模式在很长一段时间内一直被忽视在生态毒理学和风险评估中。新烟碱类杀虫剂对水生和陆地环境非靶标生物的时间累积毒性的影响是深远的。首先，新烟碱类杀虫剂与综合虫害管理（IPM）方法不兼容；其次，对这类化合物的监管评估不能仅基于暴露剂量，还需要考虑时间因素。
