Laboratory of Evolutionary Stress Ecology and Ecotoxicology, University of Leuven, Belgium.
Laboratory of Evolutionary Stress Ecology and Ecotoxicology, University of Leuven, Belgium; Institute of Aquaculture, Nha Trang University, Khanh Hoa, Viet Nam.
Sci Total Environ. 2019 Nov 10;690:1237-1244. doi: 10.1016/j.scitotenv.2019.07.030. Epub 2019 Jul 8.
To improve risk assessment there is increasing attention for the effect of climate change on the sensitivity to contaminants and vice versa. Two important and connected topics have been largely ignored in this context: (i) the increase of daily temperature variation (DTV) as a key component of climate change, and (ii) differences in sensitivity to climate change and contaminants between developmental stages. We therefore investigated whether DTV magnified the negative effects of the organophosphate insecticide chlorpyrifos on mortality and heat tolerance and whether this effect was stronger in aquatic larvae than in terrestrial adults of the mosquito Culex pipiens. Exposure to chlorpyrifos at a constant temperature imposed mortality and reduced the heat tolerance in both larvae and adult males, but not in adult females. This provides the first evidence that the TICS ("toxicant-induced climate change sensitivity") concept can be sex-specific. DTV had no direct negative effects. Yet, consistent with the CITS ("climate-induced toxicant sensitivity") concept, DTV magnified the toxicity of the pesticide in terms of larval mortality. This was not the case in the adult stage indicating the CITS concept to be dependent on the developmental stage. Notably, chlorpyrifos reduced the heat tolerance of adult females only in the presence of DTV, thereby providing support for the reciprocal effects between DTV and contaminants, hence the coupling of the TICS and CITS concepts. Taken together, our results highlight the importance of integrating DTV and the developmental stage to improve risk assessment of contaminants under climate change.
为了改善风险评估，人们越来越关注气候变化对污染物敏感性的影响，反之亦然。在这方面，有两个重要且相互关联的主题在很大程度上被忽视了：（i）日温度变化（DTV）作为气候变化的一个关键组成部分的增加，以及（ii）不同发育阶段对气候变化和污染物敏感性的差异。因此，我们研究了 DTV 是否放大了有机磷杀虫剂毒死蜱对死亡率和耐热性的负面影响，以及这种效应在水生幼虫和蚊子 Culex pipiens 的陆地成蚊之间是否更强。在恒温下暴露于毒死蜱会导致死亡率增加，并降低幼虫和雄性成蚊的耐热性，但对雌性成蚊没有影响。这首次提供了证据，表明 TICS（“有毒物质诱导的气候变化敏感性”）概念可以是性别特异性的。DTV 本身没有直接的负面影响。然而，与 CITS（“气候诱导的有毒物质敏感性”）概念一致，DTV 放大了杀虫剂对幼虫死亡率的毒性。在成虫阶段则并非如此，这表明 CITS 概念取决于发育阶段。值得注意的是，只有在存在 DTV 的情况下，毒死蜱才会降低雌性成蚊的耐热性，从而为 DTV 和污染物之间的相互作用提供了支持，因此 TICS 和 CITS 概念是相互关联的。综上所述，我们的研究结果强调了在气候变化下，为了改善污染物风险评估，需要整合 DTV 和发育阶段。
