ABSTRACT Monitoring of water quality over several years has revealed a persistent pesticide contamination of surface and groundwater in several Caribbean Islands, with pesticide concentrations locally over the drinking-water limit set in Europe, i.e. 0.1 µg L–1 per substance. For Martinique, mainly one pesticide, chlordecone (CLD), remains of major concern despite its withdrawal from the market in 1993. Since the first sampling campaign in 1999–2000, time and space variations of CLD concentrations in surface water and groundwater are still not well understood and difficult to correlate with climate, geological or hydrogeological contexts. We carried out a study in the Chalvet catchment (northeast Martinique) in order to understand more precisely how water movements may explain pesticide transfer. Various tools such as δ2H - δ18O and chemical parameters were used. Deuterium excess d was proven relevant for determining how CLD is transported in groundwater; it highlighted the role of the groundwater/surface water interaction in spatial and temporal variability of surface water quality. The resulting conceptual hydrogeological model also helps understanding why CLD still has high concentrations in surface water. The approach proposed here can be used in other Caribbean islands that are poorly equipped for explaining pesticide occurrences in surface waters.

中文翻译：

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用于了解马提尼克岛火山岛（法属西印度群岛）分水岭中农药转移的水同位素和化学工具

摘要 几年来对水质的监测表明，在几个加勒比群岛的地表水和地下水中，农药持续受到农药污染，当地农药浓度超过了欧洲规定的饮用水限值，即每种物质 0.1 µg L–1。对于马提尼克岛，主要是一种农药，十氯酮 (CLD)，尽管它于 1993 年退出市场，但仍然是主要关注点。自 1999-2000 年的第一次采样活动以来，地表水和地下水中 CLD 浓度的时间和空间变化仍然没有易于理解且难以与气候、地质或水文地质背景相关联。我们在 Chalvet 集水区（马提尼克岛东北部）进行了一项研究，以更准确地了解水流如何解释农药转移。使用了各种工具，例如 δ2H - δ18O 和化学参数。氘过量 d 被证明与确定 CLD 如何在地下水中运输有关；它强调了地下水/地表水相互作用在地表水质量时空变化中的作用。由此产生的概念性水文地质模型也有助于理解为什么 CLD 在地表水中仍然具有高浓度。这里提出的方法可用于其他加勒比岛屿，这些岛屿在解释地表水中农药发生方面的装备很差。由此产生的概念性水文地质模型也有助于理解为什么 CLD 在地表水中仍然具有高浓度。这里提出的方法可用于其他加勒比岛屿，这些岛屿在解释地表水中农药发生方面的装备很差。由此产生的概念性水文地质模型也有助于理解为什么 CLD 在地表水中仍然具有高浓度。这里提出的方法可用于其他加勒比岛屿，这些岛屿在解释地表水中农药发生方面的装备很差。