Cirad, UPR HortSys, F-97285 Le Lamentin, Martinique, France.
BRGM Martinique, F-97200 Fort-de-France, Martinique, France.
Sci Total Environ. 2017 Jan 1;574:1232-1242. doi: 10.1016/j.scitotenv.2016.07.065. Epub 2016 Sep 30.
Persistent organic pollutants like organochlorine pesticides continue to contaminate large areas worldwide raising questions concerning their management. We designed and tested a method to link soil and water pollution in the watershed of the Galion River in Martinique. We first estimated the risk of soil contamination by chlordecone by referring to past use of land for banana cultivation and took 27 soil samples. We then sampled surface waters at 39 points and groundwater at 16 points. We tested three hypotheses linked to the source of chlordecone pollution at the watershed scale: (i) soils close to the river, (ii) soils close to the sampling point, (iii) throughout the sub-watershed generated at the sampling point. Graphical and statistical analysis showed that contamination of the river increased when it passed through an area with contaminated plots and decreased when it passed through area not contaminated by chlordecone. Modeling showed that the entire surface area of the watershed contributed to river pollution, suggesting that the river was mainly being contaminated by the aquifers and groundwater flows. Our method proved to be a reliable way to identify areas polluted by chlordecone at the watershed scale and should help stakeholders focus their management actions on both hot spots and the whole watershed.
持久性有机污染物，如有机氯农药，继续在全球范围内大面积污染，这引起了人们对其管理的关注。我们设计并测试了一种方法，以联系马提尼克岛加里昂河流域的土壤和水污染。我们首先通过参考过去香蕉种植用地来估计土壤中氯丹的污染风险，并采集了 27 个土壤样本。然后，我们在 39 个点采样地表水，在 16 个点采样地下水。我们在流域尺度上测试了与氯丹污染来源有关的三个假设：（i）靠近河流的土壤，（ii）靠近采样点的土壤，（iii）在采样点生成的整个次流域。图形和统计分析表明，当河流流经受污染的农田区域时，河水的污染程度会增加，而当河流流经未受氯丹污染的区域时，河水的污染程度会降低。模型表明，流域的整个地表面积都对河水污染有贡献，这表明河水主要受到含水层和地下水流动的污染。我们的方法被证明是一种在流域尺度上识别氯丹污染区域的可靠方法，应该有助于利益相关者将管理行动集中在热点地区和整个流域上。
