Intégration de pics de contamination de durée et d’intensité variables par le « Polar Organic Chemical Integrative Sampler »

Abstract

International audienceContamination level estimate can vary abruptly, depending on season and hydrology of the river at the sampling moment. The Polar Organic Chemical Integrative Sampler (POCIS) may integrate contamination peaks of about 3 days for moderately polar compounds (log Kow = 2-3) [3]. Concerning shorter contamination peaks (less than 1 hour) generated by punctual pollutions or a brutal intake of pesticides in a river (soil leaching, for example), interrogations about its reactivity (e.g. lag time) is still remaining. In this context, a laboratory calibration was made for three different contamination peak patterns, with variable intensity and duration. This experiment was led over a total exposure time of 14 days, and with a selection of 15 pesticides which covering different polarities (log Kow = 0.6-4.7) and classes (herbicides, fungicides, insecticides). Finally, the data showed different accumulation kinetic profiles, with phenomena like burst effect or lag effect, depending on physical-chemical properties of the substances and the exposition duration