Is passive sampling suitable for monitoring the contamination of surface waters? Results for French rivers influenced by various anthropic pressures
Applicabilité de l'échantillonnage passif pour la surveillance de la contamination des eaux de surface : résultats pour 6 rivières impactées par les activités anthropiques en France
Résumé
The Water Framework Directive requires monitoring of the quality of surface waters. Passive sampling has shown high benefits to assess water contamination compared to conventional grab sampling. The aim of our study was to assess the contamination pattern of 6 French rivers influenced by agriculture, former-mining, urban and industrial activities. We report the results of a one month in situ exposition of passive samplers: DGT, POCIS and passive SBSE, designed to target 6 trace metals, 30 pharmaceutical drugs and 26 pesticides. Contamination patterns were obtained for each watershed including both the number of quantified pollutants and their levels of concentrations. Maximum concentrations of trace metals were measured for the former-mining watershed, with a maximum value of 62.7 μg L-1 for Zn. For organic pollutants, 31 substances were quantified at least once. Carbamazepine showed maximum concentrations in 3 rivers; the maximum value reached 425 ng L-1 in the most urbanised watershed. For herbicides, chlortoluron concentration reached 178 ng L-1 in the most agricultural watershed. As a result, the combination of these 3 passive sampling techniques allowed us assessing the anthropic chemical pressures onto surface waters and provided reliable information on the concentration of urban tracers mainly measured at ultra-trace levels.