Contamination of ecosystems by pesticides, pharmaceuticals and trace metals becomes a major environmental problem. Freshwater algae are well known bio-indicators of river pollution but diatom indices do not allow to evaluate the specific effects of the contaminants. Their sensitivity to pesticides differ markedly among microalgae species and therefore the toxicity data for multiple species need to be efficiently obtained. In the present work, we measured the growth of the three lotic dominant species Desmodesmus subspicatus, Nitzschia palea and Navicula pelliculosa by an automated fluorometric microplate assay to evaluate the groundwater and river quality in four riparian wetlands in the south-west of Europe(Monbéqui (France), Saragossa (Spain), Bidasoa (Spain) and Toledo (Spain)). Four campaigns of water sampling were realized during contrasted hydrological conditions under different pedo-climatic conditions in agricultural area. Pesticides, pharmaceuticalsand metals concentration were measured by HPLC-MS or ICP-MS. PCA, ANOVA and co-inertia analysis results showed that algal growth was different between freshwater and groundwater. As expected, the green alga was sensitive to alkalinity, SO4, O2and pH whereas diatoms were positively sensitive to silica concentration and dissolved organic carbon (DOC). Besides, the green alga responded positively to the metals Co and Ni and negatively to S-triazines, terbutylazine and their metabolites. At last, the pharmaceuticals benzoylecgonine and carbamazepine/irbesartan/valsartan induced growth stimulation of N. paleaand N. pelliculosa, respectively. Same records for pharmaceuticals were observed for the other three sites, excepted Bidasoa. Both extensive sampling and data analysis makes our approach a new useful bio-indicator for preliminary investigation of groundwater quality in order to predict the best location of quality water for human consumption (ATTENAGUA project)

Society of Environmental Toxicology and Chemistry (SETAC Europe) 28th Annual Meeting, Responsible and Innovative Research for Environmental Quality, 13−17 May 2018, Rome, Italy.-- 1 page

Peer Reviewed