Occurrence, distribution and bioaccumulation of endocrine disrupting compounds in water, sediment and biota samples from a European river basin.

The occurrence, distribution and bioaccumulation of five endocrine disrupting compounds (4-tert-octylphenol, 4-n-octylphenol, 4-n-nonylphenol, nonylphenol and bisphenol A) in water, sediment and biota (Corbicula fluminea) collected along the Minho River estuary (NW Iberian Peninsula) were examined. Samples were collected in two campaigns (May and November, 2012) and analyzed by different extraction procedures followed by liquid chromatography tandem mass spectrometry determination. The presence of linear isomers (4-n-octylphenol and 4-n-nonylphenol) was scarcely observed whereas branched isomers (4-tert-octylphenol and nonylphenol) were measured in almost all samples. Wastewater treatment plant effluents and nautical, fishing and agricultural activities are considered the primary source of pollution of the river by alkylphenols. The presence of bisphenol A in the river could be mainly associated to punctual sources of contamination from industrial discharges. A decrease in the total concentration of phenolic compounds in water was observed from spring to autumn (from 0.888 μg L(-1) in May to 0.05 μg L(-1) in November), while similar values were shown in C. fluminea samples from the two campaigns (1388 and 1228 ng g(-1) dw in spring and autumn, respectively). In sediments, the total concentration of the target compounds varied between 13 and 4536 ng g(-1) dw (average of 1041 ng g(-1) dw). Sediment-water partition coefficient (Kd), bioaccumulation factor (BAF) and biota-sediment accumulation factor (BSAF) were estimated and highest values were obtained for nonylphenol. Calculated risk quotients showed low and moderate risk for the aquatic environment from the presence of the target compounds at all sampling points. The estimation of the daily intake of the studied compounds via water and biota ingestion indicated no risk for human health.