Water pollution threats in important bird and biodiversity areas from Spain.

Chemical pollution is still an underestimated threat to surface waters from natural areas. This study has analysed the presence and distribution of 59 organic micropollutants (OMPs) including pharmaceuticals, lifestyle compounds, pesticides, organophosphate esters (OPEs), benzophenone and perfluoroalkyl substances (PFASs) in 411 water samples from 140 Important Bird and Biodiversity Areas (IBAs) from Spain, to evaluate the impact of these pollutants in sites of environmental relevance. Lifestyle compounds, pharmaceuticals and OPEs were the most ubiquitous chemical families, while pesticides and PFASs showed a detection frequency below 25% of the samples. The mean concentrations detected ranged from 0.1 to 301 ng/L. According to spatial data, agricultural surface has been identified as the most important source of all OMPs in natural areas. Lifestyle compounds and PFASs have been related to the presence of artificial surface and wastewater treatment plants (WWTPs) discharges, which were also an important source of pharmaceuticals to surface waters. Fifteen out of 59 OMPs have been found at levels posing a high risk for the aquatic IBAs ecosystems, being the insecticide chlorpyrifos, the antidepressant venlafaxine and perfluorooctanesulfonic acid (PFOS) the most concerning compounds. This is the first study to quantify water pollution in IBAs and evidence that OMPs are an emerging threat to freshwater ecosystems that are essential for biodiversity conservation.