Determination of 17 endocrine disruptor compounds and their spatial and seasonal distribution in the Sado River Estuary (Portugal)

Abstract

The Sado waters show signs of anthropogenic pollution. However, hardly any information exists on the levels of endocrine disrupters (EDCs) such as estrogens (17β-estradiol, estrone and 17α-ethynylestradiol) and there is no information at all on xenoestrogenic industrial pollutants (4-octylphenol, 4-nonylphenol and their mono and diethoxylates and bisphenol A). Moreover, data on plant derived phytoestrogens (formononetin, biochanin A, daidzein, genistein) and sitosterol are scarce or inexistent. To assess on the suspected influx of EDCs in this aquatic system, water samples were taken every two months, during 2010, at nine sites distributed along the Sado Estuary and River (Alcácer do Sal) being afterward analyzed by GC-MS. Data showed the ubiquitous presence of potentially hazardous amounts of estrogens (mainly of estrone and estradiol, reaching over 10 ng L−1), nonylphenol diethoxylate (up to 900 ng L−1) and nonylphenol (up to 230 ng L−1). It was concluded that there are conditions for the occurrence of endocrine disruption in local aquatic animals, even in areas included inside the Natural Reserve. Moreover, a clear seasonal pattern of fluctuation was found for phytoestrogens and sitosterol. Besides, there were high amounts of unionized ammonia (up to 0.6 mg L−1) and phosphates (up to 3.2 mg L−1) suggesting that the current status poses risks for local fauna and humans.