Presence of estrogenic endocrine disruptors in three European estuaries in Northwest Iberian Peninsula (Portugal)

Abstract

Estrone, 17β-estradiol, 17α-ethynylestradiol, alkylphenols and alkylphenol ethoxylates, are endocrine disruptor compounds. In Portugal, the report of male fish feminization in Minho, Ave and Mondego River estuaries made pertinent their evaluation in surface water samples. Data, got by specific enzyme-linked immunosorbent assays, showed that estrogens concentrations were lower in Minho than in Ave or Mondego estuaries: [Estrone] > [17β-estradiol] > [17α-ethynylestradiol] (p < 0.05). Converting estrogen concentrations in 17α-ethynylestradiol equivalents, the contribution of estrogens was 1.3 ng/L, 3.5 ng/L, and 2.4 ng/L, respectively, for Minho, Ave, and Mondego estuaries stressing out a high risk for local aquatic species. The concentrations of alkylphenols and alkylphenol ethoxylates were lower at both Minho and Mondego estuaries ≈600 ng/L and 2700 ng/L, respectively than at the Ave, ≈1070 ng/L and 4855 ng/L (p < 0.05). In conclusion, this study reports the first systematic data about the presence of the targeted endocrine disruptor compounds in the Minho River estuary and, in parallel, provides new information about their concentrations in two other habitats previously monitored. This study also shows that in Ave and Mondego estuaries the concentrations of industrial estrogens were still excessive, whereas the load of the pure estrogens has decreased significantly facing previous surveys.