Estrogenic compounds in surface waters: fish populations at risk?
In the last few years a National Study of Estrogenic Compounds was performed, as initiated by the Dutch Government. IBED researchers played a major role in this project, the results of which were recently published in a book co-edited by IBED environmental chemist Dr. Pim de Voogt.
In 1999 the Health Council of The Netherlands concluded that high priority should be given to a scientific study of the presence of endocrine disrupting substances and their effects in surface waters. As a result, the Dutch Government decided to launch the National Study of Estrogenic compounds (‘Landelijk Onderzoek Oestrogene Stoffen’ or LOES), which was completed in the period 1999-2002.
The Institute for Biodiversity and Ecosystem Dynamics (IBED) of the UvA played a major role in the Loes project. The study lead to the recent publication of a book entitled “Estrogens and Xenoestrogens in the Aquatic Environment”, edited by Dr. Dick Vethaak and Dr. Marca Schrap of the Dutch Ministry of Transport, Public Works and Water Management, together with Dr. Pim de Voogt of IBED.
The conclusions as published in the book are that exposure to endocrine disruptors as well as biological effects ascribable to such exposure are indeed observed in Dutch surface waters, especially in regional water bodies receiving effluents of wastewater treatment plants. Biological effects that have been observed include intersexuality in fish (the presence of female cells in male tissue) and shifting male-female ratios in fish. Whether such effects impact the preservation of fish populations is still unknown. So far no clear population decline in the fish under study (bream and flounder) has been observed.
In addition to observations from The Netherlands, the book reports results of similar studies in The United Kingdom, Germany and Canada as well as the European Union as a whole.