ICPR – International Commission for the Protection of the Rhine

186. Evaluation report estrogens

Strategy aimed at reducing inputs of micro-pollutants
Within the strategy aimed at reducing inputs of micro-pollutants originating from urban and industrial waste water, evaluation reports are being drafted for 10 groups of substances and are aimed at summarizing scientific and technical facts and at pointing out gaps of knowledge. Also, the evaluation reports present a variety of possible measures at the source (e.g. registration of substances, limitation of uses) to technical measures in crucial wastewater treatment plants (e.g. introduce a further treatment stage). The “Conclusions” of the evaluation reports list the most efficient measures to be further investigated into within a holistic ICPR strategy.  However, these measures are no recommendations the ICPR addresses to its member states. Measures listed in this chapter will be introduced into a survey report of all measures in order to be able to take into account eventual effects of measures on different groups of substances when proceeding with a final evaluation. Based on the final evaluation of all measures the ICPR will determine recommendations of measures for the Member States.

Evaluation report estrogens
A characteristic feature of estrogens (female hormones) is that they may lead to behavioural changes and even congenital abnormalities, sex change and infertility of organisms (endocrine effects) in surface water bodies.

Concerning the estrogens investigated, few monitoring data are available for the Rhine, but more for regional waters. The concentrations measured are very low in large water bodies and higher in tributaries. The estrogen contents in tributaries rise proportionally with the share of municipal wastewater. Toxicity for artificial and natural hormones is low, but a potential danger for fish cannot be excluded. Endocrine effects may result from concentrations a million times below concentrations leading to toxic effects. Near outlets from wastewater treatment plants estrogen concentrations may be so high, that a feminization of fish may be observed.

While municipal wastewater treatment plants constitute the most important input pathway of the analysed artificial hormones, natural hormones mostly reach the water bodies due to applying semi-liquid manure to agricultural surfaces.