Pure and Applied Chemistry

Like hardly any other issue in ecotoxicology, endocrine disruption has given rise to public concern. Reproductive, behavioral, and immunological effects in wildlife were publicly not only understood as possible threats to wildlife populations, but also as early warning signals that human health could be at risk. Above all, the public has been concerned about negative outcomes in reproductive health, and effects like feminization in fish were regarded as evidence for the biological plausibility of the hypothesis that environmental levels of hormonally active chemicals are high enough to affect human reproductive health.

Public concern has been mirrored by several parliamentary and governmental decisions emphasizing the need for extensive research and rapid measures to reduce the risk associated with endocrine-disrupting substances.

Endocrine disruption in wildlife is clearly a priority issue. At least in densely populated areas like Europe, symptoms of endocrine disruption in wildlife cannot only be detected in areas with abnormally high levels of pollution, but have also occurred in main river systems, estuaries, and even in the open sea. Imposex in mollusks and feminization in fish that were clearly related to disturbances in the hormonal system of these organisms by exogenous substances have been used as markers in monitoring programs. Though symptoms of endocrine disruption can be clearly identified, it is much more difficult to link these outcomes to causative chemicals or mixtures of substances. Natural and pharmaceutical hormones, phytoestrogens, pesticides, and industrial chemicals may all play a role to a different degree depending on the site under study. This means that several different risk-reduction strategies have to be applied, including bans of substances, use restrictions, and installation and optimization of sewage treatment works embedded in a strategy for the overall reduction of chemical input into the environment.

It should be noted that, in addition to national and international regulatory actions taken by state authorities, a considerable reduction of the environmental input could be achieved in several countries by voluntary actions taken by industry.

Regulatory bodies are still facing major problems in the field of risk assessment and risk reduction. Association between effects and causative agents or mixtures are in many cases weak. Important tools for risk assessment such as dose-response relationships or the existence of thresholds are not yet agreed on. These uncertainties are the reason that many national governments and the European Commission have identified precaution as the main element in chemicals policy for the management of endocrine disruptors.

This paper is based on documents of the German Federal Environmental Agency, but solely represents the view of the author from a regulatory perspective and emphasizes the wildlife aspects of endocrine disruption.