Endocrine Disrupting Chemicals (EDCs)-A Menace of Industrial Revolution

Endocrine Disrupting Chemicals (EDCs) are exogenous substances or mixtures that interfere with the function(s) of the endocrine system and consequently cause adverse health effects in an intact organism or its progeny or (sub) populations. Several field and laboratory studies have shown that exposure to certain EDCs has contributed to adverse effects in some wildlife species and populations. These effects vary from subtle changes in the physiology and sexual behaviour of species to permanently altered sexual differentiation. Most of the data comes from Europe and North America. Aquatic species at the top of the food chain are most affected, but effects have also been observed in terrestrial species. Some adverse effects observed in certain species are likely to be endocrine mediated, but in most cases, the causal link between exposure and endocrine disruption is unclear. To date, essentially all researches on EDCs have been driven by effects (or purported effects), many of which have caused public concern and made sensationalist stories in the media. Thus, for example, the possible decrease in sperm counts was very influential in highlighting the human issues, while intersex fish helped to highlight the wildlife aspects of the EDC issue. This is an extremely slow (and costly) way of scientific investigation. When an effect is observed, research is then carried out to determine the cause. As our understanding of the environment is very incomplete, there will always be a role for approaching many issues in this way. However, it would be more logical to start with a chemical and make an assessment of what effects, if any, it will induce.