ABSTRACT
There has been growing concern in recent years that a variety of natural and synthetic chemicals could be producing serious health effects in humans and other species by interfering in the actions of endogenous hormones. Public attention was originally drawn to the idea that environmental chemicals could disrupt the endocrine system of wildlife by the publication of Rachel Carson’s “Silent Spring” in the 1960s. This book described deleterious reproductive effects of the then commonly used insecticide, dichlorodiphenyltrichloroethane (DDT), on birds and other wildlife. However, the fi rst published evidence for environmental pollutants able to impact the endocrine system had actually appeared more than a decade earlier, when it was reported that consumption of a certain type of clover disrupted reproduction in sheep. Both of these reports involved chemicals that were able to impair the endocrine system. The organochloride pesticides, which were of greatest concern to Carson, were banned in Western Europe and North America in the 1970s, as were the polychlorinated biphenyls
Universidade Federal do Paraná, Setor de Ciências Biológicas, Departamento de BiologiaCelular, Laboratório de Toxicologia Celular, P.O. BOX 19031, ZIP CODE 81531-990, Curitiba, PR, Brazil. Email: danidmc87@yahoo.com
(PCBs) widely used as electrical insulators. Both of these classes of chemical are extremely persistent, resistant to biodegradation, and in many areas their concentrations in fi sh tissues remain unchanged several decades after production has ceased. To these have been added a vast array of other chemicals which may reside in lake, river and ocean sediments for varying periods and that can be metabolized into a wide range of products of unknown toxicity (Kime 1999).
