Considerable effort over the past several decades has significantly reduced the exposure of humans and cosystems to these persistent contaminants. However, the recent publication of Our Stolen Future , by Colborn et al. in 1996, once again heightened public awareness that very low concentrations of environmental contaminants could potentially result in adverse effects on reproduction and development in humans and wildlife. Contaminants that can alter the normal function of endocrine systems, especially during critical periods of development, could lead to irreversible effects in the organism or its offspring. These concerns have led governments worldwide to reevaluate the approaches to assessing and managing substances with the potential to disrupt endocrine function.
Endocrine systems coordinate and regulate internal communication in cellular organisms.
Endocrine cells release chemical messengers, known as hormones, which are carried into contact with target cells in the body. The endocrine system can be adversely affected by a wide variety of substances that interact with specific receptors and alter the cells ability to control physiological processes. In addition, a substance might interfere with the synthesis, transport or metabolism of hormones or receptors. To date, most of the attention has been on substances that mimic or block the feminizing effects of the estrogens such as 17b-estradiol. Not surprisingly, the mechanisms by which substances disrupt endocrine systems can be very complex and are currently not fully understood.