Pesticides and other Endocrine Disrupter Chemicals

Endocrine Disruptors

Increasing scientific and public attention has been focused on substances that have the potential of disrupting the endocrine systems of wildlife, laboratory animals, and possibly humans. Disruption of the endocrine system may occur in various ways. Some chemicals may mimic a natural hormone, in effect fooling the body into over-responding to the hormone. Other chemicals may block the effects of a hormone in parts of the body normally sensitive to it. Still others may indirectly stimulate or inhibit the endocrine system, leading to overproduction or underproduction of hormones. Endocrine disruptors may also play a role in reproductive cancers.

Scientific questions remain, however, about which chemicals are involved in disruption of the endocrine system and how children may be exposed to those chemicals. It is not yet known whether health effects similar to those observed in laboratory animals are produced in humans, and what methods are best for testing for these effects. EPA is investing significant resources to find answers to these questions.

PCBs and Dioxins

PCBs and dioxins produce a number of toxic effects in animals. They have been linked to such health concerns as decreased gestational age, lower birth weight, depressed immune responses, impaired mental development, and growth retardation. Dioxin is considered by EPA to be a known human carcinogen and as such may have adverse effects on children that do not become apparent until many years after exposure occurs. However, no direct causal relationship has been established between PCB exposure and human health effects.