Endocrine Disruption

The term "endocrine" is non-specific and encompasses any hormone-related biological process in the body. Because hormones regulate normal reproduction, growth and development, these biological processes are monitored carefully in animal studies that are required to establish adequate safety margins for chemicals. There are also special reproduction and development studies that evaluate parental animals and their offspring through two generations of life. Pathologists carefully evaluate the reproductive organs in these studies, and toxicologists evaluate the growth and reproductive function of these animals. In fact, test laboratories have toxicologists that specialize in studies of reproduction and development. If there is any sign of dysfunction, there is a wide array of additional studies that can be conducted.

Natural and synthetic chemicals that can affect endocrine function will, at high enough levels of exposure, alter reproduction and growth. For example, sometimes sweet clover has elevated levels of natural endocrine disruptors; therefore any sheep that may graze on sweet clover pastures are known to be at risk of reproductive problems.

Chlorpyrifos has been extensively studied for a wide range of biological effects, including effects on endocrine function. No endocrine effects have been found in experimental animals that have been exposed to very high levels of chlorpyrifos (several thousands of times higher than human exposure) from conception to birth to adulthood to old age. Toxicologists at regulatory agencies throughout the world evaluate these chlorpyrifos studies, and endocrine effects have not been identified as an issue.