Endocrine-Disrupting Chemicals Probed as Potential Pathways to Illness

Abstract

SAN DIEGO—For the last 60 years, humans have been exposed to an increasing number of synthetic compounds in the environment. In fact, more than 80 000 chemicals are used commercially in the United States, found in products ranging from toys and detergents to pesticides and food packaging. Accumulating evidence that some of these widely used chemicals may have hormonelike effects on the body is heightening concerns about their potential long-term health risks, particularly when developing fetuses and neonates are exposed. At a day-long symposium at the Endocrine Society meeting here in June, leading investigators shared the latest findings on the effects of these synthetic chemicals—as well as of naturally occurring substances such as phytoestrogens—that have been reported to have hormonelike activity and may be associated with an increased susceptibility to disease and dysfunction. The potential danger is greatest for “the fragile fetus” (a term coined more than a decade ago by University of California at Berkeley endocrinologist Howard Bern, PhD) and the neonate, which are particularly sensitive to perturbations by endocrine-disrupting chemicals. But such effects are often not apparent for years. “Exposure to chemicals with endocrine-disrupting activity during critical stages of differentiation may have permanent consequences that may not be expressed or detected until later in life,” said Retha R. Newbold, MS, head of developmental endocrinology studies in the Laboratory of Molecular Toxicology at the National Institute of Environmental Health Sciences. There is now greater recognition, she added, that the developing organism may be especially vulnerable to endocrinedisrupting chemicals because of such factors as deficiencies in DNA repair mechanisms, detoxification enzymes that are not completely functional, and a blood-brain barrier that is still being formed.