Large numbers and large quantities of endocrine-disrupting chemicals have been released into the environment since World War II. Many of these chemicals can disturb development of the endocrine system and of the organs that respond to endocrine signals in organisms indirectly exposed during prenatal and/or early postnatal life; effects of exposure during development are permanent and irreversible. The risk to the developing organism can also stem from direct exposure of the offspring after birth or hatching. In addition, transgenerational exposure can result from the exposure of the mother to a chemical at any time throughout her life before producing offspring due to persistence of endocrine-disrupting chemicals in body fat, which is mobilized during egg laying or pregnancy and lactation. Mechanisms underlying the disruption of the development of vital systems, such as the endocrine, reproductive, and immune systems, are discussed with reference to wildlife, laboratory animals, and humans.

Developmental effects of endocrine-disrupting chemicals in wildlife and humans.

Developmental effects of endocrine-disrupting chemicals in wildlife and humans

DISCLAIMER The use of company or product name(s) is for identification only and does not imply endorsement by the Agency for Toxic Substances and Disease Registry. A toxicological Profile for PCBs, Draft for Public Comment, was released in December 1998. This edition supercedes any previously released draft or final profile. Toxicological profiles are revised and republished as necessary, but no less than once every three years. The toxicological profiles are developed in response to the Superfund Amendments and Reauthorization Act (SARA) of 1986 (Public law 99-499) which amended the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA or Superfund). This public law directed ATSDR to prepared toxicological profiles for hazardous substances most commonly found at facilities on the CERCLA National Priorities List and that pose the most significant potential threat to human health, as determined by ATSDR and the EPA. The availability of the revised priority list of 275 hazardous substances was announced in the Administrator of ATSDR to prepare a toxicological profile for each substance on the list. Toxicological Profiles are a unique compilation of toxicological information on a given hazardous substance. Each profile reflects a comprehensive and extensive evaluation, summary, and interpretation of available toxicologic and epidemiologic information on a substance. Health care providers treating patients potentially exposed to hazardous substances will find the following information helpful for fast answers to often-asked questions. Chapter 1: Public Health Statement: The Public Health Statement can be a useful tool for educating patients about possible exposure to a hazardous substance. It explains a substance's relevant toxicologic properties in a nontechnical, question-and-answer format, and it includes a review of the general health effects observed following exposure. Chapter 3: Health Effects: Specific health effects of a given hazardous compound are reported by type of health effect (death, systemic, immunologic, reproductive), by route of exposure, and by length of exposure (acute, intermediate, and chronic). In addition, both human and animal studies are reported in this section. NOTE: Not all health effects reported in this section are necessarily observed in the clinical setting. Please refer to the Public Health Statement to identify general health effects observed following exposure. The following additional material can be ordered through the ATSDR Information Center: Case Studies in Environmental Medicine: Taking an Exposure History—The importance of taking an exposure history and how to conduct one are described, and an example of a thorough exposure history is provided. Other …

Toxicological profile for polychlorinated biphenyls (PCBs)

" In April 2000 researchers from around the world met in Lexington, Kentucky to bring together the very latest information on the chemistry and biological effects of the environmental pollutants known as Polychlorinated Biphenyls (PCBs). The result is a comprehensive and extensive treatment of the very latest findings on all significant subjects relating to PCBs and their health risks. The thorough introduction and sixty-two scientific papers presented here represent the most up-to-date research by scientists in government, private industry, and academia.

PCBs: Recent Advances in Environmental Toxicology and Health Effects

Experimental reproductive and developmental toxicity studies with polychlorinated biphenyls (PCBs) are reviewed in brief to determine their relevance for current environmental exposure of humans during the prenatal and postnatal developmental periods. Additional material is published in electronic form only, which contains graphic overviews on individual PCBs and various mixtures that are linked with the relevant citations. In this comprehensive article we focus on interactions of PCBs with biological substrates that could mediate adverse effects observed in experimental animals and in children, and the shortcomings of many of the animal studies available. A main point of criticism involves the relative lack of animal data on several of those persistent congeners, either as individual compounds or as environmentally relevant mixtures, which are currently used as a measure of human exposure. Experimental studies in animals are frequently conducted with commercial PCB mixtures, a test design that does not reflect the exposure situation in humans. Important improvements of animal experiments could be achieved by more complete reporting of litter data (pre- and post-natal losses, toxic signs in the dam and the offspring, birth weights and postnatal growth data), the inclusion of endpoints that have been found previously to be affected by PCBs, and measurements of internal exposure data.

Developmental toxicity of polychlorinated biphenyls (PCBs): a systematic review of experimental data

Males exposed to PCBs during lactation exhibited reduced fertility, i.e., reduced incidence of implantation in normal females mated to experimental males. However, a reduced weight gain during the time of treatment in the pups exposed to the higher doses of PCBs was also observed. After treatment, weight gain was comparable or greater in the experimental pups and by the time of mating and autopsy, body weights in all groups were comparable. The present experiments were designed 1) to determine if the early reduced weight gain (previously observed) has any influence on fertility, and 2) to investigate the effect of early postnatal exposure to PCBs on sperm counts and the ability of the sperm to support normal development.

W. Shih-Schroeder

Papers

Effect of early postnatal exposure to polychlorinated biphenyls (PCBs) on fertility in male rats.