Hormone havoc

The US World Wildlife Fund (WWF) released a statement signed by 23 leading North American Scientists on 20 April warning that in many cases wildlife and humans may have exceeded their capacity to compensate for exposure to chemicals. The scientists noted declines in a variety of North American wildlife populations, including beluga whales and bald eagles.
    The scientists are certain that “populations of many long-lived species are declining, some to the verge of extinction, without society’s knowledge. Some of these declines are related to exposure to man-made chemicals and their effects on the development of embryos. The embryo is the most sensitive life stage of animals to the hazards posed by chemicals” says Theo Colborn, a senior scientist at WWF.
    The development of human and wildlife embryos is under the sensitive control of the endocrine system, which is directed by hormones. Large quantities of endocrine-disrupting chemicals have been released into the environment. Exposure to these chemicals has been associated with immune and thyroid system disorders, disrupted sexual development, decreased fertility, gross birth deformities and decreased mating in birds, turtles and fish. Synthetic chemicals have been found in troubled populations of alligators, bald eagles, Forster’s terns, beluga whales, great blue herons, lake and wood ducks.
    Scientists convened by WWF believe  traditional assessments of risks posed by single chemicals are not adequate for assessing the risks for embryos exposed to multiple chemicals. The scientists issued the following recommendations:

• test chemicals before environmental release throughout a minimum of two generations for a wide variety of effects including reproductive, immunological endocrinological and neurological effects;

• raise awareness among legislators, scientists, public health officials and the general public about the danger of endocrine disrupting chemicals;

• undertake a major research effort and comprehensive assessment on a global basis.

World Wildlife Fund US, News Release, 20/4/94.

[This article first appeared in Pesticides News No. 24, June 1994, page 21]