Excerpt from Endometriosis Sourcebook

by Mary Lou Ballweg

Hormonal and Immunological Effects

In fact, it is only a recent realization that these compounds have profound immunological and reproductive impacts. In prior decades the focus of research and governmental regulation was almost exclusively on cancer. Now scientists are learning that many very toxic immune and reproductive consequences occur with exposure to levels of pollution far below the level known to cause cancer. Dioxin, for example, can induce hormonal reactions at exposures a hundred times smaller than the exposures associated with cancer, according to animal research cited by the United States Environmental Protective Agency (EPA).

Scientists studying animals in and around the Great Lakes were among the first to notice these effects. The Great Lakes are about average in their level of pollution compared with other lakes, according to the recent "Health Implications of Great Lakes Pollution" conference. But because less than 1 percent of the water in the Great Lakes flows out of them into the ocean each year, "the effects of organochlorine thus show up more quickly in the Great Lakes than in other aquatic ecosystems," according to Greenpeace. Thus, what's happening in the Great Lakes may serve as an early warning.

The Great Lakes also have been studied more extensively because of the importance to so many states and provinces. The lakes contain 95 percent to the freshwater of the United States. Twenty percent of the U.S. population and 50 percent of the Canadian population lives in the Great Lakes basin, the area that drains into the Great Lakes, according to an EPA publication.

The World Wildlife Fund has noted: "Since the mid-1950s, problems with the endocrine systems of birds, fish, and mammals in the Great lakes have been reported... In each instance, high concentrations of orgaonochloride chemicals were found in these animals or other individuals in the same population.. More recent research documents similar problems. Researchers from Guelph University can no longer find an adult salmonid [a family of salmon] in the Great Lakes that does not have an enlarged thyroid, nor can Canadian Wildlife Service researchers find a herring gull without an enlarged thyroid."

The International Joint Commission notes in a recent publication that "scientists noticed in the 1960s and 1970s that almost the entire population of cormorants, herons, and gulls living on the lakes started to die." And studies of children of mother who ate Great Lakes fish showed they were born sooner, weighted less , and had smaller head than the infants from the same community whose mothers did not eat Great Lakes fish. The infants showed significant behavioral problems, including jerky, unbalanced movement, increased startle reflexes, and decreased interest in new stimuli. In tests at seven months and four years of age these children had difficulty learning because of impairments in short-term memory and other mental functions.

Recently a group of scientists gathered at Wingspread in Racine, Wisconsin, for a conference, "Endocrine Disrupters in the Environment." They issued a consensus statement after assessing the current knowledge on endocrine (hormonal) effects of polluting compounds.

Many wildlife populations are already affected by these compounds. The impacts include thyroid dysfunction in birds and fish; decreased fertility in birds, fish, shellfish, and mammals; decreased hatching success in birds, fish, turtles; metabolic abnormalities in birds, fish, and mammals; behavioral abnormalities in birds; demasculinization and feminization of male fish and birds, and mammals; defeminization and masculinization of female fish and birds, and mammals; and compromised immune systems in birds and mammals.. ..

The mechanisms by which these compounds have their impact vary, but they share the general properties of (1) mimicking the effects of natural hormones by recognizing their binding sites; (2) antagonizing the effect of these hormones by blocking their interaction with physiologic binding sites; (3) reacting directly and indirectly with the hormone in question; (4) altering the natural pattern of synthesis of hormones; or (5) altering hormone receptor levels.

Twenty-three compounds or groups of compounds were cited by the scientists as having known ability to disrupt the endocrine system. Thus far, however, the precise impact of this disruption in humans is not known. If the dioxin and PCB links to endometriosis are borne out by further study, it may be the first human disease definitely linked to hormonal /immunological disruption due to pollutants.

At the conference the scientists used DES exposure as a model of what they expect may happen in humans. Based on the animal studies, they expect the effects, like DES, will be worse in the offspring exposed to the toxin in the mother's uterus than in the parent exposed as an adult. And, like DES, the manifestations of the exposure may not occur until sexual maturity, making it very difficult to trace the source. As the first generation to be conceived after the introduction of these chemicals, are the baby boomers the first generation to show these effects?

This gap between exposure and observable signs of disease makes it harder to be sure what is happening, at least in humans. (In the dioxin monkey colony, the monkeys were fed the dioxin in their chow as young adults, and the evidence of endometriosis was noted 10 years after exposure started. Similarly, in the PCB monkey colony, endometriosis was not noted until years after the chemical exposure.) "Because functional deficits are not visible at birth and may not be fully manifested until adulthood, they are often missed by physicians, parents, and the regulatory community, and the causal agent is never identified," the Wingspread scientists wrote.

They also pointed out that the scientific and public health communities are generally unaware of the presence of hormonally active environmental chemicals. (It was noted at the Medical College of Wisconsin conference that only two medical schools in the United States even offer a course in environmental medicine, meaning physicians are woefully uninformed on these matters.) The Wingspread scientists call for broadening the testing of products beyond simply looking for cancer and specifically studying hormonal effects in animals.