Breast Cancer: The Chlorine Connection
By Megan Williams, The Rag Times, Feb/March 1993, reprinted by Healthsharing, Summer/Fall 1993, p. 30.
A growing body of scientists, health workers and environmentalists are pointing to environmental contaminants as playing a large role in the breast cancer epidemic.

A recent study released by Greenpeace comes to the striking conclusion that chlorine-based compounds make a significant contribution to breast cancer. Current statistics estimate that an alarming one in eight women in North America will contract breast cancer at some point in her life. This makes it the most prevalent type of cancer in women and the leading cause of death in women between ages 40 and 55. These rates have risen from one in twenty in 1950 to today’s rate of one in eight. “The worldwide increase in breast cancer rates has occurred during the same period in which the global environment has become contaminated with the industrial synthetic chemicals, including the toxic and persistent organochlorines,” the Greenpeace report entitled “Breast Cancer and the Environment: The Chlorine Connection” states.

Organochlorines, first produced in the early 1900s, have been made on a large scale since World War II when they were used as chemical weapons. They include DDT, PCBs, dioxin, Agent Orange and thousands of lesser known chemical products and by-products. Each year in North America 13 tons of chlorine are produced, Greenpeace reports. Only one per cent is used to chlorinate drinking water—the rest is employed in the production of plastics, to bleach paper and for a myriad of other industrial and agricultural uses.
A recent study carried out in Hartford, Connecticut—the first of its kind in North America—found that women with breast cancer have 50 to 60 per cent higher levels of organochlorines, including PCBs in their breast tissue than in the breast tissue of women without breast cancer. Experts say these toxic compounds are attracted to fatty tissue.

Mary Wolff, an epidemiologist at Mount Sinai Medical Center in New York, who led the study, says the results surprised even her. “This is the first new evidence that could be a clue about the rising breast cancer rates. I’ve personally been a skeptic all along about the environmental connections to breast cancer, but I keep being proven wrong.”
Similar findings to Wolff’s study surfaced in a recent Finnish study. A group of 44 women with breast cancer were found to have significantly higher concentrations of the pesticide bHCH in the breast fat than a set of 33 women without breast cancer. The findings of these two studies confirm similar results by Israeli researchers.

The report also cites Israel’s decline in breast cancer rates over the last decade as the probable result of an aggressive program to phase out pesticides made from organochlorines. From 1951 to 1976, Israeli levels of chlorine-based pesticides in cow’s milk, human milk and human tissues were among the highest in the world, and five to 800 times higher than US levels. When the phase out program began, breast cancer rates in Israel dropped by eight per cent over the first ten years—a stark contrast to the rising rates in other industrialized nations.

Despite this evidence, no Canadian studies have been done exploring the link between breast cancer and environmental contaminants. Indeed, most North American cancer researchers believe this is simply not a worthwhile area of pursuit. Howard Morrison, a scientist at the Laboratory for Disease Control at Health and Welfare Canada, however, was spurred on by this evidence and, along with several other American and Israeli scientists, is currently planning a study that will look at toxins and breast cancer.
Jay Palter, a chlorine issues campaigner at Greenpeace Toronto says Greenpeace would like to see organochlorines phased out or “sunset” as a class. “This class of toxins behave in an extremely dangerous way,” he says. “Research has found that individual compounds can’t be singled out as the sole cause of cancers, that in fact it’s a combination of these toxins that’s so dangerous. That’s why it’s essential to target them as a class, rather than regulating individual chemicals.”