National Breast Cancer Coalition

(WOMENSENEWS)–Armida Mesa never knew she was at risk. At age 24, she took a job at an IBM plant in San Jose that required her to work with methylene chloride and other organic solvents that are known carcinogens.

When her colleagues in the computer-chip manufacturing room were diagnosed with breast cancer, Mesa continued working because her boss assured her that the chemicals she handled weresafe.

In 1984, at age 40, Mesa developed cancer in her left breast with no family history of the disease. After enduring radiation and chemotherapy, she went straight back to her job. At 47, she had a recurrence in her left breast and had a mastectomy.

Today, at 59, Mesa is one of 250 plaintiffs suing IBM for exposing factory workers to carcinogens. IBM workers’ combined lawsuits, now being tried in courtrooms across the country, mark the largest legal challenge of their kind against a computer manufacturer in U.S. history. Two hundred of the plaintiffs have some type of cancer. Of the 20 plaintiffs with breast cancer, six have died of the disease.

Mesa’s story sparks a flurry of questions that have baffled breast cancer researchers for decades. Which chemicals in our homes and workplaces are contributing to the breast cancer epidemic? What levels of exposure are safe? And how can we protect ourselves from potential threat?

Thanks to a new initiative at the National Institutes of Health, based in Bethesda, Md., answers may finally be on the horizon.

U.S. Breast Cancer Rates Rising

Science has yet to explain why 1 in 8 U.S. women develops breast cancer, a figure that hovered at 1 in 22 back in 1940. For the past 60 years, the incidence of breast cancer has risen steadily in the United States. Researchers note that this coincides with the use of synthetic chemicals that have not been fully tested for safety.

Once a disease of postmenopausal women, breast cancer is now the leading cause of death among women ages 34 to 44. In 2003, an estimated 211,000 women were diagnosed with the disease and 40,000 died from it.

While increased awareness and reporting may help account for the increased incidence of breast cancer, studies show that environmental toxins likely also play a role.

Since only 50 percent of breast cancer cases in the United States can be linked to standard risk factors such as cigarette smoking–and since only 5 percent can be traced to genetics–some researchers believe environmental factors may be to blame. Something in our soil. Something in our water. Or a flurry of agents that are working together to fuel this health epidemic.

Complex Problem

"Every day, we’re exposed to hundreds of carcinogens," says Marilie Gammon, an epidemiologist at the University of North Carolina in Chapel Hill. "But since these chemicals are at very low levels and since the timing of exposure is difficult to peg, scientists have struggled to establish the link between breast cancer and the environment."

In October, the National Institutes of Health launched four research centers to study environmental links to breast cancer. The centers are at the University of Cincinnati in Ohio, Michigan State University in Lansing, Fox Chase Cancer Center in Philadelphia and the University of California at San Francisco. With $35 million in funding from the National Cancer Institute and the National Institute of Environmental Health Sciences, researchers will study the effect of specific environmental agents on mammary tissue in lab animals. Then they will monitor 1,600 girls, studying their long-term exposure to chemicals in the environment.

"This is the first time we’ve examined this issue in this much depth," says Leslie Reinlib, the program director for the NIEHS Breast Cancer and the Environment Research Centers, based in Research Triangle Park, N.C. "It’s an unprecedented step."

During their seven years of research, scientists plan to investigate chemicals already known to boost the risk of breast cancer. These include organic solvents (used to make computer parts); ionizing radiation (from X-rays and power lines); dioxin (produced by burning plastic); polycyclic aromatic hydrocarbons, or PAHs (found in auto emissions and tobacco smoke); polyvinyl chloride, or PVC (found in plastics); and organochlorine pesticides (found in agricultural areas). Researchers hope to pinpoint how much exposure to each agent is dangerous and when.

"Breast cells are especially vulnerable when they are developing in utero and during the time between puberty and the first pregnancy," says Reinlib. "The younger a woman enters puberty and the later she enters menopause, the more estrogen she has in her body and the more likely she is to develop breast cancer."

The initiative is drawing applause from breast cancer activists nationwide. Though federal spending on the disease soared to $800 million from $90 million between 1990 and 2001, less than 3 percent was spent on investigating environmental causes.

"People are excited that the government is moving in this direction," says Lisa Wanzon, the assistant director of the San Francisco-based Breast Cancer Action, a nonprofit organization dedicated to ending breast cancer.

Local Clusters Link to Environment

The research follows hundreds of independent studies, many conducted in the breast cancer "clusters" across the United States. In Marin County, Calif., where breast cancer rates are the nation’s highest–almost twice the national average of 114 cases per 100,000 women–researchers found that daily alcohol consumption can boost the risk of the disease. In Cape Cod, Mass., a hot spot where the incidence of breast cancer is 20 times higher than elsewhere in the state, scientists isolated estrogenic chemicals in the household dust and drinking water of affected women. In Long Island, N.Y., which has a slightly higher-than-average incidence of breast cancer, activists lobbied Congress to mandate $30 million in research and found that exposure to PAHs can boost the risk of breast cancer by 50 percent.

Researchers involved in these and other studies say the sheer volume of chemicals flooding the environment may be their biggest challenge.

According to Breast Cancer Action, of the 85,000 synthetic chemicals in use today, only 7 percent have been screened for complete toxicological data. According to the Centers for Disease Control and Prevention in Atlanta, the average American carries 116 synthetic chemicals in his or her body, including dioxin, PAHs and other toxins proven to cause mammary cancer in lab animals. Tests on rats and mice have implicated 45 separate chemical compounds in breast cancer formation. But outside the lab, it is difficult to gauge how and when these chemicals affect living, breathing women.

While scientists work to unravel the mystery and while IBM workers fight their case in court, health advocates are urging women to take charge of the environmental factors they can control, shunning pesticides, PAHs and other chemicals known to boost their risk.

Activists say women should lobby Congress to pass the National Breast Cancer and Environmental Research Act, which would authorize $150 million more in scientific studies. They also say we must work to ban any substances that are highly suspect.

"Waiting for absolute proof only means more funerals," says Nancy Evans of The Breast Cancer Fund. "Now is the time to act on the evidence."

Molly M. Ginty is a freelance writer based in New York City.

For more information:

The Breast Cancer Fund–
"State of the Evidence: What is the Connection between
Chemicals and Breast Cancer?":

Breast Cancer Action: