GreenSpace: Chemical exposure and breast cancer risk

The first time she was diagnosed with breast cancer, Caren Kaufman was 37. She had the surgery, the chemo, the radiation.

Three years later, it returned. She had more chemo.

Now, the Cherry Hill mother of two is 46, and she's changed her life in many ways.

Among them, she has reduced her exposure to chemicals, a decision that resonated this month when a new study identified 17 groups of chemicals women should avoid if they're worried about breast cancer.

Chemicals have long been suspect, but proving a link to cancer is hard.

Ethically, researchers can't expose humans on purpose to see if they get sick.

To look at exposure from the other direction, "you need a very large group of women, you need to know a lot about them, you need to follow them for at least 20 years, or maybe more, and you need to know a lot about exposure," said Ruthann Rudel, the study's lead author. She is research director at the Silent Spring Institute, a Newton, Mass., nonprofit that studies links between the environment and women's health.

But experts know many chemicals cause mammary tumors in rodents.

So Rudel and her team analyzed substances that have been studied in both humans and rodents and found the results were largely consistent. Plus, the biology of rodents and humans is similar.

"This increases our confidence that animal results are relevant to humans," Rudel said.

Using that rationale, the group identified 102 "high priority" chemicals for breast cancer prevention and consolidated many of them into 17 groups.

They include flame retardants, perfluorinated compounds in coatings to resist stains, byproducts of water disinfection, dry-cleaning fluids and other solvents, and benzene, which is in vehicle exhaust and tobacco smoke.

To make it easier still for women to act, they devised seven tips to reduce exposure to the chemicals.

"Those are examples of chemicals that are, I would say, poor choices for widespread population exposure," Rudel said.

"What we don't have in the U.S. is a modern system of chemical regulation so that chemicals are evaluated for safety before they are used," she added. "The lack of regulation has created a situation where manufacturers are not looking for the safest alternatives."

Many health advocates hoped a congressional update to the 1976 Toxic Substances Control Act would change that. But it hasn't happened.

The study, published this month in Environmental Health Perspectives, was funded by the Avon Foundation for Women, a nonprofit focusing on breast cancer and domestic violence.

Judy Garber, a researcher at the Dana Farber Cancer Institute in Boston and past president of the American Association for Cancer Research in Philadelphia, called the study "an interesting and provocative contribution" to breast cancer research.

"It's hard to figure out how to study many chemicals that are so common in the environment" and that many people are exposed to, she said. She lauded the Silent Spring study for presenting an analysis that should stimulate the research community to reexamine environmental chemicals for their role in breast cancer.

But avoiding the chemicals should be taken in context, Rudel said. Exposure doesn't trump the most important things women can do to reduce breast cancer risk: keep a healthy weight, reduce alcohol and tobacco use, stay physically active, reduce exposure to medical radiation, and limit use of hormone-replacement therapy.

As for Kaufman, she will never know what caused her cancer. Like most with breast cancer, she has no family history of it, none of the genetic mutations.

She and her friends joked: "It must be something in the air. Something in the water." Gradually, she began to believe it.

"I started to realize individual personal health and health of the planet are so intertwined," she said. She became involved in Sustainable Cherry Hill and now cochairs its Green Health Task Force, which promotes awareness of changes people can make in their everyday lives.

Concerned not only about herself, but also for the future of her son and daughter, now in their teens, she began making changes, like many of those Silent Spring recommends.

It was easy to switch from nonstick pans to cast iron. Difficult to avoid flame retardants.

"We all talk about being on our journey and taking small steps," she said. "Whatever step you feel you can make without disrupting your whole day and life is a step in the right direction."

To read the study, and the full list of chemicals, click here.

General advice:

SOURCE: Silent Spring Institute

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