By Sally Lehrman

Nancy Evans had gone in for regular mammograms since she was 40 and nothing seemed amiss. But at age 53 when her right breast began to tingle with wiry little pains, she decided to pay attention. The radiologist examined the latest X-rays, then asked for more views. Next the clinic wanted to schedule a biopsy. Evans, who worked in medical publishing, delayed the procedure until the day after her company’s annual sales meeting a month later, in January. On the cold gray morning after she finally went in, the surgeon called with bad news.

Fortunately, the tumor was small and the doctors were able to remove it with a lumpectomy, followed by six weeks of radiation. But for Evans, the world changed.

As she read up on the disease while undergoing treatment, her uncertainty and fear turned to outrage. In the United States and elsewhere, the incidence of breast cancer continues to rise relentlessly. Over the past 25 years, an American woman’s chances of getting the disease have jumped by 40 percent. No one fully understands why.

As Evans read about the vast numbers of women with malignancies, she also learned about those who were organizing to demand answers from the scientific establishment. By the end of the year, she had quit her job and devoted her skills to the fight; she now works part-time as a consultant for the Breast Cancer Fund, a San Francisco-based advocacy group. “Breast cancer didn’t slow me down,” she says, “but it made me very angry.”

When public health officials talk about breast cancer risk, they emphasize things women have little hope of influencing: the genes that make us more susceptible, the age we began menstruating, whether we had children, and the density of our breasts. But taken together, such known contributors to breast cancer only explain about half the cases.

And the rest? It’s taken a decade of rabble-rousing by Evans and other activists, but scientists are increasingly investigating the likelihood that toxins in our environment play a role. Late last year, federal funding agencies finally agreed to put real money and effort toward the study of environmental links to breast cancer. “Breast cancer is going through the roof,” Evans says, “and it’s not because somebody suddenly poisoned the gene pool.”

The notion is both terrifying and encouraging. On the one hand, the number of potential environmental links to breast cancer is dauntingly high: Suspicious chemicals are present all around us, in the plastic that surrounds our foods, the cosmetics we smooth on our skin, and even the water that comes from our tap. Yet because many are in products we can opt not to use, we do have at least some way to limit our exposure, both by our own daily choices and in the policies we can push for in the public sphere.

Already activist groups have convinced cities to change their purchasing practices—for example, mandating that gardeners use nontoxic pest control products in public parks—in order to avoid suspected dangers. They are also lobbying corporations to stop using harmful toxins, particularly in the cosmetics and personal care products we use every day.

Still, the new focus on environmental causes of breast cancer has come about far too slowly for activists like Evans, who’s now 66. Since she discovered her own cancer 13 years ago, she has lost nearly 30 of her collaborators and friends to the disease. “Most of them,” she says, “were younger than me.”

The Clues Begin to Pile Up
Four years after her diagnosis, Evans began working on a film called Rachel’s Daughters, which followed eight women with breast cancer as they visited prominent researchers and quizzed them about the roots of the disease. She and her collaborators grew increasingly frustrated as one expert after another was unable to offer definite answers, despite an abundance of suspected causes: hormones, pesticides, electromagnetic fields, and other environmental factors.

After watching four of their colleagues die before the film could be completed, the women’s impatience turned to anger and grief. Still, scientists continued to maintain that radiation was the only environmental factor known for certain to cause changes in cells that lead to cancer. Meanwhile, most of the research money was going into the search for genes that raise cancer risk.

That picture finally began to change as scientists realized that genetic factors could account for only one out of ten women with the disease. So they began focusing their sophisticated instruments on a new target: the small changes in DNA that can be triggered every day as we come into contact with chemicals in our environment.

The four new federally funded breast cancer/environment research centers—which have received $35 million so far—will collaborate on two major projects in this area: The first is a mouse study that will look at breast development on the molecular level and the effects of ionizing radiation and various carcinogens; the other is a human study that examines contributors to the early onset of puberty, which is a risk factor for the disease. All the centers will work with local activists, as well.

Pathologist Jose Russo, who runs the breast cancer research laboratory at Fox Chase Cancer Center in Philadelphia, says the commitment of women like Evans helped to tip the balance and push the environment higher on the research agenda. “We have been working for 30 years on this and we knew it was important,” he says. “But there needed to be a critical mass of technology, science, politics, and advocacy for the issue to get the attention it deserves.”

Zeroing In on the Dangers
When she thinks back over her own life, Evans recalls the foot X-ray box that had captivated her as a child: You put your foot in it and it would show you your bones. Kids played with it in the shoe store while their mothers shopped—and Evans is convinced it played a role in her cancer.

Of course, Evans’s family also routinely used DDT to get rid of flies on the 10-acre farm in Missouri where she grew up. In fact, hundreds of household chemicals and pesticides—most of them still in widespread use (unlike DDT)—have been shown to trigger uncontrolled cell growth; the federal National Toxicology Program currently lists 48 chemicals that are linked with mammary tumors.

What’s more, recent research has shown, in eye-opening detail, that when environmental chemicals make their way into our bodies, they tend to stick around. In an ongoing sampling of the U.S. population begun in 1999, the Centers for Disease Control found that people are carrying varying amounts of dangerous substances such as phthalates, a derivative of DDT called DDE, dioxins, and PCBs. And when researchers at Mount Sinai School of Medicine conducted a more in-depth test on nine people published last year, they discovered that each harbored from 36 to 65 of the known or suspected carcinogens on the National Toxicology Program’s list. Andrea Martin, Evans’s former boss and the founder of the Breast Cancer Fund, was one of them; she carried 59 cancer-causing chemicals and 66 hormone disrupters in her tissue. Martin survived her breast cancer, but died of a brain tumor in August of 2003.

While scientists don’t know exactly how environmental toxins may cause breast cancer, it’s becoming increasingly clear that anything that disrupts hormones is likely to be dangerous. “There is a direct link between estrogen and breast cancer,” Russo says. The changes the breasts undergo throughout life are orchestrated by the interplay of estrogen and other hormones. When a substance interferes with the process—particularly by amplifying the effects of estrogen—it can trigger shifts in the molecular machinery that in turn set off uncontrolled cell growth.

Russo and his colleagues have already shown how estrogenic substances can cause changes to DNA that lead to breast cancer. And other research has found that substances such as pesticides and solvents boost circulating estrogen, which then sparks abnormal cell growth. The herbicide atrazine, which is widely used on crops in the Midwest, for instance, has been shown in animal research to stir growth in portions of the mammary gland that are especially sensitive to carcinogens. Some chemicals can even make other toxins more dangerous to breasts, by disrupting cell development and regulation or by making cells more susceptible to tumor growth.

Working on a parallel track, epidemiologists have discovered that women are especially vulnerable to the effects of such changes at certain times in their development, in particular, before birth and at puberty. The 10- to 14-year-old girls who survived the atomic bombs in Japan, for example, were more likely than older women to develop breast cancer later in life.

That means families with teenage girls should be especially careful to reduce environmental exposure, suggests Evans, who worries about her 13-year-old granddaughter. “Even though she wasn’t exposed to DDT or radiation, there are more chemicals in the environment now,” she says.

Despite all the evidence and a theory that pulls it all together, so far no one has been able to make a direct link between breast cancer and exposure to particular toxins. A study in Long Island—an area with an exceptionally high incidence—came up cold, although air pollution did appear to increase risk.

Unwilling to give up the hypothesis, activists point to tantalizing hints in the findings that could support it, and investigators agree. Some suspect that many of the studies so far missed possible links because of their design.

They now know, for instance, that you simply cannot take a snapshot of contamination levels at the time of diagnosis and expect to learn much, since exposures from years past may have triggered the cancer. To remedy that, you need to study exposure during puberty, identify markers in cells that might show long-ago exposure, and follow women over the long term—all measures scientists are hoping to take.

Seeking a Safer World Now
While encouraged by the increased scientific attention to environmental risks, breast cancer activists refuse to wait around until all the findings are in. They are insisting that policy makers begin acting on the precautionary principle by avoiding the use of potentally harmful chemicals now.

Last year, San Francisco and Berkeley became the first cities in the country to put the principle into action. Among other changes in the works, San Francisco plans to phase out its old, high-polluting diesel buses and stop using wood that’s been treated with arsenic. Dozens of city governments elsewhere are considering similar proposals.

The Breast Cancer Fund and other groups also launched a campaign in June to convince manufacturers to remove phthalates and other potentially dangerous chemicals from body care products, where they are quite common. Even though scientists have not made a direct connection between phthalates and breast cancer, the chemicals have been associated with premature breast development in girls, suggesting they disrupt hormones in a way that may raise risk. The European Parliament has asked cosmetics makers selling products in European countries to drop the phthalates DEHP and DBP, but so far, most U.S. companies have refused to change their formulations.

Jeanne Rizzo, executive director of the Breast Cancer Fund, only sees that as an invitation to step up the pressure. The fund’s coalition is asking women to change their buying habits and press cosmetics makers to reformulate their products. Twenty-one companies so far have signed a statement that their products include no chemicals known or strongly suspected to cause breast cancer. (Visit safecosmetics.org for a complete list.) Eight, including Coty, Gap, Gillette, and Schering-Plough, have agreed to use new, less toxic ingredients in the future.

If Evans ever gets tired of the fight, she doesn’t let on. “When I got into breast cancer work, it felt like everything I’d done before had been to prepare me for this,” she says. She had been involved in health care as a writer and editor for years, and her mother, she recalls, was an environmentalist before her time, inspired by Rachel Carson’s book Silent Spring.

Listening to Evans, it seems clear she doesn’t really feel like she has a choice but to try and change the course of the disease, and, by extension, the health of the planet.

“I keep fighting because of the women we’ve lost who are part of this involuntary sisterhood,” she says. “It’s the right thing to do.”

AVOIDING EVERYDAY RISKS

The truth is, it’s impossible to avoid all the things suspected of increasing breast cancer risk. It can seem overwhelming even to try.

Yet Nancy Evans believes you can focus on a few steps that will bring a big payoff. She limits her exposure to chlorine by filtering her water and using non-chlorinated paper. She eats organic food, and she doesn’t use pesticides in her garden. To avoid radiation, she sits at arm’s length from her computer and reserves her cell phone only for short calls. Here are some other products and substances that some scientists suspect may raise risk—and some simple options for minimizing your exposure.

Phthalates
These plastic softeners can disrupt hormones, some by mimicking estrogen, which is linked to breast cancer risk. They are widespread in personal care products like cosmetics, moisturizers, and perfumes, and can also be found in flavorings, processed food, and even infant chew toys.

Other options: Unfortunately, phthalates aren’t always listed on ingredient labels. Aveda, the Body Shop, and Neways make phthalate-free personal care products, though, and other companies are expected to follow suit. You’ll find listings of products made with and without phthalates at nottoopretty.org/goodbad.htm.

Radiation
Ionizing radiation is the one certain cause of breast cancer. CT scans and X-rays—including mammograms—all contribute to your lifetime exposure. (So far, however, the weight of evidence suggests that mammograms do more good than harm.) It’s less clear whether the radiation emitted by electronic tools such as computers, cell phones, and electric blankets poses a danger.

Other options: When getting an X-ray or other procedure, always ask whether it’s really necessary, and request a lead apron to cover parts of your body not being checked. If you’re worried about your computer and cell phone, you can follow Evans’s lead and type at arm’s length, and use the cell only for short calls.

Bisphenol-A
An ingredient in many plastic food containers and metal food can liners, bisphenol-A alters mammary gland development in mice, causing changes that are linked to breast cancer. An estrogen mimic, it interacts with the same pathways as the natural hormone.

Other options: This chemical is hard to avoid completely, but you can limit your exposure by not heating plastic containers in the microwave, not drinking water from plastic bottles that have heated up in the sun, and opting for glass whenever possible.

Chlorinated Products
Members of the chemical family of organochlorines accumulate in human fatty tissue and are known to disrupt the endocrine system. It’s not clear, however, whether they raise breast cancer risk. The group includes dioxin and the now-banned PCBs and DDT, as well as chemicals still used commonly in spray paints, bleach, household cleaning products, and pesticides; chlorine itself is often present in tap water.

Other options: To remove chlorine from your water, use an activated carbon filter. You can also buy chlorine-free coffee filters, facial tissue, and paper towels. If you want to switch to nontoxic household cleaners, some good ones include Lifetree Home Soap and Ecover’s Natural All-Purpose Cleaner; Bon Ami makes a chlorine-free scouring powder. Many other green household products can be found in the healthy living section of care2.com.

Pesticides
In your own home and garden, avoid using chemicals—particularly simazine, an herbicide that’s been linked to mammary cancer in animals. Skip the insecticides, too: They contain estrogenic ingredients such as methoxychlor, endosulfan, and lindane.

Other options: When you can, buy organic produce. Indoors, consider using boric acid, flypaper, and other lower-tech solutions to control pests. Plenty of nontoxic garden products are available; for more info, check govlink.org/hazwaste/house/yard or the healthy living section of care2.com.

PVC
This plastic, a.k.a. polyvinyl chloride, is found in appliances, toys, rainwear, food packaging (in particular the cling wrap used in grocery stores and delis, and some bottles of cooking oil). It contains cadmium and lead as well as phthalates and, when burned, releases dioxin into the environment.

Other options: Check the labels on the bottom of containers and bottles; any plastic with the recycling label 3 is PVC. You can remove the plastic from store-bought cheeses and meats and rewrap them in waxed paper. Transfer oil from plastic bottles into glass ones.

Hormones
It’s increasingly clear that some forms of hormone replacement therapy increase breast cancer risk. In the Women’s Health Initiative study of combined estrogen/progestin therapy, women’s risk for breast cancer increased by one quarter after an average of five years of use. The jury on birth control pills is still out.

Other options: Researchers suggest women talk with their doctors about whether a lower-dose version of the birth control pill would work for them. See “What about other risk factors?” page 120, for more ideas about reducing estrogen levels.

What about other risk factors?

It may be awhile before scientists are able to nail down the environmental causes of breast cancer. But in the meantime, there’s evidence that plenty of other everyday risk factors, such as exercise, alcohol, and weight, come into play. The thread that connects most of these to breast cancer is the way they affect our bodies’ supplies of estrogen; too much of the hormone can boost risk. Here’s the latest on how you can protect yourself.

Get moving
One excellent way to lower your risk is to exercise. At Fred Hutchinson Cancer Research Center in Seattle, researchers found that regular moderate activity reduces risk by 20 percent—no matter your family history or when you had children. They recommend at least 30 minutes of brisk walking or other type of activity five days a week. Researchers think exercise increases menstrual cycle length, which reduces a woman’s lifetime exposure to estrogen.

Keep your weight down
More than 100 studies have found an association between weight and breast cancer, particularly after menopause: One review study published last year concluded that compared with leaner women, those who are overweight or obese have up to two and a half times the risk of postmenopausal breast cancer. The reason? Fat tissue can change some other hormones into estrogen.

Don’t neglect vitamins and minerals
While fruits and vegetables have been shown to protect against other forms of cancer, studies on breast cancer have been mixed. Certain nutrients, though, do seem to help, including carotenoids (found in leafy green and deep orange vegetables), lycopene (in grapefruit as well as tomatoes), calcium, and vitamin C.

Go easy on the libations
If you drink more than one or two drinks a day—whether you’re pre- or postmenopausal—you’re upping your risk. Even if you have just a daily glass of wine, be sure to take a multivitamin containing folate, beta-carotene, lutein/zeaxanthin, and vitamin C, which can counteract the increased risk from alcohol.

GET INVOLVED
Activists say there’s enough evidence right now to warrant changes in policy that would help protect against breast cancer. They urge women to:

Press local governments to begin making purchasing decisions based on the precautionary principle of avoiding the use of chemicals suspected of causing harm. For example, you can ask the city or your children’s school to use only nonchlorinated paper and less-toxic pest control techniques on their grounds.

Petition the Food and Drug Administration to require cosmetics companies to stop using phthalates; you can use the template at nottoopretty.org/action.html or write to the companies listed on the site directly.

Support biomonitoring campaigns that aim to determine what chemicals have taken up residence in our bodies. (You’ll find info at the websites below.)

Stay informed by subscribing to email alert lists for organizations such as Breast Cancer Action(breastcanceraction.org/Pages/GetInformed/GetInformed.html) or the Breast Cancer Fund (breastcancerfund.org).