Rachel's Democracy & Health News #895
"Environment, health, jobs and justice--Who gets to decide?"
CANCER: HOW DANGEROUS ARE OUR COSMETICS?
By Devra Davis
We know that children are not simply little adults. With their quick
heartbeats, fast-growing organs and enviable metabolism, the young
absorb proportionally more pollutants than those who are older.
Exposures to minute amounts of hormones, environmental tobacco smoke
or pollutants early in the life of an animal or human embryo can
deform reproductive tracts, lower birth weight and increase the chance
of developing cancer. And yet results from an independent chemical
testing laboratory released last week found a probable human
carcinogen, 1,4-dioxane (also known as para-dioxane), in some common
children's shampoos at levels higher than those recommended by the
U.S. Food and Drug Administration. The Environmental Working
Group, a research and advocacy organization that ran the study,
estimates that more than a quarter of all personal-care products sold
in the United States
may contain this cancer-causing agent.
The presence of a cancerous agent at levels above those suggested by
the FDA is disturbing enough. The idea that such a compound exists at
any amount in products that can be in regular contact with babies'
skin is even more disconcerting. Scientists have long known that
certain chemicals like para-dioxane can cause cancer. (The World
Health Organization considers para-dioxane a probable human carcinogen
because it is proven to cause cancer in male and female mice and
rats.) Now we're beginning to realize that the sum total of a person's
exposure to all the little amounts of cancerous agents in the
environment may be just as harmful as big doses of a few well-known
carcinogens. Over a lifetime, cigarettes deliver massive quantities of
carcinogens that increase the risk of lung and other cancers. Our
chances of getting cancer reflect the full gamut of carcinogens we're
exposed to each day -- in air, water and food pollution and in
cancerous ingredients or contaminants in household cleaners, clothing,
furniture and the dozens of personal-care products many of us use
daily.
Of the many cancer risks we face, shampoos and bubble baths should not
be among them. The risks of para-dioxane in American baby soaps, for
instance, could be completely eliminated through simple manufacturing
changes -- as they are in Europe
. To remove such carcinogens, however,
would require intervention by the federal government, but the federal
Food, Drug and Cosmetic Act allows the industry to police itself.
Europe has banned the use of para-dioxane in all personal-care
products and recently initiated a recall of any contaminated products.
There's a problem with the way the United States
and other countries
look at toxicity in commercial agents. Regulators nowadays often won't
take action until enough people have already complained of harm. This
makes little sense. Scientists can seldom discern how the myriad
substances, both good and bad, that we encounter in our lives
precisely affect our health. We need to be smarter about using
experimental evidence to predict and therefore prevent harm from
happening. A few decades ago, people accepted the fact that cigarette
smoking was harmful, even though no scientist could explain precisely
how this happened in any particular cancer patient. If we had insisted
in having perfect proof of how smoking damaged the lungs before acting
to discourage this unhealthy practice, we would still be questioning
what to do. By the same token, we now have to get used to the idea
that scientists are unlikely to be able to say with certainty that a
trace chemical in shampoo accounts for a specific disease in a given
child. But if we're to reduce our cancer risk, we need to lower our
exposures to those agents that can be avoided and find safer
substitutes for those that can't.
Scientists don't experiment on humans, for obvious reasons, but we
have found some clues from lab and wildlife studies. Medical
researchers have demonstrated that trace chemicals of some widely used
synthetic organic materials can damage cultured human tissue. The
effects don't just accumulate, they mushroom. UC Berkeley Professor
Tyrone Hayes has shown that very low levels of pesticide residues in
Nebraska
cornfields can combine to create male frogs with female
features that are vulnerable to infection and can't reproduce.
Should we wait for these same things to happen to baby boys before
acting to lower exposures? There's plenty of solid human evidence that
combined pollutants can cause more harm together than they do alone.
We are not surprised to hear that people who smoke, drink and work as
painters have much higher risks of kidney cancer than those who only
engage in one of these known cancer-causing practices. We also
understand that women who use hormone-replacement therapy and drink
more than two glasses of wine daily have higher risks of breast cancer
than those who engage in only one of these practices. This tells us
that other combinations of chemicals in the environment can also lead
to other cancers. One in five cases of lung cancer in women today -- a
disease that kills more women than ovarian, breast and uterine cancer
combined -- has no known history of active or passive smoking
exposure. Rates of non-Hodgkins lymphoma and other cancers not tied
with aging or improved screening have also increased in many
industrial countries. New cases of testicular cancer continue to rise
in most industrial countries. While still rare, childhood cancer is
more common today than in the past, and most cases occur in children
with no known inherited risk of the disease.
The problem, from a scientific standpoint, is that resolving the
effects of miniscule levels of chemicals we encounter throughout our
lives is part of a complicated puzzle for which many pieces are
missing. What scientists need is data -- lots of it. Manufacturers,
however, tend to hold the precise formulations of products as trade
secrets, and the law allows them to withhold much information about
carcinogens even if they are known to be present. Of course, we should
continue to collect information to advance our ability to prevent
cancer and other chronic diseases. But when a chemical causes cancers
in both sexes of two different species of animals, we shouldn't
arrogantly presume we will escape a similar fate. Recent work on the
human and animal genomes shows us that humans differ from frogs and
mice by fewer than 10 percent of genes. We should not let the absence
of specific information on the health consequences for our infants and
toddlers of single cancer-causing contaminants like para-dioxane
become a reason to delay getting rid of such hazards.
The goal of public-health policy is to prevent harm, not to prove that
it's already happened. The Center for Environmental Oncology at the
University
of Pittsburgh Cancer
Institute advises that personal-care
products that contain hormones may, in part, account for the
continuing and unexplained patterns of breast cancer in African-
Americans under age 40, and also may explain why more girls are
developing breasts at younger ages. The Centers for Disease Control
and Prevention found generally higher residues of some plastic
metabolites in African-American women, with children ages 6 to 11
having twice the levels of whites. Dr. Chandra Tiwary, a recently
retired military chief of pediatric endocrinology at Brooks Air Force
Base, found that African-American baby girls as young as 1 year old
developed breasts after their parents applied creams that they hadn't
realized contained estrogen to their scalps. When the creams were no
longer used, these infant breasts went away. Other work published
last week by the National Institute of Environmental Health Science,
shows similar effects in young boys who had been washed with some
hormone-mimicking soaps or oils. After their parents stopped applying
these products, their breasts also receded.
In light of the growing numbers of young girls with breasts, the
Lawson Wilkins Pediatric Endocrine Society, the certifying board for
pediatric endocrinology, in 1999 changed the recommendation of what is
natural. We believe this would be a dangerous move. If we say that
it's now normal for African-American and white young girls to develop
breasts at ages 6 and 7, respectively, we will fail to pick up serious
diseases that could account for this. We will also lose the chance to
learn whether widely used agents in the environment, like those found
in personal-care products today or others that may enter the food
supply, lay behind some of these patterns.
It should not be the job of scientists, or of public-spirited leaders
or environmental groups, to find out what contaminants or ingredients
may be affecting the delicate endocrine systems of our children and
grandchildren. (The tests that found para-dioxane in shampoo were
funded privately by environmental journalist and activist David
Steinman, author of "Safe Journey to Eden
.") Manufacturers have known
for years about how para-dioxane forms as a by-product of
manufacturing and how to get rid of it. Until now, they just haven't
need to do so. People have a right to know whether products they use
on themselves and their children contain compounds that increase their
risk of disease. They also have a right to expect that government will
prevent companies from selling products that are harmful to children.
To do otherwise is to treat our children like lab rats in a vast
uncontrollable experiment.
==============
Devra Davis is director of the Center for Environmental Oncology at
the University of Pittsburgh Cancer Institute and is a professor of
epidemiology at the University
of Pittsburgh
's Graduate
School
of
Public Health. A National Book Award finalist for "When Smoke Ran
Like Water," she is completing "The Secret History of the War on
Cancer," from which this work is adapted, expected in October from
Basic Books.
Copyright 2006 Newsweek, Inc.
