Women’s ills: Are toxins to blame? New research suggests that is indeed the case

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Women’s ills: Are toxins to blame?

New research suggests that is indeed the case

By Francesca Lyman

MSNBC

Women generally view environmental and health risks as more dangerous than

men do, according to a recent study. But are their fears well founded? Some

research suggests so — that the female body may, in fact, be a greater

target for toxins. And a wide range of diseases that hit women hardest —

from asthma to breast cancer — are increasingly being studied for their

links to environmental factors.

THE QUESTION of what role environmental factors play in women’s

health problems has been the subject of intense scientific debate and

several groundbreaking conferences during the last few years. There have

been conflicting study results — some research, for example, has found a

link between breast cancer and exposure to persistent pesticides like DDT,

while a much publicized 1997 study did not bear out those findings.

Nevertheless, a growing body of evidence suggests that a broad range

of health problems now on the rise among women may very well be linked to

environmental exposures. As a result, hundreds of studies are investigating

whether exposure to carcinogens and other pollutants in the environment —

some 70,000 new synthetic chemicals have been introduced since the 1950s —

could be a key factor in a number of women’s ailments, including breast

cancer, asthma and immune system problems like lupus.

“Researchers are looking at all of this because there’s been such a

rapid increase in breast cancer and other types of reproductive cancers and

dysfunctions,” says Bill Suk, program development director at the National

Institute of Environmental Health Sciences (NIEHS), which is overseeing a

number of the studies.

Many of the studies are probing links between various disorders and

so-called endocrine-disrupting substances or “xeno-estrogens” found in many

pesticides and common synthetic chemicals. Some of the substances — dubbed

gender-bender chemicals — are thought to mimic the natural female hormone

estrogen, some the male hormone testosterone and still others, both

hormones.

While Suk cautions that “there are many things operating here that we

don’t yet fully understand, what we do know is that we’re finding some

pretty alarming phenomena. Fertility is down, male sperm count is down, kids

are undergoing puberty early, and there’s a chance of some potentially

alarming transgenerational effects as fetuses and young infants are exposed

during particularly crucial ‘windows’ of susceptibility.”

To date, most data have come from the industrial workplace, where

evidence suggests a strong link between high doses of toxic chemicals and

reproductive cancers and disorders both in men and women workers. Some of

the riskiest jobs include those in manufacturing, painting and varnishing,

petroleum refining, electronics and plastics production and fumigation.

“The entire [female] reproductive cycle may be at risk for exposures

to physical and chemical agents in the workplace,” according to a 1993

position paper by the American College of Occupational and Environmental

Medicine. It named infertility, spontaneous abortion, birth defects and

malformations, hereditary diseases, cancer and cancers passed on to

offspring as being major issues.

OTHER RESEARCH

Among other research:

A 1989 EPA study that found that breast cancer rates were higher in the 339

U.S. counties with hazardous waste sites and groundwater contamination than

in other areas. Breast cancer is the leading cause of death by cancer among

women between the ages of 18 and 54.

A study by Emory University researchers that found that exposure to

industrial emissions is linked to an increased risk of lupus. The

researchers looked at an African-American community in north Georgia where

residents were exposed to continued industrial emissions. They found that

the incidence of systemic lupus erythematosus was nine times the norm.

Scientists are also looking at steadily rising asthma rates among women in

connection with high rates of air pollution, says Lasky of the American

Academy of Allergy, Asthma and Immunology based in Milwaukee, Wis. The death

rates for asthma patients are higher among females than males. And the

prevalence of asthma among females increased by 81 percent between 1982 and

1994, almost double the increase for males.

Other studies are going forward. Glinda , an epidemiologist at

NIEHS is looking into why women have a disproportionately higher incidence

than men of automimmune diseases. “We think that high hormonal activity is

playing a role, but we don’t yet know to what extent — if any —

environmental chemicals play a part.”

WORK HAZARDS A PRIORITY

Meanwhile, occupational hazards are still a priority. The number of

women working outside the home has nearly doubled during the last

half-century, to 60 million, and this is forcing a need to better identify

and re-assess job hazards, say scientists. “More women are taking

non-traditional jobs and working longer hours,” says Shelia Zahm, deputy

director of the division of cancer epidemiology and genetics at the National

Cancer Institute.

In a chapter to appear in a forthcoming Academic Press book, “Women

and Health,” Zahm notes that in farming, where women are exposed to

pesticides, fuels and sunlight, they are showing elevated rates of cancers.

She also pointed to an elevated incidence of cancers among women in the

textile industry, electronics, and dry cleaning and in a range of health

care fields, from dentistry to nursing.

At the 1997 conference, “Women’s Health in the Workplace,”

Heinz of the Heinz Family Foundation, which sponsored the event, said that

“understanding the special relationship between the environment and health”

may be the single most important step toward solving women’s health

problems.

Undoubtedly many women would agree. According to a recent study,

women rate environmental and health risks higher than men do. The study

presented new data from a national survey of more than 800 people polled on

a range of environmental and health hazards, from pesticides and tap water

safety to radioactive wastes.

Females in general “were far more likely than males to judge risks as

moderate or high,” the study found. People of color were even more likely to

judge these risks as high. The researchers speculated that “the world seems

safer and hazards more beneficial to white males than to other groups.”

GENDER DIFFERENCES

Scientists say that there are gender-related differences in how the

body reacts to toxins. According to Frederica Pereira at the Columbia School

of Public Health, women smokers are up to three times more likely to

contract lung cancer than men.

Until now, however, “most of what we know comes from studies on

healthy male workers,” says Je-Anne Burg, chief of the Agency for Toxic

Substances and Disease Registry’s Exposure and Disease Registry Branch

(EDRB). Her team looked at groups of people not usually counted in health

assessments done to determine risk factors — the elderly, children and

pregnant women.

In the study, the team identified 5,000 people who have documented

health effects they believe to come from water contaminated by

trichloroethylene (TCE), a common solvent and water pollutant. While

researchers are still validating their conclusions, women seem to suffer

“even more health effects than men,” according to Burg. Researchers are now

examining whether exposed women have elevated incidences of uterine, breast

and cervical cancers, as well as others disorders such as diabetes and

anemia.

Some researchers suggest that there are times in a woman’s life when

she is more sensitive to toxins — during puberty, pregnancy and menopause.

Depending on when a woman is exposed during hormonal cycles, she could be

more susceptible to carcinogens, neurotoxins and the new class of

“gender-bender” chemicals thought to disrupt biochemical pathways and

natural hormones in the body. Likewise, a developing fetus or young infant

is thought to be susceptible at much lower levels of chemical exposure than

ever thought possible before.

Genetic susceptibility also plays a role, according to Ken Korach, a

NIEHS researcher looking into the biology of women’s hormones. He has

recently found that some women may be genetically more vulnerable to certain

chemicals, showing that a pollutant — such as a PCB compound,

trichlorohydroxybiphenol — could bind to certain women’s estrogen receptors.

In effect, some women’s bodies could show a preference for the fake

“gender-bender” over the natural estradiol hormone. But, he cautions,

further tests are necessary.

Until the many long-term epidemiological studies and other research

are complete, there is no way to know exactly what effects pollution has on

women’s reproductive health or what chemicals are implicated. “The evidence

is just not in yet,” says Suzanne Haynes, assistant director for science at

the Office of Women’s Health. “But it’s clear that it is women who are

raising the issues.”

Francesca Lyman is an environmental and travel journalist and editor

of the recently released “Inside the Dzanga Sangha Rainforest.”

Coming March 17, Part II: Women’s health hazards on the job.