[Pharmwaste] Inquiry Turns To Humans On Pollutant, Hormone Tie

[DeBiasi,Deborah]

http://www.washingtonpost.com/wp-dyn/content/article/2006/12/03/AR200612
0300992.html

Inquiry Turns To Humans On Pollutant, Hormone Tie
Evidence Such as Eggs In Male Fish Spurs Push

By David A. Fahrenthold
Washington Post Staff Writer
Monday, December 4, 2006; B01



Growing evidence that chemicals in the environment can interfere with
animals' hormone systems -- including the discovery that male Potomac
River fish are growing eggs -- has focused the attention of
environmentalists and scientists on a new question: Are humans also at
risk?

A decade ago, the very idea that pollutants could interfere with a
body's chemical messages was near the fringes of science. But now, it is
an urgent topic for lawmakers and researchers around the world, and
especially in the Washington area.

In recent years, researchers have linked some common chemicals to
troubling changes in laboratory rodents and wild animals, including
reproductive defects, immune-system alterations and obesity.

For now, no connections to human ailments have been proved. But some
studies have provided hints that people might be affected by crossed
hormones, and activists wonder if this kind of pollution could
contribute to diabetes, birth defects and infertility.

"There's a lot of concern that a lot of chemicals to which we are
exposed routinely, and without our knowledge, are interfering with the
way hormones work," said R. Thomas Zoeller, a professor of biology at
the University of Massachusetts at Amherst.

The Metropolitan Washington Council of Governments is planning to host a
public forum about hormone-disrupting pollution this spring. U.S. Reps.
James P. Moran Jr. (D-Va.) and Chris Van Hollen (D-Md.) have said they
plan to press the Environmental Protection Agency about its failure to
develop a program to test chemicals for hormonelike effects, as ordered
by Congress in 1996.

The idea that natural hormone messages can be tampered with is not new;
for decades, women using birth-control pills have been counting on a
man-made chemical to do just that.

But the current concern is much wider: Some fear that modern chemistry
might have unwittingly created other compounds with hormonelike effects
and that they might have spread widely around the globe.

In the past few years, scientists working with animals have found
potential problems with several pollutants, among them rocket-fuel
components, pesticides and additives to soap. Among the most heavily
researched:


* Phthalates, a family of additives used to make vinyl plastic flexible
and prevent perfume from evaporating, have been linked to lower sperm
counts and other sexual problems in male rats, as well as to heightened
allergic reactions in the animals. Chemical industry officials have said
that these tests used unrealistically high doses and that the results
are not likely to translate to humans.


* Bisphenol A, used as a building block for hard plastic goods like
bottles and as a resin to line food cans, has been connected in some
experiments to abnormal sexual development in male lab rodents, as well
as a predilection for obesity. Officials from the chemical and pesticide
industries have vigorously criticized these results, saying that other
studies have shown the chemical to be harmless.


* Treated sewage, which carries human estrogen and birth-control pill
components excreted in waste, has been linked to "feminized" male fish
in waters around the world. In the St. Lawrence River in Canada, a
recent study found that a third of male minnows had female
characteristics. Another example might be the Potomac, though the cause
of its problems has not been officially pinpointed. The EPA and
sewage-plant officials have said they are working on ways to better
clean the wastewater.

The study of endocrine disruptors began in the late 1980s and early
1990s, with scientists struggling to add up such oddities as male birds
with female organs in the Great Lakes and sexual defects in Florida
alligators.

They eventually found that some chemicals were turning on hormone
switches in the body's endocrine system that trigger biological
processes. Others blocked the switches so natural hormones couldn't get
through.

That revelation meant that a pollutant could be harmful even if it
wasn't poisonous and didn't cause cancer. Even small doses could cause
major damage, if they came at a key time when hormones were guiding
pregnancy or early development.

"We have to ask different questions," said John Peterson Myers, an
activist and former scientist based in Charlottesville. He joined with
scientist Theo Colborn and writer Dianne Dumanoski to write a book
laying out their concerns, 1996's "Our Stolen Future."

Today, despite the wealth of studies in animals, the implications for
human health are unclear. One of the most dramatic studies examined the
sons of mothers whose bodies contained phthalates. It found no major
birth defects but did show that the higher the phthalate level, the
greater chance that the boys' bodies would show subtle signs of being
"undermasculinized," according to researcher Shanna Swan, director of
the Center for Reproductive Epidemiology at the University of Rochester.

Still, that falls well short of a smoking gun: Humans are not laboratory
rats, so scientists say it is exceedingly hard to craft a study that
shows a particular chemical caused a particular problem, and not
genetics, diet or some other factor.

"They're nowhere near cause-and-effect," L. Earl Gray Jr., a senior
research biologist at the EPA, said of human studies. "We're showing
correlations and associations" between pollutants and human health
effects, he said, but no indisputable sign that one causes the other.

Officials from the chemical and pesticide industries have vigorously
defended their products, saying they see no reason for concern about
products in the environment interfering with human hormones.

Some scientists have also pointed out that human diets have always
included some estrogen-like compounds: They occur naturally in wine and
soy-based products, for example.

Stephen H. Safe, a professor of veterinary physiology and pharmacology
at Texas A&M University, said that overall, despite our poor diets,
"what does the data say about our health in this country? We're living
longer . . . You know, where are these endocrine threats?"

Still, concerns that human health might be in danger have led to recent
bans on certain phthalates in young children's toys imposed by the
European Union and the City of San Francisco.

Activists in the United States have attacked the EPA for what they
believe is a delayed response to the problem. The agency has defended
itself by saying that it has spent millions on other research programs
looking at ways to identify and limit endocrine disruptors and that it
hopes to begin the long-delayed chemical testing program next year.

Some activists fear that damage is already being done. They caution
avoiding plastic baby bottles, which could contain bisphenol A, and
reducing consumption of animal fat, where some environmental pollutants
can concentrate.

"I feel terrible because we haven't moved on this faster," said Colborn,
the activist who has served as an unofficial leader among
endocrine-disruptor researchers. "This is a transgenerational problem
that is undermining the integrity of humans."

But Paul Foster, an official who evaluates risks to human reproduction
at the National Institute of Environmental Health Sciences, said it was
hard to give useful advice at this point because the chemicals being
investigated are so ubiquitous.

"There's very little that they can do," said Foster, whose agency is
part of the National Institutes of Health. "That's why you can't be too
alarmist about it, because you can't stop people living."

 

Deborah L. DeBiasi
Email:   dldebiasi at deq.virginia.gov
WEB site address:  www.deq.virginia.gov
Virginia Department of Environmental Quality
Office of Water Permit Programs
Industrial Pretreatment/Toxics Management Program
Mail:          P.O. Box 1105, Richmond, VA  23218 (NEW!)
Location:  629 E. Main Street, Richmond, VA  23219
PH:         804-698-4028
FAX:      804-698-4032