Are our products our enemy?

[Guest guest]

Are our products our enemy?

By Weise, USA TODAY 8-3-2005@

Like the glint of a knife in the dark, a laboratory

accident in 1998 helped scientists realize that some

chemicals commonly used to make life more convenient

can be health hazards.

Since what they still call " the disaster " in

geneticist Pat Hunt's lab, more scientists have come

to suspect that, even in tiny amounts, some of the

chemicals that keep our food fresh, our hair stylish,

our floors shiny and our fabrics stain-free might be

confusing our hormone systems and derailing fetal

development.

Hunt says she's not the only researcher who has come

to study these chemicals — called endocrine disruptors

— because she got " smacked in the face " by an

unexpected result. " Almost everybody in this field was

drafted into this, but we feel we can't leave this

area, because if this stuff is dangerous, then we need

to know a whole lot more about it. "

Here's what happened seven years ago at Hunt's lab at

Case Western Reserve University in Cleveland:

While researching why women miscarry because of

chromosomal abnormalities in the fetus, Hunt found

that the eggs of the mice she was studying were

inexplicably developing serious chromosomal problems.

It took months for Hunt to realize that the problem

was caused by a temporary employee's error. " He had

two bottles of detergent, one for the floor and one

for the cages, and he picked up the wrong one. "

The harsh alkaline floor detergent caused the plastic

in the cages to begin to disintegrate, which leached a

chemical called bisphenol A into the animals' food and

water. Suddenly, 40% of the eggs had chromosomal

abnormalities.

The question this posed for scientists: If plastic can

do this to mice, what dangers do people face?

Out of sight

You can't see them. There's no way to tell from a

product label whether they've been used. And they

don't appear in every variation of the same kind of

product. Scientists are not always sure how they are

transmitted from product to person.

These man-made chemicals are endocrine mimics. By

sheer chance, their molecules are perfectly shaped to

form keys that open the hormonal locks that control

the proper development and function of our bodies.

They may do little harm to adults, but evidence mounts

that they can wreak havoc in the development of

fetuses and children:

• Ana Soto, a professor of cell biology at Tufts

University School of Medicine in Boston, found that

exposure to bisphenol A, a common ingredient in

plastics such as reusable water bottles and the

housing of laptop computers and in resins that line

some food cans and dental sealants, can change the

course of fetal development. Fetal mice developed

tissue associated with higher rates of breast cancer

later in life. Soto's findings were presented in San

Diego this summer at the yearly meeting of the

Endocrine Society, the largest professional

organization of endocrinologists.

• Exposure to phthalates (pronounced THAL-ates) comes

from direct contact with products that contain them,

such as vinyl flooring, detergents, automotive

plastics, soap, shampoo, deodorants, fragrances, hair

spray, nail polish, plastic bags, food packaging,

garden hoses, inflatable toys, blood-storage bags and

intravenous medical tubing, according to the Centers

for Disease Control and Prevention.

Research published in the journal Environmental Health

Perspectives by epidemiologist Shanna Swan at the

University of Rochester in New York found an

association between higher phthalate levels in

pregnant women and changes in the genitals in their

infant sons that suggest lower concentrations of male

hormones and can lead to incomplete testicular

descent.

Jim Pirkle, deputy director for science at the CDC's

Environmental Health Laboratory, says that while more

research must be done to replicate Swan's findings,

" The big concern of the phthalates is that they have

anti-androgen activity. They get rid of things that

are in the testosterone line, the things that make a

man a man. "

• In a separate study, Harvard and CDC researchers

found that boys in neonatal intensive care units had

phthalate levels about 25 times higher than the

general population. This is two years after the Food

and Drug Administration warned hospitals that

phthalate leaching out of plastics used in medical

devices carries such a health risk to baby boys that

those devices shouldn't be used on babies or on

pregnant women carrying male fetuses.

• Perfluorooctanoic acid (PFOA) is a building block of

chemicals used to make stain-, grease- and

water-resistant coatings such as Teflon and Gore-Tex.

An Environmental Protection Agency scientific advisory

panel recently concluded PFOA is a likely carcinogen

with liver, breast, pancreatic and testicular cancer

of specific concern. The EPA has not yet adopted the

finding and has not set acceptable limits.

• A study released last month by the U.S. Geological

Survey and the City of Austin found that runoff from

parking lot sealant, used to protect and beautify

asphalt, is a source of polycyclic aromatic

hydrocarbons known to be a likely carcinogen and a

possible reproductive toxicant.

• Research published by Skinner, director of

the Center for Reproductive Biology at Washington

State University, showed that exposure of rodents to

an insecticide called methoxychlor and a fungicide

called vinclozolin, both endocrine disruptors, caused

changes in mice that affected not just the offspring

exposed to the chemical in utero but all males born

for at least four subsequent generations.

" If an environmental toxin can cause a

transgenerational effect and affect your grandchild,

this is a much more major hazard we need to consider

in environmental toxins, " Skinner says.

Trace amounts widespread

Although these chemicals have been widely used since

the 1960s, it has been only in the past five or so

years that scientists have had tests sensitive enough

to measure the extremely low doses present in the

environment and our bodies. And they have found that

phthalates and PFOA are ubiquitous.

In random sampling of participants in a national

health survey, the CDC has found trace amounts of

phthalates in all urine tested. In January, the

Environmental Protection Agency reported that adults

tested in three human biomonitoring studies had trace

amounts of PFOA in their bloodstream.

" Certainly, we're concerned about what's happening to

adults, but we're especially concerned about

developmental exposure of the fetus and young child, "

Retha Newbold, a developmental endocrinologist at the

National Institute of Environmental Health Sciences,

told the Endocrine Society.

" Protective mechanisms that are available to the

adult, such as DNA repair, the immune system,

detoxification enzymes, liver metabolism and the

blood/brain barrier, are not fully functional in the

fetus or newborn, " Newbold says. " Exposures to

endocrine-disrupting chemicals during critical states

of development may have permanent consequences, some

of which may not be expressed or detected until later

in life. "

But chemical producers say researchers aren't coming

up with " smoking guns, " in the words of Brozena,

assistant general counsel to the American Chemistry

Council, an industry group. " The International Union

of Pure and Applied Chemistry did this pretty

comprehensive review and decided there was no evidence

of humans being adversely impacted by environmental

exposures to endocrine-active substances, " she says.

The past three years have seen significant advances in

" epidemiological evidence and the development of

animal models " to help understand how endocrine

disruptors work, says Korach, director of the

Environmental Disease and Medicine Program at the

National Institute of Environmental Health Sciences.

The means of exposure to endocrine disruptors can be

difficult to determine. " It's not like smoking was, "

says Swan, who did the phthalates research. " They're

all around us, in food, in household dust and in

products, but they're invisible.

" People don't know when they're exposed. Our old

epidemiological tools — interviews, looking at medical

records and questionnaires — are useless. We have to

look at the body. But it's expensive and hard to get

people to give blood. "

And if figuring out what a tiny amount of one chemical

does is hard, researchers say they have almost no idea

what happens when many chemicals interact. " Nobody's

exposed to one thing, " Korach says. " The problem is we

haven't done enough yet to look at combinations. "

The big picture

Of course, each of these studies is only one small

piece in a much larger puzzle that still must be

filled out, says Earl Gray, a senior research

biologist with EPA's endocrinology branch. " There are

things that we know for sure, " he says. " It's obvious

and has been for a long time that there are effects in

wildlife due to endocrine-disrupting chemicals. "

In humans, the evidence isn't clear-cut: " A single

study doesn't create a disaster; it's a hypothesis

that needs to be replicated. "

Others wonder why compounds are turning up harmful in

some studies, while " every test we've ever done in the

past says they're inactive, " says Lamb of

scientific and engineering consulting firm Blasland,

Bouck & Lee Inc.

" These things raise questions that need to be

addressed by industry and government, " Lamb says. " I'd

hate for people to come away feeling like they're in

danger if they use these products. "

Environmental groups and researchers maintain that

it's possible to have modern conveniences without all

the health risks.

They note that the government has been able to

eradicate other chemical dangers. " We've seen lead

levels dramatically decline in kids, PCB

(polychlorinated biphenyl) levels decline, all because

of direct government intervention that gets these out

of the environment, " says Jane Houlihan, a scientist

with the Environmental Working Group.

The EPA says it's working on that.

The agency's Office of Pollution Prevention and Toxics

has been exploring " green chemistry " options — a

fundamental approach to pollution prevention on a

molecular level — for 10 years now.

If the chemicals that make plastics soft are endocrine

disruptors, chemists now have the ability to design

them without that side effect. It just takes

convincing industry that the result is going to be

cheaper in the long run, says Ellen Weber,

director of the EPA's pollutions and toxics research

group. " When you can replace a known toxic chemical

with sugar or cornstarch or sunlight, you know you've

got an environmentally preferable product. "

Dr. DeSiena, D.C.

Washington Street Chiropractic Center, L.L.C.

771 Washington Street

Eugene, OR 97401

(541) 686-BACK (2225)

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