attention turns to phthalates, chemicals found in a variety of consumer product

[Guest guest]

MALE, INTERRUPTED

[Rachel's introduction: As more genital birth defects are seen in boys,

attention turns to phthalates, chemicals found in a variety of consumer

products.]

_http://www.precaution.org/lib/08/prn_male_interrupted.081027.htm_

(http://www.precaution.org/lib/08/prn_male_interrupted.081027.htm)

By Faye Flam, Inquirer Staff Writer

 

At Children's Hospital of Philadelphia, surgeon Howard Snyder says he and

his colleagues repair the genitalia of roughly 300 baby boys every year --

about double what they did when he started his practice 30 years ago.

 

He's not the only doctor who's noticed an increase in this kind of birth

defect.

 

The most common of them, hypospadias, nearly doubled in the United States

between the late 1960s and early 1990s, according to researchers from the

Centers for Disease Control and Prevention.

 

Snyder suspects that while in the womb, some of these boys may have been

affected by hormone-disrupting chemicals called phthalates, found in dozens of

consumer products.

 

These chemicals give plastics flexibility, prevent perfumes from losing

their scents, and keep nail polishes from chipping.

 

But in lab rats and mice, doses comparable to those we humans absorb from

the environment can disrupt the formation of male genitals and otherwise

feminize male animals. One small study from the University of Rochester also

linked

these chemicals to irregularities in male genital development.

 

Despite that, phthalates are added to numerous products ranging from

deodorants to shower curtains to IV tubing in hospitals.

 

While the European Union has banned one type of phthalate in nail polishes

and several others in children's toys, the U.S. Environmental Protection

Agency is " assessing the toxicity of several phthalates, " and awaiting results

of

a National Research Council study, expected next year, a spokesman said.

 

The specific problem that concerns Children's Hospital's Snyder -

hypospadias -- is considered an incomplete development of the male organs,

causing a

boy's urethra to exit the underside of his penis. In most cases, surgeons can

reroute the urethra, but it can take several difficult operations.

 

While there's yet no direct link between this defect and phthalates, the

dramatic increase in cases and the animal data have many doctors concerned.

 

The American Chemistry Council, a trade group, defends the compounds, saying

that the animal data may not apply to humans.

 

Chris Bryant, a council spokesman, cited a council news conference, stating

that dozens of studies found no link between phthalates and adult diseases.

 

Industry and federal toxicologists also questioned the validity of the one

human study, he said, because it was small and flawed in its methods.

 

But the animal data alone should prompt concern, said Theodore Schettler, a

physician and science director of the Science and Environmental Health

Network, an environmental advocacy group.

 

" There's a huge animal database showing how exposures to phthalates during

development can have effects at levels hundreds of times lower than these

needed to show any impact on an adult, " he said.

 

Timing of the exposure matters, and the most harm may occur between the

eighth and 15th weeks of pregnancy, when a fetus' sexual differentiation

starts,

he said.

 

" If my testosterone dropped by 20 or 30 percent for a couple of days, it

wouldn't matter, " he said. " But for a developing fetus, it could matter a whole

lot if there was a substantial drop in testosterone. "

 

Phthalates fall into a group of chemicals called endocrine disruptors

because they either mimic or block the action of human hormones. Phthalates

interfere with the synthesis of testosterone.

 

Bisphenol A, another controversial chemical that is found in plastics,

 

can mimic female hormones. Consumers' concerns about bisphenol A, which has

been used for years to make plastics stiff, have prompted some producers and

retailers to announce in recent months that they would stop using and selling

it.

 

The attorneys general of New Jersey, Delaware and Connecticut sent letters

to 11 manufacturers two weeks ago, urging that the chemical be eliminated from

baby bottles and other children's products. A U.S. Food and Drug

Administration advisory committee is scheduled to discuss conflicting reports

about

bisphenol A on Friday.

 

Phthlates affect males more than females, at least in animals, because of

the way sex organs grow. Developmental biologists say that up until eight

weeks, fetuses have the rudiments of both male and female sex organs. After

that

point, those with a Y chromosome develop gonads that are supposed to secrete

testosterone, after which the male hormone starts turning the fetus into a

male.

 

Testosterone starts the construction of male genitalia. As part of that, the

opening of the urethra migrates from a position near the testicles to the

end of the penis. Hypospadias is thought to result from incomplete

masculinization.

 

No studies so far have directly connected hypospadias to phthalate exposure,

but one study by University of Rochester researcher Shanna Swan suggested a

link to anatomical variations.

 

Swan, a professor of environmental medicine and obstetrics/gynecology,

collected urine samples from several hundred pregnant women and tested them for

nine compounds known to come from metabolizing phthalates.

 

Then she asked pediatricians to conduct a standard genital exam on 134 boys

born to these women.

 

She found that boys whose mothers were most exposed to certain phthalates

were more likely to have undescended testicles and to have smaller penises.

 

More pronounced was a feature known to indicate feminization in lab animals

-- a shortened distance between the genitals and the anus. This so-called

anogenital distance, or AGN, is normally twice as long in boys as in girls, as

it is in male rats compared with females. Swan found that boys of mothers with

the highest phthalate levels during pregnancy were much more likely to have

relatively short AGNs.

 

Not all phthalates affected boys in the study. A common one that did was

called DBP, or dibutyl phthalate, an ingredient in nail polish, hair sprays,

perfumes, and other personal-care products.

 

The chemistry council said the study was too small to be considered valid.

 

University of California San Francisco urologist Larry Baskin said he was

trying to get grant money for a larger study to check these findings. In the

meantime, he said, " I think there's enough animal evidence that it's reasonable

to have a warning label for pregnant women. "

 

The problem is that no one is quite sure how people are getting exposed,

said the Environmental Health Network's Schettler. The human body can clear out

phthalates in a day or two, but many people seem to continue picking it up

from the environment.

 

Another common phthalate, DEHP, is used to make plastic flexible in shower

curtains, vinyl flooring, and IV bags and tubes. Some pregnant women and their

babies may get a harmful dose of DEHP in the hospital, he said.

 

Pregnant women may also be absorbing DBP from personal-care products and

cosmetics, Schettler said. " You'll almost never find it on the label, " he said.

Because it's often used as a solvent for fragrances, companies are allowed to

simply list " fragrance " on the label of DBP- containing products.

 

He said that a few years ago he participated in a study along with the group

Health Care Without Harm. They bought dozens of common personal- care

products from supermarkets and pharmacies and analyzed them for phthalates. " We

found them in one form or another in 70 percent of the products we tested, " he

said.

 

Unfortunately, he said, regulatory agencies are swamped with untested

substances. " You're being exposed to a series of chemicals that have not

undergone

safety testing because our regulatory system is nonfunctional. "

 

Snyder, at Children's Hospital, said he became concerned about phthalates 15

years ago when he noticed the number of hypospadias cases seemed to be

rising.

 

And while hypospadias can be corrected, he said, it still can be traumatic

for patients.

 

" It's a very tricky surgery, " Snyder said. Though his specialty is

officially urology, he said, " you have to be well-versed in plastic surgery to

be able

to handle these delicate tissues in boys between 6 and 9 months old. " Some

children need to come back for several surgeries.

 

" It bothers kids to have genitalia that don't look standard, " he said. " Boys

should be able to stand up and write their names in the snow. "

 

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