The Plastics Revolution

[Guest guest]

The Plastics Revolution

It Changed Our World. But Are We Trading Safety for Convenience?

By Ranit Mishori, Special to The Washington Post

Tuesday, April 22, 2008; HE01

When people say plastics are everywhere, they really mean everywhere:

in the containers that hold your food; in the pipes that carry your

water; in the bottles you use to feed your infant; in windows frames,

shower curtains and raincoats; on your head in the form of safety

helmets; on your face in the form of eyeglasses; in your hands when

you talk on a phone or type on a keyboard. They're in clothing;

they're in toys; they're in bandages, lipstick and nail polish.

So ubiquitous. So useful. And, some say, so dangerous.

Many scientists and environmental advocates believe man-made

components in plastics -- particularly a group of compounds called

phthalates and another hormonally active chemical known as bisphenol

A, or BPA -- can leach harmful chemicals that get absorbed into our

bodies. Some blame plastics for increased rates of cancer, asthma,

neurological disorders and infertility.

Those fears, debated for more than a decade, were ratcheted up last

week by two events: A draft report by the National Toxicology Program

acknowledged for the first time " some concern " that BPA may affect

neural and behavioral development " in fetuses, infants, and children

at current human exposures. " The federal health agency's report

included early puberty in girls and hyperactivity among these

developmental disturbances. And Health Canada, the main government

health department for that country, designated BPA as a " dangerous

substance, " moving Canada a step closer to limiting the chemical's use.

" The health impacts associated with these chemicals are very severe, "

says Schade of the Center for Health Environment and Justice

(CHEJ), an advocacy group that wants these components banned from

consumer products.

Some government and academic experts agree. People worried about

chemicals in plastic aren't just " nervous Nellies, " says Lynn Goldman,

a professor of environmental health sciences at the s Hopkins

Bloomberg School of Public Health.

Others, led by the plastic and vinyl industry, say recent reports are

nothing but a scare campaign. " It is . . . foolish to ban something

that's safe and has proven itself for decades, " says Blakey, a

spokesman for the Vinyl Institute, an industry group. Blakey dismisses

the main evidence of harm cited by the anti-plastic camp -- a set of

studies that involved mostly animal subjects -- as " flimsy. "

The financial stakes are huge: Plastics is the country's third-largest

manufacturing industry, employing 1.1 million workers and producing

nearly $379 billion worth of goods each year, according to the Society

for the Plastics Industry.

The battle lines are clear. But not the science.

Before last week's report, independent panels sponsored by the

National Institutes of Health, the Environmental Protection Agency,

the Consumer Product Safety Commission and the Food and Drug

Administration examined the data on plastics safety and drew

conflicting conclusions. Shelby, an official with the National

Toxicology Program, calls the debate over plastics safety " very

polarized. "

" Similar to the tobacco companies " is how Schade describes the

chemical industry's tactics in defense of plastics, including " hiring

scientists to put out questionable studies. "

" A political campaign by extremist groups to demonize materials that

have been very useful " is what Blakey calls the anti-plastics movement.

And consumers? They've been left to sort out the mess on their own.

Food-Warming Worries

First, a look at BPA.

It's in CDs, dinnerware and sports safety equipment; incubators,

heart-lung machines and IV bags; bottle tops, packaging, dental

sealants and Nalgene bottles.

It is also in our bodies. A Centers for Disease Control and Prevention

analysis detected BPA in urine samples of nearly 93 percent of 2,517

people who took part in a national health survey from 2003 through 2004.

According to the CDC, women had higher average levels (2.9 micrograms

per liter) than men (2.6); children age 6 to 11 had higher levels

(4.5) than adults over 20 (2.5). These numbers are not in dispute.

Virtually everything else is, starting with what BPA's presence in

urine might mean. It could be evidence that the chemicals reside in

our body tissue or bloodstream; it could also suggest that our bodies

know how to expel them.

Then there's the question of how these chemicals might have gotten

there. " What's hard to do is connect the dots, " Goldman says, " between

finding it in people's urine and which uses are causing the chemicals

to be in their urine -- to understand what the pathways of exposure are. "

Also unclear is whether having BPAs in our bodies is dangerous.

" It is very difficult to show that exposures lead or have led to

adverse health effects in humans, " says Shelby, director of the

National Toxicology Program's Center for the Evaluation of Risks to

Human Reproduction. (The toxicology program is part of the National

Institutes of Health.)

Nonetheless, in a report this winter titled " Toxic Baby Bottle, " a

group of U.S. and Canadian environmental and public health groups

reviewed studies showing BPA's tendency to leach out of plastic (and

into foods and liquids) when heated. The group called on government

agencies in both countries to impose " an immediate moratorium on the

use of bisphenol A in baby bottles and other food and beverage

containers. "

The American Chemistry Council, representing many companies in the

plastics industry, protested that the study subjected bottles to

higher temperatures than are commonly used and for longer times.

" Polycarbonate baby bottles have a 50-year safety track record, " reads

a statement from the council, which said the report provided no new

relevant information on BPA safety.

But the people behind the baby-bottle report argue that exposure -- in

and of itself -- is evidence of harm. " There is growing scientific

evidence that shows that BPA is harmful even at extremely low levels

of exposure, " Schade says.

He points to a large body of studies on animals in which BPA caused

alterations to the reproductive, neurological and metabolic systems.

" Scientific studies on lab animals, " Schade says, " show that BPA might

have adverse health impacts ranging from breast and prostate cancer,

thyroid disease, early puberty in girls and ADHD. "

But animals are not humans, and Blakey says findings from animal

studies " are often not translatable to humans. "

The Coalition for Consumer Choice, an industry group made up of

organizations, associations and businesses " committed to supporting

the continued safe use of everyday products made from bisphenol A, "

adds that " human exposure levels are typically more than one million

times lower than levels shown to cause no adverse effects in

experiments involving multiple generations of laboratory animals. "

That said, virtually any scientific investigation into the safety of

suspect chemicals and drugs starts with animal models, because of

ethical concerns about exposing humans to toxins. Lab work with

animals has often resulted in specific recommendations related to humans.

In 2006, an independent panel of experts assembled by the NIH and the

EPA looked at more than 700 BPA studies and concluded that the

mechanism by which it affects cells and tissues is essentially

identical in animals and humans. The panel concluded that the animal

studies of BPA should be taken seriously as an indicator of potential

harm to humans.

The next year, another panel -- organized by Shelby's center -- issued

a far less alarming review of about 500 studies. But the panel's

integrity was damaged by a finding that a company hired to compile

data for the report had a conflict of interest.

Phthalate Debate

The U.S. chemical industry is more at odds with overseas practices in

its use of the other controversial component of many plastics: the

group of compounds called phthalates. Phthalates are banned in the

manufacture of toys in most European countries. A similar ban exists

in California, and 12 other states including land are considering

bans.

Phthalates are also known as plasticizers, chemicals that prolong the

life span and durability of plastics and increase their flexibility.

Like BPA, phthalates are used in hundreds of products, including vinyl

floors, adhesives, food packaging, automotive parts, clothing and

personal-care products such as soap, shampoo, hair spray, nail polish

and underarm deodorants. According to the Food and Drug

Administration, phthalates are used at low concentrations to reduce

cracking of nail polish, avoid stiffness in hair sprays, and as

solvents and perfume fixatives in various other products.

Within this group of chemicals, two are under particularly close

scrutiny -- DEHP, found mostly in medical products, and DINP, found

mostly in toys -- for their potential toxic effects on the

reproductive and endocrine systems.

Again, industry representatives such as the Vinyl Institute's Blakey

say " there is no proof that phthalates have ever caused harm to

humans. " The FDA, looking into the use of phthalates in cosmetics,

reported that the data it reviewed " did not establish an association

between the use of phthalates in cosmetic products and a health risk. "

As a result, the FDA determined there was " insufficient evidence upon

which to take regulatory action. "

As with BPA, the evidence is mostly limited to animal studies.

One of the few human studies, published earlier this year in the

journal Pediatrics, found that the urine of infants recently exposed

to baby lotion, powder and shampoo had higher levels of phthalates or

their byproducts. But the study did not prove the products used were

responsible for the elevated readings.

Last year, a study in Environmental Health Perspectives found that

higher levels of phthalate byproducts correlated with obesity and

insulin resistance. Another study in the same journal found that

higher levels of phthalate byproducts in urine were associated with

abnormal thyroid hormone levels in adult men.

Left in the Lurch

Advocacy groups haven't succeeded in their calls for a comprehensive

ban on phthalates and BPA, but some national retailers (including

Target and Wal-Mart), manufacturers (including Microsoft,

& amp; , Nike and Apple) and toymakers have begun voluntary

efforts to remove phthalates from their products.

Meanwhile, consumers who might want to limit their exposure to suspect

chemicals in plastics may find that difficult. Plastics components

must be labeled in some products, but not in others. (For tips on what

you can do, see the box at left.)

" Most people haven't had college-level chemistry or advanced

chemistry " to know what the alphabet soup of chemicals on labels mean,

says Caroline Baier-, a health scientist with the nonprofit

group Environmental Defense and an assistant professor in the

Department of Epidemiology and Preventive Medicine at the University

of land at Baltimore.

She urges consumers to make the best choices they can. But, she says,

" we can expect our government to do more. "

Goldman agrees that better product labeling " needs to be dealt with at

the pre-consumer level " -- before products get to the shelves -- and

urges the manufacturers, too, to " step up to the plate. "

One thing nearly everyone agrees on: More science is needed -- more

studies of short- and long-term effects, new models of interpreting

animal research, better testing methods.

The case of BPA and phthalates is " more subtle " than the classic " one

chemical, one disease " model, says Baier-, as in the case of

asbestos or tobacco.

We need a new way, she says, to look at how the " simultaneous exposure

to low levels of many chemicals throughout our lives can interact with

[biological] systems. "

Above all, she says, " we need a meaningful dialogue regarding the

interpretation of scientific data, however it is generated. "

Ranit Mishori is a family physician and faculty member in the

Department of Family Medicine at the town University School of

Medicine.

http://www.washingtonpost.com/wp-dyn/content/article/2008/04/18/AR2008041802836.\

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