Invisible hitchhikers may be lurking in your car

By Michael Abrams

updated 11:09 a.m. ET Jan. 13, 2008

"Oh great, my child's going to be a mutant," says Lou Terrier as the woman explains to him why she wants to look inside his car. Then Bobbi Chase Wilding slips into the passenger seat of Terrier's family wagon, takes a large gray gun from a shopping bag, removes a rectangular, metallic cap from the business end, aims it point-blank at the dashboard, and pulls the trigger.

Nothing happens. Or at least nothing Terrier can see. However, Wilding's weapon is working perfectly as she continues to zap the dash. The Innov-X XRF (for x-ray fluorescence) Analyzer identifies the chemical composition of materials, including the abundance of plastic and fabric, inside an automobile. A discerning eye like Wilding's can then determine that, say, chlorine in the glove-compartment door makes it a possible source of airborne toxins known as phthalates.

A poisonous glove compartment? Buckle up: Emerging research suggests that a car's capacity to do violence to the human body may not be limited to high-speed collisions. In fact, just sitting in the garage with the ignition off could be risky. Best-case scenario, the fumes wafting from the materials surrounding you might merely exacerbate pre-existing asthma or allergies; on the scarier end of the spectrum, those airborne compounds could be carcinogens. And the absolute worst-case scenario: The dashboard's to blame for your small penis.

"I love the smell of deca in the morning," says Wilding as she fires away at the car, confident the XRF will reveal the presence of decabromodiphenyl ether, the world's most common brominated flame retardant.

The dangers of phthalates
Wilding works for the Ecology Center, a nonprofit environmental watchdog group that in 2006 published Toxic at Any Speed: Chemicals in Cars and the Need for Safe Alternatives. The report examined two categories of chemicals lurking in car materials: phthalates and brominated flame retardants, such as deca. Phthalates make plastics softer and more elastic. They have also been shown to lead to liver and kidney damage in rodents. As for the flame retardants, they act like rat poison, too, causing brain damage and thyroid problems.

And while the research on humans is more limited, it's no less alarming. One 2004 study from Sweden showed that children raised in houses with high concentrations of phthalates in the dust were more likely to develop asthma and allergies. Another recent study from the University of Rochester found that men with the most phthalates in their bodies had waists 3 inches wider than those with the least. Still more research suggests that we're being attacked in utero, too: A 2005 paper in Environmental Health Perspectives reported that mothers with higher levels of phthalates in their urine had sons with less-developed genitalia.

Given the potential dangers, the researchers at the Ecology Center decided to see if these toxins would turn up inside cars. In their study of 13 different brands, they sampled the film that collected on the inside of each vehicle's windshield, working under the assumption that what makes its way onto the windshield can easily end up in your lungs. The results, published in Toxic at Any Speed, revealed significant levels of phthalates and brominated flame retardants.

The same year the Ecology Center conducted its study, Japanese scientists at the Osaka Prefectural Institute of Public Health performed an even more extensive analysis. They sampled the air inside 101 newer cars and found that each vehicle contained 241 different airborne toxins (also known as volatile organic compounds, or VOCs), including a class of carcinogens called aromatic hydrocarbons.

Finally, in a 2007 study, scientists at Taiwan's Hungkuang University analyzed the air in 20 new vehicles, including coupes, compacts, sedans and SUVs. Once again, the results revealed significantly elevated VOC levels in all of the cabins. Worse, one sedan contained 200 times more xylenes, toxic aromatic hydrocarbons, than human beings can safely inhale.

'Clearly toxic'
If that isn't enough to make you want to stick your head out of the sunroof, consider this: The threat posed by individual chemicals may be dwarfed by what happens when those chemicals gang up. "One interesting thing about indoor air pollution is that there are unique chemical reactions going on in the air between and among chemicals," says Ted Schettler, M.D., science director at the Science and Environmental Health Network, a nonprofit group pushing for changes in environmental policy on the local and national levels. "People have done the analysis and found a synthesis of new compounds, some of which are clearly toxic through a variety of mechanisms."

Terrier's car, a Toyota Matrix, turns out to be not too frightening. It has a tad too much flame retardant on the steering wheel, but the doors, seat cushions, and dashboard come out clean. However, the padding of Terrier's child seat — temporarily vacated by the potentially mutant child — contains a worrisome amount of bromine: 1,850 parts per million. In pool water, where bromine is used as a disinfectant, the concentration isn't supposed to be greater than 10 parts per million.

Given that the child seat didn't come with the car, the results don't seem to support the Ecology Center's claim that the average automobile is hell on wheels. One explanation may lie in the age of the Matrix — it's a 2003, which is the same year that University of California scientists compared new automobiles with old ones and found that the older vehicles often contained 50 percent fewer VOCs. Research suggests that after about 6 months, the seats and other surfaces in a new car have emitted most of the VOCs capable of entering the air.

But even if the car had been filthy with phthalates, some scientists would argue that Wilding still lacked proof that the passengers were being poisoned.

The worst-case scenario
"If you talk to a toxicologist, you always have to talk about dose," says Jeroen Buters, Ph.D., a toxicologist at the Technical University of Munich. He explains that low dosages of potentially poisonous substances, like, say, aspirin or whiskey, are simply not toxic. But quantifying exactly what dose of VOCs an individual driver might be receiving during his daily commute is tricky, which is why Buters decided to simply expose human cells — without the human — to that very environment.

Buters and his colleagues took two cars of the same make — one brand-new, the other 3 years old — and began by exposing them to 14,000 watts of light from 28 halogen lamps. With the windows closed, that was enough heat to raise the temperature inside both cars to 150°F. The reason for the heat treatment: When the air temp hits triple digits, there's a loosening of the molecular bonds that keep VOCs attached to cabin materials, boosting total toxins in the air. So in essence, Buters re-created the veritable sea of VOCs we wade into upon entering a car that's been baking in the sun all day.

Once the test conditions were set, Buters exposed samples of lung cells and skin tissue to air extracted from inside the enclosed cabins. Two days later, he assessed the impact. "From what we could see and test, there was nothing but a slight aggravation of allergies, and we did the worst-case scenario," Buters says.

Jeff Gearhart, the director of the Ecology Center's Clean Car Campaign, calls the study flawed. "They sampled too few vehicles and too few chemicals to say anything definitive," he says. "We have seen considerable variability among vehicles, depending on the manufacturer and the type of interior trim. He did not specify the materials or the vehicle make."

Buters says he won't reveal the makes and models of the test cars for fear of litigation (despite the happy outcome), but he does mention that the vehicles had leather interiors, which may indeed have had something to do with the results. According to the Ecology Center's ongoing evaluation of VOCs in cars (posted at healthycar.org), the pricier the car, the less toxic its materials. Luxury cars tend to contain safer flame retardants, leather instead of plasticized vinyl, and more stable plastics overall. Nevertheless, Buters believes the results send the right message to consumers.

"We all know that some people are more sensitive (to smells) than others," he says. "Sometimes if you don't feel well, you say 'why?' And you start looking for reasons."

MORE FROM ALLERGIES AND ASTHMA

Allergies and asthma Section Front

Outdoor pools can boost child's asthma risk Inhalers for lung problems tied to heart attacks French itch with complaints over Chinese chairs Confusing food allergy warnings may get clearer Stress makes allergies worse and last longer Ulcer bacteria may protect kids from asthma 'Good' bacteria may ease allergy symptoms FDA: Asthma patients should get new inhalers Peanut allergy treatment on the horizon? Dogs help keep children’s allergies at bay   Allergies and asthma Section Front   Add Allergies and asthma headlines to your news reader: