— Chris Smith, Bethesda, MD

“Indoor air pollution” in homes and offices has been studied extensively in recent years — with sometimes alarming conclusions that have led the building industry to rethink many aspects of design and choice of materials. But the health hazards lurking inside car interiors, where most Americans spend 90 minutes on average each day, have largely escaped scrutiny.

However, on January 11 of this year, the Michigan-based Ecology Center released a report entitled: “Toxic at Any Speed: Chemicals in Cars and the Need for Safe Alternatives.” In this new report, researchers detail how heat and ultraviolet (UV) light can trigger the release inside cars of a number of chemicals linked to birth defects, premature births, impaired learning and liver toxicity, among other serious health problems.

Polybrominated diphenyl ethers (or PBDEs, often used as fire retardants) and phthalates (chemicals used to soften plastics) are the primary culprits. Part of the seat cushions, armrests, floor coverings and plastic parts in most car interiors, these chemicals are easily inhaled or ingested through contact with dust by drivers and passengers. The risks are greatest in summer, when car interiors can get as hot as 192º F.

Motorists can lessen their risks by rolling down car windows, parking in the shade and using interior sun reflectors. But the Ecology Center is urging carmakers to stop using such chemicals in the first place. “We can no longer rely just on seatbelts and airbags to keep us safe in cars,” says Jeff Gearhart, the Ecology Center’s Clean Car Campaign director and co-author of the report. “Our research shows that autos are chemical reactors, releasing toxins before we even turn on the ignition. There are safer alternatives to these chemicals, and innovative companies that develop them first will likely be rewarded by consumers.”

In preparing its report, the Ecology Center collected windshield film and dust from inside 2000 to 2005 models made by 11 leading manufacturers. Volvo was found to have the lowest phthalate levels and the second lowest PBDE levels, making it the industry leader in interior air quality. Volvo also has the toughest policies for phasing out these chemicals. Other makers claim they have eliminated some but not all PBDEs and phthalates. Ford, for example, reports that it has eliminated PBDEs from “interior components that customers may come into contact with.” Honda reports it has eliminated most phthalate-containing PVC. Other carmakers tested were BMW, Chrysler, GM, Hyundai, Mercedes, Subaru, Toyota and Volkswagen.

With indoor air pollution already listed by the U.S. Environmental Protection Agency as one of the top five environmental risks to public health, the Ecology Center is especially concerned that concentrations of PBDEs are five times higher inside cars than in homes and offices. The organization is calling on the U.S. government to ban the worst forms of PBDEs and phthalates from use in any indoor environments, and has enlisted the help of several concerned members of Congress to help write legislation to that effect.