Week of 10/7/2007

Dear EarthTalk: Is it true that some ingredients in common air fresheners can cause health problems?

—Mike Jaworski, Seattle, WA

Air fresheners are a $1.72 billion industry in the United States. An estimated 75 percent of homes use them regularly. According to a September 2007 report released by the Natural Resources Defense Council (NRDC), most common household air fresheners contain potentially noxious chemicals that degrade the quality of indoor air and may even affect hormones and reproductive development, particularly in babies.

As part of its "Clearing the Air" study, NRDC researchers tested 14 brands of common household air fresheners and found that 12 contained chemicals known as phthalates. Only two, Febreze Air Effects and Renuzit Subtle Effects, contained no detectable levels of phthalates. Products testing positive included ones marketed as "all-natural" and "unscented." None of the brands tested listed phthalates on their labels.

Phthalates are "hormone-disrupting" chemicals that can be particularly dangerous for young children and unborn babies. Like some other man-made chemicals, phthalates can affect normal hormonal processes—those that control brain, nervous and immune system development, reproduction, mental processing and metabolism—by blocking them altogether, throwing off the timing or "mimicking" natural hormones and interacting with cells themselves, with very unhealthy consequences. The State of California notes that five types of phthalates—including one commonly used in air freshener products—are "known to cause birth defects or reproductive harm."

Despite these issues, the U.S. Food and Drug Administration (FDA) does not regulate the use of phthalates or require the labeling of phthalate content on products. Other governments take the phthalate threat more seriously. The European Union forbids the most harmful phthalates in cosmetics or toys, and California Governor Arnold Schwarzenegger is expected to soon sign similar legislation for his state.

NRDC bemoans the fact that the U.S. government does not test air fresheners for safety or require manufacturers to meet specific health standards. "More than anything, our research highlights cracks in our safety system," says Dr. Gina Solomon, a senior NRCD scientist. "Consumers have a right to know what is put into air fresheners and other everyday products they bring into their homes," she says, adding that the government should keep a watchful eye on potentially dangerous products.

In conjunction with the study, NRDC—along with the Sierra Club, the Alliance for Healthy Homes and the National Center for Healthy Housing—is petitioning federal agencies to start assessing the risk air fresheners pose to consumers by testing all products now on the market. And NRDC has already begun working directly with some manufacturers to find ways to eliminate phthalates from these products.

NRDC recommends that consumers be selective and purchase only air fresheners that have the least amount of phthalates. Better yet, the group suggests consumers first try to reduce household odors by tending to their root causes or improving ventilation rather than masking them. "The best way to avoid the problem is to simply open a window instead of reaching for one of these cans," concludes Solomon.

CONTACTS: Natural Resources Defense Council

Dear EarthTalk: Are there any efforts underway to lessen the environmental impact—which must be considerable—of all the "18 wheelers" and other large vehicles that are numerous on our highways?

—Sadie Strauss, Madison, WI

According to the Union of Concerned Scientists, although large trucks account for just six percent of total highway miles driven in the U.S., they are responsible for a host of environmental threats. These include over half the soot and a quarter of the smog-causing pollution generated by highway vehicles, six percent of the nation’s global warming pollution, and more than a tenth of the country’s oil consumption.

A typical diesel-powered 18-wheeler can emit as much nitrogen oxide and fine particulates—key elements in the formation of asthma-inducing smog—as about 150 passenger cars. Although strict limitations on emissions of various pollutants from cars have been in place in the U.S. since the 1970s, trucks and other large transport vehicles have been allowed to emit as much as five times as much pollution per mile.

But thanks to new regulations put in place by the U.S. Environmental Protection Agency (EPA), new trucks coming off assembly lines in the years immediately ahead promise to be much cleaner and greener. Known collectively as the EPA’s Heavy-Duty Highway Diesel Rules, the new regulations mandate that trucks manufactured in 2007 or after produce 75-90 percent less nitrogen oxide and 90 percent fewer particulates than earlier models. Of course, with most of the trucks on the road made prior to 2007 and thus exempt from the new regulations, air quality improvements won’t happen overnight.

In the meantime, though, the federal government has also instituted new regulations mandating that diesel fuels contain 97 percent less sulfur, another primary component of smog, than previously required. This means that all diesel-powered vehicles in the U.S., new or old, will be polluting less. Regulators hope that the combination of greener trucks and cleaner fuel will eventually bring emissions from large trucks into parity per mile driven with cars and light trucks (SUVs, pickups and minivans).

Beyond making existing truck engines more efficient, new technologies promise to green the trucking industry even more. Biodiesel, a form of diesel fuel derived from renewable plant crops, is coming on strong. According to the U.S. Department of Energy, use of the most common blend, B20 (80 percent regular diesel and 20 percent biodiesel), cuts petroleum use by 19 percent, greenhouse gas emissions by 16 percent and hydrocarbon emissions by 20 percent.

Also, hybrid technologies popularized by the Toyota Prius are starting to show up in trucks. Federal Express is pioneering the use of hybrid technology in trucks by outfitting many of its new delivery trucks accordingly. And several U.S. cities now run hybrid diesel-electric buses. Environmental leaders hope such fuel- and emission-saving technologies will trickle down into the private trucking industry as well.

CONTACTS: Union of Concerned Scientists; EPA’s Heavy-Duty Highway Diesel Program