Vehicle emissions might be dropping, but your perfume and nail polish are as bad as ever.

Would you ever let your child stand behind the tailpipe of an idling vehicle? It's unlikely. But there's a good chance you wouldn't say anything if your kid wandered into a room while you were spritzing yourself with perfume, repainting your nails, varnishing a shelf, or scrubbing a bathtub with a chemical cleaner. For many people, these are common, everyday actions that are not associated with danger. But a new study reveals that personal products are responsible for a great deal more air pollution than we may realize.

Up until recently, vehicles were thoughts of as the greatest source of air pollution. Indeed, the Environmental Protection Agency estimates that about 75 percent of volatile organic compounds (or VOCs) come from fuel-related sources and about 25 percent from chemical products. But researchers at the University of Colorado at Boulder think otherwise, based on a study of roadside air in Los Angeles. They say the split is closer to 50-50. From the press release:

"The scientists concluded that in the United States, the amount of VOCs emitted by consumer and industrial products is actually two or three times greater than estimated by current air pollution inventories, which also overestimate vehicular sources."

In other words, everyday products like hair spray, air freshener, cleaners, colognes and perfumes, pesticides, glues, and conventional cleaning products contribute a far greater amount of pollution to the atmosphere than previously thought. Cars, in the meantime, have been subject to tighter emissions regulations that have resulted in them becoming cleaner than they used to be (although never clean enough, as we often lament on TreeHugger). This study shows that regulatory efforts to curb emissions have been effective in the U.S., but that those regulations need to extend to other categories.

Why do household products have such a significant effect on air quality? Study co-author and atmospheric scientist Jessica Gilman says it is because of how they're used. Obviously we use far more gallons of fuel in a lifetime than we do perfume, but these products are stored and used in drastically different ways:

"Gasoline is stored in closed, hopefully airtight, containers and the VOCs in gasoline are burned for energy. But volatile chemical products used in common solvents and personal care products are literally designed to evaporate. You wear perfume or use scented products so that you or your neighbor can enjoy the aroma. You don't do this with gasoline."



Another study author, Joost de Gouw, breaks it down further: "For every kilogram of fuel that is burned, only about one gram ends up in the air. For these household and personal products, some compounds evaporate almost completely."

The problem with personal care and cleaning products is that they are largely unregulated. Clearly, this needs to change. Alastair Lewis, a professor of atmospheric chemistry at the University of York, told the Guardian:

"This paper is interesting because it shows that domestic use of VOCs is beginning to dominate, displacing the traditional sources from vehicles and industry. If the paper is right then many countries will need to rethink how they plan to meet their international obligations to reduce emissions."



VOCs have been linked to a broad range of health problems, including headaches, nausea, dizziness, respiratory irritation, visual disorders, and memory loss. In laboratory animals, longterm exposure to high levels of some VOCs has caused cancer and affected the liver, kidney and nervous system (via New York State Dept. of Health).

It's as good a reason as any to switch to clean, green, homemade cleaning and beauty products. Check out our vast archives on TreeHugger for ideas to get started.