Air pollution in cities is a global problem that has reached crisis proportions in places like China and India. In our country, since the Clean Air Act was passed in 1970, there has been a great deal of effort exerted in controlling pollution from vehicles. A combination of pollution-limiting changes to engines, fuels, and pollution control systems has significantly reduced the amount of air pollution associated with the transportation sector.
As a result, chemical products like household cleaners, pesticides, paints and perfumes containing petroleum-derived compounds now rival motor vehicle emissions as the largest source of urban air pollution.
According to a recent study led by the National Oceanic and Atmospheric Administration, even though motor fuel utilizes 15 times more petroleum than chemical products, the chemical products contribute just about as much to air pollution. Worse still, these products produce about twice as many tiny particles that can damage people’s lungs as vehicle emissions do.
One of the reasons for the disproportionate impact of chemical product emissions is that vehicle systems are designed to minimize the loss of gasoline to evaporation in order to maximize fuel efficiency. Chemical products, on the other hand, are often literally designed to evaporate (for example paints and perfumes.) So more so-called volatile organic compounds get into the air.
Basically, as transportation becomes cleaner, other sources become more and more important. In Los Angeles, for example, chemical pollutants now are a bigger problem than car exhaust. In addition, in contrast with vehicle exhaust, emissions from chemical products are typically much more concentrated indoors than outdoors, leading to even greater health risks.
As we focus on cleaning up our air, we have to realize that the problem is not just cars anymore.
Photo, posted April 11, 2011, courtesy of Flickr.