The next time someone talks trash about L.A. smog, surprise him with this:
Vehicle pollutants in the Los Angeles Basin have dropped 98 percent since the 1960s—even though drivers burn triple the gasoline and diesel fuel they did back then.
The specific pollutants caught on the decline are volatile organic compounds (VOCs), a key ingredient in the formation of ground-level ozone, which can hurt people’s lungs and damage plants.
Between 2002 and 2010 alone, the concentration of VOCs in L.A. air decreased by half, according to a new study out this month in the Journal of Geophysical Research-Atmospheres.
“The reason is simple: Cars are getting cleaner,” said the study’s lead author, Carsten Warneke, in a press release.
Warneke, an environmental scientist at the University of Colorado, Boulder, points out that this air quality upgrade won’t surprise many longtime Angelinos. In the 1960s, people in the city often couldn’t see nearby mountains through the smog. Today such poor visibility is relatively rare.
Warneke and his colleagues cite required catalytic converters, use of reformulated fuels less prone to evaporate, and improved engine efficiency as all making a positive difference. Kudos to California! Strict emissions standards pay off!
That said, there are two caveats to this comforting news. Complex air chemistry means that ozone levels have not dropped as dramatically as VOCs have. Ozone pollution in the L.A. Basin has definitely dropped since the 1960s, but it still exceeds standards set by the Environmental Protection Agency.
Another study, published this month in Geophysical Research Letters, revealed that one particular VOC, ethanol, is on the rise. Ethanol’s use in transportation fuels is increasing, so it’s no surprise that ethanol’s atmospheric concentrations are rising as well.
Okay, so L.A. can’t blame all of its lingering ozone problems on China.
Images:
Los Angeles Traffic Jam Caused by Transit Strike in the 1950s. (Corbis)
Rush Hour on I-405. (Corbis)
