Danger in the Air
If nothing else, new data on the cancer risk posed by air pollutants demonstrate once again that the path to cleaner air in Southern California and elsewhere remains tortuous.
The study released Monday by a congressional committee computed the specific health risks posed by various pollutants. Using thousands of air samples collected over the past three years at sites in the Los Angeles Basin, the researchers concluded that local residents are still breathing unusually dangerous levels of cancer-causing pollutants. The report found toxics so strong that the risk of developing cancer was deemed 426 times higher than the health standard of one additional case per million established by the 1990 federal Clean Air Act.
These are sobering findings, but they don’t mean that smog is worsening. Southern California has seen dramatic improvement in controlling air pollution in recent decades. The number of smog alerts and health advisories is down. Cleaner auto emissions and tighter controls on local industry deserve much of the credit.
The congressional findings don’t minimize these important gains, but they do underscore why much more must be done. Unlike earlier studies that relied on statistical modeling, this analysis is based directly on data from monitoring.
For years regulators have concentrated on cutting emissions from automobile engines, with impressive results. But changing consumer preferences, particularly the growing popularity of high-powered sport utility vehicles, threaten those gains. Light trucks and SUVs now account for nearly half of all vehicle sales in the United States and generate a disproportionate, increasing share of air pollution. New federal and state regulations, which will require SUVs to meet the same emissions standards as cars starting in 2004, should help.
The diesel engines that power larger trucks and buses are another major source of toxic contaminants, the state Air Resources Board confirmed last year. That agency is now charged with seeking ways to cut diesel exhaust by requiring cleaner-burning engines or their replacement with alternative-fuel engines. But the timetable is timid. The new data on cancer risk should prompt quicker action.
