Oct 2, 2014 4:29 PM
Study: Cancer risk eases in Southern California
The Associated Press
LOS ANGELES (AP) By at least one measure, Southern California's air is getting healthier.
The risk of cancer from airborne pollutants has dropped by more than 50 percent on average since 2005, according to a study released Thursday by the region's air quality regulators.
Concerted efforts to reduce emissions from trucks and other vehicles account for much of the drop.
The findings may not surprise residents of the region long cited for poor air quality. Unlike previous decades, it's now uncommon for smog to brown out the mountains that crisscross the region.
Still, risks persist from toxic pollutants such as diesel particulate matter and benzene.
Those risks are still some of the highest in the nation, said Philip Fine, assistant deputy executive officer with the South Coast Air Quality Management District, which conducted the study.
Exact comparisons between Southern California and other metropolitan areas are not possible because other areas compute risk differently, according to officials with the air district.
For every 1 million people who live in Southern California for 70 years, 418 would be expected to develop cancer due to the current levels of toxic air compared to 1,194 extra cases based on 2005 air quality, according to the study.
That reduction is probably larger than anyone expected, said Scott Fruin, a professor of preventive medicine at the University of Southern California who has studied the region's air quality.
The area of greatest concern remains around the massive ports of Los Angeles and Long Beach, where thousands of trucks and huge ocean-going ships carry goods near neighborhoods. Air-associated cancer risk there is twice as high as some other urban areas of Los Angeles, Orange, Riverside and San Bernardino counties.
Changes to diesel trucks starting in 2007 had a major impact on reducing emissions. Both of the ports also have made efforts to reduce pollution from cargo ships.
In one sign of how effective those efforts have been, the study showed that cancer risk in areas near the ports had dropped to risk levels measured in 2005 levels far from the ports.
Overall, based on measurements from 10 monitoring stations spread across the four counties, cancer risk declined 65 percent. Computer models for areas elsewhere in the region concluded that risk fell 57 percent.
Contact Justin Pritchard at https://twitter.com/lalanewsman .