L.A. air pollution may endanger babies, people in general
It looks like L.A. air could be killing us in more ways than one.
Two studies released Wednesday have linked toxic air pollution in Southern California to cancer and complications with birth.
Exposure to local traffic-generated pollution increased the risk of major complications and preterm birth, concluded a report published online in Environmental Health Perspectives. Local scientists studied the relationship of traffic pollution, preterm birth and a complication called preeclampsia that can lead to maternal and perinatal morbidity.
By measuring pregnant women's exposure to chemicals emitted by local traffic (nitrogen oxides and particulate matter), the researchers concluded that the risk for preeclampsia increased by as much as 42% at the highest exposures. The risk for "very preterm delivery" (meaning delivery when the fetus is less than 30 weeks old) increased by as much as 128% for women exposed to the highest levels.
The study was the first to look at the connection between preeclampsia and air toxics. It focused on births in Los Angeles and Orange counties.
Meanwhile, an Environmental Protection Agency study found that Los Angeles has some of the highest levels of cancer-related toxic air pollutants in the country. For residents of Cerritos, located at the heart of the L.A. basin, the EPA estimated the cancer risk due to air toxics at 1,200 in 1 million, the highest in the country and more than 33 times the national average. The statistic represents the expected number of additional deaths per million people, based on a lifetime exposure to the chemicals.
For much of the rest of the Los Angeles area, cancer risks ranged from 50 per million to 75 per million, according to the EPA.
The South Coast Air Quality Management District last year arrived at the same figure -- 1,200 per million -- for the Southern California region. But it noted that the cancer risk had come down since 1999. The study collected samples from sites around the Los Angeles basin, but not from the city of Cerritos.
The discrepancies may be partly because of AQMD's decision to include the cancer-causing potential of diesel emissions in its report. AQMD found that diesel was by far the biggest contributor to cancer-related air toxics. EPA did not assess the cancer-causing potential of diesel, stating "there currently is no unit risk estimate available."
Most of the cancer-causing chemicals the EPA detected in Cerritos were attributed to hydrazine, a chemical that could be coming from a nearby facility that recovers precious metals from old industrial parts.
Field inspectors and engineers were sent to the facility on Thursday to investigate, said AQMD's Sam Atwood. Although the air management authority has confirmed that the plant uses hydrazine, Atwood says "there is no reason for alarm at this point."
Photo: Smog over Los Angeles. Credit: Bryan Chan / Los Angeles Times