Study Correlates Smog to Heart, Lung Ailments

In the first study of its kind in the Los Angeles Basin, medical researchers say they have confirmed that more people are hospitalized for lung and heart ailments as smog increases.

The yearlong study by the Kaiser Foundation Research Institute found a particularly strong correlation between hospital admissions and elevated levels of coarse particles that typically come from road dust, tire wear and airborne erosion from construction sites.

The preliminary results of the ongoing research project, which will be formally unveiled today, are based on more than 10,000 admissions to Kaiser Permanente hospitals throughout 1995. The patients were living in or near Southern California communities where the South Coast Air Quality Management District was making daily pollution measurements for the major components of smog--particulate matter and ozone.

“The maximum effect was on people with preexisting diseases,” said Shankar Prasad, health effects officer for the AQMD, which paid for the study.

Hospital admissions for chronic respiratory disease were found to rise by 7% for every 10-microgram increase in particulate pollution--basically grit--in the air. Admissions rose 3.5% for acute respiratory illness and 3% for those with cardiovascular disease.

“Seven percent is a big number, almost twice what has been reported in other studies,” said Prasad.

Other experts concurred. “It is a surprisingly big increase in the number of patients for a relatively small change in the level of pollution,” said Henry Gong, a professor of medicine and environmental health specialist at USC.

“The preliminary results . . . indicate there are significant adverse health outcomes to ozone and particle pollution.”

Hospitalizations increased at lesser rates as ozone levels rose. With an increase of 10 parts per billion, admissions went up 5.7% for cardiovascular disease, 2.7% for chronic respiratory problems and 1.5% for acute respiratory illness.

A number of previous studies have shown connections between smog and various types of illness. One research project, released last year, estimated that 64,000 people in major American cities may die each year from lung or heart problems made worse by inhaling particulates.

The Kaiser study is different, however, because of its local focus.

Up to now, Prasad said, 90% of health effects studies relating to smog have been conducted in the Eastern and Midwestern United States, where there are significant sources of pollution not found in Southern California.

Many of the studies are out of date, he added, but in this study, “we’re not looking back at 15-year-old records. We have fresh data.”

The strength of the Kaiser study, he said, derives from the number of patients involved, from the uniformity of medical data coming from a single health maintenance organization, and from the intensity of the pollution monitoring.

It was done on a daily basis in downtown Los Angeles, Anaheim, Diamond Bar, Fontana and Rubidoux in Riverside County.

The results are also significant, in part, because they depart from the current emphasis on extremely fine particulate matter, the object of controversial new air pollution regulations by the Clinton administration.

Those small particles come largely from fuel combustion, such as car and truck exhaust.

On the other hand, the coarser particles that tend to correlate more closely with hospital visits in the study come largely, but not entirely, from dirt roads and construction sites.

Coarse particles are also formed by ammonium nitrate, the components of which come from a variety of sources, including combustion and diesel engine exhaust, industrial boilers, waste water treatment plants, dairies and composting facilities.

Along with the Kaiser study, the AQMD plans today to present the findings of a related research project by the California Environmental Protection Agency.

Conducted in the Coachella Valley, the Cal EPA study found a 2.5% increase in emergency room visits for pneumonia and 1% increase in deaths corresponding to a 10-microgram increase in daily amounts of coarse particulates.