L.A’s Foul Air Blamed for Rise in S.D.’s Smog : Environment: Population growth and increased traffic is reversing a trend toward cleaner air.

Smog in San Diego County worsened for the second straight year in 1989, primarily gauged by an increase in the number of days when polluted air was pushed south from Los Angeles, according to an annual air quality “report card” released Tuesday by the county Air Pollution Control District.

Preliminary data showed that the county exceeded federal ozone levels on 55 days last year, up from 45 in 1988. Also, as in 1988, there were two Stage 1 smog alerts in 1989--both of them caused by transported pollution, officials said.

R. J. Sommerville, the county’s air pollution control officer, said extended Santa Ana conditions played a major role in the increase of smoggy days. Under certain conditions, Santa Ana winds send smog generated in Los Angeles over the ocean. High pressure systems then force that smog back toward shore, frequently hitting North San Diego County.

“Last year, 41 of the days over (federal) standard, or 75%, was from smog blown here from Los Angeles,” Sommerville said.

Sommerville also noted, however, that a five-year trend from 1980 to 1985 of reducing locally generated pollution is being counterbalanced by population growth and increased traffic.

“California has now learned what many of us already knew: transportation-related growth can overcome any technological control program,” Sommerville said. “It appears that those dramatic reductions are not going to be coming forward until we do added work.”

Smog is produced by a photochemical reaction in the atmosphere among sunlight and hydrocarbon emissions and oxides of nitrogen. In San Diego, about 80% of the oxides of nitrogen and half of the hydrocarbons come from motor vehicle emissions, which are consistently rising. According to the San Diego Assn. of Governments, the number of miles driven in San Diego County has increased 56% in nine years, from 36 million in 1980 to 56.4 million in 1988.

Even with the increase from 1988 of 10 days with high ozone levels, the 1989 smog statistics are consistent with a trend toward cleaner air in San Diego County, Sommerville insisted. By contrast, in 1980, there were 87 days of excess smog and eight smog alerts, statistics show.

Sommerville said the Air Pollution Control District is revising its air quality plan to further reduce emissions and counter trends. Among the approximately 50 strategies under consideration are reducing volatile chemicals in solvents and requiring state-of-the-art technology to be installed on boilers and power generation plants.

Under provisions of the 1988 California Clean Air Act, the District will also have the authority to recommend measures designed to reduce the number of vehicles on highways and the number of miles driven.

“We need to look at van pools and car pools designed to really move people and take them where they want to go,” Sommerville said. “It’s easy now to get a bus to a mall. It’s not so easy to get to work. We need to change that.”

The federal minimum health standard for smog is 12 parts per hundred million (p.p.h.m.) for one hour. Anything that exceeds that affects the lungs of normal individuals.

Smog detected at 20 p.p.h.m. or greater triggers a Stage 1 Alert, during which the elderly, children and people with respiratory and cardiac problems are advised to limit their physical activity. A Stage 2 Alert is called when smog exceeds 35 p.p.h.m.

Smog in San Diego County As map shows, the number of days on which areas of San Diego exceeded federal smog standards increased from 45 to 55 in 1989. While the number of those days caused by local pollution sources has remained roughly steady during the past five years, pollution transported from other areas-mainly the Los Angeles area-increased for the second straight year. Source: San Diego County Air Pollution Control District