SMOG CITY? PICTURE'S HAZY HOUSTON TRIES TO DUMP DIRTIEST-AIR TITLE BACK ON LOS ANGELES.

Byline: Nicole M. Campbell Staff Writer

Houston, we have a problem.

Los Angeles residents breathed a collective, carbon dioxide-rich sigh of relief last year when, for the first time, the Texas city ranked as the nation's smoggiest.

But now officials there say it's Southern Californians who are living high on the smog. After conducting a new study, they claim some air-polluting emissions are showing up at lower levels than in previous reports.

``We don't think we have the dirtiest air,'' said Paul Bettencourt, the Harris County tax assessor in Houston, who led the latest study.

Think again, say California smog watchers. In fact, Bettencourt's study - which added the number of cars in Houston to the smog equation - is just a bunch of hot air, they say.

The Environmental Protection Agency uses ``monitoring sites that measure the various pollutants, not the number of cars on the road,'' said spokesman Randy Wittorp in the agency's San Francisco's office.

And Wittorp said, while the number of cars on the road certainly contributes to smog levels, numbers are relative.

``You could have 2 million cars in Los Angeles and 2 million cars in Hawaii, where it's always windy and you've got storms blowing through, and you're going to have totally different air quality,'' Wittorp said.

Despite such apparently crystal-clear logic, Bettencourt remains determined. He said last year's study was ``just guesswork'' because ``no one had counted the number of vehicles on the road.''

The new data put smog-producing nitrous oxide emissions at 7 percent lower than previous readings, putting Houston below Los Angeles on the national smog meter.

There never used to be a tug of war over the title ``Nation's Smoggiest City'' - the car capital of California, some would say the world, always won.

But last year, according to the EPA, Houston recorded at least 50 days in 1999 in which it exceeded federal health standards for ozone, a component of smog.

``Certainly, many took it to be a mark, which we do too in a way, of continuing improvement in air quality,'' said Bill Kelly, spokesman for the South Coast Air Quality Management District in Diamond Bar. ``For the first time, this area was not the one that had the most (dirty air) days.''

Smogwash, Bettencourt said.

``This is national media hype to a certain degree,'' he said. ``This year, we've only had 10 ozone events recorded. Last year we had 52 so we're running ahead of that schedule. In my opinion, (last year's data) was taking advantage of a snapshot of just one year.''

So far this year, Los Angeles has had 17 days over the acceptable federal standard for air quality, Kelly said.

Bettencourt conceded Houston's ozone level is still too high to comply with the federal Clean Air Act. But he said the air in Los Angeles has excessively high levels of particulate matter - minuscule particles such as dust, diesel soot and sea salt that obscure a person's vision or scenic views - and carbon monoxide as well as ozone, making L.A. the country's smoggiest.

``On a personal opinion, I get tired of seeing Houston labeled as the smoggiest city,'' Bettencourt said. ``To be declared the smoggiest, frankly, I think you've got to have more than one problem.'' <Staff Writer Benjamin Parke and The Associated Press contributed to this report.