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Mobile lab to scope out air hazards

A specially equipped car will measure pollution levels in several South Bay communities to help fill gaping holes in environmental data.

February 05, 2007|Janet Wilson | Times Staff Writer

Determined to pinpoint what kind of pollution is swirling in the air around the region's ports, a crew of scientists this week will begin cruising Southern California streets and freeways in a one-of-a-kind mobile research lab.

In a car equipped with $450,000 worth of the world's most sophisticated air monitors and a wind sensor protruding like a giant metal claw from the roof, researchers Tuesday will begin sampling the air in several South Bay communities, examining exhaust from cars, trucks and other sources.

"We want real-life conditions, and if real-life conditions means people in traffic, then that's what we want," said Kathleen Kozawa, 28, a UCLA School of Public Health doctoral student who was at the wheel of the mobile lab on a recent weekday.

Chasing pollution in a laboratory on wheels helps fill gaping holes in data about what we breathe in sprawling Southern California, which has just 35 fixed air-monitoring stations spread across 10,743 square miles.

The scientists, from the California Air Resources Board, completed a similar study a few years ago, showing how much bad air we breathe in our cars.

The publicly funded researchers learned that commuters on the Harbor and Long Beach freeways ingested half of their daily pollution while on the road -- even though most people spend just 6% of their day driving.

"We're taking the instruments to where people live and where people spend their time -- in their cars and their neighborhoods," said Scott Fruin, an air resources board pollution specialist who helped design and build the mobile lab and is now a USC assistant professor.

For the latest experiment, Fruin and other air board staff borrowed a discontinued model of an electric Toyota RAV-4 (so they wouldn't be measuring their own exhaust), ripped out the back seats and sawed, nailed, clamped and bungee-corded to the innards a dozen sophisticated monitors, a police "stalker vision" video camera, five marine batteries weighing a combined 400 pounds and a tangle of extension cords. On the roof they glued the giant claw to locate wind direction and plumes and a jumbo antennae to track humidity and temperature.

For the first study, completed in 2004 in a nearly identical lab, the scientists drove and re-drove a 75-mile freeway loop between Pasadena and Long Beach.

They learned that the air in a moving vehicle can change dozens of times in an hour, even if the windows are closed.

Drivers breathe four to eight times as much of the carcinogen benzene as found in normal air levels, five to 15 times as much choking diesel soot and 50 to 100 times as much butadiene, which is used in automobile tires and has been linked to cancer, especially in women.

On a hazy afternoon last month, with the downtown skyline and San Gabriel Mountains looking like they'd been rinsed in dirty dishwater, Kozawa and Fruin took a reporter on a portion of the route used during the first study.

The research vehicle, with two large dryer hoses affixed to the back windows to catch outside air, merged onto the Harbor Freeway near USC. Inside, the needles on a laptop monitor began jiggling upward, measuring black carbon from diesel trucks, nitrogen oxide from hot rods and other toxins. The chemical levels climbed inexorably as the vehicle headed under the four-level interchange. When a dingy white panel truck lumbered by in the right lane, a black carbon meter jumped from 430 to 7,608 micrograms per cubic meter.

"That's a pretty good one," Kozawa said.

Black carbon is a strong indicator of fine particles, or soot, which lodge deep in the lungs and can lead to premature death from heart attacks, strokes and other diseases.

The scientists say their own chests grow tight and their throats sore after a typical 150-mile day in traffic, but they shrug it off as the cost of research.

The meters spiked upward as a wide Chrysler sedan with a stained tailpipe pulled in front.

"That's pretty gross," Kozawa said.

The needles danced in the medium high range as traffic flowed sluggishly under Stadium Way, then through four tunnels. Trucks lined the onramps, traffic idled at the exit for the Golden State Freeway.

It was difficult to maneuver the heavy, equipment-packed vehicle, which drew the occasional obscene gesture from fellow motorists, but also curiosity. One pickup truck driver honked loudly after Kozawa unintentionally cut him off, scowled as he pulled alongside, then gaped in amazement.

As the mobile lab reached the historic, leafy section of the highway past Via Marisol, the glut of traffic opened up. The needles drooped as the air freshened.

Near Avenue 60, a Chevy Trailblazer zipped past in the fast lane. The nitrogen oxide sensor leaped from 27 to 108 parts per cubic meter. A key component of smog, nitrogen oxide can cause asthma and other respiratory problems.

The drivers of such cars don't have to breathe their own fumes, Fruin said. It's those downwind who catch the noxious stream.

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