Study to Examine South Bay’s High Carbon Monoxide Levels

Air quality experts and an auto maker initiated a joint study last week to find out why the worst readings for the air pollutant carbon monoxide in Los Angeles County are in the southeast area, and the next worst in the South Bay.

Carbon monoxide is dangerous to people with heart and respiratory problems because it inhibits the blood’s ability to carry oxygen. It hits its highest levels in the cool winter months, forming in areas with a lot of traffic. Summertime smog, on the other hand, features high ozone levels that cover wide areas.

The highest readings for carbon monoxide have been found in an area composed of Lynwood, South Gate, Bell and Compton. Concentrations in that area surpassed federal standards on 51 days last year, with the highest reading recorded at 32 parts per million. The federal standard for carbon monoxide is 9.5 parts per million during an eight-hour period.

The South Bay area runs west from Hawthorne to Marina del Rey and then south along the coast to take in San Pedro. The area had the second-highest levels of carbon monoxide in the county, exceeding federal standards for carbon monoxide on 26 days last year. The highest reading in that area last year was 23 parts per million.

The study, which is being done by General Motors Corp., the state Air Resources Board and the South Coast Air Quality Management District, will examine carbon monoxide levels in portions of southeast Los Angeles County and the South Bay.

Over the next three months, scientists will study everything from wind direction to traffic flow in an effort to determine why carbon monoxide levels in the two study areas are often double those in nearby monitoring areas, even though auto exhaust emissions--the major cause of carbon monoxide--have sharply dropped throughout the state since 1968. That was the year California dictated pollution controls for auto makers.

“The idea is that . . . there are some peculiar circumstances that are causing the high carbon monoxide concentrations,” said Bill Kelly, AQMD spokesman.

It is known, Kelly said, that two areas with high readings of carbon monoxide--the Hawthorne and Lynwood monitoring areas, as they are called--have a “surface-level inversion.” When the ground cools off at night during the fall and winter, he said, the air layer closest to the ground also cools and traps carbon monoxide that is emitted when cars start moving in the morning. The layer of trapped air is shallow, often only five to 10 feet deep.

However, that does not explain why carbon monoxide levels at the Lynwood monitoring station are double the levels at stations in other monitoring areas, where surface-level inversions also exist, he said.

Places with consistently high levels of carbon monoxide, the so-called hot spots, have been found in Spokane, Wash.; New York City and Denver. This latest study will augment one done last winter by the University of Denver.

Eight research teams, including one from Denver, will use weather balloons and sophisticated measuring instruments to monitor the area’s weather conditions, including wind direction and speed. The scientists will also chart traffic volume and speed.

Factors such as train traffic, fast-food drive-up windows or space heaters could be contributing to the carbon monoxide problem, Kelly said. Trains give off some carbon monoxide, as do space heaters when they are not properly adjusted, he said. Drive-up windows concern air quality experts because idling cars emit larger levels of carbon monoxide than moving vehicles.

During the study, about 75 air monitoring devices, a 150% increase over the usual number, will be placed throughout the entire Southland air basin. Most of the devices will be in the Hawthorne and Lynwood areas, but others will go elsewhere to serve as the scientific control group for the study.

General Motors will hire people to drive two specially equipped cars to measure changes in carbon monoxide emissions under various driving conditions, such as rapid acceleration and differing speeds.

“(We’re) interested, believe it or not, in clean air and have been for years,” said Bill Ott, a spokesman for General Motors. “We’ve been working with various government agencies, be they state, regional or federal, for many years.”

The study will cost $510,000, with the Air Resources Board contributing $350,000 and the air quality district, $60,000. About $100,000 will come from General Motors. Results of the study are not expected for about a year.