AQMD Launches Largest Toxic Air Pollution Study In A Decade

June 12, 1998

"Hot Spot" Monitoring Scheduled in 14 Southland Communities

Environmental scientists deployed this week the first of a series of mobile "toxic hot spot" monitors as part of the largest study in a decade of toxic air pollution in the Southland.

During the next 10 months, the South Coast Air Quality Management District will measure toxic air pollutants in 14 cities using three specially designed, mobile monitoring stations. A second component of the study, monitoring toxic air pollution at 10 fixed monitoring sites, started in April and will continue through next spring.

"AQMD’s Environmental Justice Initiatives, adopted last fall, place a significant emphasis on studying toxic air pollution, and if needed, strengthening our regulations to reduce this potential health threat to all Southland residents," said William A. Burke, AQMD’s Governing Board chairman.

The "hot spot" study started last month with monitoring at a fixed station in Hawthorne. The first mobile monitoring station is scheduled to start operating this week in Pacoima. Mobile monitors are scheduled to be placed in San Pedro, Torrance, Norwalk, the Bell/Downey area, South El Monte, Van Nuys, Costa Mesa, Anaheim, Montclair, the Colton/Rialto area, the Norco/Corona area and Riverside. Samples of 30 toxic air pollutants will be collected at each of those sites three times a week for four weeks.

AQMD staff and an independent group of scientists specializing in health studies, risk assessment and computer modeling used a four-step evaluation process to select and prioritize monitoring locations in potential "hot spots" -- typically residential communities immediately downwind of industries.

Sites were chosen based on past air pollution complaints and concerns from community members, toxic emissions databases, location of facilities emitting toxic air pollutants and meteorological factors. AQMD’s Environmental Justice Task Force, composed of community and environmental group representatives, also contributed information to the site selection process.

Air toxic monitoring devices will be housed in 20-foot-long, beige metal containers with tubes to the outside to sample ambient air.

Toxic air pollutants include chemical compounds such as benzene, 1,3-butadiene and hexavalent chromium that are known or suspected of causing cancer, birth defects and other serious illness.


In addition to the "hot spots" program, AQMD initiated a 12-month regional study of toxic air pollution in April called MATES II, or Multiple Air Toxics Exposure Study.

MATES II will measure toxic air pollutants at the following 10 fixed monitoring sites: Long Beach, Wilmington, Compton, Huntington Park, Pico Rivera, downtown Los Angeles, Burbank, Anaheim, Rubidoux and Fontana.

MATES II aims to assess residents’ exposure to toxic air pollution in ambient air from all sources -- vehicles, businesses, factories and consumer products.

The region’s last major toxics study, MATES I, monitored 20 cancer-causing compounds at 10 locations in 1986 and 1987. The study showed that toxic air pollution from all sources was responsible for up to 200 cancer cases in the Southland each year. Monitoring data since then indicates that residents’ exposure to toxic air pollution has declined significantly due to reduced industrial toxic emissions and reformulated gasoline.

"Even though toxic air pollution has been significantly reduced in Southern California, it still poses a health threat," said Barry Wallerstein, AQMD’s acting executive officer. "Our study will provide a more comprehensive and current look at the health risks posed by air toxics."

As part of its Environmental Justice Initiatives, AQMD’s Governing Board this year is scheduled to consider amendments to the agency’s rules governing toxic emissions from new and existing facilities.

AQMD will spend a total of $700,000 for equipment and contracts for the hot spots and MATES II studies. Final results from the studies are expected by late summer of 1999.

AQMD is the air pollution control agency for the urban portions of Los Angeles, Orange, San Bernardino and Riverside counties.