The South Coast AQMD recently began
a year-long air sampling initiative in its fourth study of
levels of cancer-causing toxic air pollutants and the risk
they pose to Southland residents.
“While we saw an overall decrease in the
risk from toxic air contaminants in our 2008 study, the
risks are still unacceptable,” said
William A. Burke,
Ed.D., AQMD’s Governing Board Chairman.
“Data collected will help guide efforts to continue
to reduce overall exposures to air toxics.”
AQMD has started collecting air samples
for substances to be measured in the Multiple Air Toxics
Exposure Study IV (MATES IV), a follow up to three previous
air toxics studies done in the Southland.
To assess trends over time, the same 10 monitoring
sites used for the last study, MATES III (see list below),
will be used for this year’s study.
Monitoring at each
site will be for a 24-hour period and occur every one-in-six
days for one year. A final report is expected by March 2014.
MATES IV will monitor for more than 20
toxic air contaminants and several other substances.
This year’s study will also include additional
monitoring of ultra fine particles and black carbon.
Mobile monitoring stations will be used to conduct
short-term monitoring in about eight locations to assess
localized impacts from combustion sources, such as airports,
freeways, rail yards, busy intersections and warehouse
operations. The modeling area will also be expanded this
year to include the Coachella Valley.
A technical advisory group was formed to
provide advice and assistance in selecting the specific
neighborhood monitoring sites.
The group includes representatives of other
environmental agencies, universities, industry and
environmental groups, and will help guide the study from
start to finish.
The results of MATES III, completed in
- An 8 percent decrease
overall in estimated cancer risk from air
pollution, from 931 in 1 million in 1998-99
to 853 in 1 million in 2005;
- A 17 percent increase in
estimated cancer risk from air pollution
around ports, likely due to an increase in
- Slight increases in
estimated cancer risk in areas of Riverside
County, possibly due to increased truck
traffic and warehouse growth; and
- About 84 percent of all
estimated cancer risk from air pollution is
due to diesel exhaust from trucks, trains,
ships, locomotives and other diesel
AQMD continues to adopt policies and implement programs
to reduce exposures to air toxics across the region,
including ongoing incentive funding to replace older diesel
school buses and heavy-duty trucks with cleaner models,
school air filtration projects and the adoption of the 2010
Clean Communities Plan to address air toxics and air-related
nuisances, with an emphasis on addressing cumulative
AQMD is the air pollution control agency for Orange
County and major portions of Los Angeles, San Bernardino and
MATES IV Fixed Monitoring Site