Release 09-44
May 12, 2009

    Mary Fricke
Air Quality Almanac includes state air quality trends
San Joaquin Valley and South Coast Air basins show lower PM levels and fewer ozone days

SACRAMENTO -The Air Resources Board released its annual California Almanac of Emissions and Air Quality this month that shows dramatic improvement in air quality in two of the historically troubled areas - Southern California and the Central Valley - despite increased trucking, port activities and population growth.

The almanac indicates pollutants have dropped significantly over the last 20 years in both San Joaquin Valley and the South Coast Air basins. Ozone levels have decreased approximately 10 percent in the San Joaquin Valley and 35 percent in the South Coast Air basins since 1990. Fine particulate matter in the South Coast region has decreased nearly 35 percent and the San Joaquin Valley 20 percent for the period of 1999 to 2007 namely due to regulations aimed at reducing ozone and coarse particulate matter.

Data from the statewide 2009 almanac also shows that over the last 20 years:

"These good statistics covering the past 20 years show a lot of progress simultaneous with growth in population and economy but, there is still more to be done," said ARB Chairman, Mary D. Nichols. "We will continue to employ innovative approaches to keep California on the right track so we protect public health which will result in a healthier workforce and fewer hospital visits for families."

These air pollution reductions are a result of regulations adopted by ARB and the 35 local air quality districts over the last 40 years. Recent efforts such as the adoption of tougher particulate matter and NOx regulations from big-rig trucks and buses, and equipment enhancements at California service stations are expected to help the state meet more stringent air quality standards.

ARB's California Almanac of Emissions and Air Quality is produced annually and contains information about historical, current and forecasted emissions trends as well as historic air quality data. The data is collected from over 200 monitoring stations that are operated and maintained in partnership with local air districts.

Each year, more than 10 million air quality measurements are collected from all the stations and are stored in a comprehensive air quality database maintained by the ARB. To ensure the integrity of the data, ARB routinely audits and reviews the monitoring instruments and data.

To view a downloadable version of the almanac, go to: /aqd/almanac/almanac09/almanac09.htm

The Air Resources Board is a department of the California Environmental Protection Agency. ARB's mission is to promote and protect public health, welfare, and ecological resources through effective reduction of air pollutants while recognizing and considering effects on the economy. The ARB oversees all air pollution control efforts in California to attain and maintain health based air quality standards.