Strong new air quality standards for particulate matter to be considered by the California Air Resources Board

provided by American Lung Association


he staff of the California Air Resources Board has proposed to dramatically strengthen the state air quality standards for particulate matter, under the Children's Environmental Health Protection Act.

    California's air quality standards for particulate matter (PM), now 20 years old, are in critical need of updating and strengthening in light of hundreds of recent studies demonstrating premature mortality, increased hospital admissions for cardiopulmonary causes, acute and chronic bronchitis, asthma attacks and emergency room visits, respiratory symptoms, and days with some restriction in activity, at levels well below the current standards. The adverse health effects have been reported primarily in infants, children, the elderly, and those with preexisting heart or lung disease.

    The proposed standards have important public health implications, not only for California, but also nationally, because of the potential impact on the ongoing EPA review of the National Ambient Air Quality Standards for particulate matter.

    Attaining the proposed standards will result in a reduction of an estimated 6,500 cases of premature mortality per year, and reduce annual hospitalizations by an estimated 1,200 for chronic obstructive pulmonary disease, 1,700 for pneumonia, 3,100 for cardiovascular disease, and 960 for asthma. Among children ages 7-14, attainment of the PM2.5 standard will result in about 389,000 fewer days of lower respiratory symptoms per year.

Proposed California ambient air quality standards


    The staff of the Air Resources Board strengthened air quality standards for PM10 and new standards for PM2.5 that are far more stringent than the National Ambient Air Quality Standards established by US EPA in 1997.

    The recommendations are to:

  • Lower the current annual average standard for PM10 from 30 to 20 ug/m3. (The federal standard is 50 ug/m3).
  • Retain the current 24-hour standard for PM10 at 50 ug/m3, not to be exceeded. (The federal standard is 150 ug/m3, 3 year average of 99th percentile concentrations).
  • Establish an annual average standard for PM2.5 of 12 ug/m3. (The federal standard is 15 ug/m3, spatial averaging allowed).
  • Establish a new 24-hour PM2.5 standard of 25 ug/m3, not to be exceeded. (The federal standard is 65 ug/m3, 98th percentile concentrations, which allows 7 exceedances per year). This provision was added to the proposal following the suggestion of health and environmental organizations and the unanimous recommendation of the Air Quality Advisory Committee.
  • Retain the current 24-hour standard for sulfates of 25 ug/m3. (There is no federal standard).

Take action


    The proposed changes are opposed by a broad coalition of industry groups and are likely to be extremely controversial.

    Particulate air pollution represents the most significant environmental health threat facing the state and the nation. Health and environmental organizations strongly support the establishment of a stringent new standards for PM2.5 and the tightening of the standards for PM10. The new standards have the potential to save lives and improve health for thousands of California's most vulnerable citizens.

    Letters of support for the California proposed standard should be sent to ARB Board Chair Alan Lloyd by the morning of June 19, 2002. The letters should point out that:

  • Hundreds of scientific studies published in the last decade demonstrate associations between particulate air pollution, illness, emergency room visits, hospitalization, and premature death, at levels well below the current standards.
  • The Board should approve the proposed standards to protect the health of infants and children, the elderly, and people with heart and lung disease.
  • The “not to be exceeded” form of the standards must be retained to provide a margin of safety.
  • Both strong “annual average” and “24-hour” standards are needed for bothPM10 and PM2.5 to protect against the full range of health effects demonstrated in the studies.
  • The Board should not weaken the standards in any way. Thousands oflives are at stake.

Timeline and action opportunities

May 3, 2002: Staff Report: Public Hearing to Consider Amendments to the Ambient Air Quality Standards for Particulate Matter and Sulfates is released for public comment. The report is available at: Hard copies may be requested from Ms. Jacqueline Cummins at 916-445-0753.

    Technical questions about the review of the standards may be directed to: Dr. David Mazzera, Air Resources Board Research Division; 916-445-9488; Email:

June 5, 2002, 1-3pm: Public Workshop to discuss Staff Report and to take public questions and comments. Monitoring and Laboratory Division, Air Resources Board, Conference Room North, 1927 13th Street, Sacramento, CA.

June 6, 2002, 1-3 pm: Public Workshop to discuss Staff Report and to take public questions and comments. Air Resources Board, El Monte Facility Auditorium, 9528 Telstar Avenue, El Monte, CA.

June 19, 2002, 12:00 noon: Deadline for written comments. Comments should be addressed to: Alan C. Lloyd, PhD, Chair, California Air Resources Board c/o Clerk of the Board, 1001 “I” Street, 23rd Floor, Sacramento, California 95814; Email:; Fax: 916-322-3928.

June 20 - 21, 2002, 9am: Air Resources Board meets to consider staff's final recommendations on revisions to the standards. The meeting will be held in the Auditorium of the California Air Resources Board at 9350 Telstar Ave., El Monte, California. Written comments (30 copies) and oral testimony (5 minutes) will accepted at the meeting. Sign up with the Clerk of the Board at the meeting.