State of California AIR RESOURCES BOARD Yolo Room, Sacramento Convention Center K Street Mall and 13th Street Sacramento, CA November 3, 1975 10:00 a.m. AGENDA 75-21-1 Public Hearing - Reconsideration of the California Ambient Air Quality Standard for Lead. 75-21-2 Other Business a. Executive Session - Personnel & Litigation b. Research Proposals 75-21-3 Remarks from Audience. ITEM NO.: 75-21-1 Reconsideration of the California Ambient Air Quality Standard for Lead. RECOMMENDATION Based on staff and State Department of Health evaluation of available information on the relationship between airborne lead concentrations and health effects, there is no evidence to recommend that the standard, 1.5 micrograms per cubic meter as a 30-day average, be changed. Consider public hearing testimony on this issue. SUMMARY Five petitioners have challenged the validity of the California ambient air quality standard for lead. The standard is frequently exceeded, especially in communities with heavy traffic, and most of the lead in the air is in the respirable particle size range. Deposition of airborne lead particles has produced substantial increases of lead in the biosphere, especially in urban areas. No thresholds have been established for the subtle and possibly irreversible changes found to occur as a result of chronic exposure to levels of lead above the air quality standard. The evidence in support of the air quality standard adopted in 1970 is much more substantial today.