California Air Resources Board

SACRAMENTO – Particulate matter and its effect on human and environmental health were reviewed yesterday by the California Air Resources Board (ARB), a department of the California Environmental Protection Agency.  Particulate matter, or PM, is a major component of air pollution in California.

    Dr. Alan Lloyd, ARB Chairman, said, "The broad health impact of particulate emissions are just beginning to be discovered.  Our scientists are working hard to understand the health consequences of PM emissions and work toward further reducing those emissions in California through aggressive air quality programs."

    The Board heard a presentation from ARB and Office of Environmental Health Hazard Assessment (OEHHA) staff experts and researchers that underscored the need to reduce particle emissions that can lodge deep in the lungs, exacerbating and/or causing respiratory disease, including asthma, bronchitis and emphysema, heart problems and even cancer.  PM emissions can also affect visibility, causing haze in our cities, rural areas and pristine areas, such as state and national parklands and forests.

    Major sources of PM include:
 

• Motor vehicle exhaust
• Woodburning stoves and fireplaces
• Dust from construction, roads, landfills and agriculture
• Wildfires and brush/waste burning
• Industrial sources
• Windblown dust from open lands

    PM can be a mixture of materials that include smoke, soot, dust, salt, acids and metals. It can also form when chemical reactions occur in the atmosphere due to man-made emissions, such as auto exhaust and industrial operations.

    Programs designed to reduce PM include emission reduction measures from woodstoves and fireplaces; cleaner-burning fuels; emission control devices for motor vehicles and industrial facilities; dust control for roads, construction and landfills; and, measures to mitigate windblown dust with the use of landscaping methods.

    ARB staff is currently working with staff from the OEHHA to review the scientific bases regarding health effects and exposure to PM to determine how to revise the PM standards.  Short- and long-term exposure to PM has been associated with increased mortality and cardiopulmonary disease in a number of epidemiology studies.  Staff expects to present its recommendations for revising the PM Standards to the Board in April 2002.

    In 1998, the ARB declared the particulate portion of diesel exhaust a toxic air contaminant.  Currently, the Board is readying itself to adopt several air toxic control measures that include cleaner diesel fuel and engines, retrofit devices, and clean-engine incentives, among others.