A key document in U.S. Environmental Protection Agency’s review of national air quality standards for particle pollution recommends the administrator consider strengthening and refining current standards to better protect public health and visibility. Based on the latest science, the "final staff paper" does not change current air quality standards. It does, however, contain EPA staff recommendations for the administrator to consider in upcoming decisions about revising the agency's national standards for fine (PM2.5) and coarse particles (PM10).
The Clean Air Act requires EPA to periodically review air quality standards to ensure they provide adequate health and environmental protection and to update those standards if necessary. In December 2004, EPA and states began implementing the first fine particle standard when the agency designated areas of the country that require additional local, state and federal steps to reduce PM 2.5.
While acknowledging remaining uncertainties, the staff paper concludes that the latest scientific, health and technical information about particle pollution supports strengthening EPA's current health-based standards for fine particles. The paper recommends approaches for doing so.
The staff paper recommends that EPA continue to regulate but revise the current PM10 standards with a new health-based standard for particles known as "thoracic coarse" particles -- particles between 2.5 and 10 micrometers in diameter that can be deeply inhaled. Staff recommends that such a standard apply to more toxic urban coarse particles.
In addition to the changes to improve public health protection, the staff paper recommends that the administrator consider revising the existing secondary fine particle standard to improve protection of visibility in urban areas.
The assessments, conclusions, and recommendations included in the staff paper are staff judgments. They do not represent agency decisions on the PM standards. The agency is required by a consent decree to issue a proposal regarding the particle pollution standards by Dec. 20, 2005, and to issue a final rule by Sept. 27, 2006. That rule may, or may not, include changes to the existing standards.
EPA estimates that meeting existing PM 2.5 standards will prevent at least: 15,000 premature deaths; 75,000 cases of chronic bronchitis; 10,000 hospital admissions for respiratory and cardiovascular disease; hundreds of thousands of occurrences of aggravated asthma; and 3.1 million days when people miss work because they are suffering from symptoms related to particle pollution exposure.
The reduction of fine particle pollution is a critical element of the Administration's comprehensive national clean air strategy. The strategy includes EPA's recent Clean Diesel Program to reduce pollution from highway, non-road and stationary diesel engines, the Clean Air Interstate Rule to reduce pollution from power plants in the eastern United States, and the Clean Air Visibility Rule.