Deliver Your News to the World

Stronger Standards for Particles Proposed


(Washington, D.C.-12/21/05) To further improve public health across the country, EPA is proposing revisions to its national air quality standards for fine particle pollution (also called fine particulate matter) and from some coarse particles.

“Our nation’s air is the cleanest it has been in over a generation and today’s proposal begins our next step in the steady march toward cleaner air and healthier lives by addressing particle pollution,” said EPA Administrator Stephen L. Johnson. “Armed with the Bush Administration’s innovative clean air policies and the best available science we will continue to improve air quality and public health.”

Particulate matter is a complex mixture of extremely small particles and liquid droplets. Particulate matter can be directly emitted, as in smoke from a fire, or it can form in the atmosphere from reactions of gases such as sulfur dioxide.

EPA is basing its proposal on an extensive review of thousands of scientific studies on the risks associated with exposure to particle pollution. The agency will also conduct an assessment of significant new studies before this rule is finalized.

The proposed revisions will address two categories of particulate matter: fine particles which are particles 2.5 micrometers in diameter and smaller; and “inhalable coarse” particles, which are particles between 2.5 and 10 micrometers (PM10-2.5).

Numerous studies have associated fine particulate matter with a variety of respiratory and cardiovascular problems, ranging from aggravated asthma, to irregular heartbeats, heart attacks, and early death in people with heart or lung disease. EPA has had national air quality standards for fine particles since 1997 and for coarse particles 10 micrometers and smaller (PM10) since 1987. Particle pollution can also contribute to visibility impairment.

The proposed revisions include the significant strengthening -- by nearly 50 percent -- of EPA’s standards to protect the public from short-term exposure to high levels of fine particles. For fine particles, EPA is also taking comment on a range of annual and 24-hour standards, including strengthening these standards as well as retaining the standards at their present levels.

In addition, EPA is proposing a standard for reducing inhalable coarse particles, or PM10-2.5. For these particles, EPA is proposing a 24-hour standard of 70 micrograms per cubic meter. The standard would apply to airborne mixes of coarse particles that come from sources such as high-density traffic on paved roads and industry. The proposed standard would not apply to mixes of coarse particles that do not pose much risk to public health, such as windblown dust and soils and agricultural and mining sources.

Reducing fine particles is a central element of the administration’s comprehensive national clean air strategy. The Bush Administration has proposed Clear Skies legislation and issued a number of rules that will make significant strides toward reducing particles regionally and nationally -- the Clean Air Interstate Rule to reduce emissions from power plants in the eastern United States; the Clean Diesel Program to reduce emissions from highway, nonroad and stationary diesel engines across the country; and the Clean Air Visibility Rule to reduce emissions near national parks.

In a separate but related action, EPA is proposing amendments to its national air quality monitoring requirements, including those for monitoring particle pollution. The changes will help EPA, states and local air quality agencies in their efforts to improve public health protection and inform the public about air quality in their communities, and they will allow air quality regulators to take advantage of improvements in monitoring technology.

EPA is seeking comments on a number of alternative levels for the PM standards, including retaining the current standards. The agency will take public comment for 90 days following publication of the proposal in the Federal Register and will hold three public hearings.

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. EPA last updated the particle standards in 1997. This proposed rule covers only the air quality standards for particle pollution. It does not address all of the issues involved in implementing a new standard, such as designating what areas are or are not attaining any new standard, and determining the best and most cost-effective implementation strategies. EPA and the states will address those in later actions.

For additional information on today’s action, visit EPA’s Web site at: For information on particle pollution, visit:


This news content was configured by WebWire editorial staff. Linking is permitted.

News Release Distribution and Press Release Distribution Services Provided by WebWire.