PM_2.5 Designation Fact Sheet

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What is particulate matter or particle pollution?

Particulate matter, also referred to as particle pollution, consists of a mixture of microscopic solids and liquid droplets suspended in air. The particles may be emitted directly (primary emissions), or formed secondarily in the atmosphere.

Primary emissions are derived from sources that include diesel engines, wood burning activities, and other industrial and commercial combustion processes.

Secondary particles are formed through the reactions of gases in the atmosphere. An example of this is sulfur dioxide gas from coal combustion in power plants and industrial boilers reacting with other gases in the atmosphere to form sulfate particles. Other secondary particles include nitrate particles and organic carbon particles.

“Fine particles” are 2.5 microns or smaller in diameter (PM_2.5). “Coarse particles” are 2.5 – 10 microns in diameter (PM₁₀) .

Known Health Effects

Numerous health studies have been conducted that draw a direct correlation between exposure to PM_2.5 to increases in an individual’s vulnerability to a range of serious respiratory and cardiovascular effects and even premature death. Special populations—individuals with heart or lung disease, older adults and children—are considered to be at greater risk from particles than others.

The respiratory effects of an increased exposure to PM_2.5 include:

aggravation of lung diseases including asthma and bronchitis;
coughing and chest discomfort; and
wheezing and shortness of breath.

The cardiovascular symptoms related to increased exposure to PM_2.5 include:

chest pain;
palpitations;
shortness of breath;
heartbeat irregularities; and
heart attacks.

Regulatory Overview

EPA issued fine particle standards in 1997
the annual PM_2.5 standard is 15 micrograms per cubic meter; the 24-hour standard is 65 micrograms per cubic meter
the annual PM₁₀ standard is 50 micrograms per cubic meter; the 24-hour standard is 150 micrograms per cubic meter
two laws require EPA to designate areas as attainment or nonattainment for the fine particle standards—the Clean Air Act and the Transportation Equity Act for the 21^st Century (TEA-21)
the Clean Air Act requires state, local and tribal governments to control particle pollution in nonattainment areas; including stricter controls on industrial facilities and transportation planning
TEA-21 requires states to submit recommendations for PM_2.5 designations to EPA within one year of the time that three years of monitoring data become available

Designations

An area will be designated as nonattainment by the EPA if it has violated the fine particle standards over a three year period, or if it is determined that the area contributes to violations in an adjacent community.

Attainment and Nonattainment Areas in the U.S. PM_2.5 Standard

PM Standard map

green legend Attainment (or Unclassifiable) Areas

orange legend Nonattainment Areas – Entire Counties

yellow legend Nonattainment Areas – Partial Counties

Source: U.S. Environmental Protection Agency, 2004.

The final PM_2.5 designations were developed in stages. Initial recommendations on the appropriate boundaries for nonattainment areas were made by state governors and tribal leaders at the request of EPA. In June 2004, the EPA reviewed and revised the initial recommendations, adding an additional 100 counties. A comment period followed and the final designations were issued on December 17, 2004.

Timeline

April 1, 2003 – EPA issued a schedule for area designations under the PM_2.5 standard

February 15, 2004* – states and tribes submitted preliminary area designations to EPA (while all states were required to submit recommendations, tribes were not required to do so)

June 28, 2004 – EPA released its desired modifications to states responding to PM_2.5 designation recommendations

Fall 2004 – EPA proposed a PM_2.5 implementation rule

December 2004 – EPA finalized nonattainment designations

Spring 2005 – EPA finalizes the PM_2.5 implementation rule

February 2008 – State Implementation Plans (SIP) due to EPA

2010-15** – attainment dates for nonattainment areas

* The Consolidated Appropriations Bill of FY2004 required designations by 12/31/04. The SIP due dates for PM_2.5 and regional haze are 3 years from the effective date of PM_2.5 designations.

**Areas with more severe problems may request, and be granted, one five-year extension pushing back the attainment date to 2015.

Nonattainment Designation

Should an area receive a nonattainment designation, the Clean Air Act requires state and local governments to take steps to reduce the fine particle pollution in those areas. The steps must be detailed in a plan that demonstrates how they will meet the fine particle standards. The plans are known as state implementation plans (SIPs). A local and regional approach is recommended to achieve the national air quality standards for fine particulates.

In addition to the SIP requirement, nonattainment areas are subject to a “transportation conformity” measure, requiring local transportation and air quality officials to coordinate their planning to ensure that transportation projects do not hinder an area’s ability to reach its clean air goals. These requirements become effective one year after an area’s nonattainment designation.

All nonattainment areas are subject to New Source Review requirements. New Source Review is a permitting program for industrial facilities, the aim of which is to ensure that new and modified sources of pollution are compatible with an area’s goal of cleaner air.

Comparison of PM_2.5 and Ozone Designations

The following map illustrates state designations for compliance with both the PM_2.5 and Ozone standards. (See the 8-Hour Ozone Standard Fact Sheet for more information on the 8-Hour Ozone Standard at www.ncsl.org/print/environ/ozonestandards.pdf.)

State PM_2.5 and Ozone Attainment Status

ozone map

dblue legend PM_2.5 and Ozone Attainment

medium blue legend PM_2.5 Attainment – Ozone Nonattainment

light blue legend PM_2.5 Nonattainment – Ozone Attainment

yellow legend PM_2.5 and Ozone Nonattainment
Source: NCSL, 2004.

Prepared by the National Conference of State Legislatures

Staff Contact: Jennifer DeCesaro at 303.856.1379

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PM2.5 Designation Fact Sheet

What is particulate matter or particle pollution?

PM_2.5 Designation Fact Sheet