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Particulate Matter (PM)

Agriculture

THE U.S. ENVIRONMENTAL PROTECTION AGENCY’S
COARSE PARTICULATE MATTER (PM10) STANDARDS AND AGRICULTURE
FACT SHEET

June 14, 2012

WHAT EPA IS DOING

  • On June 14, 2012, the U.S. Environmental Protection Agency (EPA) issued proposed updates to its national ambient air quality standards (NAAQS) for particle pollution, also called particulate matter or PM. As part of this action, the agency proposed to retain the existing standard for coarse particle pollution (PM10).
  • EPA also proposed to strengthen the national air quality standards for fine particle pollution (PM2.5) to improve public health and visibility, by revising the annual health standard for PM2.5 and by setting a separate fine particle standard to improve visibility, primarily in urban areas. Read more about the proposed changes to the fine particle standards (PDF) (5pp, 400k)
  • The existing PM10 standard, of 150 micrograms per cubic meter, was set in 1987. It is what is known as a “one expected exceedance” standard, meaning that an area is violating if it exceeds the standard more than once a year, on average, over a three-year period.
  • As part of the June 14 action, EPA also proposed updates and improvements to the nation’s PM2.5 monitoring network. The agency is not proposing any changes to the coarse particle monitoring network.
  • EPA will take public comment for nine weeks (63 days) after the proposal is published in the Federal Register. The Agency will hold two public hearings, in Sacramento, Calif. And Philadelphia.
  • EPA will issue final standards by Dec. 14, 2012.

WHAT THE EXISTING PM10 STANDARDS HAVE MEANT FOR AGRICULTURE

  • Protecting and improving our nation’s air quality is the work of a federal-state partnership established in the Clean Air Act. EPA issues national standards and designates the “nonattainment areas” that must reduce pollution in order to meet them, generally basing these designations on data collected at air quality monitors. States then determine what those pollution reduction steps will be and outline those steps in plans known as “state implementation plans.”
  • Like all national air quality standards, the existing PM10 standards set the amount of PM10 pollution allowed in the outdoor air. But the standards themselves do not establish emission control requirements for any particular industry, including agriculture. Each state determines how to reduce a nonattainment area’s pollution to meet the standards in a way that makes the most sense for that area.
  • The vast majority of states have not required the agriculture industry to take any actions that require PM10 emission reductions; focusing their efforts to reduce PM10 on sources such as industrial processes, and construction and demolition. California and Arizona are addressing PM10 from agriculture by incorporating conservation management practices developed with growers and USDA into PM10 implementation plans for some nonattainment areas.
  • Similarly, EPA PM10 monitoring requirements do not target rural areas. EPA requires PM10 monitoring in areas with populations of 100,000 or more, with more monitors required in areas of higher population and with higher PM10 levels. States have the discretion to site additional PM10 monitors to meet their own clean air objectives.

COARSE PARTICLES AND HEALTH

  • A particle that is 10 micrometers in diameter is extremely small and can get past the respiratory system’s natural defenses (the nose and throat). For comparison, the diameter of an average human hair is about 50-70 micrometers – five to seven times larger than the largest coarse particle.
  • Scientific studies have linked exposure to coarse particles to a variety of health problems, including hospital admissions for heart disease, hospital admissions and doctors’ visits for respiratory diseases, increased respiratory symptoms in children, and premature death in people with heart or lung disease.

THE REVIEW OF THE PM10 STANDARDS

  • Reviews of a national air quality standard are thorough and extensive, taking several years before EPA reaches the point of proposing a rule.  To date, the review for PM10 has included:
    • An “integrated science assessment,” which is a review and assessment of the available science about the pollutant and its effects on public health and the environment;
    • A risk assessment, which quantifies the risks to public health from exposure to current levels of coarse particles; and
    • A staff “policy assessment document.” This document, previously known as a “staff paper,” includes staff conclusions about a range of policy options that could be supported by the available evidence. This includes conclusions about the current standard and possible alternative standards for the Administrator to consider.
    • Review by EPA’s independent science advisors, the Clean Air Scientific Advisory Committee (CASAC). CASAC reviewed drafts of the integrated science assessment, the risk assessment, and the staff policy assessment, and the public had the opportunity to comment on them.

FOLLOWING THE SCIENCE:  HOW PM REGULATIONS HAVE CHANGED OVER TIME

  • EPA has regulated particle pollution since 1971. Our standards have evolved over time, as science has taught us more about how exposure to particles affects health and welfare.
  • The 1971 standards, for example, set levels for all particles in the air, known as “total suspended particulate.” This covered all sizes of airborne particles, including dirt and other larger particles.
  •  In 1987, EPA changed the standards to focus on those particles 10 micrometers in diameter and smaller, because particles larger than that don’t generally get past the nose into the respiratory system. The Agency set both daily and annual PM10 standards at that time.
  • In 1997, based on an expanding body of scientific evidence linking fine particles (PM2.5) to serious health effects, EPA added both daily and annual standards for fine particles.
  • The Agency revised those standards in 2006, tightening the daily standard. That same year, EPA revoked the annual standard for PM10, because there was insufficient evidence linking long-term exposure to inhalable coarse particle pollution to health problems. EPA retained the daily PM10 standard – at 150 micrograms per cubic meter, the same level since 1987.

FOR MORE INFORMATION:

 

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