From US EPA |
On Friday, December 14th in a conference called followed by
a press release the U.S. Environmental Protection Agency, EPA, announced the
reduction to the fine particle pollution, PM2.5, average annual allowed level
to 12 micrograms per cubic meter (ug/m3) from 15 ug/m3. The EPA requires states
to monitor air pollution to assess the healthfulness of air quality and ensure
that they meet minimum air quality standards, and has some monitoring stations,
but not all of the nation is monitored. The US EPA has established both annual
and 24-hour PM2.5 air quality standards (as well as standards for other
pollutants). The annual standard is now 12 ug/m3 (an AQI of 39). The 24-hr
standard was recently revised to a level of 35 ug/m3 (an AQI of 99) and will
remain unchanged. States will have until 2020 to meet the revised annual PM2.5
health standard. EPA projections show 99% of U.S. counties with monitoring
stations will meet the standard with only 7 counties in California failing to
meet the Annual Fine Particle Health Standard of 12 μg/m3. For coarse
particles, PM10, EPA is retaining the existing 24-hour standard at 150 μg/m3
the same standard that has been in place since 1987.
Particulate matter is made up of particles that are emitted
directly, such as soot and dust, as well as secondary particles that are formed
in the atmosphere from reactions of precursor pollutants such as oxides of
nitrogen (NOx), sulfur oxides (SOx), volatile organic compounds (VOCs), and
ammonia (NH3). Particle are either directly emitted or formed in the
atmosphere. Directly-emitted particles come from a variety of sources such as
cars, trucks, buses, industrial facilities, power plants, construction sites,
tilled fields, unpaved roads, stone crushing, and burning of wood. Other
particles are formed indirectly when gases produced by fossil fuel combustion
react with sunlight and water vapor. Many combustion sources, such as motor
vehicles, power plants, and refineries both emit particles directly and emit
precursor pollutants that form secondary particulates. Ammonium nitrate and
ammonium sulfate are the principal components of secondary particulates.
Particulate matter has immediate health impacts: itchy,
watery eyes, increased respiratory symptoms such as irritation of the airways,
coughing or difficulty breathing and aggravated asthma. Health effects can
result from both short-term and long-term exposure to particulate pollution.
Exposure to particles can also trigger heart attacks and cause premature death
in people with pre-existing cardiac or respiratory disease. People most
sensitive to particulate pollution include infants and children, the elderly,
and persons with existing heart and lung disease. The particles can travel deep
into the lungs, enter the bloodstream, and penetrate into cells. Smaller
particles can penetrate deepest, causing the greatest harm. Researchers are
still trying to identify which types and sources of particles are most
hazardous to human health. Though, particles created from combustion soot tend
to be fine particles with diameters smaller than 2.5 microns (PM 2.5) which are
the most dangerous because it lodges in the lungs. Dust is mostly coarser
particles.
Since most counties will be in compliance with the new
standard based on previous EPA regulations and auto emission standards, EPA estimates
that meeting the annual fine particle standard of 12.0 μg/m3 will cost only between
$53 million to $350 million, but provide health benefits worth an estimated $4
billion to $9.1 billion per year in 2020. If you would like to read about how
these assessments are made see section 5 of “Regulatory Impact Analysis for theFinal Revisions to the National Ambient Air Quality Standards for ParticulateMatter” it is a window into the art and science of projecting benefits.
Currently, EPA reports that there are 66 counties of the 569
that are monitored in the nation that do not meet the 12 ug/m3 annual standard.
You might want to look to see if you live in one on this list, but not every
county is monitored. Prince William is not, but Fairfax is. The new PM2.5
standard is the last in a long list of regulations to improve air quality in
the United States and have resulted in even the seven worst counties in the
country (all in California) having significantly better air quality than the
PM2.5 air monitor atop the US Embassy in Beijing reports. Below is the list of air quality rules that have resulted in the tremendous improvement in air quality from 2000-2010 in the chart above and bring the United States to the next level in clean air.
·
Light-Duty Vehicle Tier 2 Rule (U.S. EPA, 1999)
·
Heavy Duty Diesel Rule (U.S. EPA, 2000)
·
Clean Air Nonroad Diesel Rule (U.S. EPA, 2004)
·
Regional Haze Regulations and Guidelines for
Best Available Retrofit Technology Determinations (U.S. EPA, 2005b)
·
NOx Emission Standard for New Commercial
Aircraft Engines (U.S. EPA, 2005)
·
Emissions Standards for Locomotives and Marine
Compression-Ignition Engines (U.S. EPA, 2008)
·
Control of Emissions for Nonroad Spark Ignition
Engines and Equipment (U.S. EPA, 2008)
·
C3 Oceangoing Vessels (U.S. EPA, 2010)
·
Hospital/Medical/Infectious Waste Incinerators:
New Source Performance Standards and Emission Guidelines: Final Rule Amendments
(U.S. EPA, 2009)
·
Reciprocating Internal Combustion Engines (RICE)
NESHAPs (U.S. EPA, 2010)
·
Mercury and Air Toxics Standards (U.S. EPA,
2011)
·
Cross-State Air Pollution Rule (U.S. EPA, 2011)
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