United States Air and Radiation EPA420-F-03-010
Environmental Protection April 2003
Agency
Office of Transportation and Air Quality
&EPA Regulatory
Announcement
Public Health and Environmental
Benefits of EPA's Proposed
Program for Low-Emission Nonroad
Diesel Engines and Fuel
The U. S. Environmental Protection Agency (EPA) has proposed
emission standards for nonroad diesel engines and fuel. This fact
sheet summarizes the estimated benefits of the proposal to public
health and the environment.
Background
EPA has proposed a comprehensive national program to reduce emis-
sions from future nonroad diesel engines and fuel. The proposed exhaust
emission standards would apply to new diesel engines used in most kinds
of construction, agricultural, industrial, and airport equipment. To meet
the proposed emission standards, engine manufacturers will produce new
engines with advanced systems for controlling emissions. These emission
control devices would be damaged by sulfur, so the proposal also aims to
dramatically reduce the level of sulfur in nonroad diesel fuel used by this
equipment, and the fuel used by locomotive and marine engines.
Air Quality Impact of Nonroad Diesel Engines
EPA estimates that the nonroad engines covered by this proposal contrib-
ute over 44 percent of diesel particulate matter (PM) emissions nationally
and over 12 percent of nitrogen oxides (NOx) emissions from mobile
sources. In some urban areas the contribution is greater. Without this
proposed control program, these percentages would continue to increase.
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Air quality problems are widespread in the United States. Hundreds of
millions of Americans currently live in counties with unhealthy air. This
proposal would help reduce harmful pollution. For more information
about air quality where you live, see the web page: http://www.epa.gov/
air/data/geosel .html.
Human Health and Environmental Impacts of These
Air Pollutants
The engines covered by the proposed standards contribute to formation
of fine particles and ozone. In addition, these engines emit Mobile Source
Air Toxics such as diesel exhaust, benzene, 1,3-butadiene, formaldehyde,
acetaldehyde, acrolein, and other substances.
Particulate Particulate matter represents a broad class of chemically and physically
Matter diverse substances. "Fine particulate matter" includes liquid and solid
particles with a diameter of 2.5 microns or less (also known as PM25).
Fine particles are produced any time fuels such as coal, oil, diesel fuel,
gasoline, or wood are burned. Power plants, various industries, cars and
trucks, buses, nonroad diesel and gasoline engines, wood stoves, forest
fires, agricultural burning, and marine engines are all sources of fine
particles. Fine particles are directly emitted or formed in the atmosphere
from precursors such as NOx and Sulfur Oxides.
Particulate matter has been linked to a range of serious respiratory and
cardiac health problems, including premature mortality, and hospital
admissions or emergency room visits for lung and heart diseases. Particles
can aggravate lung diseases such as asthma and bronchitis, causing
increased medication use, doctors visits, and restriction in activity or
missed days of work and school. Particles can aggravate heart diseases
such as congestive heart failure and coronary artery disease. Particles
have also been associated with cardiac arrhythmias (heartbeat irregulari-
ties) and heart attacks. There is emerging evidence suggesting increased
blood markers of inflammation (indicators of cardiac risk) are associated
with ambient PM. These effects have been associated with both short-
term (usually over a 24-hour period, but possibly as short as 1-hour) and
long-term exposures (years).
Groups of people considered to be the most sensitive to particles include
people with heart or lung diseases; older adults - possibly because they
are more likely to have undiagnosed heart or lung diseases; and children -
whose bodies are still developing and who are more likely to be active
outdoors and to have asthma.
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Diesel In addition to its contribution to ambient PM inventories, diesel exhaust is
Exhaust of specific concern because it has been judged to pose a lung cancer
hazard for humans as well as a hazard from noncancer respiratory effects.
In EPA's final "Health Assessment Document for Diesel Engine Exhaust,"
which received extensive scientific peer review, EPA classified diesel
exhaust as likely to be carcinogenic to humans by inhalation at environ-
mental exposures. Several other agencies have made similar classifica-
tions, including the National Institute for Occupational Safety and Health,
the International Agency for Research on Cancer, the World Health
Organization, California EPA, and the U.S. Department of Health and
Human Services. EPA also recently assessed air toxic emissions and their
associated risk and concluded that diesel exhaust ranks with other sub-
stances that the national-scale assessment suggests pose the greatest
relative risk.
Air Toxics Emissions from the engines covered by this proposal also contain several
Mobile Source Air Toxics, including benzene, 1,3-butadiene, formalde-
hyde, acetaldehyde, and acrolein, which cause a variety of health-related
problems. Users of these engines may experience high levels of personal
exposure to these substances.
Ozone Ground-level ozone, the main ingredient in smog, is formed by complex
chemical reactions of NOx and volatile organic compounds in the pres-
ence of heat and sunlight. Ozone forms readily in the lower atmosphere,
usually during hot summer weather. Volatile organic compounds come
from some natural sources (such as vegetation), but mostly come from
mobile sources (such as nonroad engines, cars, and trucks), chemical
plants, refineries, factories, consumer and commercial products, and other
industrial sources. NOx emissions come largely from motor vehicles,
nonroad equipment, power plants, and other sources of combustion.
Ozone can irritate the respiratory system, causing coughing, throat
irritation, and/or uncomfortable sensations in the chest. Ozone can reduce
lung function and make it more difficult to breathe deeply; breathing may
become more rapid and shallow than normal, thereby limiting a person's
normal activity. Ozone can also aggravate asthma and other respiratory
diseases, leading to more asthma attacks, use of additional medication,
more severe symptoms that require a doctor's attention, more visits to the
emergency room, and increased hospitalizations. In addition, ozone can
inflame and damage the lining of the lungs, which may lead to permanent
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changes in lung tissue, irreversible reductions in lung function if the
inflammation occurs repeatedly over a long time period and a lower
quality of life. People who are particularly susceptible to the effects of
ozone include healthy children and adults who are active outdoors,
people with respiratory disease, such as asthma, and people with unusual
sensitivity to ozone.
Visibility Visibility is important because it directly affects people's enjoyment of
daily activities in all parts of the country. Visibility is highly valued in
significant natural areas such as national parks and wilderness areas
because of the special emphasis given to protecting these lands now and
for future generations. Fine particles from sources such as power plants
using fossil fuels, motor vehicles, and nonroad engines are the major
cause of reduced visibility.
Other Emissions from nonroad diesel engines contribute to other effects includ-
Environmental ing ecosystem damage, acid deposition, odor, production of organic
Effects matter in water bodies that leads to nuisance algal blooms, crop damage,
soiling, and material damage.
Air Quality Benefits of This Proposal
When fully implemented, this proposal would reduce nonroad diesel
PM25 and NOx emissions by over 90 percent. It will reduce NOx emis-
sions nationwide by over 825,000 tons annually and PM emissions by
over 125,000 tons. It will also virtually eliminate SOx emissions from
nonroad diesel engines, which amount to nearly 300,000 tons per year,
and reduce air toxic emissions by about 30 percent.
These dramatic emission reductions are a critical part of the effort by
federal, state, local, and tribal governments to reduce the health related
impacts of air pollution. The reductions will help areas to reach attain-
ment of the National Ambient Air Quality Standard (NAAQS) for PM
and ozone. These reductions are also needed to help our national parks
and wilderness areas, which have particular needs for reducing haze to
protect scenic vistas.
These controls will help reduce ambient concentrations of fine PM,
ozone, and air toxics. EPA modeling projections show that this proposal
will substantially reduce exposures nationwide, including improvements
that allow several areas to attain air quality standards. Specifically, EPA
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projects that the number of people living in counties with PM2 5 levels
above the NAAQS in 2020 would be reduced from 66 million to 60
million. That represents a reduction of 9 percent in exposed population
and 15 percent in the number of counties. In 2030, there would be a
reduction from 85 million people to 71 million exposed to high PM
levels, which represents an even greater improvement than projected for
2020 because of the increased turnover of nonroad equipment. This
corresponds to a 16 percent reduction in exposed population and a 21
percent reduction in the number of counties. In addition, those areas that
continue to have high PM levels would be closer to meeting air quality
standards and areas that already meet air quality standards for PM would
be better able to remain in attainment. The proposed program would also
reduce ozone and toxics nationally.
Health Benefits of the New Standards
The PM air quality improvements expected from this proposal produce
major benefits to human health and welfare. By the year 2030, this pro-
posed rule would annually prevent all of the following:
• 9,600 premature deaths
• 16,000 nonfatal heart attacks
• 5,700 cases of chronic bronchiti s
• 8,300 hospital admissions
• 14,000 acute bronchitis attacks in children
• 260,000 respiratory symptoms in children (related to PM)
• nearly 1 million lost work days among adults
• 6 million days where adults have to restrict their activities due to
respiratory symptoms
In monetary terms, EPA estimates annual benefits in 2030 to be about
$81 billion when the program is fully phased in. The proposed program
will reduce personal exposure for people who operate or are otherwise
close to these engines. There are additional health and welfare benefits,
such as those related to reduced levels of ozone, carbon monoxide, and
air toxics, that are not included in the above estimate.
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Where Can I Get More Information?
For more information on the environmental and health impacts of these
proposed emission standards, see the Draft Regulatory Impact Analysis
(especially Chapter 2—Air Quality, Health, and Welfare Effects). You can
access that document and others related to the rulemaking on EPA's Web
site at:
www.epa.gov/nonroad
You can also contact us at:
U.S. Environmental Protection Agency
Assessment and Standards Division
2000 Traverwood Drive
Ann Arbor, MI 48105
Voice-mail: (734)214-4636
E-mail: asdinfo@epa.gov
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