The Clean air act A Proven Tool for Healthy Air - A report from physiciAns for sociAl - Physicians for Social Responsibility
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The Clean Air Act
A Proven Tool for Healthy Air
A report from
Physicians for social
responsibility
By
Kristen Welker-Hood,
ScD MSN
Barbara Gottlieb
and John Suttles, JD LLM
with Molly Rauch, MPH
May 2011
The Clean Air Act
A Proven Tool for Healthy Air
A Report From
Physicians For Social
Responsibility
By
Kristen Welker-Hood, ScD MSN
Barbara Gottlieb
John Suttles, JD LLM
with Molly Rauch, MPH
Acknowledgments The authors gratefully acknowledge the assistance of the following people who helped make this report possible: William Snape III, JD of the Center for Biological Diversity read an early draft and provided invaluable input. Jared Saylor and Brian Smith of Earthjustice also read the text and offered suggestions. David Schneider, Shoko Kubotera and Tony Craddock Jr., PSR interns, provided much-appreciated research assistance; David also collaborated on the writing. Finally, we thank the Energy Foundation, Compton Foundation, Marisla Foundation and Earthjustice for their generous financial support. Any errors in the text are, of course, entirely our own. For an electronic copy of this report, please see: www.psr.org/resources/clean-air-act-report.html About Physicians for Social Responsibility PSR has a long and respected history of physician-led activism to protect the public’s health. Founded in 1961 by a group of physicians concerned about the impact of nuclear proliferation, PSR shared the 1985 Nobel Peace Prize with International Physicians for the Prevention of Nuclear War for building public pressure to end the nuclear arms race. Today, PSR’s members, staff, and state and local chapters form a nationwide network of key contacts and trained medical spokespeople who can effectively target threats to global survival. Since 1991, when PSR formally expanded its work by creating its environment and health program, PSR has addressed the issues of global warming and the toxic degradation of our environment. PSR presses for policies to curb global warming, ensure clean air, generate a sustainable energy future, prevent human exposures to toxic substances, and minimize toxic pollution of air, food, and drinking water. May 2011
Contents Executive Summary iv 1. america’s urgent need for clean air 1 2. what does the clean air act do? 9 3. The Clean Air act, a success story 17 4. opportunities for saving lives 22
Executive Summary
S
ince Congress created the Clean Air Act
in 1970, it has proven to be one of the na-
tion’s most important tools for improving
public health. Air pollution from industri-
alization, motor vehicles, and fossil fuel combus-
tion is pervasive across America, and millions of
Americans suffer death and debilitating illnesses
as a result: respiratory illnesses, heart attacks,
strokes, cancer, birth defects, mental retardation,
and more.
The Clean Air Act, by reducing emissions from
many of the worst sources of air pollution, has
dramatically improved air quality. In so doing it
has prevented hundreds of thousands of prema-
ture deaths and reduced disease and suffering for
millions of people. Yet despite that resounding
history of achievement, we as a nation still face
major opportunities and challenges for improving
air quality and public health. A fully implemented iStockphoto/Aldo Murillo
Clean Air Act remains our best tool for making
those improvements.
How the Clean Air Act Works
The Clean Air Act combines several distinct ap-
proaches in order to prevent air pollution at the
source. For six harmful air pollutants that are ants in the atmosphere. The 50 states then develop
found widely across the U.S.—particulate matter, their own strategies for implementing the NAAQS
ground-level ozone, nitrogen oxides, sulfur diox- standards. Pollutants subject to the NAAQS are
ide, carbon monoxide and lead—the Act requires known as “criteria pollutants” because the EPA
the EPA to establish National Ambient Air Quality sets the standards using science-based guidelines
Standards, or NAAQS. These standards identify (criteria) reflecting these substances’ damaging
the allowable concentration of each of these pollut- impacts on human health and the environment.
Physicians for Social Responsibility The Clean Air act v
The Clean Air Act also establishes a category of The number of lives saved and poor health out-
hazardous air pollutants, commonly abbreviated as comes averted by the Clean Air Act are estimated
HAPs and referred to as “toxic air contaminants” to be substantial. A recent EPA assessment deter-
or “air toxics.” These are 188 pollutants and chemi- mined that in 2010, the Act and its 1990 amend-
cal groups known or suspected to cause serious ments prevented 160,000 premature deaths due
health effects including cancer, birth defects, and to fine particulate matter alone; in 2020, the esti-
respiratory tract and neurologic illness, even when mated number of lives saved will rise to 230,000.
exposure levels are low. Because HAPs are so po- Reductions in particulate pollution are projected
tent, the EPA must address all categories of major to prevent as many as 200,000 heart attacks and
air toxics sources and develop highly protective 2.4 million asthma attacks in 2020. Reduction of
control standards for each category. ozone pollution has reduced hospital admissions,
Finally, the Act sets operating standards for cer- emergency room visits, restricted-activity days, and
tain categories of major polluters. These include days lost at school and work.
stationary sources of pollution, such as power There is another yardstick by which this legisla-
plants and factories, and mobile sources such as tion can be measured: The Clean Air Act has also
cars, trucks and trains. Stationary sources are proven to be an excellent investment in economic
subject to different requirements depending on terms. Cost-benefit analysis demonstrates that the
whether they are located in areas in compliance dollars saved from reduced illnesses, hospital ad-
with the NAAQS standards or in non-compliance missions, and lost days from work and school have
areas. Controls over stationary sources may include greatly exceeded the costs associated with reducing
permitting requirements to assure clean function- air pollution. The EPA estimates a return of $30 in
ing, as well as offset requirements to reduce emis- benefits for every one dollar spent on implemen-
sions of criteria pollutants from other sources. tation of pollution controls by 2020. By a similar
Because mobile sources move readily across token, the Act succeeded in reducing air pollution
state lines, the EPA has near-exclusive authority while the nation’s population and economy both
over them. To control mobile sources, EPA sets grew. Clean Air Act regulations have also spurred
vehicle performance standards and operates a fuel technological innovation, generating jobs and eco-
regulation program. nomic growth. The successes of the Clean Air Act
have shown that protection of health and econom-
ic growth can and do work hand in hand.
A History of Success
Finally, a success of a different sort: The Clean
The Clean Air Act has demonstrated dramatic suc- Air Act was enacted in nonpartisan fashion, with
cess over its 40-year history. Its success is visible in leadership from both sides of the aisle, under
improvements to air quality and in the decreased multiple administrations, both Republican and
cases of morbidity and mortality resulting from Democrat. Lawmakers clearly recognized that the
reduced air pollution. The pollution controls put goal of improving America’s health was a shared
in place by 1990 led to major decreases in ambi- interest, far more important than the differences
ent criteria pollutant concentrations, compared to that sometimes hinder policy-making.
the levels that would have been expected without
implementation of the Act. The greatest reductions
Future Opportunities for Cleaner
were achieved through requiring power plants and
Air, Greater Benefits
industries to install smokestack scrubbers to cap-
ture sulfur dioxide and filters to capture particu- Even as the benefits of the Act accrue, ambi-
lates; switching to lower-sulfur fuels, and install- ent concentrations of several pollutants are still
ing catalytic converters to reduce nitrogen oxide too high to adequately protect the American
emissions from vehicles. people, especially children, the elderly, those
vi The Clean Air act Physicians for Social Responsibility
istockphoto/ Daniel Stein
l iving in highly polluted communities, and those Particle emissions are likewise in urgent need
with chronic health problems. Some 127 million of stronger regulations. Fine particulate matter
people live in areas of the country that are in (particles smaller than 2.5 microns in diameter,
non-attainment for at least one or more NAAQS. called PM 2.5) poses a significant cardiovascular
Additionally, according to EPA estimates, breath- risk and contributes to heart attacks, strokes,
ing air toxics over a lifetime of exposure contrib- heart failure, and irregular heartbeats. The cur-
utes to nearly 30 percent of overall cancer risk in rent PM 2.5 standards were last revised in 2006 but
the U.S. Some regions in the U.S. are even more are not stringent enough to protect public health.
heavily affected, with two million (one in 10,000) EPA was scheduled to propose new national limits
people facing increased lifetime cancer risk from (standards) for PM 2.5 in February 2011, but had not
air toxics exposure. These risks far overshoot EPA’s done so as of mid-April.
“acceptable” risks goal of one in a million and
highlight the need to control pollutant emissions
A Health Imperative
more effectively.
Two criteria pollutants stand out as in need of The U.S. medical and health community has sup-
immediate strengthening of pollution controls. ported federal action for clean air for over half
Fortifying the standards for ground-level ozone a century. Cognizant that clean air to breathe
should be a top priority. When EPA last revised the is essential to America’s health, groups such as
ozone standard in 2008, it disregarded the recom- the American Medical Association, American
mendations of its own panel of expert scientists Public Health Association, American Academy of
and physicians, the Clean Air Scientific Advisory Pediatrics, and Physicians for Social Responsibility
Committee, which advised that the maximum limit continue to press for robust, proactive and nation-
for ambient ozone concentrations be lowered from ally uniform protection from deadly air pollutants.
84 parts per billion (ppb) to a range between 60 The Clean Air Act is our best tool to that end. It
to 70 ppb measured as an 8-hour average. Instead, is essential that we safeguard the Clean Air Act
EPA proposed a limit of 75 ppb. To protect public from political maneuvering. It is a public health
health, the EPA should set the ozone standard law that is a proven life-saver, and its job — and
at the most health-protective level of 60 ppb its benefits to the American people — are still far
immediately. from complete.
1. America’s Urgent Need
for Clean Air
Introduction
D
Its passage paved the way for monumental gains in
angerous air pollutants damage public health, including major reductions in blood
our health from before we are born lead levels nationwide and reductions in premature
through our final days. Such pollutants deaths, illnesses and hospitalizations stemming
as particulate matter, nitrous oxides, from air pollution exposure.
sulfur dioxide, ozone, heavy metals and other air This report reviews the role the CAA has played
toxics inflict irreparable harm on our airways, in health promotion and disease prevention over
lungs, heart and circulatory systems, undermin- the past 40 years. It reviews the context in which
ing all our major organ systems. Air pollutants in- the CAA was created, the methods by which it reg-
crease hospitalizations and emergency room visits, ulates pollutants, its successes in protecting health,
time lost from school and work, and premature and the challenges it faces for controlling the air
deaths due to cardiopulmonary disease. In fact, pollutants of today. The report begins by examin-
air pollution contributes to four of the five leading ing the air pollution calamities that revealed to the
causes of mortality in the United States: heart dis- nation the depth of its air pollution problem and
ease, cancer, stroke, and chronic lower respiratory prompted a powerful national response.
diseases.1
To curb the rising incidence of these diseases,
Air Pollution Calamities Lead
we must reduce the pollutants that contribute to
to the Clean Air Act
their development and exacerbation. That means
controlling emissions of pollutants from the dirti- Air pollution isn’t a new problem; throughout histo-
est and most widespread sources: coal-fired power ry there have been accounts of large cities plagued
plants, motor vehicles, heavy industry, and refiner- by “heavy air” and acrid odors. In the industrial age,
ies. The Clean Air Act (CAA) is the most effective with coal feeding the fires of the industrial revolu-
tool we have to accomplish this goal. It allows com- tion, air toxics joined the mixture of urban pollut-
munities across the U.S. to combat multiple pol- ants. Today, emissions from the combustion of coal
lutants at their source, resulting in significant pro- and oil have been joined by a multitude of toxic
tections for human health. The CAA is designed air pollutants, including gasoline and diesel fuels,
to establish science-based pollution mitigation heavy metals, asbestos, solvents, paint strippers, and
strategies that will safeguard public health, protect persistent organic pollutants, among others. Despite
our most vulnerable individuals, and assure envi- the dangers to health from this chemical stew, it
ronmental quality for future generations. The Act took decades of air pollution tragedies to spur ad-
has been highly successful in achieving these goals. equate action for air pollution controls.
2 The Clean Air act Physicians for Social Responsibility
those with respiratory problems. A similar incident
recurred in 1956. This led to the establishment in
England of stringent air pollution laws including
the Clean Air Acts of 1956 and 19685 that required
relocating power stations outside cities, increas-
ing stack heights, fuel switching to cleaner fuel,
and banning black smoke. These statutes greatly
decreased the smoke that was able to accumulate
Pittsburgh Post-Gazette
during fog inversion caps, making London’s “killer
smog” a thing of the past.
Large industrial cities in the U.S. such as
Pittsburg, St. Louis, New York and Los Angeles
suffered their own deadly bouts of smog. West
Coast cities witnessed a new kind of air pollution
Noontime smog on a street in Donora, PA, 1948
on hot, sunny days. This pollution hung over cit-
ies as a thick brown haze, causing lung irritation
One of the earliest documented air pollution and burning eyes. Los Angeles’ poor air quality
tragedies occurred in Belgium in 1930. A five-day resulted from growing motor vehicle usage, waste
fog and temperature inversion trapped cold air incineration, maritime and rail shipping, and an
close to the earth, preventing air circulation and increase in petrochemical and refinery activity.
causing a tremendous build-up of smoke and other During the 1960s, New York’s dangerous air pollu-
contaminants from nearby industries. The result tion resulted in over 1,100 deaths, with additional
of this toxic accumulation was 60 deaths and over cases of non-fatal illnesses.6
6,000 illnesses.2 While there had been earlier ac-
counts of illness and premature death associated
The Fight for Clean Air
with fogs in other cities of the world (such as in
Glasgow and London), the Meuse River Valley The shocking morbidity and mortality caused
event was the fist case in which increased incidence by air pollution spurred the American public to
of morbidity and mortality was directly associated demand action to clean up the air. Initially, air
with air pollution.3 The U.S. experienced a similar pollution control strategies in the U.S. relied on
tragic event in 1948, when a temperature inver- legal challenges such as common-law torts, public
sion cap occurred in a river valley near the small nuisance, private nuisance, trespass and liability
industrial town of Donora, Pennsylvania, trapping lawsuits. Plaintiffs rarely won these cases because
air pollution from a local zinc smelter for five days. of the inherent difficulty in identifying a pollut-
The first documented U.S. air pollution disaster, ant’s source (since air pollutants can travel long
it killed 20 people and caused 6,000 of the town’s distances), demonstrating harm (due to the la-
14,000 residents to fall ill.4 tency periods of many diseases), and limitations
In 1952, air pollution created the first large- in scientific knowledge regarding toxicants and
scale disaster. The trade winds that normally car- related illnesses. Even when cases were successful,
ried away London’s air pollution died down, allow- defendants were often paid a pittance of the real
ing a “killer fog” to set in. The combination of fog damages incurred, and the polluter was able to
and coal smoke was so intense that people were return to business as usual. Not surprisingly, this
forced to breathe through cloth masks to protect approach garnered only mediocre pollution con-
their burning throats and lungs, and visibility was trols, with the result that by the mid-1960s, states
so reduced that people had to feel their way down and local governments were stepping up to take
the sidewalk. Four thousand people died as a result control of air quality problems by passing local
of this event, including the elderly, the young, and ordinances.7Physicians for Social Responsibility The Clean Air act 3
The state-based approach, however, had its own rules and standards. The timeline of these clean
weaknesses. The patchwork of pollution rules that air acts and their regulatory scope is presented
emerged was inadequate to protect public health. in Figure 1.
Not only did protection of public health vary from With each amendment to the original Clean
state to state, but the states had no mechanism Air Act of 1970, the regulation was enhanced to
for regulating the sources of windborne pollution provide better solutions for controlling different
that blew in from neighboring jurisdictions. To types of pollutants from different sources. While
aid the states’ efforts and more effectively protect considerable health improvements were achieved
public health, the federal government began to during the CAA of 1970, acid rain caused by
pass a series of “clean air acts” establishing federal Midwestern coal power plants burning high-sulfur
programs to control air pollution using nationwide coal was killing lakes and forests in the Northeast
Figure 1. Timeline of U.S. air pollution regulation and highlights of regulatory strengthening
Air Pollution Clean Air Clean Air Act Clean Air Act Clean Air Act
Control Act Air Act Quality Act Extension Amendments Amendments
1955 1963 1967 1970 1977 1990
The first federal The first Clean Divided the Increased Authorized provi- Established the
legislation involv- Air Act. It grant- nation into Air federal enforce- sions related to Acid Rain Pro-
ing air pollution. ed $95 million Quality Con- ment authority. prevention of gram to control
It recognized air dollars to state trol Regions Authorized the significant dete- sulfur dioxide
pollution as a and local govern- and initiated development of rioration (PSD), and nitrogen
danger to public ments in order enforcement comprehensive requiring areas oxides.
health and the to research air proceedings in federal and state with air quality Created the
environment. monitoring and areas subject regulations to better than the emissions trad-
Gave the Secre- create pollution to interstate limit emissions national stan- ing program
tary of Health, control programs. air pollution so from industrial dard to maintain (the original
Education and Set emission as to achieve stationary sourc- their level of air cap & trade
Welfare the standards for consistent air es and mobile quality. program)
power to under- stationary quality. sources. Authorized provi- to achieve
take and recom- sources such as Established a It set forth four sions to NAAQS air p
ollution
mend research power plants and national emis- major regulatory to establish a reductions
programs for air steel mills. sions standard programs: major permitting from stationary
pollution control. Authorized for stationary review require- sources like
1. National Am-
Dedicated federal research into sources as op- ment for areas coal-fired power
bient Air Qual-
funds to support techniques to posed to regu- unable to attain plants.
ity Standards
research and minimize air pol- lating emissions air quality stan- Authorized a
(NAAQS);
technical as- lution. by industry. dards. program to
2. State Imple-
sistance for the Motor Vehicle Air Authorized ex- Marked the control 189 toxic
mentation
states. Pollution Act of panded studies first attempts air pollutants.
Plans;
State and local 1965—an amend- of air pollutant to p revent the Added provi-
emission inven- 3. New Source destruction of
governments ment of the CAA Performance sions requiring
maintained the that established tories, ambi- stratospheric the phase-out of
ent monitoring Standards; ozone.
authority to set standards for ozone-depleting
techniques, and 4. National Emis-
air pollution laws, automobile chemicals.
control tech- sion Standards
but reserved for emissions. Established
niques. for Hazardous
Congress the Title V per-
Air Pollutants.
right to act in the mit program
future. requirements.
Sources: U.S. Environmental Protection Agency (2010, Nov.). History of the Clean Air Act. Retrieved April 18, 2011 from http://www.epa.gov/air/
caa/caa_history.html#milestones
American Meteorological Society. (n.d.). Clean Air Acts 1955, 1963, 1970 and 1990: a look at U.S. Air pollution laws and their amendments.
Retrieved April 18,2011 from http://www.ametsoc.org/sloan/cleanair/cleanairlegisl.html4 The Clean Air act Physicians for Social Responsibility
Health community support for the CAA
One notable element in the effort to create contained in the CAA “necessary public health
clean air legislation was the growing support of measures.” 15
the organized health and medical community, The American Public Health Association
which has been visible for over half a century. (APHA) chose to focus on the scientific validity
As far back as 1955, the American Medical of the then-current air quality standards. Much
Association (AMA) testified before the U.S. that is known about air pollution today was
Senate, applauding the idea of a coordinated new at that time, since much of the research
national program to “stimulate the interest was conducted only after CAA air quality
of local agencies” in air pollution control and standards were promulgated. For example, the
supporting “limited federal funds” to support APHA testimony drew attention to the fact that
research activities in the field.12 By the time sulfur dioxide and particulate matter, when in-
the Air Quality Act of 1967 was introduced, haled together, created synergistic effects; that
the AMA was urging the federal government because fine particulate matter was so signifi-
to take a preventive approach to air pollution, cant to health, pollution abatement measures
with a special emphasis on cleaner fuel and that reduced coarse particulates might fulfill air
vehicles. The AMA also recognized that pollu- quality standards without benefitting human
tion was often an interstate problem and called health; and that studies had clarified the mech-
for regional air quality commissions. While anisms by which carbon monoxide interfered
emphasizing action by local, state and regional with cardiac function. The APHA concluded
jurisdictions, the AMA supported enactment of that the available scientific evidence gave no
uniform national laws to control air pollution.13 grounds for relaxing air quality standards.16
Only a few years later, the AMA’s tone had In the wake of the 1974 oil shortage, the Amer-
become more urgent. In testimony before the ican Lung Association (ALA)’s testimony urged
U.S. Senate in 1970, it emphasized that air in “that attempts to weaken (the CAA) under the
the United States had grown more polluted guise of energy or economic need be rejected,
and that hazards to health had increased. “We and that the nation’s halting progress toward
must take stronger action to reverse this direc- clean air be speeded up, not aborted.”17 It called
tion . . . than we have taken in the past,” AMA for a robust program to desulfurize gasoline and
urged. “Measures which a few years ago were for maximum sulfur dioxide emissions controls
deemed adequate . . . simply have not achieved on stationary sources that burned fossil fuels.
the desired goals.”14 The ALA also opposed extending the deadlines
By 1975, the American Public Health As- for implementing air quality controls. And with
sociation and the American Lung Associa- prescience, it proposed an amendment to the
tion had joined the AMA in testifying before CAA to allow the EPA to regulate any pollutants
Congress for clean air legislation. The AMA which were significantly related to serious health
focused on the health impacts of air pollu- effects, including where sufficient scientific data
tion, calling for additional research into the was not yet available.
health impacts of prolonged exposure to low Today these and other national health organi-
levels of air pollution, the impacts of simul- zations, such as Physicians for Social Responsi-
taneous exposure to multiple pollutants, and bility and the American Academy of Pediatrics,
the role of air pollution as a causative agent continue to present the medical community’s
in diseases then on the rise: heart disease, consensus: that having clean air to breathe is
stroke, chronic bronchitis and emphysema essential to America’s health, and that a robust,
and cancer, especially lung cancer. It called fully implemented Clean Air Act is our best tool
the air quality standards and time schedules to that end.Physicians for Social Responsibility The Clean Air act 5
istockphoto/ Nina Shannon
and Canada.8 In 1984 the Union Carbide disaster ipartisan fashion to add strengthening measures.
b
occurred in Bhopal, India, when a pesticide plant Through a process of debate and public hear-
leaked forty tons of deadly methyl isocyanate gas, ings, the result became the modern Clean Air Act
killing 3,000 people and damaging the health of Amendments of 1990.
over 100,000.9 This accident prompted U.S. citi- Even this brief summary of the Clean Air Act’s
zens to worry just how safe their air at home was history underscores several significant points. First,
from toxic air chemicals. Congress investigated real improvement to air quality occurred only after
and determined that in the 14 years since the pas- consistent federal standards were set for the whole
sage of the CAA of 1970, the EPA had recognized nation. Because air pollution is mobile and does
only five substances as toxic under the Act, leaving not stay within geographic boundaries, it was nec-
thousands of chemicals registered and in produc- essary to establish national air quality standards;
tion yet unevaluated for safety. This finding led preservation of downwind air quality depended
Congress to pass a right-to-know law that included on addressing interstate pollution. Second, the
a Toxic Release Inventory to assist communities health and medical communities supported fed-
in accessing valuable information about the types eral regulation of air pollutants and continue to
and amounts of chemicals released into their air.10 do so today: They find it an essential component
In 1989 George H.W. Bush became president of safeguarding public health. Finally, in response
and prioritized as a goal of his Administration the to the growing evidence of air pollution’s threat
strengthening of the CAA to address Americans’ to health, various Congresses took action to cre-
concerns for both acid rain and air toxics.11 ate federal regulation of air pollution. This hap-
President Bush submitted a bill to strengthen the pened over the course of many years and multiple
Clean Air Act, which Congress then worked in presidential administrations, yet was achieved in6 The Clean Air act Physicians for Social Responsibility
essentially bipartisan fashion. The EPA was born
during the tenure of President Richard Nixon, a
Republican, and the Clean Air Act itself was re-
peatedly strengthened—as with the addition of the
Clean Air Act Amendments in 1990—under both
Republican and Democratic presidents.
istockphoto/matteo NATALE
Common but Deadly: The “Criteria”
Air Pollutants
Since the nation launched its earliest attempts
to regulate air pollution, scientific research has
proceeded to identify and document the most
common and most health-damaging air pollutants
and has pinpointed many of their impacts on the lower and upper respiratory diseases such as
human body. The EPA has flagged six pollutants as chronic and acute bronchitis; asthma and asthma
particularly widespread across the nation and harm- exacerbations; heart attacks; strokes, and cancer.
ful to both health and the environment. These six Particle pollution is also linked to low birth weight,
are: particulate matter, ground-level ozone, carbon premature birth, and sudden infant death. It is
monoxide, sulfur oxides, nitrogen oxides, and lead. estimated that PM causes an estimated 60,000 pre-
They are known as “criteria pollutants” because the mature deaths each year.
EPA sets national air quality standards for their con-
centration in the atmosphere, using science-based ground-level ozone: Ozone, the major component
guidelines (criteria) that reflect their impact on of smog, is the most pervasive outdoor air pollut-
human health and the environment. ant in the U.S. It forms when pollutants released
Criteria pollutants share two defining charac- by cars, power plants and other sources react with
teristics: They endanger public health and wel- sunlight and heat. In conjunction with particulate
fare, and they are widely present in the outside matter, ozone can cause and exacerbate respiratory
air, a ffecting much of the U.S. As a rule, criteria problems. It is linked to lung cancer development
pollutants are emitted by multiple sources, com- and mortality and also harms the cardiovascular
monly found, such as cars, diesel vehicles, coal- system.
fired power plants and industrial facilities. In ad-
dition, rather than settling out of the air to form ( no x ): Nitrogen oxides are
n i t roge n ox i de s
“hotspots” in the immediate vicinity around their irritants to the eyes, nose, throat, and lungs. High
source, these pollutants tend to disperse widely. levels of exposure can seriously damage tissues in
For these reasons, effective regulation of criteria the throat and upper respiratory tract. Nitrogen
pollutants is done not on a source-by-source basis, oxides are linked to respiratory disease and
but by monitoring their level in the atmosphere premature death.
in every state and assuring that they remain at
non-harmful levels. The health effects of the six su l f u r diox i de ( so 2 ): Sulfur dioxide can cause
criteria pollutants are summarized below; more breathing difficulty for people with asthma, while
information is presented in Figure 2 (on pages long-term exposure causes respiratory illness and
14–15). aggravates cardiovascular diseases. It is linked to
infant death, ischemic stroke, respiratory disease,
pa rt icu l at e m at t e r : Particulate matter is one and premature death. Its effects on infants include
of the nation’s deadliest air pollutants. It causes low birth weight, preterm birth, and increased risk
or contributes to decreased pulmonary function; of infant death.Physicians for Social Responsibility The Clean Air act 7
c a r bon monox i de ( co ): Carbon monoxide inter- Thirty-three of these compounds are included in
feres with oxygen transport through the body by a priority list of HAPs that are of special concern
bonding with hemoglobin in the blood. CO expo- because of their widespread use and potential
sure has been linked to death from cardiovascular for causing cancer (carcinogenicity) and devel-
effects, including stroke. People with pre-existing opmental malformations, especially in the fetus
heart conditions, infants (who require more (teratogenicity).
oxygen than adults) and pregnant women are Studies have found that estimated levels of some
particularly vulnerable to harm. Risks to fetuses, of the HAPs are a potential public health problem
newborns, and children include birth defects, low in many parts of the United States.19,20,21 Among
birth weight, neonatal respiratory mortality, and them, benzene, formaldehyde, and 1,3-butadiene
asthma. may contribute to extra cases of cancer (at least
1 extra case per million people exposed) in more
l e a d ( pb ): Lead, a heavy metal, is highly neuro- than 90 percent of the census tracts in the lower
toxic. It damages kidney function as well as the 48 states of the U.S. Vehicles account for approxi-
nervous, immune, reproductive, developmental, mately half of HAPs emissions but may contribute
and cardiovascular systems. In infants and young to 88 percent of the added risk from HAPs.22 In
children it contributes to learning problems, be- general, the health risks from this broad category
havioral problems, learning deficits, and decreased of air pollutants may be underestimated, because
IQ. In adults it is linked to high blood pressure and there is limited information on toxicity values for
heart disease. many of the HAPs,23 and the risk models did not
consider the greater vulnerability of children.
Air Toxics
Vulnerable Populations:
The six criteria pollutants may be the most wide-
Most Affected by Air Pollution
spread air pollutants in the nation, but they are far
from the only dangerous ones. The EPA has also While air pollution is a problem that affects many
established a category of hazardous air pollutants, Americans, some groups of people are more vul-
commonly abbreviated as HAPs and referred to nerable than others. These groups are multiple
as “toxic air contaminants” or “air toxics.” These and may be overlapping; they include people with
are 188 pollutants and chemical groups known or respiratory ailments such as asthma, chronic bron-
suspected to cause serious health effects including chitis and emphysema; people with cardiovascular
reproductive dysfunction, developmental disabili- disease or diabetes; young children; the elderly,
ties, birth defects, cancer, cardiovascular, respira- and the poor. When ambient air quality standards
tory tract and neurologic illness.18 are set, special attention needs to be paid to ensure
The Clean Air Act directs the EPA to regulate that the levels established are stringent enough to
HAPs, which include compounds such as polycyclic protect these vulnerable populations and not only
aromatic hydrocarbons, acrolein, and benzene, those who are fully grown and in good health.
found in gasoline; solvents such as hexane and tol- Children are especially vulnerable to the harm-
uene; hexavalent chromium from chrome-plating ful effects of air pollution.24, 25, 26, 27, 28 Children’s
facilities; perchloroethylene, which is emitted from ongoing lung development, incomplete metabolic
some dry cleaning facilities; methylene chloride, systems, high infection rate, and behavioral traits
which is used as a solvent and paint stripper by like high activity levels and time spent outdoors
a number of industries; asbestos; metals such as make children more susceptible to harm from air-
mercury and cadmium; and persistent organic pol- borne pollutants. 29, 30Air pollution can also harm
lutants such as polychlorinated biphenyls. In 2001, children before they are born. Intrauterine mortal-
diesel exhaust was listed as a mobile-source HAP. ity has been linked to exposure to nitrogen oxides,8 The Clean Air act Physicians for Social Responsibility
as well as to the synergistic effects of simultaneous
exposure to nitrogen oxides, sulfur dioxide, and
carbon monoxide. 31 The developing fetal lung, as
well as the infant lung, is more susceptible to injury
by lung toxicants (including air pollutants), even
at exposure levels below the official “no-effects
level” for adults.32 These findings highlight the vul-
nerability of the 41.7 million children age 18 and
under who live with dangerous levels of ozone pol-
lution, the 17.6 million children exposed to dan-
gerous short-term particulate pollution, and the
7.7 million children living in areas with dangerous
year-round particulate levels. 33 Standards for air
pollution levels may have to be adjusted to protect
istockphoto/iofoto
this v ulnerable population.
The elderly are also highly susceptible to crite-
ria air pollutants. The findings of one study indi-
cate that carbon monoxide, nitrogen oxides and
particulate matter are associated with increased
cardiovascular hospital admissions in the elderly.34
Another study suggests that the elderly are at risk levels of short-term particle pollut ion, and nearly
of dying from air pollution at levels deemed ac- 1.8 million adults and over 721,000 children with
ceptable for the general population.35 These find- asthma who live in counties with unhealthy year-
ings are particularly significant in light of the over round levels of particle pollution. People with car-
19.8 million people over the age of 65 who live in diovascular disease (coronary heart disease, heart
counties with unhealthy levels of ozone, the nearly attacks, strokes, hypertension and angina pectoris)
8.2 million seniors living in areas with unhealthy are among those who are particularly sensitive to
short-term PM levels, and the over 3.1 million se- particulate matter, and a whopping 18.6 million
niors living in areas with dangerous year-round people with cardiovascular diseases live in counties
levels of PM. 36 with unhealthful levels of short-term particle pollu-
Another vulnerable population is made up tion, putting them at risk for additional complica-
of people with pre-existing medical conditions, tions and possibly premature death.
especially asthma and cardiovascular conditions. Finally, the simple fact of living in poverty is
These populations are particularly susceptible correlated with elevated risk for harm from air
to particulate matter. Millions of people in air pollution. People living in poverty are particularly
pollution-sensitive populations live in counties with at risk from particulate matter. Over 9.8 million
high levels of particulate matter. This includes, ac- people in poverty live in counties with unhealthful
cording to the American Lung Association, nearly levels of short-term particle pollution, and nearly
4.6 million adults with asthma and nearly 1.7 mil- 4.4 million live in counties with unhealthy year-
lion children with asthma living in areas with high round levels of particle pollution.2. What Does the Clean Air Act Do?
T
he Clean Air Act is a remarkably com- elimination of air pollution at its source—is the
prehensive and complex statute,37, 38 best way to protect public health from harmful air
but its fundamental purpose is simple: pollution.41 This critical determination animates
Congress enacted the Clean Air Act the Clean Air Act’s pollution control programs
to protect people and the environment from the and is an essential reason for the Act’s profound
mounting dangers of air pollution caused by rapid success in protecting the American public.
industrialization, urban growth, and increasing
use of motor vehicles.39 The overarching goal of How the Clean Air Act Works
the Act is “to protect and enhance the quality of
the Nation’s air resources so as to promote the The Air Quality Approach
public health and welfare and the productive The most prominent feature of the Clean Air Act
capacity of the population.” 40 In its scope and its is a system to ensure that outside air quality in all
effect, the Clean Air Act has proven to be one of areas of the country meets minimum standards to
the most important and successful public health protect people and the environment. Under this
laws ever enacted. system, EPA first identifies air pollutants that are
To achieve the Act’s public health and environ- widely present in the outside air and which endan-
mental protection goals, Congress has established ger public health and welfare.42 These pollutants
a number of programs to address air pollution are known as “criteria pollutants,” because the Act
threats from different types of significant pollu- requires EPA to establish air quality “criteria” that
tion sources: mobile sources like cars, trucks, and reflect the kinds and extent of adverse effects the
off-road equipment, small stationary sources like various pollutants may have on people and the
dry cleaners and paint shops, and large station- environment.43
ary sources like power plants, refineries, and large After designating criteria pollutants, EPA must
industrial factories. Each of these types of air then determine the maximum allowable levels
pollution sources poses different challenges and of these air pollutants in the outside air to pro-
opportunities that require different regulatory tect people’s health and the environment. These
approaches. In response, Congress has designed are known as the National Ambient Air Quality
the Clean Air Act as a carefully crafted, targeted, Standards, or “NAAQS.”44 Primary NAAQS are
and integrated statutory system that effectively ad- designed to protect people’s health, with an ad-
dresses these diverse challenges. And each of the equate margin of safety to protect especially vul-
Act’s various programs reflects and builds upon nerable people such as children, the elderly, and
an essential Congressional determination: that the people who suffer from chronic illnesses.45 EPA
prevention of pollution—that is, the reduction or is required by law to set primary NAAQS at the10 The Clean Air act Physicians for Social Responsibility
levels necessary to protect public health, without quality in the area fails to meet the Act’s health-
regard to costs. Secondary NAAQS are designed to protection-based NAAQS for one or more pollut-
protect public welfare, which includes the environ- ants; or (3) unclassifiable, meaning there is not
ment, wildlife, weather, visibility, crops and plants, enough data to determine if an area meets or fails
and personal comfort and well-being.46 Congress to meet the NAAQS; these areas are considered to
has directed EPA to review and update the NAAQS be in attainment unless otherwise shown.49 Each
at least every five years to reflect advances in medi- state’s implementation plan has to meet minimum
cal and scientific understanding of the adverse federal requirements and must contain enforce-
health effects of criteria pollutants.47 able limitations on air emissions plus other control
Once EPA sets these nationwide air quality measures for stationary and mobile air pollution
standards, the states are primarily responsible for sources, as well as air quality monitoring to show
implementing them by enacting a system of state- compliance with the NAAQS. In attainment areas,
specific regulations known as “state implementa- state implementation plans must demonstrate that
tion plans.” States, with EPA approval, first are the plan will preserve healthy air quality and pro-
required to sub-divide geographical areas within tect against degradation from new or expanded air
their borders into “air quality control regions.”48 pollution sources. State implementation plans for
Based on monitored air pollution levels, EPA clas- nonattainment areas must contain more stringent
sifies each air quality control region as either: pollution reduction requirements to bring the ar-
(1) an attainment area, meaning the area meets eas into attainment as expeditiously as practicable,
the Act’s health-protection-based NAAQS for each and by no later than specific deadlines included in
pollutant; (2) a nonattainment area, meaning air the Act.50
istockphoto/Catherine YeuletPhysicians for Social Responsibility The Clean Air act 11
Controlling Air Pollution at the Source standards—and another for non-attainment
areas, where air quality does not meet NAAQS
To control harmful pollution from major station-
health-protection standards for one or more cri-
ary air sources, Congress developed a comprehen-
teria pollutants. The prevention of significant
sive system of complementary approaches. They
deterioration, or “PSD,” program covers areas that
rely principally on three programs: (1) New Source
meet—or have “attained”—ambient air quality
Performance Standards, which establish minimum
standards. The non-attainment new source re-
pollution control standards for new and existing
view, or “NNSR,” program applies in areas that
sources and acts as a safety net; (2) the “new source
do not meet air quality standards, and it contains
review” program, which is designed to make sure
more rigorous requirements that are designed to
that large, new sources of air pollution do not de-
improve air quality to meet and maintain healthy
grade air quality or threaten people’s health; and
air quality. An area can be in attainment for one
(3) the hazardous air pollution program, which re-
criteria pollutant and non-attainment for another.
quires the most stringent pollution controls for 188
Under those circumstances, the PSD provisions
of the most toxic air pollutants. Pollution sources
would apply to all pollutants that meet the air qual-
that are subject to new source performance stan-
ity standards and the NNSR provisions would apply
dards, new source review, and the hazardous air
to any pollutant that does not.
pollution program must undergo rigorous analysis
The PSD program requires a preconstruction
and, before the source can be constructed, modi-
analysis and demonstration that a proposed new
fied, or operated, obtain a permit demonstrating
pollution source will meet three essential require-
that they are designed and will be constructed and
ments before the source can commence construc-
operated to meet the requirements of each pro-
tion.53 First, the proposed source must demon-
gram.
strate that its projected air pollution emissions will
New Source Performance Standards not cause or contribute to a violation of the health-
based NAAQS, which is essential to maintaining
Congress required EPA to identify categories of
healthy air quality.54 Second, to make sure that new
new and modified pollution sources that contribute
air pollution sources do not degrade existing air
significantly to air pollution that may endanger
quality or create a risk of violating health protec-
public health or welfare.51 EPA must then establish
tion standards, the source must demonstrate that
quantified emission limits for each source category,
it will not exceed a specified “increment” of al-
based on the best level of emission control that has
lowable additional air pollution.55 In this manner,
been adequately demonstrated for that type of pol-
the Clean Air Act balances the desire for future
lution source.52 These “new source performance
industrial growth with the need to achieve and
standards” operate as a baseline level of the mini-
maintain healthy air quality. Third, the source
mum allowable pollution control for each source
must demonstrate that it will meet the best level
category. More stringent pollution controls may
of pollution control that is achievable based on
be required for criteria pollutants under the new
available technology.56 This technology-based re-
source review program and for hazardous air pol-
quirement is known as the best available control
lutants under the hazardous air pollutant program.
technology, or “BACT,” standard, and it is designed
New Source Review to require state-of-the art controls for new and
modified sources and to promote technological
The new source review program focuses on “cri-
advancement and innovation.57
teria pollutants,” such as soot-forming particle
The non-attainment new source review
pollution and ground level ozone (smog). The
(“NNSR”) program for areas in non-attainment
new source review provisions actually comprise
is more rigorous.58 Its level of stringency depends
two distinct programs: one to address attainment
to some degree on the severity of the air pollution
areas—in which air quality meets all the NAAQS12 The Clean Air act Physicians for Social Responsibility
problem in the area and the amount of time that better protect public health and the environment
has elapsed beyond the Act’s deadline for attaining from routine emissions of air toxics.65
the applicable air quality standards.59 In general, Those updates classify nearly 200 contaminants
however, the NNSR program requires states to as hazardous air pollutants and create a stringent
demonstrate the methods by which they will re- national program to lower their emissions.66
duce pollution concentrations in the ambient air to In particular, Congress directed EPA to list all
meet applicable air quality standards by specified categories of major sources of air toxics and to
deadlines.60 The new implementation plans also develop highly protective, maximum achievable
must provide for “reasonable further progress” in pollution control standards for each listed catego-
improving air quality to confirm the areas are on ry on an aggressive schedule.67 For new sources,
target to meet the attainment deadlines.61 the resulting emission controls were required
Under the non-attainment program, all new or to achieve levels of emission control achieved in
modified major sources of air pollution must ob- practice by the best-controlled similar source.
tain preconstruction permits demonstrating that This established a minimum or “floor” level of
the source will meet an enhanced level of pollution control. Beyond that floor, control levels must
control, known as the “lowest achievable emission be tightened as much as possible, taking into ac-
rate,” for all “non-attainment pollutants.” The “low- count available technologies, costs, non-air qual-
est achievable emission rate” is based on either the ity health and environmental impacts, and energy
most stringent emission limitation adopted as part requirements.68 Existing sources also must at least
of any state’s implementation plan, or the lowest meet a “floor” level of control that is based on the
emission rate achieved in practice by any similar best performing 12 percent of sources.69 The floor
pollution source, whichever is lower.62 In addition, level of control for new and existing sources is set
the new or modified pollution source must obtain irrespective of the cost or difficulty in achieving
emission offsets, which are reductions of the same the level of emission control and can result from
nonattainment pollutant from other, existing the application of technological controls as well
sources in the area in order to offset the new pollu- as from other factors like the use of cleaner fuels
tion.63 In this way, the NNSR program assures that or raw materials.70
new pollution sources do not increase air pollution To enforce these standards, the Act prohibits
concentrations, while allowing for additional in- construction or modification of a major source
dustrial growth and economic expansion. of hazardous air pollutants unless EPA (or a state
with delegated authority) first determines and
Hazardous Air Pollutants issues a permit requiring that the source will
When Congress enacted the modern Clean Air meet maximum achievable pollution control re-
Act in 1970, it recognized that certain types of air quirements.71 Where EPA has not yet established
pollutants, known as “hazardous air pollutants,” a federal maximum pollution control require-
are acutely and chronically toxic to people even ments for a category of sources, the Act and its
in small amounts and, thus, present greater risks implementing regulations require a “case-by-case”
of serious harm to public health. Thus Congress determination.72
directed EPA to establish highly protective stan-
dards for toxic air pollutants and the sources that
Mobile Sources
emit them. However in the ensuing 20 years, EPA
established standards for only seven hazardous air Mobile sources such as cars, trucks, trains, air-
pollutants and addressed only a limited number of planes and boats emit many of the same types of
possible sources of these pollutants.64 Thus, when pollutants as large stationary sources, particularly
Congress updated the Act in 1990, it overhauled volatile organic compounds, carbon monoxide,
the hazardous air pollutant provisions of the Act to nitrogen oxides, and particulate matter. Moreover,Physicians for Social Responsibility The Clean Air act 13
istockphoto/David Parsons
while individual mobile source emissions pale in the types and amounts of pollutants that different
comparison to large stationary sources, cumula- mobile sources can emit, typically on a per-mile-
tively, mobile sources account for an enormous traveled basis. These standards are designed to
percentage of emissions of these pollutants. assure that mobile source engines will comply with
Nevertheless, Congress treated mobile sources applicable emission standards over the life cycle of
quite differently than stationary sources. the source. This involves initial certification that
Whereas states have a great deal of discretion as each engine prototype meets emission standards;
to how they implement the Clean Air Act’s mini- evaluation of production processes to assure that
mum requirements for stationary sources, EPA has the “as-manufactured” product meets the same
near-exclusive authority to set mobile source stan- standards as the prototype; in-use testing, to assure
dards.73 This owes in large part to the fact that mo- that the engines perform properly under normal
bile sources, by their nature, regularly cross state operating conditions; and provisions to recall
boundaries. Additionally, Congress determined faulty engines. These standards are “technology-
that a patchwork of different regulations by the forcing”—meaning they should spur technological
states could wreak havoc with the motor vehicle advancement and innovation—and, accordingly,
manufacturing industry. Thus, mobile source regu- are u
pdated as the state of technology improves.
lation is largely a federal matter, and it is illegal The second type of mobile source regulation
to market or sell a mobile source engine without focuses on fuels.78 These regulations are designed
complying with EPA regulations.74 either to reduce mobile source emissions, or to re-
Title II of the Act establishes EPA’s authority to quire a public health assessment of the risks associ-
regulate mobile sources and provides for two basic ated with different types of fuels. If a public health
types of regulations.75 The first involves perfor- assessment indicates that certain fuels present a
mance standards for different categories of mobile significant risk to public health—as was the case
sources, such as cars, heavy duty truck, buses, and with leaded gasoline—then EPA may limit or pro-
diesel locomotives, that emit significant amounts hibit use of that fuel.79 Conversely, if available in-
of air pollution.76,77 Performance standards limit formation demonstrates that different fuels result14 The Clean Air act Physicians for Social Responsibility
Figure 2. Health Effects of Criteria Pollutants
Description Sources Health Effects
Mixture of small solid par- Fuel combustion; electricity Dependent on the size of the particle
ticles and tiny acid droplets. generation, especially coal-fired and how deeply it penetrates into the
Some can be seen with power plants; motor vehicles; airway
the naked eye (dust, dirt, industrial processes Exposure to PM2.5 (fine particles) is as-
soot, or smoke). Others can Windblown dust from fields, sociated with:1, 2, 3, 4, 5, 6,7, 8, 9,10,11,12,13
be detected only with an construction, landfills, and increased respiratory symptoms,
Particulate Matter (PM2.5 and PM10)
electron microscope. agricultural processes such as irritation of airway, coughing,
Inhalable “coarse particles” Wildfires, cooking fires, and or difficulty breathing
(PM10) have diameters brush/waste burning decreased lung function
between 2.5 and 10 micro– Can be formed in the atmo- worsening asthma
meters. These particles sphere by emissions of other development of chronic bronchitis
serve as the general indica- gases (ex. SO2, NOx, or VOCs) irregular heartbeat and fatal heart
tor of exposure to PM. PM10 is a good measure of attacks
“Fine particles” (PM2.5) the complex mix of particles premature death in people with
have diameters that are 2.5 and dust that result from fuel preexisting heart or lung disease
micrometers and smaller. combustion in vehicles. ischemic stroke
There is a strong correla- lung cancer
tion between the presence Particle pollution is also linked to:14
of PM10 and that of other air low birth weight
pollutants. premature birth
PM2.5 NAAQS standards: chronic airway obstruction and
15 µg/m3 annual (arithme- remodeling
tic average) and 35 µg/m3 sudden infant death
per 24 hours. PM10 NAAQS
standards: 150 µg/m3 per
24 hours
Group of highly reactive Formed from high-temperature Short-term exposures (30 minutes to
gases known as “oxides of combustion of fossil fuels, 24 hours):15
nitrogen” or “nitrogen ox- including: airway inflammation in healthy
ides” (NOx) including nitrous Generation of electricity; coal- people
acid and nitric acid fired power plants coughing, shortness of breath, nau-
Reddish-brown in color with Non-vehicle equipment burning sea
an acrid, biting odor gasoline or diesel dampens immune function,
Precursor to ozone forma- To a lesser extent, chemical
Nitrogen Oxides (NOx)
decreasing ability to resist respira-
tion and acidic precipitation plant emissions tory infections such as influenza
(acid rain) worsening asthma symptoms
Forms acidic PM particles in increased emergency room vis-
the atmosphere its, hospitalizations for respiratory
Nitrogen dioxide NAAQS issues, especially asthma
standards: 100 ppb per hour fatal cardiac arrhythmias
and 53 ppb annually When NOx mixes with ammonia,
(arithmetic average). moisture and other chemicals, small
particles created can:
penetrate deeply into sensitive parts
of the lung
cause or worsen respiratory disease
such as emphysema and bronchitis
aggravate existing heart disease
lead to increased hospital admissions
and premature death
The notes to this table appear on pages 30–31.You can also read
