Transcript Developing the NAAQS

Developing the NAAQS
(National ambient air quality standards)
NESCAUM Health Effects Workshop
Bordentown, NJ
July 29, 2008
Introduction
What are the NAAQS?
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The Clean Air Act, requires EPA to set National Ambient Air Quality Standards (40 CFR
part 50) for pollutants considered harmful to public health and the environment.
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Different considerations apply to setting NAAQS than to achieving them
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NAAQS that "are requisite to protect the public health “ with “adequate margin of safety”
NAAQS need to protect sensitive subgroups
Standards not “risk free ” and not based on cost
Setting NAAQS: health and environmental effects only
Achieving NAAQS: account for cost, technical feasibility, time needed to attain
The Clean Air Act established two types of national air quality standards:
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Primary standards set limits to protect public health, including the health of "sensitive" populations
such as asthmatics, children, and the elderly.
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Secondary standards set limits to protect public welfare and the environment, including protection
against decreased visibility, damage to animals, crops, vegetation, and buildings.
Introduction
• EPA classifies ambient air pollutants
– Hazardous Air Pollutants (HAPs) or air toxics
• Cause serious health and environmental hazards
• known or suspected to cause cancer or other serious
health effects, such as reproductive effects or birth
defects, or adverse environmental effects.
– Criteria Pollutants.
• identified as being both common and detrimental to
human welfare and are found over all the United States
(ubiquitous pollutants).
• NAAQS established
Why do we have NAAQS?
• Protect public health, with an adequate margin
of safety
• Protect public welfare and the environment
National Ambient Air Quality
Standards (NAAQS)
• The EPA Office of Air Quality Planning and
Standards (OAQPS) has set NAAQS for six principal
pollutants, which are called "criteria" pollutants.
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Ozone
Particulate Matter (PM2.5 & PM10)
Lead
Carbon monoxide
Nitrogen oxide
Sulfur dioxide
• EPA is required to review and revise if appropriate
each NAAQS every 5 years, with input from
CASAC.
The NAAQS
Pollutant
Primary Stds.
Averaging Times
Secondary Stds.
Carbon Monoxide
9 ppm
8-hour(1)
None
1-hour(1)
None
Quarterly Average
Same as Primary
Annual (Arithmetic Mean)
Same as Primary
Annual(2) (Arith. Mean)
Revoked(2)
24-hour(3)
Same as Primary
Annual(4) (Arith. Mean)
Same as Primary
24-hour(5)
Same as Primary
0.075 ppm
8-hour(6)
Same as Primary
0.12 ppm
1-hour(7)
Same as Primary
3
(10 mg/m )
1994
35 ppm
3
(40 mg/m )
Lead
1978
Nitrogen Dioxide
1.5 µg/m
1996
3
0.053 ppm
3
(100 µg/m )
Particulate Matter (PM10)
Revoked(2)
2006
150 µg/m
Particulate Matter (PM2.5)
15.0 µg/m
2006
Ozone
2008
Sulfur Oxides
1996
35 µg/m
3
3
3
(Applies only in limited areas)
0.03 ppm
Annual (Arith. Mean)
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0.14 ppm
24-hour(1)
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3-hour(1)
0.5 ppm
3
(1300 µg/m )
Health Effects of Criteria Pollutants
Ozone
• Scientific evidence indicates that ground-level ozone not only affects
people with impaired respiratory systems (such as asthmatics), but healthy
adults and children as well.
• Exposure to ozone for 6 to 7 hours, even at relatively low concentrations,
significantly reduces lung function and induces respiratory inflammation in
normal, healthy people during periods of moderate exercise.
– Chest pain, coughing, nausea, and pulmonary congestion.
– Results from animal studies indicate that repeated exposure to high levels of
ozone for several months or more can produce permanent structural damage in
the lungs.
• In 1997, the EPA promulgated ozone national ambient air quality standard
of 0.08 ppm (8 hour averaging time).
• In 2008, the EPA promulgated a new standard of 0.075 ppm (8 hour
averaging time)
Where does it come from?
Ozone
– Ozone is not emitted directly into the air by specific sources.
– Ozone is created by sunlight acting on nitrogren oxides (NOx) and
volatile organic compound (VOC) emissions in the air.
– Common sources include gasoline vapors, chemical solvents,
combustion products of various fuels, and consumer products. They can
originate from large industrial facilities, gas stations, and small
businesses such as bakeries and dry cleaners.
– Often these "precursor" gases are emitted in one area, but the actual
chemical reactions, stimulated by sunlight and temperature, take place
in another.
– Combined emissions from motor vehicles and stationary sources can be
carried hundreds of miles from their origins, forming high ozone
concentrations over very large regions.
Health Effects of Criteria Pollutants
PM 10 and PM2.5
• Particle pollution - especially fine particles - contains
microscopic solids or liquid droplets that are so small
that they can get deep into the lungs and cause serious
health problems. Numerous scientific studies have
linked particle pollution exposure to a variety of
problems, including:
– effects on breathing and respiratory systems
– damage to lung tissue
– cancer, and premature death.
Where does it come from?
Particulate Matter
– Solid or liquid particles found in the air. Some
particles are large or dark enough to be seen as
soot or smoke. Others are so small they can be
detected only with an electron microscope.
Because particles originate from a variety of
mobile and stationary sources (diesel trucks, wood
stoves, power plants, etc.), their chemical and
physical compositions vary widely.
Health Effects of Criteria Pollutants
Carbon Monoxide
• Reduces oxygen delivery to the body's organs (like the heart
and brain) and tissues.
• Cardiovascular Effects. The health threat from lower levels
of CO is most serious for those who suffer from heart disease,
like angina, clogged arteries, or congestive heart failure.
• Central Nervous System Effects. Even healthy people can
be affected by high levels of CO. People who breathe high
levels of CO can develop vision problems, reduced ability to
work or learn, reduced manual dexterity, and difficulty
performing complex tasks. At extremely high levels, CO is
poisonous and can cause death.
• Smog. CO contributes to the formation of ground-level ozone,
which can trigger serious respiratory problems
Where does it come from?
Carbon Monoxide
– Colorless, odorless poisonous gas formed when carbon in
fuels is not burned completely.
– Byproduct of motor vehicle exhaust, which contributes
more than two-thirds of all CO emissions nationwide. In
cities, automobile exhaust can cause as much as 95 percent
of all CO emissions.
– Other sources of CO emissions include industrial processes
and fuel combustion in sources such as boilers and
incinerators. Despite an overall downward trend in
concentrations and emissions of CO, some metropolitan
areas still experience high levels of CO.
Health Effects of Criteria Pollutants
Nitrogen Oxides
• Irritate the lungs and lower resistance to respiratory infections
such as influenza.
• The effects of short-term exposure are still unclear, but
continued or frequent exposure to concentrations that are
typically much higher than those normally found in the
ambient air may cause increased incidence of acute respiratory
illness in children.
• Nitrogen oxides are important in forming ozone
• Nitrogen oxides in the air are a potentially significant
contributor to a number of environmental effects such as acid
rain and eutrophication in coastal waters like the Chesapeake
Bay.
Where does it come from?
Nitrogen Dioxide
– Nitrogen dioxide belongs to a family of highly reactive
gases called nitrogen oxides (NOx). These gases form
when fuel is burned at high temperatures, and come
principally from motor vehicle exhaust and stationary
sources such as electric utilities and industrial boilers.
– Strong oxidizing agent that reacts in the air to form
corrosive nitric acid, as well as toxic organic nitrates. It
also plays a major role in the atmospheric reactions that
produce ground-level ozone (or smog).
Health Effects of Criteria Pollutants
Sulfur Dioxide
• Breathing difficulties, respiratory illness, alterations in
pulmonary defenses, and aggravation of existing
cardiovascular disease.
• Major subgroups of the population that are most sensitive to
SO2 include asthmatics and individuals with cardiovascular
disease or chronic lung disease (such as bronchitis or
emphysema) as well as children and the elderly.
• SO2 and NOX is a major precursors to acid rain, which is
associated with the acidification of lakes and streams,
accelerated corrosion of buildings and monuments, and
reduced visibility.
Where does it come from?
Sulfur Dioxide
– Sulfur dioxide belongs to the family of sulfur
oxide gases (SOx).
– Fuel containing sulfur (mainly coal and oil) is
burned, and during metal smelting and other
industrial processes.
Health Effects of Criteria Pollutants
Lead
• Exposure to lead mainly occurs through inhalation of air and ingestion of
lead in food, paint, water, soil, or dust.
• Lead accumulates in the body in blood, bone, and soft tissue.
• Because it is not readily excreted, lead can also affect the kidneys, liver,
nervous system, and other organs.
• Excessive exposure to lead may cause anemia, kidney disease, reproductive
disorders, and neurological impairments such as seizures, mental
retardation, IQ loss and/or behavioral disorders.
• At low doses, lead exposure is associated with changes in fundamental
enzymatic, energy transfer, and other processes in the body.
• Recent studies show that lead may be a factor in high blood pressure and
subsequent heart disease in middle-aged white males.
• Lead may also contribute to osteoporosis in postmenopausal women.
Where does it come from?
Lead
– Smelters and battery plants
– The highest concentrations of lead are found in the
vicinity of nonferrous smelters and other stationary
sources of lead emissions.
The NAAQS Development Process
The Old Process?
STEP 1- Criteria Document
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EPA Office of Research and Development (ORD) develops a criteria document
– Compilation and evaluation of the latest scientific knowledge useful in assessing the health and welfare
effects of the air pollutant
– In developing this document, EPA must consider the advice of the Clean Air Scientific Advisory
Committee (CASAC).
STEP 2- Staff Paper
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Based on the criteria document, EPA’s Office of Air Quality Planning & Standards develops a staff
Translate the science into terms that can be used for making policy decisions.
Includes recommendations to the EPA Administrator about any revisions to the standards
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paper
ensure that they protect public health with an adequate margin of safety
protect the environment and the public welfare.
STEP 3- Review
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Before either the criteria document or staff paper can be used as the basis for any policy decisions, they
undergo rigorous review by the scientific community, industry, public interest groups, the general
public and CASAC.
STEP 4- Revisions
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Based on the scientific assessments in the criteria document and on the information and recommendations in
the staff paper, the EPA Administrator determines whether it is appropriate to propose revisions to the
standards.
Evidence- based Assessment
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Epidemiological studies of normal exposures to ambient mix of air pollutants
– Population-level data (e.g., mortality, hospital admissions)
– Individual-level data (e.g., mortality, respiratory function and symptoms, blood levels)
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Controlled-exposure human effects studies
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Transient, reversible functional/symptomatic acute effects
Effects of different patterns of exposure, ventilation rates
Markers of exposure in blood, pulmonary fluid
Dosimetry studies
Mechanisms of action
Animal studies, especially with long long-term exposures
Structural damage
Impaired host defense mechanisms
Mechanisms of action
Risk Analysis Assessment
• Provide estimates of health risk associated with current air quality and a
hypothetical situation where the standards are just met
– Number of people & % of population experiencing a given health effect
– Number of occurrences of health effect
• Gain insights into the nature of risks associated with optional standards
(level & form)
• Characterize uncertainties to decision decision-makers & the Public
• An important tool to aid Administrator’s judgment “as to the point at
which risks would be reduced to achieve protection of public health with an
adequate margin of safety”
Current NAAQS Process
(From EPA)
Scientific studies related to
health and environmental
effects
EPA Criteria Document:
Integrative assessment
of scientific studies
Scientific peer review of
published studies
Workshops involving
the scientific community
and reviews by CASAC
and the public
EPA Staff Paper: Policyrelevant science and risk
assessment; staff
recommendations on
ranges of standards
Reviews by CASAC and
the public
Agency decision makding
and draft proposal notice
Interagency Review
EPA Final Decision on
Standards
Interagency
review
Agency decision making
and draft final notice
Public hearings and
comments on proposal
EPA proposed decision
on standards
Summary of Process
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EPA required to review each National Ambient Air Quality Standard (NAAQS) every 5 years
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There are many types of information and analyses that are considered in review and revision
of NAAQS
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No simple formula or numerical criteria used in deciding which standard(s) will protect public
health with an adequate margin of safety
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Very open and deliberative process with multiple opportunities for input from scientific
community, stake stake-holders, and the general public
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One health health-based standard for entire country
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Account for cost and time to achieve in implementation planning
Enforced by law
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After review process, Administrator can either retain or revise the NAAQS
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If revised, the Clean Air Act established the timetable for implementation
Implementation of NAAQS
• As NAAQS established, EPA assesses the expected impact of the new
standards nationwide
• EPA conducts a Regulatory Impact Analysis (RIA) to estimate the costs and
monetized human health benefits projected to result from attainment of the
NAAQS
– Project future air quality throughout the country
– Which areas don’t meet standards?
• Which local control strategies/options are available and might be used in
non-attainment areas?
– Support emissions inventory and source apportionment to determine sources
that need to be controlled
• Determine expected air quality improvements based on implementation of
controls
• Estimate anticipated health impacts and benefits
• Implementation of NAAQS
– Accounts for cost, technical feasibility, time for attainment, monitoring data
Designation & Implementation
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A geographic area that meets or does better than the primary standard is called an
attainment area
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Areas that do not meet the standards, or contribute pollution to nearby areas that do
not meet the standards, are called nonattainment areas (NAAs).
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An area may be designated attainment for some pollutants and nonattainment for
others.
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An unclassifiable area is any area that cannot be classified on the basis of
available information as meeting or not meeting a national primary or secondary
ambient air quality standard for the pollutant.
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State governments have the primary responsibility for achieving compliance with
the NAAQS. The principle mechanisms for achieving this goal are the State
Implementation Plans (SIPs) and Tribal Implementation Plans (TIPs).
NAAQS Process Review
• “Top-to-bottom” review of process by which NAAQS are
reviewed and revised was requested by EPA Deputy
Administrator in December 2005
• EPA workgroup formed to address issues and make
recommendations
• Key issues:
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Timeliness (how to complete reviews on 5-year cycle)
Consideration of most up-to-date scientific information
Differences between scientific and policy judgments
Defining and expressing uncertainties in scientific and technical
information
• Meetings with CASAC, stakeholders, and congressional staff
(borrowed from Lydia Wegman’s slides)
Pb NAAQS Process
In the Middle
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ANPR: Part of the New NAAQS Review Process
EPA has been transitioning to a new NAAQS review process during the lead NAAQS review.
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The ANPR is a key feature of the new NAAQS review process and this rulemaking marks the first time EPA has issued an
ANPR as part of a NAAQS review.
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The ANPR pulls together the information the agency is now considering as it reviews the lead NAAQS, and invites broad
public input on the policy options for several aspects of the review.
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The new process will enable broader participation by interested parties earlier in the NAAQS review by providing to the
public the scientific information, exposure and risk assessments and several policy options, and by seeking comment on that
information and those options before EPA issues a proposal.
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Historically, rather than an ANPR, EPA has issued a Staff Paper that evaluates the policy implications of the science and the
exposure and risk information. The Staff Paper is prepared by the staff in the EPA’s Office of Air Quality Planning and
Standards.
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Since EPA initiated the lead NAAQS before the institution of changes in the NAAQS process, the agency has produced a
Staff Paper and an ANPR. For future NAAQS reviews, the EPA will prepare an ANPR and not a staff paper.
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EPA will propose whether to revise or retain the current lead standards no later than May 1, 2008, with a target date of March
2008, and take final action by September 1, 2008, pursuant to a court order.
Comments on Pb
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Maintain Staff Paper
PM10 vs TSP lead
Recommended standard for ambient air
Averaging time- monthly?
Frequency of monitoring
The Schedule
Borrowed from Illa Cote’s slides- EPA
Borrowed from Illa Cote’s slides- EPA
What’s next?
• The Integrated Science
Assessment (ISA) for Oxides of
Nitrogen – Health Criteria
document (replacing CD)
– concise synthesis and evaluation
of the most policy-relevant science
– A series of Annexes to the draft
ISA provides more extensive and
detailed summaries of the most
pertinent scientific literature.
– will ultimately provide the
scientific bases for EPA’s decision
regarding whether the current
standard for NO2 sufficiently
protects public health.
Causal Determinations
• Two-step approach
– Determine causality
– Further evaluation of population response
Health Effects- current review
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Lung host defenses and immunity
Airway responsiveness
Airway inflammation
Lung function
AQI= Air Quality Index
Air Quality Guide for Ozone
Air Quality
Air Quality Index
Good
0-50
Moderate
51-100
Unhealthy for
Sensitive Groups
101-150
Unhealthy
151-200
Very
Unhealthy
(Alert)
201-300
Protect Your Health
No health impacts are expected
when air quality is in this range.
Unusually sensitive people should
consider limiting prolonged
outdoor exertion.
Active children and adults, and
people with respiratory disease,
such as asthma, should limit
prolonged outdoor exertion.
Active children and adults, and
people with respiratory disease,
such as asthma, should avoid
prolonged outdoor exertion;
everyone else, especially children,
should limit prolonged outdoor
exertion.
Active children and adults, and
people with respiratory disease,
such as asthma, should avoid all
outdoor exertion; everyone else,
especially children, should limit
outdoor exertion.
Air Quality Guide for Particle Pollution
Air Quality
Good
Air Quality Index
0-50
Moderate
51-100
Unhealthy for
Sensitive Groups
101-150
Unhealthy
151-200
Very
Unhealthy
(Alert)
201-300
Health Advisory
None.
Unusually sensitive people should
consider reducing prolonged or heavy
exertion.
People with heart or lung disease,
older adults, and children should
reduce prolonged or heavy exertion.
People with heart or lung disease,
older adults, and children should avoid
prolonged or heavy exertion. Everyone
else should reduce prolonged or
heavy exertion.
People with heart or lung disease,
older adults, and children should avoid
all physical activity outdoors. Everyone
else should avoid prolonged or heavy
exertion.
Thank you