1. Health Effects of Air Pollution
4/25/2017
Health Effects of Air Pollution
Thank you, Mr. Corey.
Good morning Chairman Nichols and members of the Board. This morning’s presentation is an overview of the health effects of air pollution.
[ADVANCE]
April 24, 2014

2. Presentation Overview
4/25/2017
Presentation Overview
Major Health Effects
Vulnerable Populations
Toxic Air Contaminants
Air Quality Standards
The presentation will focus on four topics. We will start with an overview of the major health effects of air pollution and a discussion of factors that increase people’s vulnerability to the adverse health effects of air pollution. I will then discuss health risk from toxic air contaminants, and how air quality standards set public heath goals that lead to reduced health risk from particulate matter and ozone air pollution.

3. Major Health Effects 4/25/2017
This morning we will focus on the health effects of particulate matter and ozone, two key air pollutants for which there are national ambient air quality standards (NAAQS). We will also touch on another class of air pollutants, toxic air contaminants, some of which can cause cancer.
Major Health Effects

4. Air Pollution and Public Health
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Air Pollution and Public Health
Science on the health impacts of air pollution dates back to 1930’s
Health effects observed worldwide
Particulate matter (PM) and ozone account for over 90% of identified health impacts
Air pollution poses cancer risk
We have known since the 1930’s of the serious health effects of air pollution. Some of the most notable air pollution events occurred in the Meuse Valley of Belgium in 1930, in Donora, Pennsylvania in 1948, and in London in During each of these episodes many people died and many more were sickened. Since these dramatic episodes, scientific studies of the relationship between air pollution exposure and health effects have been performed in countries world-wide. The results of decades of studies make it clear that air pollution contributes to health impacts in California even today, when air pollution levels have dropped significantly. Particulate matter (PM), and ozone account for over 90% of the identified air pollution-related health impacts. In addition, there are many toxic air contaminants in the air that pose a risk for cancer.
Extra material:
PM and ozone account for about 95% of health impacts (morbidity + mortality); PM effects substantially larger – this is based on econ value of benefits – there are few data estimating impacts of other criteria pollutants because there are no strong links to mortality, and the morbidity impacts noted are of relatively low $ value using the usual monetizing methods.

5. Mechanisms for Air Pollution Health Effects
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Mechanisms for Air Pollution Health Effects
Air pollution exposure can:
Worsen existing disease
Cardiovascular diseases
Respiratory diseases
Cause disease
Cancer
Asthma
Air pollution exposure influences health in one of two ways. Either by worsening pre-existing chronic diseases, primarily those of the cardiovascular system and lungs, or by causing disease, primarily cancer. While we know that ozone and traffic pollutants can trigger an asthma attack, there is also emerging evidence for onset of asthma associated with exposure to pollution.

6. Major Health Effects of Air Pollution
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Major Health Effects of Air Pollution
Premature Death
Heart Attacks and Stroke
Asthma
Cancer Risk
There is a consistent body of scientific evidence that exposure to particulate matter and ozone can lead to premature death. It can also worsen the impact or even accelerate the progression of chronic disease. The people who experience most of the adverse health effects related to air pollution exposure suffer from an underlying chronic health problem, particularly cardiovascular or respiratory disease. In these vulnerable populations, air pollution increases the risk of heart attacks and stroke, and worsens asthma symptoms. Air pollution can impact even healthy adults at levels we still experience in California. The latest studies on ozone air pollution show some impacts on lung function in healthy adults exposed to ozone while exercising.
In addition to the major health effects associated with particulate matter and ozone pollution, cancer risk increases with exposure to toxic air contaminants, such as benzene, formaldehyde and diesel particulate matter.

7. Premature Death
Strongest evidence for premature death from air pollution is for PM exposure
Studies link PM to premature death in people with cardiovascular and respiratory disease
Premature mortality from ozone exposure linked to respiratory causes
The strongest evidence for premature death from air pollution is associated with exposure to particulate matter both for short- and long-term exposures. Risk of death is especially elevated for cardiovascular causes, including heart attacks and congestive heart failure. There is also elevated risk for premature death for respiratory causes. This effect is observed in older adults who have established cardiovascular disease. Ozone exposure is also associated with premature death in people with pre-existing respiratory diseases such as asthma and chronic obstructive pulmonary disease.

8. Cardiovascular Effects
Studies show daily exposure to PM2.5, PM10, and ozone can worsen preexisting chronic cardiovascular disease
Human health studies consistently show that exposure to particulate matter and ozone pollution can worsen chronic cardiovascular disease. Studies in California, in US cities and countries worldwide find high levels of these pollutants associated with increases in hospitalizations and emergency department visits. Ozone is also associated with cardiovascular health effects, but the greatest effects are from particulate matter.
While it is clear that PM worsens cardiovascular disease, there is little evidence that air pollution is the primary cause of cardiovascular disease.

9. Respiratory Effects Air pollution effects on the lungs can result in:
Asthma exacerbation
Increased asthma medication
Hospitalization
Emergency department visits
The respiratory effects of air pollution, especially for asthmatics, are a well recognized public health problem. While PM and traffic exposure can cause respiratory symptoms, ozone is the more potent respiratory toxicant. Ozone air pollution effects on the lungs include asthma exacerbation, increased asthma medication usage, and hospitalization and emergency department visits for exacerbation of asthma and other chronic lung diseases.

10. Asthma and Air Pollution
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Asthma and Air Pollution
Nearly 3 million Californians are asthmatic
1 million children
1.9 million adults
14% of San Joaquin Valley children are asthmatic
Ozone and traffic related air pollutants shown to worsen asthma
Perhaps the most significant health outcome associated with air pollution is increasing the frequency and severity of asthma symptoms. Statewide, about 10% of children are asthmatic, and about 8% of adults are asthmatic. This translates into nearly three million Californians, including about 1 million children. There is strong evidence that O3 can lead to asthma attacks, evidenced by correlations between ozone exposure and emergency department visits, and increased symptoms and medication use.
Traffic is also a contributor to asthma attacks. Studies show that children with asthma living near busy roads experience more respiratory symptoms than those living further away from roadways.
(based on CHIS ; and CHIS surveys)

11. Cancer Risk from Air Pollution
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Cancer Risk from Air Pollution
Specific pollutants are “toxic air contaminants (TAC)” due to cancer risk
Human epidemiological studies and animal exposure studies show air pollution is linked to cancer risk
Peer review by mandated “Scientific Review Panel”
ARB regulations are reducing cancer risk form TACs
There is another group of air pollutants called toxic air contaminants or TACs, which are linked to increased cancer risk. Evidence from epidemiological studies and animal exposure studies show that long-term exposure to these air pollutants increases risk of cancer.
California state law requires ARB to identify and regulate TACs. To ensure the best available science underpins the identification of TACS, the technical assessment for TAC listings undergoes independent peer review by the Scientific Review Panel.
Over the past 30 years, California has prioritized and controlled the most significant TACs. The success of the program is evidenced in dramatically reduced levels of TACs like benzene and diesel PM.
The goal is to reduce regional, neighborhood, and hot spot risk.

12. Vulnerable Populations
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Next I’ll talk about vulnerable populations.
Vulnerable Populations

13. Who Is Especially Vulnerable to Air Pollution?
Children
Elderly people
People with chronic disease
Outdoor workers and athletes
People in low socioeconomic communities
The scientific literature makes it clear that some individuals or sub-sections of the population are more vulnerable to air pollution than others. This can be due to either greater sensitivity because of age and health status or greater exposure leading to larger effects.

14. What Population Characteristics Influence Vulnerability?
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What Population Characteristics Influence Vulnerability?
Childhood: more outdoor activity and higher breathing rate
Elderly: Chronic health conditions including heart and lung disease, diabetes
Socioeconomic status: poverty, low level of education, other environmental justice community indicators
The scientific literature has identified several groups that are vulnerable to air pollution, including children, the elderly, people with chronic health conditions and low socioeconomic status.
Children’s vulnerability comes particularly from their greater exposure related to more outdoor activity and a higher breathing rate.
As a group, the elderly are at risk due to the greater prevalence of chronic disease. People with chronic diseases of the heart or lungs, diabetics and the obese experience larger effects with exposure to air pollution than people without chronic health conditions.
Socioeconomic status can also affect vulnerability to air pollution. Studies suggest that factors associated with low socioeconomic status like educational attainment increase risk of experiencing adverse air pollution-related health effects. Studies also show greater levels of pollution and greater number of pollution sources in poor and minority communities. Lastly, socioeconomic factors such as poverty, food insecurity, and access to health care may also contribute to stress that could influence responses to air pollution.

15. Toxic Air Contaminants
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Next, I’ll talk about Toxic Air Contaminants.
Toxic Air Contaminants

16. Toxic Air Contaminants
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Toxic Air Contaminants
Diesel PM is the TAC posing greatest statewide cancer risk
Other key TACs:
Benzene
1,3-butadiene
Chromium
Chlorinated solvents
ARB has been identifying Toxic Air Contaminants and developing measures to control their levels in the air for decades. There are currently 191 chemicals on the TAC list. Of this group, diesel PM poses the greatest statewide cancer risk. To address this issue, the Board adopted the Diesel Risk Reduction Plan in The plan called for a series of regulations to meet the goal reducing the cancer risk from diesel PM by 85% by the year 2020.
Several other TACs, most importantly benzene and 1,3-butadiene, also come from mobile sources. Mobile source TACs influence exposures to communities near roadways. And ARB monitors have recorded a 90% reduction statewide in these pollutants
We have also developed regulations in cooperation with the districts to reduce the ambient levels of other key TACs that come from stationary sources, including chromium from chrome platers and chlorinated solvents widely used in industrial applications. These pollutants have also gone down by 90% statewide.
AB 1807 (1983) -21 Identified by ARB
AB 2728 (1993) US EPA HAPs were added to TAC list
19 already identified by CARB

17. Proximity Increases Health Risk
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Proximity Increases Health Risk
Risk assessments show how TACs increase health risk in neighborhoods
ARB regulations are reducing health risk near sources of air pollution
That was statewide, pollution levels are lower locally too.
Over the past decade, ARB prepared a number of risk assessments focused on health risk from diesel emissions. These assessments helped to prioritize our diesel rulemaking to achieve the fastest possible risk reduction in neighborhoods near these sources.
One example is a comprehensive set of regulations was adopted to reduce emissions from goods movement activities. These include rules on ships, harbor craft, cargo handling equipment and truck activities at ports. These actions have reduced the cancer risk for communities near ports and freeways. Monitors at the port of LA and Long Beach have shown a 50% reduction in diesel PM levels.

18. Air Quality Standards 4/25/2017
Ambient air quality standards represent public health goals set by U.S. EPA to limit exposure to particulate matter and ozone. California also sets air quality standards, and the national standards have become increasingly more similar to the California standards. There are a number of air quality standards, but PM and ozone standards are the remaining challenge for California.
Air Quality Standards

19. 4/25/2017
Air Quality Standards
U.S. EPA must set National Ambient Air Quality Standards (NAAQS) based on health impacts
Level of NAAQS is specific to each pollutant
Required NAAQS reviews are necessary to reflect new health research
U.S EPA NAAQS assessments are subject to scientific peer review by the Clean Air Scientific Advisory Committee (CASAC)
The Clean Air Act requires U.S. EPA to set national ambient air quality standards or NAAQS. These standards are based on the latest and best research published in the peer reviewed literature. There are six pollutants with national standards and each standard is specific to each pollutant. They are also solely based on the protection of human health and the environment. The standards are reassessed at five year intervals so that they reflect the most recent health science. The assessments undergo scientific peer review by the Clean Air Scientific Advisory Committee or CASAC, which is charged with providing advice and recommendations to U.S. EPA on the national standards. The members of CASAC are nationally and internationally recognized experts on air quality and health.

20. Nature of NAAQS Level of NAAQS designed to:
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Nature of NAAQS
Level of NAAQS designed to:
protect public from short and long term air pollution exposure
protect sensitive populations
NAAQS are a mandatory public health goal to be met by specific deadlines
States must demonstrate how NAAQS will be met
The level of a standard is designed to protect the public, including sensitive and vulnerable populations, from both long- and short-term exposure to air pollutants.
The standards are mandatory public health goals that must be met by specific deadlines. States must develop air quality plans that demonstrate how each nonattainment region will meet and maintain air quality standards.
Clearly the federal Clean Air Act has succeeded in providing cleaner, more healthful air to the nation, especially California. The Board has a long history of working to attain the NAAQS, and California has attained multiple ozone and particulate matter standards in regions throughout the state. However, we still have a ways to go to attain the ozone standards in the South Coast and San Joaquin Valley.

21. Ongoing Scientific Studies
Improve understanding of:
Multi-pollutant exposures
Near source exposures
Impacts on vulnerable populations
Role of genetics
Research aimed at improving our understanding of the health effects of air pollution is ongoing world-wide. Several current topics of particular interest include understanding whether and how exposure to the complex mixture of ambient air differs from that of exposure to single pollutants, characterization of exposures in close proximity to emissions sources, such as roadways and industrial facilities, and elucidation of factors that increase vulnerability, both on an individual and a community basis.
A new area of study is the role of genetics.
Recent research has shown that the genetic makeup of an individual can make one more susceptible to the adverse effects of air pollution. And exposure to air pollutants can modify genes in a way to put people at greater risk of developing illness, such as asthma. 21

22. Summary Health impacts of air pollution include:
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Summary
Health impacts of air pollution include:
Premature death
Heart disease and stroke
Asthma
Cancer risk
California’s improving air quality is providing public health benefits
Meeting NAAQS and reducing risk from TACs requires ongoing new emission reductions
To summarize, air pollution exposure can impact health in a number of ways. These impacts include premature death, worsening of heart disease leading to heart attack or stroke, asthma attacks, and increased risk of cancer. California’s air has been improving steadily as ARB has worked to meet increasingly stringent national standards. This improvement in air quality provides public health benefits by reducing exposure to the pollutants we have discussed this morning. And standards are becoming increasingly stringent as the science shows health effects at lower levels of pollution. Meeting these new standards and reducing the health risks from Toxic Air Contaminants will require ongoing efforts to achieve new emission reductions.

23. Clean Air in all communities
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Our Goal:
Clean Air in all communities
ARB's health effects research has contributed to the scientific basis for the development of national and state ambient air quality standards. The Program also investigates emerging toxicological issues as they relate to public health, and quantifies the health benefits of ARB regulations. The good news is that air quality in California has steadily improved since the inception of ARB as we have acted to achieve our goal of ensuring clean air in all of California’s communities. 23