Years of scientific research have clearly established that particle pollution and ozone are a threat to human health at every stage of life, increasing the risk of premature birth, causing or worsening lung and heart disease, and shortening lives. Some groups of people are more at risk of illness and death than others, because they are more likely to be exposed, or are more vulnerable to health harm, or often both.

Air pollution can harm children and adults in many ways

Respiratory

  • Wheezing and coughing,
  • Shortness of breath,
  • Asthma attacks,
  • Worsening COPD,
  • Lung cancer
figure

Other

  • Premature death,
  • Susceptibility to infections,
  • Heart attacks and strokes,
  • Impaired cognitive functioning,
  • Metabolic disorders,
  • Preterm births and low birth weight

Health Effects of Particle Pollution

Particle pollution—also known as particulate matter—is a deadly and growing threat to public health in communities around the country. The more researchers learn about the health effects of particle pollution, the more dangerous it is recognized to be.

Particle pollution refers to a mixture of tiny bits of solids and liquids in the air we breathe. Particle pollution comes from many sources. Factories, power plants, and diesel- and gasoline-powered motor vehicles (cars, trucks and buses) and equipment either directly emit fine particles or generate other pollutants such as nitrogen oxides (NOx), known as precursors because they can then form into fine particles in the atmosphere. Other sources of particle pollution include wildfires, burning wood in wood stoves or residential fireplaces and burning biomass for electricity. 

Sources of particle pollution include motor vehicles, factories, power plants, equipment, wood burning and wildfires.


Individual particles may be too small to be visible, but when pollution levels are high, they can make the air appear thick and hazy. Researchers and regulators categorize particles according to size, grouping them as coarse, fine and ultrafine. Coarse particles, called PM10, can include wind-blown dust, ash, pollen and smoke. Fine particles, PM2.5, are most often a by-product of burning wood or fossil fuels. The tiniest are called ultrafine particles, or PM0.1, which are also produced by combustion.

The differences in size make a big difference in where and how particles affect our health. Our bodies’ natural defenses help us to keep coarse particles out of the deepest parts of our lungs, although these particles do deposit in the larger airways. However, those defenses do not keep smaller fine or ultrafine particles from penetrating to the air sacs of the lungs. Many of these particles get trapped in the air sacs, while the smallest are so minute that they can pass from the air sacs into the bloodstream and disperse to other organs of the body.

Particle pollution can be very dangerous to breathe, especially at higher concentrations. It can trigger illness, hospitalization and premature death. Researchers estimate that PM2.5 is responsible for nearly 48,000 premature deaths in the United States every year.1

Short-Term Exposure

Short-term spikes in particle pollution that last from a few hours to a few days can kill. Premature deaths from breathing these particles can occur on the very day that particle levels are high, or up to a month or two afterward. Most premature deaths are from respiratory and cardiovascular causes. Particle pollution does not just make people die a few days earlier than they might otherwise—in many cases these deaths would not have occurred for years if the air were cleaner.2

Studies linking short-term exposure to PM2.5 to death from all causes have been accumulating for a number of years. Taken together, this body of research provides consistent evidence of positive associations between particle pollution and mortality across diverse geographic locations and in populations with a wide range of demographic characteristics. Recently, a large international study found an association between short-term exposure to PM2.5 and daily all-cause, cardiovascular and respiratory mortality in more than 600 cities across the globe.3

Even low daily levels of fine particles can be deadly. A 2016 study found that people aged 65 and older in New England faced a higher risk of premature death from particle pollution, even in places that met current standards for short-term particle pollution.4 Looking nationwide in a 2017 study, researchers found more evidence that older adults faced a higher risk of premature death even when levels of short-term particle pollution remained well within the current national standards. This was consistent whether the older adults lived in cities, suburbs or rural areas5.

Particle pollution also has many other harmful effects, ranging from decreased lung function to heart attacks. Extensive research has linked short-term increases in particle pollution to:

  • increased mortality in infants;6
  • increased hospital admissions for cardiovascular disease, including heart attacks and strokes;7
  • increased hospital admissions and emergency department visits for COPD;8
  • increased severity of asthma attacks and hospitalization for asthma among children;9,10

Year-Round Exposure

Decades of research have firmly established that breathing particle pollution day in and day out can also be deadly. Across numerous seminal studies that look at different groups of people living in different parts of the country the results consistently showed a clear relationship between exposure to particulate matter and mortality.11

Recent research using publicly available data on a cohort of more than one million adults in the U.S. reconfirmed that long-term exposure to PM2.5 was associated with elevated risks of early death. The increased risk was primarily associated with death from cardiovascular and respiratory causes, including heart disease, stroke, influenza and pneumonia. Researchers also found a similar association between exposure to fine particle pollution and an increased risk of death from lung cancer among never-smokers.12 Another study of 68.5 million Medicare-enrolled adults in the United States between 2000 and 2016 found a 6-8% increase in risk of all-cause mortality for every 10µg/m3 increase in PM2.5.13

Research has also linked year-round exposure to particle pollution to a wide array of serious health effects at every stage of life, from conception through old age. Among pregnant people, fetuses and children, long-term particle pollution exposure is linked to:

  • Increased risk of preterm birth and low birth weight;14
  • Increased fetal and infant mortality;15
  • Reduced lung development and impaired lung function in children;16
  • Higher likelihood of children developing asthma.17

In adults, long-term particle pollution exposure is linked to:

  • Increased risk from existing cardiovascular and respiratory disease, including a worsening of heart disease, atherosclerosis and COPD;18,19
  • Higher likelihood of developing diabetes;20
  • Higher likelihood of getting lung cancer and of dying from it;21
  • Impaired cognitive functioning and an increased risk of Parkinson’s disease, Alzheimer’s disease and other dementias later in life.22, 23

The good news is, cleaning up particle pollution makes a difference. Research has shown a consistent relationship between decreasing PM2.5 concentrations and improving respiratory health in children and adults in communities that have reduced their levels of year-round particle pollution.24

Air Pollution and COVID-19

In the early days of the COVID-19 pandemic, several well-respected research teams in the U.S. set out to investigate possible links between long-term exposure to air pollution, especially PM2.5, and increased risk of infection and death from the SARS CoV-2 virus that causes the disease. Using the limited population-based data available at the time, some of them found a positive association and estimates of a specific percentage of COVID deaths attributable to air pollution. However, there were a number of methodological issues that may have influenced their results. The virus had not yet reached many parts of the country; community testing was extremely limited; the number of infections and death was probably dramatically undercounted; and little was known about how the disease was spreading through the population.

Since that time, the virus has become more widespread and better understood, but much remains uncertain about the nature of the mechanisms linking exposure to air pollution with COVID-19-related infection, severity and death. But some connections are clear. Air pollution is known to impact the functioning of the immune system and increase susceptibility to respiratory infections in general. Air pollution also increases the risk of chronic lung and cardiovascular diseases that put people at higher risk of poor outcomes from COVID-19. Communities of color, which have been especially hard hit by the pandemic, are also disproportionately exposed to unhealthy air.25

Anyone who lives where particle pollution levels are high is at risk. Some people face higher risk, however, based on their underlying health and other characteristics. (See the People at Risk section for more information about vulnerable groups.) Research has shown that the groups at the greatest risk from particle pollution include:

Research has shown that the groups at the greatest risk from particle pollution include:

  • Pregnant people and fetuses;26
  • Infants, children and older people (>65 years of age);27
  • People with lung disease, especially asthma, but also people with COPD;28
  • People with cardiovascular disease;29
  • People with lung cancer;30
  • People of color;31
  • Current or former smokers;32
  • People with low incomes;33 and
  • People who are obese or have diabetes.34

Summertime should be a great time to be outdoors in Montana, with warm weather and sunshine in a state full of natural splendors. But wildfire smoke often forces people to stay indoors. 

Bailey B. lives in Butte, a western Montana city surrounded by mountains on three sides. Some days in the summer, thick smoke fully obscures the mountains. “There are times you can’t go outside in the summertime,” she says.  

“There’s no point in going outside if you can’t breathe.” 

She notices more issues with runny noses, irritated eyes and coughing when wildfire smoke is in the air. Her father-in-law, who uses supplemental oxygen, can’t leave the house on such days without wearing a good mask. 

A Montana resident for the last 12 years, Bailey looks forward to hiking and camping in the summer, but she says wildfire smoke makes her consider spending those months elsewhere. 

“The air quality in Montana is bad enough that if I could leave in the summers, I would.” 

Bailey B.
Butte, Montana

Health Effects of Ozone Pollution

Ozone air pollution, sometimes known as smog, is one of the most widespread pollutants in the United States. It is also one of the most dangerous. Scientists have studied the effects of ozone on human health for decades. Hundreds of studies have confirmed that ozone harms people at levels currently found in many parts of the United States.

Ozone is a gas composed of molecules with three oxygen atoms. (The oxygen we need for life is made up of molecules with two oxygen atoms). Ozone forms in the lower atmosphere when a combination of other pollutants, usually nitrogen oxides (NOx) and volatile organic compounds (VOCs), “cook” together in sunlight through a series of chemical reactions. NOx and VOCs are produced primarily when fossil fuels such as gasoline, diesel, oil, natural gas or coal are burned or when solvents and some other chemicals evaporate. NOx is emitted from power plants, motor vehicles and other sources of high-heat combustion. VOCs are emitted from motor vehicles, oil and gas operations, chemical plants, refineries, factories, gas stations, paint, consumer products and other sources.

If these ingredients are present under the right conditions, they react to form ozone. Sunlight is key, with higher temperatures increasing ozone production. Because the reactions take place in the atmosphere, ozone often shows up downwind of the sources of the original emissions, sometimes many miles from where it formed. 

Ozone air pollution is sometimes called ground-level ozone, to distinguish it from the much higher-altitude stratospheric ozone layer that protects the Earth from damaging ultraviolet rays from the sun. 

Ozone gas is a powerful lung irritant. When it is inhaled into the lungs, it reacts with the delicate lining of the airways, causing inflammation and other damage that can impact multiple body systems. Ozone exposure can also shorten lives.

Ozone has a serious effect on the respiratory system, both in the short term and over the course of years of exposure. When ozone levels are high, many people experience breathing problems such as chest tightness, coughing and shortness of breath, often within hours of exposure. Even healthy young adults may experience respiratory symptoms and decreased lung function.35

Other breathing problems that have been tied to short-term exposure to ozone include:

  • Worsening of symptoms, increased medication use and increased emergency department visits and hospital admissions for people with asthma and COPD;36
  • Susceptibility to respiratory infections such as pneumonia, resulting in an increased likelihood of emergency department visits and hospitalizations.37

Living with ozone pollution long-term may cause lasting damage to respiratory health, including:

  • Development of new cases of asthma in children;38
  • Damage to the airways, leading to development of COPD;39
  •  Increased allergic response.40

The inflammation and systemic stress caused by short- and long-term exposure to ozone can also do damage to tissues, DNA and proteins throughout the body, which can cause or worsen other disease conditions over time. These include:

  • Increased risk of metabolic disorders, including glucose intolerance, hyperglycemia and diabetes;41
  • Impact on the central nervous system, including brain inflammation, structural changes and possible increased risk of cognitive decline;42, 43
  • Increased likelihood of reproductive and developmental harm, including reduced fertility, preterm birth, stillbirth and low birth weight;44, 45
  • Possible cardiovascular effects – although according to the most recent EPA review, the evidence linking ozone to heart disease, heart failure and stroke is mixed.46

The damage ozone does to the body can be deadly. Recent research has affirmed earlier findings that short-term exposure to ozone, even at levels below the current standard, likely increases the risk of premature death, particularly for older adults.47 There is also a growing body of evidence that long-term exposures to ambient ozone may be associated with an increased risk of cardiovascular and respiratory disease mortality.48

Anyone who spends time outdoors where ozone pollution levels are high may be at risk. Some people face a higher-than-average risk, however, because of their underlying health and other characteristics. (See the People at Risk section for more information about vulnerable groups.) Research has shown that the groups at greatest risk from ozone pollution include:

  • pregnant people and fetuses49
  • children;
  •  anyone age 65 and older;
  • people with existing lung disease such as asthma and COPD;
  • people who work or exercise outdoors;50

People at Risk

The health burden of air pollution is not evenly shared. There are people more at risk of illness and death from air pollution than others. Several key factors affect an individual’s level of risk: 

  • Exposure – Where someone lives, where they go to school and where they work make a big difference in how much air pollution they breathe. In general, the higher the exposure, the greater the risk of harm. 
  • Susceptibility – Pregnant people and their fetuses, children, older adults and people living with chronic conditions, especially heart and lung disease, may be physically more susceptible to the health impacts of air pollution than other adults. 
  • Access to healthcare – Whether or not a person has health coverage, a healthcare provider and access to linguistically and culturally appropriate health information may influence their overall health status, and how they are impacted by environmental stressors like air pollution. 
  • Psychosocial stress – There is increasing evidence that non-physical stressors such as poverty, racial/ethnic discrimination and fear of deportation can amplify the harmful effects of air pollution.

These risk factors are not mutually exclusive and often interact in ways that lead to significant health inequities among subgroups of the population. 

Research has shown that people of color are more likely to be exposed to air pollution and more likely to suffer harm to their health from air pollution than white people.51, 52 Much of this inequity can be traced to the long history of systemic racism in the United States. Practices such as redlining, the discriminatory outlining of riskier neighborhoods by mortgage lenders, institutionalized residential segregation in the 20th century, impairing the ability of many people of color to build wealth and limiting their mobility and political power. Over the years, decision-makers have found it easier to place sources of pollution, such as power plants, industrial facilities, landfills and highways, in economically disadvantaged communities of color than in more affluent, predominantly white neighborhoods. The resulting disproportionate exposure to air pollution has contributed to high rates of emergency department visits for asthma and other diseases.53, 54

People of color are also more likely than white people to be living with one or more chronic conditions that make them more susceptible to the health impact of air pollution, including asthma, diabetes and heart disease.55

There is evidence that having low income or living in lower income areas puts people at increased risk from air pollution, although the correlation is not as strong as with race and ethnicity.56, 57 People living in poverty are more likely to live in close proximity to sources of pollution and have fewer resources to relocate than people with more financial security.58 Poverty itself, along with the problems that beset many low-income communities, such as lack of safety, have been associated with increased psychosocial distress and chronic stress, which in turn make people more vulnerable to pollution-related health effects.59 People with low income also have lower rates of health coverage and less access to quality and affordable healthcare to provide relief to them when they get sick.

Children are both more susceptible to harm from air pollution and more likely to be exposed than adults. The growth and development of a child’s lungs and breathing ability start in utero and continue into early adulthood. Exposure to air pollution at any stage of that development process can have both immediate and lasting impacts on developing lungs and children’s health. In addition, the body’s defenses that help adults fight off infections are still developing in children. Children have more respiratory infections than adults, which also seems to increase their susceptibility to air pollution.60

Children breathe more rapidly and inhale more air relative to their size than do adults. They are more likely to spend time outdoors, running around, being active and breathing hard. Consequently, they are more exposed to polluted outdoor air than adults typically are.

Much of the illness and premature death caused by air pollution occurs in older adults, who are at increased risk of harm for several reasons. As a person ages, the normal process of thinning and weakening of the lung tissue and the supporting muscle and bones of the ribcage results in diminishing lung function over time. The increased impairment that results from exposure to air pollutants then has an add-on effect, putting stress on the lungs and heart. Older people are also more likely to be living with chronic diseases, and there is evidence that co-existing chronic lung, heart or circulatory conditions may worsen following exposure to environmental pollutants.61

The strength of the immune system also declines with age, leaving older people at greater risk of contracting infections and less able to get them under control before they become serious. Because exposure to air pollution increases susceptibility to respiratory infections, it also increases the risk of severe illness and death in older adults.

For the millions of people in the U.S. living with illnesses such as asthma, COPD, diabetes, heart disease and lung cancer, exposure to air pollution places them at greater risk of harm to their health than those without disease. The cellular injury and systemic inflammation triggered by breathing ozone and particle pollution put additional stress on people’s lungs, heart and other organs already compromised by disease. This can result in a worsening of symptoms, increased medication use, more frequent emergency department visits and hospitalizations, an overall reduced quality of life and, far too often, premature death.

Pregnancy is always a susceptible time for both the pregnant person and the developing fetus. The pregnant body undergoes dramatic physiological changes in hormone levels, metabolism and circulation throughout months of gestation. The rapid and complex development of the fetus is a precisely timed and sequenced process. The inflammation and oxidative stress resulting from exposure to air pollution during pregnancy can increase the risk of hypertensive disorders, including preeclampsia, in the pregnant person and lead to intrauterine inflammation and damage to the placenta that can disrupt the growth and development of the fetus. Fetal health may also be impacted in a number of ways by environmental contaminants that have been shown to cross the placenta.62

Exposure to both ozone and particle pollution during pregnancy is strongly associated with premature birth, low birth weight and stillbirth. These risks are amplified in pregnancies where the pregnant person is already at higher risk, such as people of color and those chronic conditions, especially asthma.63

There is some recent evidence suggesting that current and former smokers are at greater risk of health harm from exposure to fine particle pollution compared with never-smokers. They are more likely to develop lung cancer and to die prematurely.64 Smoking damages the lungs, heart, blood vessels and other organs.65 This impairment leaves the person with a smoking history more vulnerable to the health impact of air pollution than a never-smoker.

For people with lung conditions like asthma, checking the air quality is a regular part of life. 

“It’s something we automatically think about before we do outside activities,” says LA resident Jaime K., who has asthma. “If the air quality is bad, we don’t go out to the grocery store, out for walks or out to play with my daughter.” 

She says in an ideal world, she’d live near the ocean. But because housing costs by the water are so high, she purchased a home further inland near a highway. Despite using air filters to improve the air quality inside, soot builds up daily due to vehicles and, increasingly, wildfire smoke. 

“No matter how much I clean,” Jaime says, “I always have a layer of dust the next day.” 

Jamie K.
Los Angeles, California

Emerging Threats

Since the passage of the Clean Air Act in 1970, the federal, state, local and Tribal governments and businesses, community leaders and advocates have invested years of effort into reducing the public health threat from air pollution. By many measures, the air the nation breathes is dramatically cleaner than it was 50 years ago.  “State of the Air” has documented this long-term improvement over the past 22 years. In recent years, however, new threats have emerged that are causing air pollution levels to rise and the potential harm to vulnerable populations to increase.

The scientific evidence has clearly shown for years that impacts from climate change threaten human health. These health impacts are no longer a concern for the future. They’re happening now. What remains to be seen is how much these impacts increase in severity, how much action to reduce greenhouse gas emissions is able to mitigate them, and how much communities are able to adapt to the impacts that can’t be avoided. 

The rising global temperatures and disruption of short- and long-term weather patterns caused by climate change are putting the health Americans at risk. The impacts of climate change currently being experienced in communities nationwide include an increase in extreme weather events, deterioration of air quality from increased ozone formation and wildfire smoke, expansion of the range of disease-carrying pests and increased stresses that affect mental health and well-being. 

People and communities are differentially exposed to these climate-related hazards as well as being disproportionately affected by climate-related health risks. Populations experiencing greater health risks include children, older adults, low-income communities and some communities of color.  

“State of the Air” largely focuses on the health harms linked to increases in particle pollution and ozone, but increasing heat itself is another significant risk factor that adds to the climate vulnerability of some of the same populations who face increased risk from air pollution.66 Children are especially vulnerable to extreme heat. They spend more time playing outside and participating in vigorous activity than the average adult. Their bodies have a high surface area-to-mass ratio, so must divert more blood flow to their skin to dissipate heat, which may strain other bodily functions.67  

Among older adults, increased heat and exposure to air pollution raises the risk of premature death and results in more emergency room visits and hospital admissions, especially among those older adults who spend more time outdoors. The physical changes associated with aging—including those that affect breathing and movement—can make it even more difficult to respond to climate change. In the past two decades, heat-related mortality for older persons has almost doubled, reaching a record high 19,000 deaths in 2018.68 Heat waves also significantly increase the risk of illness and death in people living with chronic lung disease.69

 Wildfires are posing a growing threat to public health in many parts of the U.S. Increased heat and drought caused by climate change are resulting in larger, more frequent fires that blanket communities in smoke and leave residents gasping for air. Smoke from large fires can spread over hundreds or thousands of miles, polluting the air breathed by millions of people. In the years 2016-2019, individuals in the U.S. experienced a 19% increase in the number of days they were exposed to high wildfire risk compared to 2001-2004.70

Wildfire smoke is a complex mixture of fine and course particulate matter and gases, including carbon monoxide, nitrogen oxides, volatile organic compounds and air toxics. The chemical composition of wildfire smoke varies widely depending on the location of the fire and the material burned. The details of how these differences impact health is the subject of ongoing research.71

The most widespread health threat from smoke is from fine particles. Like other sources of fine particle pollution, wildfire smoke can be extremely harmful to the lungs, especially for children, older adults and people with asthma, COPD, chronic heart disease and diabetes. Recent research has confirmed that severe wildfire episodes are associated with increased risk of hospital admissions for respiratory diseases for Medicare recipients.72 Pregnant people exposed to wildfire smoke are more likely to experience adverse pregnancy outcomes, including preterm birth.73 There is also strong evidence linking smoke exposure to increased risk of premature death.74

The health impact of breathing wildfire smoke for extended periods of time, year after year, as is happening in some hard-hit communities, remains unknown.

The COVID-19 pandemic has transformed personal shopping behavior, accelerating the shift from in-store shopping for products and services to ordering them online. This has increased demand for fast, personalized delivery service and has resulted in a rising number of delivery trucks and vans on neighborhood streets, supported by a proliferation of warehouses, distribution centers and long-distance haulers on highways. To maximize their efficiency, large retailers and shipping companies are clustering new warehouses together in sprawling complexes, often in already highly-polluted communities. More traffic in and out of these areas, especially since the bulk of it is diesel-powered, brings more unhealthy air pollution to the communities where it is concentrated.75 U.S. EPA estimates that 72 million Americans live along major truck freight routes, and notes that they are more likely to be people of color and have lower incomes.76

Changes in consumer behavior have also had a major impact on port cities, which are dealing with an increase in cargo imports. The rapid growth in shipping traffic has resulted in backlogs of ships idling in harbors and off-shore waiting to unload, as well as increased congestion of the port-related cargo freight system of trucks, trains and planes. Between January and September 2021, the busy Ports of Los Angeles and Long Beach in California saw an average increase of 20% in cargo movement compared to the same time in 2019 prior to the COVID-19 pandemic. According to estimates from the California Air Resources Board, as of October 2021, the increased congestion had resulted in overall container ship emissions increases of 20 tons per day (tpd) of oxides of nitrogen (NOx) and 0.5 tpd of particulate matter. This increase in NOx emissions from container ships is roughly equivalent to the total emissions from 5.8 million passenger cars. Additionally, the increased diesel particulate emissions are comparable to the exhaust particulate emissions from almost 100,000 diesel trucks.77

Exposure to traffic-related pollution is a serious health hazard to those living in freight-impacted communities. The mixture of emissions has been linked to poor birth outcomes, reduced lung and cognitive development, development and worsening of chronic respiratory and cardiovascular diseases, increased risk of dementia, cancer and premature death.78 Unfortunately, the health burden for e-commerce-related pollution tends to disproportionately impact disadvantaged communities. Since low-income communities and communities of color make up a significant proportion of residents in disadvantaged communities, they are often burdened with the negative by-products of congestion and exposure to on-road emissions.79

Did You Know?

  1. More than four in ten Americans live where the air they breathe earned an F in “State of the Air” 2022.
  2. More than 137 million people live in counties that received an F for either ozone or particle pollution in “State of the Air” 2022.
  3. Close to 19.8 million people live in counties that got an F for all three air pollution measures in “State of the Air” 2022.
  4. Breathing ozone irritates the lungs, resulting in inflammation—as if there were a bad sunburn within the lungs.
  5. Breathing in particle pollution can increase the risk of lung cancer.
  6. Particle pollution can cause early death and heart attacks, strokes and emergency room visits.
  7. Particles in air pollution can be smaller than 1/30th the diameter of a human hair. When you inhale them, they are small enough to get past the body's natural defenses.
  8. Ozone and particle pollution are both linked to increased risk of lower birth weight in newborns.
  9. If you live or work near a busy highway, traffic pollution may put you at greater risk of harm.
  10. People who work or exercise outside face increased risk from the effects of air pollution.
  11. Millions of people are especially vulnerable to the effects of air pollution, including children, older adults and people with lung diseases such as asthma.
  12. People of color and those earning lower incomes are disproportionately affected by air pollution that puts them at higher risk for illness.
  13. Air pollution is a serious health threat. It can trigger asthma attacks, harm lung development in children, and even be deadly.
  14. You can protect yourself by checking the air quality forecasts in your community and avoiding exercising or working outdoors when unhealthy air is expected.
  15. Climate change enhances conditions for ozone pollution to form and makes it harder clean up communities where ozone levels are high.
  16. Climate change increases the risk of wildfires that spread particle pollution in the smoke.
  17. The Biden Administration has made bold commitments to improve air quality, especially in communities that have faced disproportionate levels of pollution. The Lung Association is advocating to make sure they are realized.
  18. The nation has the Clean Air Act to thank for decades of improvements in air quality. This landmark law has driven pollution reduction for 50 years.
  19. Cutting air pollution through the Clean Air Act was projected to prevent over 230,000 deaths and save nearly $2 trillion in 2020 alone.
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  1. U.S. EPA. Integrated Science Assessment for Particulate Matter. December 2019 EPA/600/R-19/188. Section 11.1.

  2. Health Effects Institute. State of Global Air. Boston, MA. 2020.

  3. C. Liu, R. Chen, F. Sera, A.M. Vicedo‑Cabrera, Y. Guo, S. Tong, M.S.Z.S. Coelho, P.H.N. Saldiva, E. Lavigne, P. Matus, N. Valdes Ortega, S. Osorio Garcia, M. Pascal, M. Stafoggia, M. Scortichini, M. Hashizume, Y. Honda, M. Hurtado‑Diaz, J. Cruz, B. Nunes, J.P. Teixeira, H. Kim, A. Tobias, C. Íñiguez, B. Forsberg, C. Åström, M.S. Ragettli, Y.-L. Guo, B.-Y. Chen, M.L. Bell, C.Y. Wright, N. Scovronick, R.M. Garland, A. Milojevic, J. Kyselý, A. Urban, H. Orru, E. Indermitte, J.J.K. Jaakkola, N.R.I. Ryti, K. Katsouyanni, A. Analitis, A. Zanobetti, J. Schwartz, J. Chen, T. Wu, A. Cohen, A. Gasparrini, and H. Kan. Ambient Particulate Air Pollution and Daily Mortality in 652 Cities. N Engl J Med. 2019; 381(8):705-15.

  4. Shi L, Zanobetti A, Kloog I, Coull BA, Koutrakis P, Melly SJ, Schwartz JD. Low-concentration PM2.5 and mortality: estimating acute and chronic effects in a population-based study. Environ Health Perspect. 2016; 124:46-52. http://dx.doi.org/10.1289/ehp.1409111.

  5. Di Q, Dai L, Wang Y, Zanobetti A, Choirat C, Schwartz JD, Dominici F. Association of Short-Term Exposure to Air Pollution with Mortality in Older Adults. JAMA. 2017; 318:2446-2456.

  6. U.S. EPA. 2019, Section 9.1.2.6.

  7. U.S. EPA. 2019, Section 6.1.2.

  8. U.S. EPA. 2019, Section 5.1.2.1.1.

  9. U.S. EPA. 2019, Section 5.1.2.1.

  10. U.S. EPA. 2019, Section 5.1.2.2.1.

  11. U.S. EPA. 2019, Section 11.2.

  12. Pope CA, Lefler JS, Ezzati M, Higbee JD, Marshall JD, Kim S, Bechle M, Gilliat KS, Vernon SE, Robinson AL, Burnett RT. Mortality risk and fine particulate pollution in a large, representative cohort of U.S. Adults. Environ Health Perspect. 2019; 127(7):077007-1-077007-9.

  13. Dominici F, Zanobetti A, Schwartz J, Braun D, Sabath B, Wu X. Assessing Adverse Health Effects of Long-Term Exposure to Low Levels of Ambient Air Pollution: Implementation of Causal Inference Methods. Health Effects Institute. 2022; Research Report 211.

  14. Bekkar B Pacheco S, Basu R, DeNicola N_Association of air pollution and heat exposure with preterm birth, low birth weight and stillbirth in the U.S.: A systemic review. JAMA Network Open. 2020; 3(6):e208243.

  15. Bekkar B et al. 2020.

  16. U.S. EPA. 2019, Section 5.2.2.2.1.

  17. U.S. EPA. 2019, Section 5.2.3.1.

  18. U.S. EPA. 2019, Section 6.2.2.

  19. U.S. EPA. 2019, Section 5.2.5.

  20. Bowe B, Xie Y, Li T, Yan Y, Xian H, Al-Aly Z. The 2016 global and national burden of diabetes mellitus attributable to PM2.5 air pollution. Lancet Planet Health. 2018; 2:e301-12.

  21. U.S. EPA, 2019. Section 10.2.5.1.

  22. U.S. EPA. 2019, Section 5.1.2.1.

  23. Kilian J and Kitazawa M. The emerging risk of exposure to air pollution on cognitive decline and Alzheimer's disease -- evidence from epidemiological and animal studies. Biomed J. 2018; 41:141-162.

  24. Shi L, Wu X, Danesh Yazdi M, Braun D, Abu Awad Y, Wei Y, Liu P, Di Q, Wand Y, Schwartz J, Dominici F, Kioumourtzoglou M-A, Zanobetti A. Long-term effects of PM2.5 on neurological disorders in the American Medicare population: a longitudinal cohort study. Lancet Planet Health. 2020; 4:e557-65.

  25. U.S. EPA. 2019, Section 5.2.11.

  26. Boudrel T, Annesi-Maesano I, Alahmad B, Maesano CN, Bind M-A. The impact of outdoor air pollution on COVID-19: a review of evidence from in vitro, animal, and human studies. Eur Respir Rev. 2021; 30:200242.

  27. Bekkar B et al. 2020.

  28. U.S. EPA. 2019, Section 12.5.1.1.

  29. U.S. EPA. 2019, Section 12.3.5.

  30. U.S. EPA. 2019, Section 12.3.1.

  31. U.S. EPA. 2019, Section 10.2.5.1.

  32. U.S. EPA. 2019, Section 12.5.4.

  33. U.S. EPA. 2019, Section 12.6.1.

  34. U.S. EPA. 2019, Section 12.3.3.

  35. Kilian J and Kitazawa M. The emerging risk of exposure to air pollution on cognitive decline and Alzheimer's disease -- evidence from epidemiological and animal studies. Biomed J. 2018; 41:141-162.

  36. U.S.EPA. Integrated Science Assessment for Ozone and Related Photochemical Oxidants. April 2020. EPA/600/R-20/012. Section 3.1.4.1.

  37. U.S. EPA. 2020, Section 3.1.7.

  38. U.S. EPA. 2020, Section 3.2.4.1.

  39. U.S. EPA. 2020, Section 3.2.4.3.

  40. U.S. EPA. 2020, Section 3.2.4.6.

  41. U.S. EPA. 2020, Section 5.1.3.

  42. U.S. EPA. 2020, Sections 7.2.1 and 7.2.2.

  43. Gao Q, Zang E, Bi J, Dubrow R, Lowe SR, Chen H, Zeng Y, Shi L, Chen K. Long-term ozone exposure and cognitive impairment among Chinese older adults: A cohort study. J Env Int. 2022; 160:107072.

  44. U.S. EPA. 2020, Section 7.1.3.

  45. Mendola P, Ha S, Pollack AZ, Zhu Y, Seeni I, Kim SS, Sherman S, Liu D. Chronic and acute ozone exposure in the week prior to delivery is associated with risk of stillbirth. Int J Environ Res Pub Health. 2017; 14:731.

  46. U.S. EPA. 2020, Sections 4.1 and 4.2.

  47. Di et al. 2017.

  48. Lim CC, Hayes RB. Ahn J, Shao Y, Silverman DT, Jones RR, Garcia C, Bell ML, Thurston GD. Long-term exposure to ozone and cause-specific mortality risk in the United States. Am J Respir Crit Care Med. 2019; 200(8):1022–1031.

  49. Bekkar B et al. 2020.

  50. U.S. EPA. 2020, Section IS.4.4.

  51. U.S. EPA. 2019, Section 12.5.4.

  52. Liu J, Clark LP, Bechle MJ, Hajat A, Kim S-Y, Robinson AL, Sheppard L, Szpiro AA, Marshall JD. Disparities in air pollution exposure in the United States by race/ethnicity and income, 1990–2010. Environ Health Perspect. 2021; 129(12).

  53. Nardone A, Casey JA, Morello-Frosch R, Mujahid M, Balmes JR, Thakur N. Associations Between Historical Residential Redlining and Current Age-Adjusted Rates of Emergency Department Visits Due to Asthma Across Eight Cities in California: An Ecological Study. Lancet Planet Health. 2020:4(1):e24-e31.

  54. Erqou S, Clougherty JE, Olafiranye O, Magnani JW, Aiyer A, Tripathy S, Kinnee E, Kip KE, Reis SE. Particulate Matter Air Pollution and Racial Differences in Cardiovascular Disease Risk. Arterioscler Thromb Vasc Biol. 2018; 38:00-00.

  55. Centers for Disease Control and Prevention. National Center for Health Statistics. National Health Interview Survey, 2019. Analysis performed by the American Lung Association Epidemiology and Statistics Unit using SPSS software.

  56. U.S. EPA. 2019, Section 12.5.3.

  57. Liu et al. 2021.

  58. Mikati I, Benson AF, Luben TJ, Sacks JD, Richmond-Bryant J. Disparities in Distribution of Particulate Matter Emission Sources by Race and Poverty Status. Am J Public Health. 2018; 108(4):480–485.

  59. Kioumourtzoglou M-A, Schwartz J, James P, Dominici F, Zanobetti A. PM2.5 and mortality in 207 US cities: modification by temperature and city characteristics. Epidemiology. 2016; 27(2):221-7.

  60. Johnson NM, Hoffmann AR, Behlen JC, Lau C, Pendleton D, Harvey N, Shore R, Li Y, Chen J, Tian Y, Zhang R. Air pollution and children’s health—a review of adverse effects associated with prenatal exposure from fine to ultrafine particulate matter. Environ Health Prev Med. 2021; 26:72.

  61. Simoni M, Baldacci S, Maio S, Cerrai S, Sarno G, Viegi G. Adverse Effects of Outdoor Pollution in the Elderly. J Thorac Dis. 2015; 7(1):34-45.

  62. Klepak P, Locatelli I, Korošec S, Künzli N, Kukec A. Ambient air pollution and pregnancy outcomes: a comprehensive review and identification of environmental public health challenges. Environ Research. 2018; 167:144-159.

  63. Bekkar B et al. 2020.

  64. U.S. EPA. 2019, Section 12.6.1.

  65. U.S. Department of Health and Human Services. The Health Consequences of Smoking - 50 Years of Progress: A Report of the Surgeon General. 2014.

  66. Ebi, K.L., J.M. Balbus, G. Luber, A. Bole, A. Crimmins, G. Glass, S. Saha, M.M. Shimamoto, J. Trtanj, and J.L. White-Newsome, 2018: Human Health. In Impacts, Risks, and Adaptation in the United States: Fourth National Climate Assessment, Volume II [Reidmiller, D.R., C.W. Avery, D.R. Easterling, K.E. Kunkel, K.L.M. Lewis, T.K. Maycock, and B.C. Stewart (eds.)]. U.S. Global Change Research Program, Washington, DC, USA, pp. 572–603.

  67. Anderko, L et al. Climate changes reproductive and children’s health: a review of risks, exposures, and impacts. Pediatr Res. 2020; 87:414–419.

  68. Watts N, Amann M, Arnell N et al. The 2020 report of The Lancet Countdown on health and climate change: responding to converging crises. Lancet 2020.

  69. Witt C et al. The effects of climate change on patients with chronic lung disease—a systematic literature review. Dtsch Arztebl Int. 2015; 112:878–83.

  70. Watts et al. Lancet. 2020.

  71. Reid CE et al. Critical review of health impacts of wildfire smoke exposure. Env Health Perspect. 2016; 124(9):1334-1343.

  72. Liu JC et al. Wildfire-specific fine particulate matter and risk of hospital admissions in urban and rural counties. Epidemiology. 2017; 28(1):77-85.

  73. Abdo M et al. Impact of wildfire smoke on adverse pregnancy outcomes in Colorado, 2007-2015. Int J Environ Res Pub Health. 2019; 16:3720.

  74. Cascio WE. Wildland fire smoke and human health. Sci Total Environ. 2018; 624: 586–595.

  75. Waddell K. When Amazon Expands, These Communities Pay the Price. Consumer Reports. Dec 2021. Accessed at https://www.consumerreports.org/corporate-accountability/when-amazon-expands-these-communities-pay-the-price-a2554249208/

  76. US Environmental Protection Agency. Regulatory Announcement: Transportation and Environmental Justice. March 2022. Accessed at https://www.epa.gov/system/files/documents/2022-03/420f22007.pdf

  77. California Air Resources Board. Emissions Impact of Ships Anchored at Ports of Los Angeles and Long Beach. November 9, 2021. Accessed at https://ww2.arb.ca.gov/sites/default/files/2021-11/SPBP_Congestion_Anchorage_Emissions_Final.pdf

  78. Lim S, Holliday L, Barratt B, Griffiths CJ, Mudway IS. Assessing the exposure and hazard of diesel exhaust in professional drivers: a review of the current state of knowledge. Air Qual Atmos Health. 2021; 14:1681–1695.

  79. South Coast Air Quality Management District (SCAQMD). (2021, Apr). Second Draft Socioeconomic Impact Assessment for Proposed Rule 2305 – Warehouse Indirect Source Rule – Warehouse Actions and Investments to Reduce Emissions (WAIRE) Program and Proposed Rule 316 – Fees for Rule 2305.