Scientific research has 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.

One new study by the AQLI finds that particulate air pollution takes 2.2 years off global average life expectancy, or a combined 17 billion life-years, relative to a world that met the World Health Organization (WHO) guideline. This impact on life expectancy is greater than that of smoking—cigarette smoking in total reduces life expectancy by 1.9 years. Whereas it is possible to quit smoking or take precautions against diseases, everyone must breathe air, thus, air pollution affects many more people.

The World Health Organization (WHO) recently revised its guideline (from 10 µg/m³ to 5 µg/m³) for what it considers a safe level of exposure of particulate pollution, bringing most of the world—97.3 percent of the global population—into the unsafe zone. Reducing air pollution to meet international health guidelines would increase the global average life expectancy from roughly 72 to 74.2 years.

Sustained enforcement of strong air pollution policies in the United States has significantly reduced particulate pollution. Since the Clean Air Act was enacted in 1970, particulate pollution has declined by 66.9 percent—extending the life expectancy of an average American by 1.4 years. Despite this success, the latest scientific evidence on the impact of air pollution at even the low levels that exist in much of the United States reveals that 92.8 percent of the population is now considered to be living in areas with unsafe levels of pollution. In the United States, average pollution was 7.1 µg/m³ in 2020, slightly above the WHO guideline. At this level, residents could expect to gain roughly 2.5 months from clean air—equivalent to 68 million total life years. Some Americans could add more than a year to their lives if they lived in a place with cleaner air.

In 2020, 19 out of the top 20 most polluted counties in the United States were in California. Average pollution concentrations ranged from 13.0 μg/m³ in Sierra County to 22.6 μg/m³ in Mariposa County. In Mariposa, residents stand to gain 1.7 years of life expectancy if air quality were kept below the WHO guideline. For those living in the smog capital of Los Angeles, particulate pollution has declined by almost 53 percent, extending life expectancy for the average Angeleno by 1.3 years. The average Californian could expect a roughly 7-month further boost to lifespan if air quality met standards.

Sixty percent of particulate matter air pollution is caused by fossil fuel combustion, 18% comes from natural sources (including dust, sea salt, and wildfires), and 22% comes from other human activities. Particulate matter air pollution is categorized by its size. The smaller it is, the deeper it can get into the body. Particulate matter with a diameter of less than 10 micrometers, often designated PM10, can pass through the hairs in the nose, down the respiratory tract and into the lungs. Smaller particulate matter with a diameter less than 2.5 micrometers, often designated as PM2.5, can get into the bloodstream by way of the lungs. It can affect blood flow, eventually causing a stroke, heart attack and other health issues. Researchers estimate that PM2.5 is responsible for nearly 48,000 premature deaths in the United States every year.

Air pollution can affect not only the lungs but also the heart and many other organs. Extensive research has linked short-term increases in particle pollution to: increased mortality in infants; increased hospital admissions for cardiovascular disease, including heart attacks and strokes; increased hospital admissions and emergency department visits for COPD; and increased severity of asthma attacks and hospitalization for asthma among children. Long-term exposure increases risk of death from cardiovascular and respiratory causes, including heart disease, stroke, influenza and pneumonia. Researchers also found an association between exposure to fine particle pollution and an increased risk of death from lung cancer among never-smokers. Long-term exposure is also linked to a higher likelihood of developing diabetes, impaired cognitive functioning and an increased risk of Parkinson’s disease, Alzheimer’s disease and other dementias later in life.

Ozone air pollution, sometimes known as smog, is one of the most widespread pollutants in the United States. In addition to particulate air pollution, it is also one of the most dangerous. The damage ozone does to the body can be deadly. Living with ozone pollution long-term may cause lasting damage to respiratory health, including:

• Development of new cases of asthma in children
• Damage to the airways, leading to development of COPD
• Increased allergic response
• Increased risk of metabolic disorders, including glucose intolerance, hyperglycemia and diabetes
• Impact on the central nervous system, including brain inflammation, structural changes and possible increased risk of cognitive decline
• Increased likelihood of reproductive and developmental harm, including reduced fertility, preterm birth, stillbirth and low birth weight
• Possible cardiovascular effects

The “State of the Air” report—which looks at two of the most widespread and dangerous air pollutants: fine particles and ozone—finds that despite decades of progress on cleaning up sources of air pollution, more than 40% of Americans—over 137 million people—are living in places with failing grades for unhealthy levels of particle pollution or ozone. Spikes in particle pollution and high ozone days related to wildfires and extreme heat are putting millions more people at risk.

There is not much you can do in the short term about your air quality—but you can move. I chose to move to Honolulu, Hawaii, which is ranked as the #3 cleanest US city, from New York, New York, which gets a failing grade for ozone pollution. You can use the Compare Your Air tool to preview your potential move and get a report card on your current location. See my results below:

High Ozone Days	New York-Newark, NY-NJ-CT-PA	Urban Honolulu, HI
Ozone Grade:	F	A
Weighted Average:	18.8	0.0
Particle Pollution – 24 Hour	New York-Newark, NY-NJ-CT-PA	Urban Honolulu, HI
Grade:	C	A
Weighted Average:	1.3	0.0
Particle Pollution – Annual	New York-Newark, NY-NJ-CT-PA	Urban Honolulu, HI
Grade:	Pass	Pass
Design Value:	8.7	3.8

Longer term, we should continue to push for improvements in air quality globally—we could all use the extra years.