According to data from the American Lung Association’s State of the Air report for 2024, a list of the most polluted cities in the US is provided below, with Bakersfield, CA, and Visalia, CA, topping the list.
The World Health Organization estimates that air pollution causes seven million deaths per year and might cost the world economy $18–25 trillion in welfare expenditures annually by 2060, or roughly 4–6% of GDP.
Furthermore, cities are quickly emerging as key players in the worldwide drive to clean up the air, with projections indicating that by the middle of the century, seven out of ten people will live in metropolitan areas.
The most polluted cities in the US are displayed in this visualization by Chris Dickert of Visual Capitalist, which makes use of data from the American Lung Association’s State of the Air report for 2024.
What is Air Pollution?
Air pollution is a complicated mixture of gases, particles, and liquid droplets that can originate from a range of sources, including wildfires and cookstoves in rural regions, as well as road dust and vehicle exhaust in cities.
While ozone and carbon monoxide are two types of air pollution that are particularly harmful to human health, the fine particulate matter that is less than 2.5 microns, or PM2.5 for short, is the subject of our concern here.
Particulate matter that fine can enter the bloodstream and cause a variety of health problems, such as lung cancer, chronic pulmonary disease, and cardiovascular disease. This is the reason for the focus.
The World Health Organization has set a far stricter limit of 5 µg/m³ for PM2.5, whereas the American Lung Association has set an annual average guideline of 9 µg/m³.
The 21 Worst Polluted Cities in the U.S.
Listed below are the top 21 most polluted cities in the United States based on average annual PM2.5 concentrations:
| Rank | City, State | Annual average concentration, 2020-2022 (µg/m3) |
|---|---|---|
| 1 | Bakersfield, CA | 18.8 |
| 2 | Visalia, CA | 18.4 |
| 3 | Fresno, CA | 17.5 |
| 4 | Eugene, OR | 14.7 |
| 5 | Bay Area, CA | 14.3 |
| 6 | Los Angeles, CA | 14.0 |
| 7 | Sacramento, CA | 13.8 |
| 8 | Medford, OR | 13.5 |
| 9 | Pheonix, AZ | 12.4 |
| 10 | Fairbanks, AK | 12.2 |
| 11 | Indianapolis, IN | 11.9 |
| 12 | Yakima, WA | 11.8 |
| 13 | Detroit, MI | 11.7 |
| T14 | Chico, CA | 11.6 |
| T14 | Spokane, WA | 11.6 |
| 15 | Houston, TX | 11.4 |
| 16 | El Centro, CA | 11.1 |
| 17 | Reno, NV | 11.0 |
| 18 | Pittsburgh, PA | 10.9 |
| T19 | Kansas City, KS | 10.8 |
| T19 | Las Vegas, NV | 10.8 |
Four of the top seven cities are located in California’s Central Valley, a 450-mile flat valley that runs parallel to the Pacific coast and is surrounded by the Sierra Nevada and Coast mountain ranges. Six of the top seven cities are located in California. Because of this, pollution from the major coastal cities—cities #5 and #6 on the list—that is blown inland by the wind often becomes trapped in the valley.
The southern part of the valley is hotter and drier, which makes the air quality worse. This is where Bakersfield (#1), Visalia (#2), and Fresno (#3) are situated. Road dust (14%), agricultural waste burning (20%), and farms (20%) were the top three local sources of PM2.5 emissions in 2023.
Benefit to Economy
The effects on health are widely recognized, but the effects on the economy are less so.
Poor air quality raises the expenses of both direct and indirect health care, hurts worker productivity, and increases absenteeism. On the other hand, there is a quantifiable benefit to the overall economy from better air quality. In a study released by the EPA, the economic advantages of every metric ton of particulate matter that was kept out of the atmosphere were broken down by industry.
| Sector | Benefits per metric ton |
|---|---|
| Residential Woodstoves | $429,220 |
| Refineries | $333,938 |
| Industrial Boilers | $174,229 |
| Oil and Natural Gas Transmission | $125,227 |
| Electricity Generating Units | $124,319 |
| Oil and Natural Gas | $88,838 |
The primary federal law overseeing air quality, the Clean Air Act, was determined to have cost the economy around $65 billion between 1990 and 2020, but it also generated $2 trillion in benefits, according to an updated cost-benefit analysis by the EPA.
Benefit to Business
However, that pertains to the macroeconomic domain; what about specific businesses?
Employees will, if given the option, prefer to work somewhere else because they enjoy breathing clean air. Nearly 70% of highly trained individuals stated that air quality was an important consideration when deciding which place to live and work in, according to a 2022 Deloitte case study.
Simultaneously, poor air quality can lower the risk pool’s general health, which can affect employer-sponsored health insurance rates. And given that the average annual insurance cost for a single employee increased to $21,931 in 2022 from $7,590, that may add up quickly.
In addition, buyers are considering environmental factors when making decisions, and many investors are prioritizing environmental considerations due to ESG, triple-bottom-line, and impact investment.
And for those businesses for whom the carrot is insufficient, there is always the stick. In what the EPA is referring to as “the largest civil penalty in the history of the Clean Air Act and the second largest environmental penalty ever,” the company Cummins, which makes vehicle engines, was just given over two billion reasons to contribute to enhanced air quality.
Last year, GreatGameIndia reported on data from IQAir’s World Air Quality Report, revealing the 20 most air-polluted cities on Earth, with Lahore, Pakistan, topping the list.
