The Natural Resources Defense Council also says cleaner air helps avoid an estimated 370,000 premature deaths in the U.S. each year and leads to 189,000 fewer hospital admissions for cardiac and respiratory illnesses, such as heart diseases, asthma or pneumonia.
In short, you can expect numerous benefits from living in an area with clean air. That's good news for residents of several states, according to a new U.S. News and World Report analysis, which ranked all 50 states according to how polluted they are and the risk that pollution poses to their population's health.
The ranking is based on 2019 data from the U.S. Environmental Protection Agency, which measured the total toxic chemical pollution generated in each state and the risks of long-term, chronic health effects — such as cancer and birth defects — posed to each state's population per capita.
Those measurements accounted for air and water emissions from manufacturing, electric power generation, mining and hazardous waste treatment, according to the U.S. News and World Report. They didn't account for pollution from transportation, agriculture or small facilities like dry cleaners and auto body shops.
Here are the seven least polluted states, according to the ranking:
- New Hampshire
- South Dakota
- New Mexico
- Rhode Island
Vermont comes in first as the least polluted state in the nation, a fitting title for "The Green Mountain State" that is known for its pristine natural attractions. That ranking is consistent with other 2022 analyses: The American Lung Association (ALA) says Vermont's cities are among the cleanest by air quality in the country, and have low levels of the most harmful and widespread types of air pollution.
The state's Burlington-South metro area in particular is one of only two U.S. cities that rank as the cleanest for the worst types of air pollution, which include particle pollution and ozone air pollution.
New Hampshire's status as the second-least polluted state may come as somewhat of a surprise. In 2022, the ALA said the state's air quality got "mixed grades." Overall, New Hampshire showed improvement in the ozone air pollution category, but three counties experienced higher long-term particle pollution — which is deadly — compared to the previous year, according to the ALA.
Another surprise is California's high ranking, considering that many of its cities rank among the country's most polluted, according to the ALA. California may have more stringent emission standards than most states, but factors like wildfires and drought have been found to worsen the state's air quality.
What's not surprising is the state ranked as the most polluted in the U.S.: Louisiana. Several pieces of research point to the state's poor air quality. For instance, a 2020 analysis by the Environmental Integrity Project found that Louisiana is home to four of the top ten "super polluter" chemical plants in the U.S. A 2019 ProPublica investigation also found that the number of plants in Louisiana with high emissions has actually increased since the 1980s, despite the overall number decreasing nationally.