What states have the worst air pollution? Photo of a gigantic nose inhaling pollutants.

Page Contents

Advertiser Disclosure: At ElectricityRates.com, our number one goal is to help you make better energy decisions. We adhere to strict editorial guidelines, however this post may include references to products offered from our partners.

Recently, conversations regarding air quality have become quite commonplace.

Experts estimate that over 105,000 people die prematurely in the U.S. annually from air pollution. Additionally, air pollution is estimated to cost our country nearly $900 billion annually (that’s over 5% of the national GDP). It’s a huge deal!

Keep reading as we dive more into the truth about air quality in the United States and share with you the top 5 states with the worst air quality.

Measuring and Understanding Air Quality

To help monitor air quality, The Environmental Protection Agency (EPA) tracks and publicizes data across the United States. Their Air Quality Index (AQI) is a scale used to report daily air quality. It runs from 0 to 500, with higher numbers indicating worsening quality and potential for health concerns.

So, what are the primary air pollutants and causes of air pollution that we should avoid? The EPA has set national standards for six of the most common air pollutants
carbon monoxide, lead, ground-level ozone, particulate matter (tiny particles of pollution), nitrogen dioxide, and sulfur dioxide.

The sources of air pollution are numerous, but the main culprits are facility emissions, agricultural sources, heavy manufacturing, natural sources like wildfires, as well as chemical pollutants that build up over time. In general, ground-level ozone pollution and particulate matter are considered the most hazardous to our health and the primary pollutants that contribute to poor air quality in the top 5 worst states.

While there are many factories and other point-source polluters in these states, a significant contributing factor to their bad ranking is primarily due to anthropogenic emissions meaning emissions from human activities.

Factors like driving cars and burning wood all add up! Agricultural production is also a key player, particularly livestock operations and crop production/pesticide use. These ag operations produce methane gas and ammonium nitrate particles which rise into the atmosphere and eventually drift downwind, negatively impacting areas far from where they were emitted.

Air quality matters so much because it directly affects our health. Poor air quality can cause irritation to the eyes, nose, and throat, as well as shortness of breath and other respiratory issues. Long-term exposure can lead to permanent lung damage and a greater risk of developing cancer, asthma, and other chronic illnesses.

Top Five States with the Worst Air Quality

According to the EPA, these five states have the worst air quality nationwide in 2023. See how your state fares and what we can all do to help improve things for ourselves and future generations.


California may be known for its picturesque beaches, mountains, sunny weather, and bustling cities, but unfortunately, it is one of the top five states with the worst air quality.

The state has experienced an increase in air pollution due to the state’s large population and urban sprawl. Another source of pollution here is wildfires. California makes national news nearly every year for its raging fires that force tens of thousands to evacuate their homes for safety.

Attempting to mitigate the dangerous impacts of air pollution, California lawmakers are taking action by strengthening regulations against emissions from motor vehicles and energy production. Furthermore, various initiatives such as green energy credits, LEED certification standards for buildings, and infrastructure improvements have been implemented to help bring cleaner air to citizens across the state.

And while there’s still much more work to be done to improve air quality in California, citizens can take comfort that their lawmakers are committed to making this beautiful state a healthy place to live again. See below for more ways you can help improve the air quality, no matter what state you live in.


Arizona is one of the five most air-polluted states in the United States.

The Phoenix-Mesa-Scottsdale Metropolitan area, in particular, has faced several episodes of elevated ozone levels due to the large population and increasing number of cars on the roads. In addition, Arizona is a major producer of electricity, which contributes to particulate emissions through burning coal and fossil fuels.

With nearly one-third of their population affected by polluted air, toxic chemicals, and other environmental pollutants, Arizona residents have to be conscious of their environment and the hazards that come with it. Carpooling, using a smart thermostat, and considering a renewable energy electricity plan, are all great ways to use less energy, save money, and improve the air quality.

But there is good news! Arizona also offers numerous opportunities for outdoor activities with clean air. The Grand Canyon, Havasu Falls, Lake Page, and many other natural areas have hiking trails, reserves, and parks to help get away from dangerous city pollutants. Spending time in the great outdoors is a fun way to reduce exposure to air pollution.


Illinois is, unfortunately, within the top 5 states with the worst air quality. Despite its flat land and large open areas, air pollution in the Land of Lincoln has passed health standards set by the EPA. The cause of these environmental issues is primarily attributed to transportation emissions, industrial production, agricultural production, and residential energy use.

The state has made strides in reducing emissions by implementing new programs such as the Illinois Environmental Protection Agency’s Clean Air Counts initiative. This program works with businesses, schools, and municipalities across the state to reduce air pollution through energy efficiency and renewable energy projects.

Additionally, citizens of Illinois can take action by driving less, using energy-efficient appliances, and reducing the overall usage of electricity. If most citizens participate in these efforts, the air quality can improve to a much healthier level.


Pennsylvania suffers from some of the worst air quality in the country. The state is particularly prone to high ozone and particle pollution ratings, both of which can be extremely hazardous to our health. These high levels of air pollution are mainly attributed to an increase in industry and traffic due to the state’s large population and its proximity to other polluted areas such as New York City and Washington D.C.

To combat these issues, Pennsylvania has implemented various initiatives to reduce transportation and energy production emissions. Furthermore, PA legislators have adopted the Clean Air Act Amendments of 1990, which establishes regulations on emissions from both stationary sources (e.g., factories) and mobile sources (e.g., cars, buses, trucks).

If you live in PA and are looking to do your part in improving its air quality, a great way to start is by reducing emissions from vehicles, reducing air-born pollution sources, as well as identifying areas that require comprehensive cleanup.


From smog-filled cities to dusty rural outposts, Nevada has long had air quality issues. The Silver State frequently finds itself at the top of lists for worst air quality in terms of combined airborne particulates, ozone, and other pollutants throughout the year.

This is especially bad news for people living in urban areas like Las Vegas and Reno, where sources like auto exhaust contribute to already dangerous levels of air pollution, leading to severe damage to cardiovascular and respiratory organs.

For those living in Nevada, it’s essential to take extra steps to maintain healthier air indoors and outdoors, such as recycling, using public transportation, and choosing clean, renewable energy sources whenever possible. The effort put in now could have significant benefits for future generations so they’re not stuck dealing with this same problem.

How to Protect Yourself

These five states have the worst air quality in America. If you live in any of these states, be sure to take precautions. Regularly replace air filters in your home and automobile. Watch the weather report to stay indoors on days when pollution or ozone is high, and try to find ways to use less energy in general.

Before you venture outside, you can also check the Air Quality Index for your area to see how polluted the air is. Do your part to improve air quality in your state by reducing your own emissions and encouraging others to do the same. Together, we can all stay healthy and make a difference in the fight against poor air quality no matter where you call home.

Looking for more information on how to reduce your environmental impact in 2023? See our article on how you can go green and save money at the same time.