Almost half of the US population suffers from air pollution; 44% of the US is plagued with toxic air, which means that more than 138 million people breathe it in.

The American Lung Association has released a report called the State of the Air, which studies air pollution in cities across the US. While air quality has improved in many areas over recent years, many US citizens are at severe risk of breathing in ozone, which can cause a wide range of health issues from shortness of breath to lung cancer. 

For the first time since the State of the Air began collecting data 16 years ago, two rural counties in Utah made it in the top-25 counties for ozone. Urban areas are thought of as the dirtiest, but due to oil and gas wells in rural areas, chemicals from extraction and production activities get trapped to form smog, making rural areas succeptable to high levels of pollution too.

California continues to obtain the most polluted counties, with Long Beach suffering from the highest concentration of ozone. The city with the least ozone is Bellingham, Washington and Prescott, Arizona is the cleanest in terms of year-round particle pollution. Go here to see how your city ranked.