A new report has shed light on the locations of the most polluted cities in the U.S. On Tuesday, IQAir, a Swiss tech company that tracks global air quality, released the report, which evaluated the state of global air quality based on fine particulate matter,

Data from more than 40,000 air quality monitoring stations in 138 countries, territories and regions were analyzed for the report, IQAir said.

The countries with the worst air quality included Bangladesh and India, according to an annual report from IQAir.

The cities with the worst air pollution in North America were Ontario, Bloomington and Huntington Park – all in Southern California