US Air Quality: Mixed Results Across States and Cities.

While fewer people in the US are breathing unhealthy air than a few years ago, California and other Western states are seeing more dramatic short-term spikes in air pollution due to events like wildfires, according to a report by the American Lung Association. The report found that nearly 120 million people lived in a place with unhealthy levels of air pollution from 2019 to 2021, down from 137 million from a prior three-year period. However, pollution from events like wildfires has gotten worse, particularly in Western states. California cities dominated the report's rankings of the most polluted metropolitan areas in the US.