The New York Times writer, Nadja Popovich, reports that after nearly a decade of improving the air quality nationally, the US EPA's data shows that PM 2.5 has increased in the past two years. This 180 turn of progress has been identified as likely primarily coming from increases in driving and the burning of natural gas. However, in the West, wildfires has been a large cause of the increase as well. Researchers suggest that due to a decrease of enforcement of the Clean Air Act, less businesses are concerned with their pollution.
The Clean Air Act had strict standards for air pollution that had saved hundreds of thousands of lives. This 5.5% increase in PM 2.5 is associated with nearly 10,000 premature deaths over the 2016-2018 years. PM 2.5 has been linked to a variety of health problems including lung cancer, heart attacks, stroke, asthma, respiratory inflammation and more recently a risk of miscarriage. Read the cost-benefit analysis of the Clean Air Act by the US EPA.