Ambient air pollution is the largest environmental health problem in the United States and in the world more generally.
You're more likely to die from air pollution, from which 200,000 Americans die every year, than from diabetes, influenza, kidney disease or suicide.
Fine particulate matter smaller than 2.5 millionths of a meter, known as PM2.5, was the fifth-leading cause of death in the world. Around seven million people die each year from air pollution.
Exposure to PM2.5 has been linked to several health conditions, including psychiatric disorders, mental health disorders (including depression), dementia, emphysema and lung disease. There is also evidence that it is making us less intelligent.