Apache County, Ariz., at 2.8 ug/m3.
Ezzati and his colleagues used data from the Center for Air, Climate and Energy Solutions at Carnegie Mellon University in Pittsburgh, plus death records from the U.S. National Center for Health Statistics. They developed computer models to combine these data and arrive at the number of deaths that could be attributed to air pollution.
In all, of the nearly 42 million deaths in the United States from 1999 to 2015, the researchers estimated that 18 million were due to cardiorespiratory diseases, likely linked to air quality. They took into account factors such as age, education, poverty and smoking, though the study does not prove that air pollution kills people.
The report was published online July 23 in the journal PLOS Medicine.
Dr. Brian Christman, a spokesman for the American Lung Association and vice chair of the department of medicine at Vanderbilt University’s School of