American Lung Association’s “State of the Air” 2019 found that, in 2015-2017, more cities had high days of ozone and short-term particle pollution compared to 2014-2016 and many cities measured increased levels of year-round particle pollution. The “State of the Air” 2019 report shows that too many cities across the nation increased the number of days when particle pollution, often called “soot,” soared to often record-breaking levels. More cities suffered from higher numbers of days when ground-level ozone, also known as “smog,” reached unhealthy levels. Many cities saw their year-round levels of particle pollution increase as well.