Air Quality Indicators The Tracking Network includes data about
ozone and particulate matter (PM2.5). - Ozone - Days Above
Regulatory Standard: The number of days in which the daily
maximum 8-hour average ozone concentration exceeds a standard
provides an indication of short-term spikes in ozone
concentrations. This may give you an idea of how many days per
year you may be exposed to unhealthy levels of ozone. - PM2.5 -
Days Above Regulatory Standard: These data help summarize short-
term trends in particle pollution concentrations. This may give
you an idea of how many days per year you may be exposed to
unhealthy levels of particulate matter. - Annual PM2.5 Level:
These data help summarize long-term trends in particle pollution
concentrations. This will give you an idea of what the yearly
level of PM2.5 is in an area. Monitor + Model Air Data Air
monitoring in the United States is conducted by many federal,
state, local, and tribal air agencies. The Environmental
Protection Agency (EPA) provides air pollutio