The ozone indicator in EJScreen reflects potential ozone exposure measured in terms of summer
seasonal daily average maximum concentrations in an 8-hour period measured in parts per billion.
Ozone information included in EJScreen highlights areas across the U.S. that are not meeting the
national ambient air quality standard for ozone. In other words, the levels of ozone present in these
areas are deemed harmful to human health.
The ozone indicator in EJScreen is a measure of potential exposure but not a measure of risk. The raw
ozone data is compiled by census tract, which is supplied for use in the tool by EPA’s OAQPS. For air
toxics risk measures (as opposed to exposure) users can turn to EJScreen’s other three indicators: cancer
risk, respiratory HI, and diesel PM.
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This layer displays the daily average concentration of ozone and the percentage of days with concetrations of ozone above the National Ambient Air Quality Standard (NAAQS) of 0.075 parts per million in 2015.
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This layer displays the daily average concentration of fine particulate matter and the percentage of days with concetrations of fine particulate matter above the National Ambient Air Quality Standard (NAAQS) of 35.0 micrograms per cubic meter in 2016.
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This layer displays the percentage of days with concetrations of ozone matter above the National Ambient Air Quality Standard (NAAQS) of 35.0 micrograms per cubic meter.
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This layer displays the daily average concentration of fine particulate matter and the percentage of days with concetrations of fine particulate matter above the National Ambient Air Quality Standard (NAAQS) of 35.0 micrograms per cubic meter in 2014.
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This layer displays the daily average concentration of ozone and the percentage of days with concetrations of ozone above the National Ambient Air Quality Standard (NAAQS) of 0.075 parts per million in 2014.
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