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 2018.
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 2017.
The PM 2.5 indicator is a measure of potential exposure to inhalable particles that are 2.5 micrometers or smaller. This is measured in terms of annual average concentration in air measured in micrograms per cubic meter. PM 2.5 information included in EJScreen highlights areas across the U.S. that are not meeting the national ambient air quality standard for PM 2.5. In other words, the levels of PM 2.5 present in these areas are deemed harmful to human health. The PM 2.5 indicator in EJScreen is a measure of potential exposure but not a measure of risk. The raw PM 2.5 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.
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.
The Diesel PM indicator is the estimated concentration of Diesel PM as provided by the 2017 Air Toxics
update. The value of the indicator is in μg /m3
, and reported at the Census tract level. Block group level
values are assigned by repeating each parent tract level value.
The air toxics cancer risk indicator is the estimated lifetime inhalation cancer risk from the analyzed
carcinogens in ambient outdoor air, as provided by the 2017 Air Toxics data Update. The value of the
indicator is persons per million lifetime. The data is reported at the Census tract level. Block group level
values are assigned by repeating each parent tract level value.
The air toxics respiratory HI indicator is the respiratory HI from the analyzed carcinogens in ambient
outdoor air, as provided by the 2017 Air Toxics Data Update. The data is reported at the Census tract
level. Block group level values are assigned by repeating each parent tract level value.
Layer displays the modelled cancer risk associated with air toxics exposure. Figures represents the liklihood of hazardous exposure per 1 million population.
Layer displays the modelled non-cancer risk associated with air toxics exposure. A hazard index (HI) of 1 or lower means air toxics are unlikely to cause adverse noncancer health effects over a lifetime of exposure.
Layer displays the locations of brownfield sites based on the September 2013 version of the EPA Assessment, Cleanup and Redevelopment Exchange System (ACRES) database.