The RMP facility proximity is reflective of the total count of RMP facilities in each block group within 5
km of the average resident in a block group, divided by distance, calculated as the population-weighted
average of blocks in each block group
The hazardous waste proximity indicator is reflective of the total count of hazardous waste facilities in
each block group within 5 km of the average resident in a block group, divided by distance, calculated as
the population-weighted average of blocks in each block group. Hazardous waste facilities are defined as
Resource Conservation and Recovery Act (RCRA) handlers that are either operating TSDFs from RCRA or
reporting LQGs from the 2019 BR.
The UST indicator quantifies the relative risk of being affected by a LUST for a block group. The indicator
is derived by the weighted sum of active LUSTs and sum of active and temporarily out of service USTs
within a certain distance from a block group.
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.
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.
This layer displays RSEI score by county. A RSEI Score is a unitless value that accounts for the size of the chemical release, the fate and transport of the chemical through the environment, the size and location of the exposed population, and the chemical’s toxicity. RSEI scores are designed to be compared to each other. A RSEI Score 10 times higher than another RSEI Score suggests that the potential for risk is 10 times higher. Relatively small releases may lead to high RSEI Scores if the toxicity weight is particularly high or if the estimated exposed population is large. Conversely, large releases may lead to low RSEI Scores if the toxicity weight is low or if the estimated exposed population is small. A low RSEI Score indicates low potential concern from reported TRI releases, but other kinds of environmental risk may also be present, including pollution from mobile sources like cars and trucks, hazardous waste, and unreported releases from facilities.
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.