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.
Assisted Housing Resident Characteristics, HUD
This layer displays information about public housing unit residents who are disabled, single parents, or elderly. Data are available in percentage and total number. Additional measures are available which show public housing and housing choice vouchers, and can also displayed by county or by unit.
Population Living in Rural Areas
This layer displays percent of population living in rural areas as of 2020. This data was released as part of the decennial census in April 2020. Learn more about this dataset at Census.gov.
EJ Screen Traffic Proximity
The traffic proximity indicator is based on AADT count divided by distance in meters from the Census
block centroid. The proximity score is based on the traffic within a search radius of 500 meters (or
further if none is found in that radius). This distance was selected to be large enough to capture the
great majority of road segments (with traffic data) that could have a significant impact on the local
residents, balanced against the need to limit the scope due to computational constraints. The closest
traffic is given more weight, and the distant traffic is given less weight, through inverse distance
weighting. For example, traffic 500 meters away is given only one tenth as much weight as traffic 50
meters away.
Preventable Hospitalization by County, Medicare Population, 2021
This layer displays the total number and rate of preventable hospitalization events among Medicare beneficiaries. Preventable hospitalizations include hospital admissions for one or more of the following conditions: diabetes with short-term complications, diabetes with long-term complications, uncontrolled diabetes without complications, diabetes with lower-extremity amputation, chronic obstructive pulmonary disease, asthma, hypertension, heart failure, bacterial pneumonia, or urinary tract infection. Rates are presented per 100,000 beneficiaries.
Population Living in Urban Areas
This layer displays percent of population living in urban areas as of 2020. Urban areas are identified using population density, count, and size thresholds. This data was released as part of the decennial census in April 2020. Learn more about this dataset at Census.gov.
EJ Screen RMP Facility Proximity
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
Breast Cancer Screening (Mammogram), by County, Medicare Population, 2021
This layer displays the percentage of Medicare beneficiaries who received a mammography in the latest report year (2020).
Vacant Housing Units
This layer displays information from the US 2020 Decennial Census, which provides vacant housing units for all geographic areas. A vacant Housing Unit is when no one is living in it at the time of the interview, unless its occupants are only temporarily absent. This data was released as part of the decennial census in April 2020. Learn more about this dataset at Census.gov.
Influenza Vaccination by County, Medicare Population, 2021
This layer displays the percentage of Medicare beneficiaries who received a mammography in the latest report year (2020).