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EJSCREEN: Environmental Justice Screening and Mapping Tool

Overview of Environmental Indicators in EJSCREEN

EJSCREEN provides 11 environmental indicators:

Summary Table of Environmental Indicators and Data Sources
Key Medium Indicator Details Source Data Year
Air National-Scale Air Toxics Assessment (NATA) air toxics cancer risk Lifetime cancer risk from inhalation of air toxics EPA NATA 2011
Air NATA respiratory hazard index Air toxics respiratory hazard index (ratio of exposure concentration to health-based reference concentration) EPA NATA 2011
Air NATA diesel PM Diesel particulate matter level in air, µg/m3 EPA NATA 2011
Air Particulate matter PM2.5 levels in air, µg/m3 annual avg. EPA, Office of Air and Radiation (OAR) fusion of model and monitor data 2013
Air Ozone Ozone summer seasonal avg. of daily maximum 8-hour concentration in air in parts per billion EPA, OAR fusion of model and monitor data 2013
Air/other Traffic proximity and volume Count of vehicles (AADT, avg. annual daily traffic) at major roads within 500 meters, divided by distance in meters (not km) Calculated from 2014 U.S. Department of Transportation (DOT) traffic data, retrieved 2016 2014
Dust/ lead paint Lead paint indicator Percent of housing units built pre-1960, as indicator of potential lead paint exposure Calculated based on Census/American Community Survey (ACS) data, retrieved 2015 2011-2015
Waste/ air/ water Proximity to Risk Management Plan (RMP) sites Count of RMP (potential chemical accident management plan) facilities within 5 km (or nearest one beyond 5 km), each divided by distance in kilometers Calculated from EPA RMP database, retrieved 03/2017 2017
Waste/ air/ water Proximity to Treatment Storage and Disposal Facilities (TSDFs) Count of TSDFs (hazardous waste management facilities) within 5 km (or nearest beyond 5 km), each divided by distance in kilometers Calculated from EPA RCRAInfo database, retrieved 01/2017 2017
Waste/ air/ water Proximity to National Priorities List (NPL) sites Count of proposed or listed NPL - also known as superfund - sites within 5 km (or nearest one beyond 5 km), each divided by distance in kilometers Calculated from EPA CERCLIS database, retrieved 12/05/2016 2016
Water Wastewater Dischargers Indicator (Stream Proximity and Toxic Concentration) RSEI modeled Toxic Concentrations at stream segments within 500 meters, divided by distance in kilometers (km) Calculated from RSEI modeled toxic concentrations to stream reach segments, created 01/2017 2017

Note: EJSCREEN’s EJ Indexes also include demographic information that is obtained from the U.S. Census Bureau’s American Community Survey (ACS). The 2017 version of EJSCREEN includes 2011-2015 ACS 5-year summary file data, which is based on 2014 Census boundaries.

It is important to understand what each of these is measuring or indicating, in order to use EJSCREEN appropriately. There are important caveats and limitations to these screening-level indicators and anyone using EJSCREEN is encouraged to read these carefully.

Read more information about Environmental Indicators (PDF)(123 pp, 1 MB, About PDF), including documentation of data sources.

Some of these environmental indicators quantify proximity to and the numbers of certain types of potential sources of exposure to environmental pollutants, such as nearby hazardous waste sites or traffic. The lead paint indicator indicates the presence of older housing, which often, but not always, indicates the presence of lead paint, and therefore the possibility of exposure. In some cases, the term "exposure" is used very broadly here to refer to the potential for exposure. Others indicators in EJSCREEN are estimates of ambient levels of air pollutants, such as PM2.5, ozone and diesel particulate matter. Still others are actual estimates of air toxics-related cancer risk or a hazard index, which summarizes the ratios of ambient air toxics levels to health-based reference concentrations. In other words, these environmental indicators vary widely in what they indicate.

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