EPA EJ Hot Spots Mapping Tool

The U.S. EPA's "Plan EJ 2014" is a road map for incorporating the needs of poor, minority and overburdened communities in the government's day-to-day activities. Enter EJ Screen is an EPA mapping tool designed to help the agency spot pockets of people whose health has suffered disproportionally over the years because of environmental factors. The database uses census data, poverty levels, toxic emissions and documented pollution events to assign a score to 217,000 geographic "block groups" around the country. The program represents both the advances and the limitations of EPA's effort to bring clarity to the environmental justice effort.

EJ Screen overlays minority and low-income demographics on a map of 217,000 block groups, each having 500 to 5,000 people. (An alternative method under consideration includes additional demographic data including the percentage of people in a block group with less than a high school education, the percentage who speak English, and the number under the age of 5 and over the age of 64.)

EPA then puts that information over a map of environmental factors.  Among the 12 factors EPA has selected for its first version of EJ Screen is air pollution -- including ozone levels and soot from diesel exhaust and smokestacks. The agency also includes data on a community's proximity to environmental hazards including Superfund dumps, water discharge facilities, high traffic areas and buildings built before 1960 that have a high risk for lead paint.

The result is a graphic illustration showing each block group's ranking nationwide for each environmental factor. And the maps can also be used to show how block groups compare by state or by region when it comes to each factor.

But the maps are also limited, EPA. They don't, for example, combine all the environmental factors to show cumulative impacts. For instance, how does one scientifically weigh a person's proximity to a lead paint structure against exposure to particulate matter in the air?  (E&E Publishing, 7/27/2012)