Scorecard shows comparative information on four specific environmental burdens, chosen because data on these four are available for every area in the U.S. It shows comparative impacts on each of seven demographic groups, chosen because the U.S. Census provides data on the population of each of those groups in every area in the U.S. Combined, these data make up the most detailed and comprehensive information that is available for every area of the country. However, these data do not and cannot provide a complete picture for purposes of environmental justice analysis. Keep in mind that:
- Four environmental burdens do not represent all potential impacts of all environmental conditions. For example, the cancer risk statistic for hazardous air pollutants does not account for other health risks from air pollutants, such as birth defects, asthma, etc., or for health risks from water, etc. See separate discussions of each burden.
- The units of measurement for each environmental burden are not perfect indicators of actual impact. For example, the distance that a person lives from a Superfund site may or may not be a good indicator of actual exposure to harm from that site, depending on circumstances that vary from site to site. See separate discussions of each burden.
- The accuracy of each measurement is not perfect. Accuracy considerations are different in each case, see separate discussions of each burden.
- Comparisons made within standard geographic areas may not reveal disparities in communities that do not correspond with standard areas. Scorecard shows comparative data for every U.S. county and for every U.S. state. For example, disparities could exist between neighborhoods within a county, or in neighborhoods that span two or more counties, which county-level data might not disclose. See how to get data at the most local level.
- The age of the data varies. Demographic data is from the 1990 U.S. Census and therefore does not show changes since 1990 in the population makeup of any particular area. See also separate discussions of each burden.
- Numerical differences in the measurement of a particular impact may or may not be significant. If one group lives an average distance of 4.0 miles from the nearest Superfund site, and another lives an average distance of 4.1 miles, Scorecard will show a numerical difference, whether or not that difference would ever be claimed by anyone to demonstrate that the two groups experience actual disparate impacts from Superfund sites.