This layer displays the toxicity-weighted concentrations of chemical releases to air from facility emissions and off-site incineration averaged over a three-year period (2012-2014).  Communities living near areas of routine chemical releases may bear a disproportionate burden to the pollution being released into the environment.  A detailed description is available here: https://fortress.wa.gov/doh/wtn/WTNPortal#!q0=4732