The quality of the air we breathe is a significant indicator of a healthy environment. The US Environmental Protection Agency calculates an Air Quality Index for each day. This index looks at five major pollutants (ground-level ozone, particle pollution, carbon monoxide, sulfur dioxide, and nitrogen dioxide) and gives each day a grade. Sustainable wants the more days graded ‘Good’ or ‘Moderate’.
Source: Air Quality Trends and Non-Attainment Status for Northeast Ohio - Northeast Ohio Areawide Coordinating Agency