Air quality affects everyone. Every year, outdoor air pollution causes around 4.2 million premature deaths globally (WHO, 2018). Fine particulate matter (PM2.5) is so small that it can find its way into the lungs, then into the bloodstream, causing cardiovascular disease, respiratory disease, and cancer. Analyzing and understanding areas of concern helps decision makers protect people and the environment.

New air quality maps and layer, available in ArcGIS Living Atlas of the World, highlight important air quality patterns in the United States over a 19-year period (1998-2016). The layer is derived from NASA's Socioeconomic Data and Applications Center (SEDAC) and contains valuable information at many levels: states, counties, congressional districts, and 50km hexbins.

Esri's Living Atlas Policy Maps team created 10 maps from just 1 layer. In this story, the team members describe and explore patterns that answer 5 major questions.

How has air quality changed over time?
Where are areas with air quality that are concerning?
How is poor air quality related to poverty and minority populations?
Which year had the worst air quality?
How can we analyze air quality using population patterns?

The story ends with a gallery showing other air quality maps created from the new Living Atlas layer.