Air Quality in the U.S.

5 policy mappers explore air quality patterns in 5 short videos

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.

Air pollution sources include factories, vehicle exhaust, dust, wildfires, pollen, and volcanoes.

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.

Air Quality Questions

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

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

#1: How has air quality changed over time?

Fine particulate matter (PM 2.5) is a major health risk. Because of this, the World Health Organization (WHO) set a guideline of no more than 10 micrograms per cubic meter on average annually. This goal aims to reduce air pollution deaths, particularly in cities. The first map shows which areas meet the target of 10 micrograms per cubic meter, and which areas do not meet the target on average over the 19-year study period.

The second map shows the statistical hot spots of PM 2.5 in the United States at 50 km hex bins. The dataset was run through a multidimensional space time cube and emerging hot spot analysis.


#2: Where are areas with air quality that are concerning?

The multi-scale map shows the counties and congressional districts with high levels of fine particulate matter (PM 2.5). Areas of concern are grouped into 5 categories, each with a different need for attention:

  • Areas where people have been exposed to high levels of PM 2.5 for a long time (Persistent Hot Spot)
  • Areas that have had high levels of PM 2.5 in recent years (Consecutive Hot Spot)
  • Areas in which high levels of PM 2.5 are intensifying (Intensifying Hot Spot)
  • Areas where high levels of PM 2.5 have been detected for the first time (New Hot Spot)
  • Areas that have had both high and low levels of PM 2.5, but high levels in recent years (Oscillating Hot Spot) 


#3: How is poor air quality related to poverty and minority populations?

The first map compares the relationship between air quality and the percent of minority populations.

The second map compares the relationship between air quality and the percent of households that are below the poverty level.


#4: Which year had the worst air quality?

This map shows which year had the worst air pollution according to fine particulate matter (PM2.5) air quality data for the United States between 1998 and 2016.


#5: How can we analyze air quality using population patterns?

This map depicts a population-weighted measure of particulate matter 2.5 (PM 2.5) for the US for 2016. The measure factors in where population is concentrated within a state or county to see which populations are most impacted.


Air Quality Gallery

The videos in the previous section only cover half the maps that were made with the  new air quality layer in Living Atlas . This gallery highlights different maps of air pollution trends. Find a map of interest, select it, and search for your location to learn more about the air quality in your area.


This story introduced the new air quality layer and maps in Living Atlas and the team shared map patterns and policy implications. Check out the maps and layer, and maybe even create a map to answer additional questions about air quality. If you'd like to do the analysis yourself, you can follow along with this helpful  Learn Lesson  on investigating pollution patterns with space-time analysis.


Related Links

Air pollution sources include factories, vehicle exhaust, dust, wildfires, pollen, and volcanoes.