Welcome to the Agency’s Community Air Tool (CAT). This tool helps identify and prioritize communities that face multiple impacts including air pollution sources, pre-existing health conditions and vulnerabilities, and socioeconomic factors like race and income. This interactive map compares communities within the Puget Sound region (King, Kitsap, Pierce, and Snohomish Counties).

What makes this map different from other environmental justice maps?

The Community Air Tool (CAT) focuses specifically on air quality. Unlike other environmental justice maps, it uses health data related to air pollution risks—like asthma hospitalizations—and includes only air quality information, not factors like water quality, hazardous waste, or noise pollution. We use this tool in conjunction with other environmental justice maps that together define our overburdened communities (see below).

More details about the CAT

The latest version of the CAT can be found here, along with its metadata.

Originally conceptualized in 2012, the CAT Version 3 has updated datasets and includes minor revisions. We plan to continue to update the tool every six years as newer census data and other data become available.

How the CAT Works 

At its core, the CAT integrates data from 13 categories to assess impacts in different communities. These include socioeconomic indicators, types of nearby air pollution sources, and hospitalization data. Each category is scored to reflect the air pollution-related cumulative impacts present within a given census block group.

The CAT data sources include the Washington State Department of Health's Comprehensive Hospital Abstract Reporting System (CHARS) hospitalization data, Washington State Department of Transportation’s freight data, US Census data, and Puget Sound Clean Air Agency’s registered source records.

To make the tool easier to use, the CAT uses a quartile classification system that scores categories from “0” (least impact) to “3” (highest impact) for census block groups.

The CAT and the Agency’s Strategic Plan

We used the CAT along with 3 other maps (listed below) to update the Agency Overburdened Communities designation for our PSCAA 2030 strategic plan: 

• WA Environmental Health Disparities Map
• WA Climate Commitment Act Overburdened Communities Map
• Climate and Environmental Justice Screening Tool Disadvantage Communities Map

For more details, contact the Agency’s Technical Analysis Manager. You can access the shapefile here.