What Areas in Our Region Are Affected by NOx Pollution?

This map shows the areas most impacted over time by nitrogen oxides (NOx) in the Puget Sound region. These are the areas that would benefit the most from diesel reduction projects.

NOx pollution comes from cars, trucks, trains, airports (indicated by the airplane icons on the map), and large industries (red circles on the map).

The map represents our best estimate of populations where three factors overlap: 1) disproportionate exposure to NOx pollution, 2) poorer health outcomes, and 3) economic or cultural barriers to taking part in air quality policy decisions. Not surprisingly, the map highlights the fact that areas close to major roadways or many large industrial facilities experience higher impacts from NOx pollution.

How This Map Was Made

To estimate the pollution levels in each census block group, we used information from our emission inventories, results from United States Environmental Protection Agency (EPA) models, and state traffic count data. We then applied a weighting factor that includes both demographic and health-based data.

Demographic data included: income, percent minority race, English language proficiency, percent of residents with a high school diploma, percent of households with a single female as the head of household, and age. Health data included health outcomes related to exposure to air pollutants (asthma hospitalization rates, chronic obstructive pulmonary disease (COPD) hospitalization rates; and cardiac-related hospitalization rates).