Huxley College Graduate and Undergraduate Publications

College Affiliation

Huxley College of the Environment


Particulate matter (PM) air pollution is a major public health issue across the United States. PM air pollution is sourced from a variety of industrial, transportation, and fuel combustion processes (EPA 2016). Through increases in regulation standards, PM air pollution has been gradually decreasing over the past twenty years (Appendix 1.1). Between 1990 and 2011 air toxins and toxicants in the United States decreased by over 60% according to the EPA (2016). Unhealthy air quality days, caused by ozone and particulate matter 2.5 microns (PM2.5), also decreased from 2,076 days in 2000 to 675 days in 2014 (EPA 2016). Many of these reductions have been from changes in the National Ambient Air Quality Standards (NAAQS) through the Environmental Protection Agency (EPA). Unfortunately, EPA’s PM2.5 health standard goals still are not being met. In the Puget Sound region, three counties are still exceeding NAAQS PM2.5 standard goals (PSCCA 2014). While the EPA’s most recent air quality assessment has shown positive results in air quality mitigation (Appendix 1.2), the results fail to recognize the continued public health issues and disparities of air pollution in neighborhoods within cities. Research has shown less affluent communities and communities of color are exposed to higher levels of air pollution than the wealthier and whiter communities (Bell 2012). This trend is clearly shown in Seattle, Washington.

Document Type

Honors Senior Project

Subject – LCSH (for OAI)

Trees in cities--Effect of pollution on--Washington (State)--Seattle--Measurement; Air--Pollution--Washington (State)--Seattle--Measurement

Geographic Coverage

Seattle (Wash.)


Western Washington University



First Advisor

Abel, Troy D.

OCLC Number



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