The Puget Sound Maritime Air Emissions Inventory quantifies maritime-related emissions from pollutants, relevant U.S. Environmental Protection Agency criteria pollutants and precursors, including carbon monoxide (CO), nitrogen oxide (NOx), sulfur dioxides (SO2), volatile organic compounds (VOC), and fine particulate matter (PM2.5), as well as greenhouse gases (CO2e), diesel particulate matter (DPM), and black carbon (BC). The 2020 NWPCAS focuses primarily on DPM, because of the harmful impacts to human health, and greenhouse gas emissions to address climate change.