What is black carbon? Black carbon, commonly known as soot, is produced by the incomplete combustion of wood and fossil fuels. Once created, black carbon remains in the atmosphere for days to weeks, affecting climate and human health. Because black carbon is an effective light absorber, it contributes to climate change by exacerbating the warming of the air and surfaces where it is concentrated.
Black carbon is a component of fine particulate matter, which is the main air pollutant in Spokane. Fine particle pollution is emitted primarily from combustion-related activities. Because of their microscopic size, fine particles are deeply inhaled into the lungs and the bloodstream.
With federal and state grant funding, Spokane Clean Air conducted a study to identify black carbon “hotspots” in two Spokane neighborhoods: East Central and Chief Garry Park. These two areas were selected based on population density and proximity to major traffic routes. During the winters of 2023 and 2024, staff conducted mobile sampling using equipment mounted on an agency vehicle. The ideal sampling conditions were cold and calm winter evenings.
The study results indicate that emissions from wood burning likely contribute more significantly to total PM2.5 (and thus black carbon) emissions than from transportation. This information is helpful as Spokane Clean Air looks to secure additional state grant funding to replace older wood stoves across Spokane County.
In the future, Spokane Clean Air may conduct additional black carbon monitoring at fixed stations to further analyze the relative contributions of emission sources to PM2.5, depending on the availability of grant funding. These types of studies help Spokane Clean Air identify new and evaluate existing programs aimed at reducing air emissions.
