Characterization of the short-term temporal variability of road dust chemical mixtures and meteorological profiles in a near-road urban site in British Columbia
Creators: name: Coker, Eric S.
name: Turna, Nikita Saha
name: Schouwenburg, Mya
name: Jalil, Ahmad
name: Bradshaw, Charles
name: Kuo, Michael
name: Mastel, Molly
name: Kazemian, Hossein
name: Roushorne, Meghan
name: Henderson, Sarah B.
Publisher: name: Taylor & Francis
Year: 2023
Subjects: classificationCode: 59999
subject: Environmental Sciences not elsewhere classified
classificationCode: 39999
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences
classificationCode: 69999
subject: Biological Sciences not elsewhere classified

description: Springtime road dust is a common air quality concern for northern latitudes communities. Traction material, brake wear, tire wear, and other particles entrained in snow during winter become re-suspended into the air as the snow melts. Characterization of within-season variability of road dust composition and weather conditions is critical to understanding its acute health impacts. Sixty 24-hour samples of PM<sub>10</sub> were collected with a high-volume sampler at a near-road site in Prince George, British Columbia. Near-road samples were collected intermittently in winter and daily in spring. All samples were analyzed for 18 trace elements. We used data from a nearby regulatory monitor to estimate daily coarse fraction (PM<sub>10–2.5</sub>). Proportion of PM<sub>10–2.5</sub> in PM<sub>10</sub> was used to classify days as high or low road dust based on a threshold of 65% PM<sub>10–2.5</sub>. We identified clusters of near-road samples based on weather parameters and PM<sub>10</sub> components using Bayesian profile regression (BPR). Twenty-one near-road PM<sub>10</sub> samples were classified as high road dust days and 34 as low road dust days. Concentrations of total trace elements and specific trace elements were significantly higher on high road dust days (aluminum, chromium, iron, lead, tin, vanadium, and zinc). High road dust days also had low relative humidity and precipitation and higher temperature and air pressure. We identified five clusters of near-road PM<sub>10</sub> mixtures that suggested an interaction between temperature and humidity for road dust impacts. Samples from a near-road site indicated days highly affected by springtime road dust are distinct from other days based on particulate mixtures and meteorological factors. Higher loading of trace element mixtures in PM<sub>10</sub> on high road dust days has important implications for acute toxicity of road dust. Relationships between road dust and weather may facilitate further research into health effects of road dust as the climate changes. <i>Implications</i>: Non-tailpipe emissions driven by springtime road dust in northern latitude communities is increasing in importance for air pollution control and improving our understanding of the health effects of chemical mixtures from particulate matter exposure. High-volume samples from a near-road site indicated that days affected by springtime road dust are substantively different from other days with respect to particulate matter mixture composition and meteorological drivers. The high load of trace elements in PM<sub>10</sub> on high road dust days has important implications for the acute toxicity of inhaled air and subsequent health effects. The complex relationships between road dust and weather identified in this study may facilitate further research on the health effects of chemical mixtures related to road dust while also highlighting potential changes in this unique form of air pollution as the climate changes.