Fugitive Road Dust PM_2.5 Emissions and Their Potential Health Impacts

Fugitive road dust (FRD) particles emitted by traffic-generated turbulence are an important contributor to urban ambient fine particulate matter (PM_2.5). Especially in urban areas of developing countries, FRD PM_2.5 emissions are a serious environmental threat to air quality and public health. FRD PM_2.5 emissions have been neglected or substantially underestimated in previous study, resulting in the underestimation of modeling PM concentrations and estimating their health impacts. This study constructed the FRD PM_2.5 emissions inventory in a major inland city in China (Lanzhou) in 2017 at high-resolution (500 × 500 m²), investigated the spatiotemporal characteristics of the FRD emissions in different urban function zones, and quantified their health impacts. The FRD PM_2.5 emission was approximately 1141 ± 71 kg d^-1, accounting for 24.6% of total PM_2.5 emission in urban Lanzhou. Spatially, high emissions exceeding 3 × 10⁴ μg m^-2 d^-1 occurred over areas with smaller particle sizes, larger traffic intensities, and more frequent construction activities. The estimated premature mortality burden induced by FRD PM_2.5 exposure was 234.5 deaths in Lanzhou in 2017. Reducing FRD emissions are an important step forward to protect public health in many developing urban regions.