Evaluating city road dust emission characteristics with a dynamic method: A case study in Luoyang, China

Road dust, a significant contributor to non-exhaust particulate matter emissions in urban transport, poses considerable health risks, necessitating accurate and high-resolution data for effective control. The traditional AP-42 method offers data on point-specific dust emissions, while vehicle-based testing ascertains the relative emission intensity in the road network. However, a clear mathematical relationship between these measurements has been elusive, limiting efficiency in emission control. By integrating the On-board Conventional Pollutant Monitoring System with the AP-42 method, we devised a dynamic link between the concentration of particles in vehicle plumes and actual road dust emissions. This relationship is substantiated by a notable correlation (R2 = 0.91) between our emission factors and those calculated using the AP-42 method. Significant variations emerged in dust emission factors across road types, with changes between-30.1 % to +57.79 % from the average (0.05 g & BULL;vehicle- 1 & BULL;km-1), in tandem with traffic flow fluctuations of approximately & PLUSMN;90 %. Meteorological factors, except for continuous rainfall, showed minimal impact on dust emissions. However, our findings revealed a significant underestimation (58.87 %) of road dust PM10 emissions by the AP-42 method. Intriguingly, we found that short-range emission hotspots substantially contribute to total emissions, suggesting a potential 50 % reduction by controlling merely 8.8 % & PLUSMN; 2.5 % of the total road length. Our research elucidates the interplay between road dust emissions, road types, and human activities. The application of a dynamic, high-resolution assessment method enhances our understanding of the impacts of road dust on urban particulate pollution, al-lows accurate hotspot identification, and aids in developing efficacious strategies for air quality enhancement.

Automated summary

Road dust, a significant contributor to non-exhaust particulate matter emissions in urban transport, poses considerable health risks. By integrating the On-board Conventional Pollutant Monitoring System with the AP-42 method, we devised a dynamic link between the concentration of particles in vehicle plumes and actual road dust emissions. Our research elucidates the interplay between road dust emissions, road types, and human activities, enhancing our understanding of the impacts of road dust on urban particulate pollution.