Spatial distribution of PM 2.5 concentration around high-rise residential buildings during peak traffic hours in autumn and winter seasons

This research aimed to investigate the spatial distribution of PM 2.5 in residential areas near major urban roads during the autumn and winter seasons. A traffic pollution distribution model was developed using ENVI-met software to predict the distribution of pollution in and around the residential area. The experimental results indicated that during peak hours, the concentration of PM 2.5 inside the residential area exceeded 140 μg/m 3 . The simulations indicated a horizontal diffusion range of traffic pollution up to 300 m, with the most significant effects observed within a radius of 20 m where the pollutant concentration decreased from 131.6 μg/m 3 to 93.5 μg/m 3 . The vertical diffusion of traffic pollution extended to approximately 100 m, with the highest impact observed within a distance of 22.5 m (7 floors). Furthermore, pollution diffused up to a height of 47.5 m near major urban roads, resulting in a decrease in the concentration of PM 2.5 from 140 μg/m 3 to 70 μg/m 3 . Quantitative comparisons showed that street pollution was higher in autumn than in winter, whereas pollution outside buildings near the street was higher in winter compared to autumn. Simultaneously, the impact of pollutants on human health was evaluated using the decrease in life expectancy (DLE) index. The results revealed a DLE of 13.16 years in areas with the highest pollution levels, while most residential areas had a DLE ranging between 3.2 and 3.88 years. These findings are significant in terms of raising awareness and providing valuable references for the development and planning of urban health initiatives.