Temporal distribution of environmental pollutants in high-occupancy buildings transitional spaces and exposure risk assessment for different flow paths

As urbanization progresses, high-occupancy buildings have become the predominant urban residential form, but their transitional spaces may pose significant health risks. This study examines the temporal distribution of physical and chemical pollutants in these spaces and assesses exposure risks associated with resident flow. The results showed that the distribution of PM_2.5, PM₁₀, Total Volatile Organic Compounds (TVOC), and ozone is closely linked to residents' cooking and smoking behaviors, significantly increasing health risks on the same floor. Frequent carbon monoxide exceedances in elevator cars also indicates serious risks. The architectural design of transitional spaces shows efficacy in mitigating pollutants, with reductions of 9.8 %, 13.4 %, 36.5 %, and 90.4 % for PM_2.5, PM₁₀, TVOC, and ozone, respectively, from the apartment entrance to the foyer. Airflow patterns in the stairwell impact ozone and TVOC distribution, with pollutant molecular weight and reactivity being key factors in accumulation. This study used Bayesian Model Averaging (BMA) to develop an exposure risk assessment model, identifying noise, TVOC, and ozone as the primary risk factors of the apartment building. In elevator car (high-risk area), noise and TVOC accounted for 5.1 % and 94.9 % of the independent risk, respectively. Additionally, the synergistic effects of multiple pollutants at apartment entrance were significant, contributing 16.8 % to overall risk and further exacerbating health hazards. Flow path analysis indicated the highest exposure risks during elevator use, emphasizing the need for improved ventilation systems. These findings provide a scientific basis for optimizing apartment environments, assessing exposure risks, and promoting sustainable building designs that prioritize health.