Pollutant Dispersion in and Around Buildings: A Critical Review of Modelling, Mitigation, and Future Opportunities

Manash Jyoti Gogoi

Abstract: Pollutant dispersion in and around buildings is governed by the coupled behavior of atmospheric flow, building aerodynamics, ventilation, source characteristics, and pollutant-specific transport processes. Openings, leakage, air intakes and exhausts cause an interaction between outdoor pollution and indoor emissions, resulting in spatially heterogeneous and time-dependent concentrations. This narrative review summarizes experimental and numerical studies on pollutant sources, transport, modelling, measurement and exposure mitigation. Additionally, it focuses on validation against wind-tunnel, tracer-gas, and field measurements. It compares Reynolds-averaged Navier-Stokes (RANS), large-eddy simulation (LES), and transport-based recurrence computational fluid dynamics (CFD), and it also compares URANS. The reviewed literature shows that the prediction accuracy depends on inflow turbulence, source representation, geometry, numerical resolution, atmospheric stability, validation targets and turbulence closure. While RANS provides an affordable alternative for engineering evaluation when necessary, LES can remove the effects of unsteady transport and concentration fluctuations; neither is dependable without application-specific validation and verification. The indoor-outdoor coupling concept is effective depending on facade concentration, wind direction and opening configuration and shows dilution of indoor emissions and increased intake of outdoor air pollution. These modelling limitations are connected to sensor placement, exposure assessment, and energy-air-quality trade-offs through the synthesis. The review does not provide complete coverage or combined effect estimates, as the literature collection was not achieved by a documented systematic search. Priorities include reproducible benchmarks, uncertainty-aware validation, indoor-outdoor models by pollutant, and ventilation and filtration controls based on occupant exposure, energy demand, and robustness of operations.

Keywords: pollutant dispersion, indoor air quality, building aerodynamics, computational fluid dynamics, air-quality management