Health impact reduction design strategies according to the circulation pattern of indoor PM _2.5 using computational fluid dynamics models

Humans spend approximately 80% of their lifetime indoors, exposing themselves to indoor pollutants for prolonged periods. There has been considerable focus on outdoor and indoor air pollution sources in academic research. However, the mechanism of PM 2.5 (particulate matter with a diameter of 2.5 µm or less) diffusion from outdoors to indoors, which governs indoor PM 2.5 distribution, has been significantly overlooked. Human behaviours, particularly window opening habits, have a critical impact on the distribution of indoor PM 2.5 concentration. We investigated the distribution of indoor PM 2.5 under different natural ventilation conditions; furthermore, we quantified the health risks associated with PM 2.5 inhalation. The results showed that natural ventilation modes have a substantial influence on the distribution of indoor PM 2.5 through the vortex end of airflows, especially at different window opening angles. The thermal convection effect induced by radiators shifts indoor airflow, resulting in altered distribution of dust PM 2.5 during winter. The excess carcinogenic risk for children due to indoor PM 2.5 exposure during non-heating periods was higher for boys (1.12 × 10 −6 ) as compared to girls (1.05 × 10 −6 ). This study provides a useful perspective on the health effects of indoor PM 2.5 pollution caused by dust aerosols on low-income groups.