Indoor distribution and personal exposure of cooking-generated PM2.5 in rural residences of China: A multizone model study

The fine particulate matter (PM2.5) emitted during cooking is a significant contributor to household air pollution in rural China, resulting in millions of premature deaths annually. Since cooking is an internal pollution source, the indoor concentration of cooking-generated PM2.5 can vary among different rooms in multizone rural residences. This study provides a comprehensive understanding of indoor PM2.5 from cooking in rural residences by utilizing on-site investigations to gather information on cooking behavior and dwelling layout in three Chinese villages, and subsequently simulating indoor spatiotemporal concentrations of cooking-generated PM2.5 using a multizone model. Our findings indicate that the type of zone significantly influences the zonal concentration of PM2.5, with the highest concentrations found in kitchens (i.e., 13.9 to 188.0 μg/m³) and lowest in non-adjacent zones to the kitchen (i.e., 0.01 to 7.5 μg/m³) among all the modeled conditions. More importantly, the study also assesses the resulting personal exposures for occupants with different time-spent patterns, revealing that the main cook at home and preferring to stay in the adjacent rooms to the kitchen are at the highest risk for personal exposure. The highest personal exposure levels of cooking-generated PM2.5 are 28.5 ± 30.1 μg/m³, which is 34 times that of occupants who stay away from the kitchen. The study provides a deeper scientific insight into the indoor spatial distribution and personal exposure to cooking-generated PM2.5 in rural residences, which is crucial for developing effective interventions to mitigate the detrimental health impacts of household air pollution in rural areas.