Residential cooking-related PM_2.5: Spatial-temporal variations under various intervention scenarios

Some cooking events can generate high levels of hazardous PM_2.5. This study assesses the dispersion of cooking-related PM_2.5 throughout a naturally-ventilated apartment in the US, examines the dynamic process of cooking-related emissions, and demonstrates the impact of different indoor PM_2.5 mitigating strategies. We conducted experiments with a standardized pan-frying cooking procedure under seven scenarios, involving opening kitchen windows, using a range hood, and utilizing a portable air cleaner (PAC) in various indoor locations. Real-time PM_2.5 concentrations were measured in the open kitchen, living room, bedroom (door closed), and outdoor environments. Decay-related parameters were estimated, and time-resolved PM_2.5 emission rates for each experiment were determined using a dynamic model. Results show that the 1-min mean PM_2.5 concentrations in the kitchen and living room peaked 1-7 min after cooking at levels of 200-1400 μg/m³, which were more than 9 times higher than the peak bedroom levels. Mean (standard deviation) k for the kitchen, ranging from 0.58 (0.02) to 6.62 (0.34) h^-1, was generally comparable to that of the living room (relative difference < 20%), but was 1-5 times larger than that of the bedroom. The range of PM_2.5 full-decay time was between 1-10 h for the kitchen and living room, and from 0 to > 6 h for the bedroom. The PM_2.5 emission rates during and 5 min after cooking were 2.3 (3.4) and 5.1 (3.9) mg/min, respectively. Intervention strategies, including opening kitchen windows and using PACs either in the kitchen or living room, can substantially reduce indoor PM_2.5 levels and the related full-decay time. For scenarios involving a PAC, placing it in the kitchen (closer to the source) resulted in better efficacy.