Experimental study of exposure to cooking emitted particles under single zone and two-zone environments

Cooking is a major indoor pollutant source. It is important to know the exposure not only inside but also outside the kitchen. However, the spatial distribution of particle concentration in two indoor zones has not been studied extensively. Therefore, this study investigated particle transport between two zones for a water boiling process under four kitchen hood operation scenarios. Particles were counted using a condensation particle counter; since most of the particles were less than 100 nm in diameter, the study may be considered a study of ultrafine particles. If the range hood operates during the cooking period, or both during and after the cooking period, exposures can be substantially reduced. For the single zone scenario (connecting door closed), operation of the hood during the cooking period reduces exposure by 87-92%, compared to the no-hood operation. When the door between the two zones is opened and the hood is not operated, the exposure in non-kitchen zone ranged from 30% to 54% of that near the stove. Strong exhaust airflow from the kitchen hood interacted with the ventilation airflow, generating complex airflow which resulted in varying concentrations at different points in the kitchen zone. Under the scenario with the range hood off both during and after cooking, comparing at point nearest the stove, the exposure at the other points ranges from 65 to 90% while under the range hood on both during and after cooking scenario, the exposure ranges from 30 to 90%.