Compilation of Published PM2.5 Emission Rates for Cooking, Candles and Incense for Use in Modeling of Exposures in Residences

A recent analysis of health impacts from air pollutant inhalation in homes found that PM_2.5 is the most damaging at the population level. Chronic exposure to elevated PM_2.5 has the potential to damage human respiratory systems, and may result in premature death. PM_2.5 exposures in homes can be mitigated through various approaches including kitchen exhaust ventilation, indoor pollutant source reduction, filtration of incoming ventilation air to reduce the entry of PM_2.5 from outdoors, or filtration of air within the living space. Analysis of the potential benefits and costs of various approaches can be accomplished using computer codes that simulate the key physical processes including emissions, dilution, ventilation, and removal processes. The largest sources of PM_2.5 in residences are entry from outdoors and emissions from indoor combustion. The largest indoor sources are tobacco combustion (smoking), cooking and the burning of candles and incense. Data on the magnitude of PM_2.5 and other pollutant emissions from these events and processes are required to conduct simulations for analysis.

The goal of this study was to produce a database of pollutant emission rates associated with cooking and the burning of candles and incense. The target use of these data is for indoor air quality modeling.

Potentially relevant data were identified through searches of relevant terms on citation indexing services that list peer-reviewed journal articles and by searching government-sponsored research reports. Studies that appeared to have relevant data were examined. When relevant data were identified, they were compiled into a master database that was used to produce distributions of emission rates (mass of pollutant emitter per unit time) related to various factors that impact emissions from cooking and food; these include food type, cooking temperature, oil type, cooking method, stove type, and others. The emissions data were aggregated into a database of cooking and candle burning emission rates for use in indoor air quality modeling.

Although many papers explore the impact of cooking on indoor air quality, only a few of them report PM_2.5 emission rate data and even fewer provide detailed cooking conditions. We collected cooking emission data for 541 cooking events from 13 studies. Through analysis of these data we found that the type of cooking device used (i.e. microwave vs. stove) and the type of cooking (cooking in the oven vs. cooking on the stovetop) resulted in distinctly different distributions of PM_2.5 emissions. The remaining cooking parameters that showed significant impacts on emissions during individual studies, such as fuel type of stove and cooking method, did not show significant differences in emissions when data from multiple studies were compared. Incense burning was shown to have higher PM_2.5 emissions than candle burning for the limited data available. This paper also includes an extensive annotated bibliography of studies that have examined indoor cooking and candle burning emissions, which can be useful for pollutant source research and assessments of indoor air quality.