Humans spend approximately 80%-90% of their lives indoors. Studies have shown that indoor particulate matter (PM) negatively affects human health. Previous indoor PM measurements were performed in laboratories or “test-houses” without residents living inside, thus not being fully-representative of real living environments. Continuous long-term measurements in real houses are essential for assessing diurnal and seasonal changes as well as PM response to everyday human activities. In this study, we show 1-year long continuous measurements of PM in real residential homes using a prototype monitor (Portable Aerosol Spectrometer Dust Decoder, Model 11-D, Grimm Inc.). This instrument does not require chemicals, pumps, or radiation sources to operate, allowing long-term measurements of PM in residential households under unperturbed conditions. We looked at how cooking, cleaning, and other everyday activities affect indoor PM levels at three households in the Southeastern U.S from May 2019 to May 2020. Our study shows that oil-rich cooking releases more PM than methods like boiling or steaming, whereas cooking time does not necessarily play a distinctive role. Cooking intensity (e.g., high temperature) plays a role in the amount of PM despite the type of appliance used. In particular, intensive cooking holidays, such as Thanksgiving and Christmas, produce large amounts of PM (averaging around 20 micrograms per cubic meter throughout the experiment) even with proper ventilation. Compared to cooking, which produces more fine mode particles, cleaning with a vacuum cleaner produces more coarse mode particles. Other cleaning activities, such as spraying air freshener and using the dishwasher, produce elevated PM levels. Measurements during the COVID-19 social distancing period provide important insight on how human occupancy also affects indoor air quality. Our study reinforces the findings of previous research from simulated home environments and further provides a big picture on how authentic household diversity plays a role in indoor PM levels.

Long-term measurements of particulate matter in authentic residential households

ACS Fall 2020 Virtual Meeting

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