Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 May;31(3):769-782.
doi: 10.1111/ina.12765. Epub 2020 Nov 26.

Particulate matter emitted from ultrasonic humidifiers-Chemical composition and implication to indoor air

Chester J Lau  1 , Max Loebel Roson  1 , Keifer M Klimchuk  1 , Tania Gautam  1 , Boyang Zhao  1 , Ran Zhao  1
Affiliations

Particulate matter emitted from ultrasonic humidifiers-Chemical composition and implication to indoor air

Chester J Lau et al. Indoor Air. 2021 May.

Abstract

Household humidification is widely practiced to combat dry indoor air. While the benefits of household humidification are widely perceived, its implications to the indoor air have not been critically appraised. In particular, ultrasonic humidifiers are known to generate fine particulate matter (PM). In this study, we first conducted laboratory experiments to investigate the size, quantity, and chemical composition of PM generated by an ultrasonic humidifier. The mass of PM generated showed a correlation with the total alkalinity of charge water, suggesting that CaCO3 is likely making a major contribution to PM. Ion chromatography analysis revealed a large amount of SO42- in PM, representing a previously unrecognized indoor source. Preliminary results of organic compounds being present in humidifier PM are also presented. A whole-house experiment was further conducted at an actual residential house, with five low-cost sensors (AirBeam) monitoring PM in real time. Operation of a single ultrasonic humidifier resulted in PM2.5 concentrations up to hundreds of μg m-3 , and its influence extended across the entire household. The transport and loss of PM2.5 depended on the rate of air circulation and ventilation. This study emphasizes the need to further investigate the impact of humidifier operation, both on human health and on the indoor atmospheric chemistry, for example, partitioning of acidic and basic compounds.

Keywords: Indoor air quality; air circulation and ventilation; chemical analysis; household measurement; humidifier; indoor air pollutants; particulate matter.

PubMed Disclaimer

References

REFERENCES

    1. Lim SS, Vos T, Flaxman AD, et al. A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet. 2013;380:2224-2260.
    1. Leech JA, Nelson WC, Burnett RT, Aaron S, Raizenne ME. It’s about time: A comparison of Canadian and American time-activity patterns†. J Expo Anal Environ Epidemiol. 2002;12:427.
    1. Nazaroff WW, Weschler CJ.Indoor acids and bases. Indoor Air. 2020. April 17, 2020. https://onlinelibrary.wiley.com/doi/abs/10.1111/ina.12670. Accessed May 19, 2020
    1. Weschler CJ, Carslaw N. Indoor chemistry. Environ Sci Technol. 2018;52:2419-2428.
    1. Chen C, Zhao B. Review of relationship between indoor and outdoor particles: I/O ratio, infiltration factor and penetration factor. Atmos Environ. 2011;45:275-288.

Publication types

LinkOut - more resources