Levels of Selected Indoor Air Pollutants: A Case Study in a Residential Room with Incense Burning Practice

Abstract:

Incense burning is a significant source of indoor air pollution. In Vietnam, this practice is deeply rooted in cultural and religious traditions and is commonly observed in most households. Assessing the pollution levels associated with incense burning is essential for providing timely health recommendations to the public. This study conducted indoor air quality monitoring in a room in a residential property in Vinh Yen City, Vinh Phuc Province. This room is designated for ancestor worship, with frequent practice of incense burning. PM_2.5, NO_2, and O₃ were monitored continuously using AQMesh sensors from December 22, 2021, to February 18, 2022. The mean and standard deviation of hourly indoor PM_2.5, NO₂ and O₃ concentration during whole monitoring period were 59 ± 50 µg/m³, 24 ± 13 µg/m³, 9 ± 5 µg/m³, respectively. Indoor to outdoor (I/O) ratios of the three parameters were lower than 1 for most of the study period, indicating that outdoor sources were generally dominant. The I/O ratio of PM_2.5 rose above 1 during incense burning periods and for some time afterward, indicating a dominant contribution from indoor sources. Six PM_2.5 pollution events were recorded during incense burning periods, with the average peak hourly concentration of indoor PM_2.5 reaching 571 µg/m³, while outdoor concentrations remained largely unchanged. These findings highlight the substantial impact of incense burning on indoor air quality and emphasize the need to raise public awareness about its potential health risks in residential environments.

• Periodical: Engineering Headway (Volume 40)
• Pages: 93-104
• DOI: https://doi.org/10.4028/p-0CKWqm
• Online since: July 2026
• Authors: Thi Hong Nhung Nguyen, Thi Thao Duong, Bich Thuy Ly*, Mark Broomfield, Thi Le Ha Vo
• Keywords: Incense Burning, Indoor Air Pollution, PM_2.5, Vietnam, Vinh Yen

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