Air pollutants from burning incense in a simulated home environment

The aim of this study was to compare the concentrations of air pollutants emitted from various types of commercial incense (Hsing-Shan, Wu-Chen, Liao, and smoke-free) in a simulated home environment. The changes in the following environmental factors were measured during 1 hour of incense burning: temperature, relative humidity, and concentrations of carbon monoxide (CO), total volatile organic compounds (TVOCs), formaldehyde (HCHO), and fine suspended particles (PM2.5). The mass proportions of carbon, hydrogen, nitrogen, and oxygen in each of the incenses were also analyzed. The results showed that the concentrations of HCHO produced by Hsing-Shan incense and TVOCs produced by Hsing-Shan and Wu-Chen incenses exceeded the indoor air quality standards in Taiwan. The concentrations of CO and PM2.5 produced by all types of incense evaluated met the national standards. Smoke-free incense had the lowest hydrogen-to-carbon ratio, which might explain why it produced lower concentrations of air pollutants than the other incenses. The use of smoke-free incense should be encouraged for burning at home.