Diffusion characteristics of indoor pollutants from incense sticks combustion in Tibetan Plateau buildings: An experimental study

Abstract

Incense burning, a common practice among ethnic Tibetans in Qinghai-Tibet Plateau of China, generates pollutants that can impact indoor air quality and, subsequently, human health. In this paper, we investigate the diffusion characteristics of four prevalent pollutants emitted during the burning of local Tibetan incense under low-pressure conditions specific to the plateau region. The diffusion behavior of these incense burning pollutants deviates from that observed under standard atmospheric pressure due to the unique conditions prevailing at high altitudes. The research results reveal that the primary pollutants released during Tibetan incense combustion are carbon dioxide, inhalable PM2.5, and PM10. Furthermore, ambient temperature exerts a substantial influence on the concentration of pollutants emitted during incense burning. A 6 °C increase in ambient temperature results in a 1.17-fold rise in the combustion rate. Consequently, higher temperatures correspond to larger diffusion coefficients, increased gas diffusion rates, and elevated pollutant concentrations at equivalent combustion times. Simultaneously, the low oxygen content characteristic of plateau regions has a notable impact on the diffusion rate of gaseous pollutants. This study of pollutant concentration and diffusion characteristics during incense burning offers valuable insights for determining the minimum ventilation rate in plateau areas.