Emission of Dust and VOCs as Burning Incense Under Ventilation Conditions

This study determined emissions of incense burning, a traditional worship activity in Asian countries, under different ventilation conditions. The experiments were conducted in a chamber with a volume of 1 m3 (1´1´1 m3) without ventilation or under mechanical ventilation (6 m3/h). There were four different types of traditional and aromatic incense in terms of length (in centimeter) and color, including 27.0 cm (traditional Inc1 - yellow), 21.5 cm (aromatic Inc2 - brown), 30.0 cm (aromatic Inc3 - dark yellow) and 19.0 cm (traditional Inc4- dark red color). The incence was placed and lighted at 0.5 m in height inside of the chamber. PM10 and PM2.5 were directly monitored in the whole process of incense burning using Air Quality Detector (GM8803 and SIBATA - LD-5R) at the same position of 0.5m in height. VOCs was measured by chromatography at three different periods, i.e., before the incense was lighted, during the process of burning, and after the incense burned out. Study results showed that the variation of PM concentrations was separated into three phases: (p1) PM concentrations quickly increased within 15 minutes after being lighted, (p2) PM concentrations were stable from 20 minutes to 35 minutes, (p3) PM concentrations decreased gradually. The maxinum concentrations of PM10 without ventilation for Inc1, Inc2, Inc3, Inc4 were 2138, 2293, 2259, 2210 µg/m3, respectively; and they decreased about 40-70% under ventilation. The maxinum PM2.5 concentrations were about 870-1210 µg/m3 under ventilation or without ventilation. VOCs ended up no Benzen emissions with all the types of experimental incense. Inc1 emitted HCHO concentrations from 4.8 ppm to 5.4 ppm, which was one of the two types containing highest concentrations of Formaldehyde. Meanwhile, Inc3 emitted the lowest VOCs concentrations among the three remaining types, and no Toluen was detected, which showed the optimum effect of clean incense in comparison with traditional one. Key words: incense, VOC, particulate matter, ventilation, indoor pollution