Characteristics of Polychlorinated Dibenzo-p-dioxins and DibenzoFurans Emitted from Incense and Joss Paper Burned in Temples

• Main Authors: Ming Tsan, Hu, 胡明燦
• Other Authors: Shui-Jen Chen
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/10900348124669223872

博士 === 國立屏東科技大學 === 環境工程與科學系所 === 97 === Polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) did cause adverse health effects. However, PCDD/F emissions from burning incenses and joss papers in temples have seldom been addressed. Therefore, this study investigated PCDD/F and metal emissions from burning incenses in four temples (M, T, F and H) in south Taiwan. There were four sampling sites in temple M. Sites I-A and I-B were located inside the temple. The third sampling site was at the temple entrance (Site O). Site E was regarded to the environmental background. PCDD/F and metal samples were collected from stack flue gas of the furnace in temple T, F and H. PCDD/F emissions and profiles from burning joss paper in a temple H furnace were examined, and PCDD/F removals by two wet scrubbers was assessed. The results show that the PCDD/F emissions from burning incenses in temple M. It is found that the mean total PCDD/F concentrations reached 72.4–82.2 pg Nm-3 at two indoor sites, and their corresponding mean total PCDD/Fs I-TEQ concentrations (0.24–0.27 pg I-TEQ Nm-3) were ~11 times that of an environmental background location. For the air samples collected from burning incenses, the OCDF accounted for ~90% of total PCDD/Fs at the two indoor sites and the outdoor site near the temple, while the major PCDD/Fs in incense ashes were PCDDs. The total PCDD/F content and toxic equivalent value of incense ashes were 617 ng kg1 and 1.55 ng I-TEQ kg1, respectively. At the three sites inside/outside the temple, the air and ash samples exhibited the same four primary PCDD/Fs (OCDD, 1,2,3,4,6,7,8-HpCDD, OCDF and 1,2,3,4,6,7,8-HpCDF). The Cl emission factor (related to the PCDD/F formation) from burning incenses was 0.454 mg g1. The resultant lifetime average daily dose and excess cancer risk for the temple workers (0.00570 pg I-TEQ d-1 kg-1 and 5.70×10-6, respectively) were approximately two times that for residents near the temple (0.00330 pg I-TEQ d-1 kg-1 and 3.30×10-6, respectively). We strongly suggest that the chlorine content in incense must be regulated, and the high risk of PCDD/F exposure from burning incense for temple workers and visitors should be concerned. A popular temple equipped with a mid-size furnace (denoted as Temple T) and a small-size one located in a rural area (denoted as Temple F) were investigated. It was found that the mean total I-TEQ contents in the original (unburned) joss paper from Furnaces 1 and 2 were 1.41 and 4.51 ng I-TEQ kg-1, respectively. The mean total I-TEQ content in the residue of burned joss paper from Furnace 1 (7.97 ng I-TEQ kg-1) was approximately 15-fold that of Furnace 2 (0.490 ng I-TEQ kg-1). OCDD was the most abundant congener in the joss paper and in the residues from burned joss paper. Moreover, the emission factor of total PCDD/Fs I-TEQ content of Furnace 1 (176 μg I-TEQ Ton-feedstock-1) was one to two orders of magnitude higher than that of Furnace 2 (20.3 μg I-TEQ Ton-feedstock-1). This phenomenon is probably associated with the high chlorine content in the unburned joss paper of Furnace 1, and high exhaust temperature from burning joss paper in Furnace 1 (271 oC) was possibly within a range that might highly promote PCDD/F formation by de novo reaction. It is necessary for the investigated furnaces to install air pollution control devices in order to reduce the PCDD/F emissions from joss paper burning. Temple H furnace connected two wet scrubbers. The mean total PCDD/F content and corresponding toxic equivalent quantity (TEQ) in joss paper were 193 ng kg1 and 0.645 ng I-TEQ kg1, respectively, whereas those in bottom ash from burned joss paper were 18.5 ng kg-1 and 1.92 ng I-TEQ kg-1, respectively. The wet scrubbers decreased individual PCDD/F emissions by 26.7–71.0% and those of total PCDD/Fs and I-TEQ by 47.2% and 66.0%, respectively. The total PCDD/F I-TEQ emission factors before and after the wet scrubbers were 8.14 and 3.42 μg I-TEQ ton-feedstock-1, respectively. The estimated total PCDD/F and corresponding TEQ emissions were 6.39 g year-1 and 0.651 g I-TEQ year-1, respectively, in Taiwan. Burning joss paper in temple furnaces is a significant source of PCDD/F emissions. Although the wet scrubbers reduced PCDD/F emissions from burning joss paper, their PCDD/F removal efficiencies must be improved. Other devices for controlling air pollution with enhanced PCDD/F removal efficiencies are required for temples in which joss paper is burned frequently. Thus, based on their toxic effects, PCDD/F emissions from burning joss paper are a health concern in Taiwan. We suggest that air pollutant control devices are necessary for the temples in which joss paper is burned frequently to reduce harmful emissions that adversely affect resident health.