A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science Inter-University Program on Environmental Toxicology, Technology and Management, School of Environment, Resources and Development

Thesis (M.Sc.) - Asian Institute of Technology, 2006

Exposure to particulate bound PAHs emitted from incense sticks was an area of interest for study, because some PAHs have been classified as human carcinogens. The main objective of this study was to determine the characteristics of PAHs emitted from incense sticks and human exposure in temples. This study comprised two parts: a laboratory setting study and a field study. Comparing the potential PAHs pollution level emitted from incense sticks and cigarettes in the experimental set-up, total PAHs of Thai and Myanmar incense brands and cigarettes were 40.73 ± 8.43 ug/m3, 137.10 ± 36.68 g/m3 and 32.89 ± 2.82 g/m3 respectively and emissions of incense sticks were statistically significantly higher than those of cigarettes (P< 0.001). The most abundant PAHs in Thai and Myanmar incense brands were fluoranthene and Benzo(ghi)perylene (BghiP) respectively. The main carcinogenic Benzo (a)pyrene (B(a)P) found showed a difference between Thai incense sticks and cigarettes in the mean emission level, approximately one and half fold higher than cigarettes and the highest level in Thai incense brand was 1.37 pg/m3 and 0.87gg/m3 in cigarette. Myanmar incense brands were approximately two to three fold higher than cigarette (P< 0.01) and the highest mean emission level of B(a)P was 2.38 g/m3. In comparing PAHs emission per minute, the emission of PAHs from Thai incense brands were lower compared to those of cigarettes. But, Myanmar incense brands were still much higher than cigarettes. The emission patterns of PAHs between incense brands and cigarettes were more or less similar to each other. To detect the actual exposure of PAHs emitted from incense sticks, the field study was conducted. The ambient total PAHs level of temples was 18.02±10.76 .tg/m3 and it was statistically significantly higher than those of non-exposed areas 1.44±0.45 (P< 0.01). The most abundant PAHs in temples were chrysene, (BghiP) and fluoranthene. The main carcinogenic B(a)P found in temple ambient area was approximately 38 times higher than non-exposed areas (P< 0.01). The highest mean emission levels of B(a)P in temples were 3.34 ng/m3 and 0.08 ng/m3 for the non-exposed areas. Total mean PAHs exposure in temple workers was 19.56 ± 5.74 ng/m3 and the statistically significant difference with non-exposed workers 2.09 ± 0.65 ng/m3 (P< 0.001). Main carcinogenic B(a)P was higher in temple workers than non-exposed workers (P< 0.001). Urinary (1-HOP) levels in the temple workers were higher compared to the control group but statistically were not significant. In this study, 1-HOP biomarker did not reveal a perfect relationship between personal exposures due to other confounding factors. It cannot be assumed that chance was the low internal exposure of PAHs in the high exposed workers. The corresponding concentrations of B(a)P for temple (1),(2) and (3) were 0.12ng/m3 , 4.12ng/m3 and 16 ng/m3 respectively. The excess life time cancer risk assessments (ELCR) were 3.45x10-4, 4.14x 10-4 and 55.20x 10-4 respectively. Based on these findings, it is suggested that temple workers are exposed to an exceedingly large amount of particulate bound carcinogenic PAHs and exposure to incense smoke in the temples can be a serious health concern