Fig. 1 shows the abundances of the major VOC species at the two temples during peak and
non-peak periods. Within the expectation, the species of
VOCs detected during peak period were more than those
during non-peak period. The total concentrations of the
detected VOC species measured during peak period
(870±63 μg m−3 for Temple 1, 260±17 μg m−3 for
Temple 2 indoor site, and 39±4.9 μg m−3 for Temple 2
outdoor site) were much higher than non-peak period
(52±7.1 μg m−3 for Temple 1, 23±2.1 μg m−3 for
Temple 2 indoor site, and 9.8±1.0 μg m−3 for Temple 2
outdoor site). In addition, the average VOC concentrations
at outdoor sampling location at Temple 2 were
much lower than those at the indoor one, which was
similar to the situation of carbonyl compounds.
The recommended benzene and toluene levels
according to IAQO Good Class are 16.1 μg m−3 and
1092 μg m−3, respectively. The benzene concentrations
obtained during peak period at both Temple 1 (146±
14 μg m−3) and indoor sampling location of Temple 2
(84±7.4 μg m−3) were significantly higher than the
standard. Especially at Temple 1 during peak period, the
average benzene concentration exceeded almost 8 times
more than IAQO criteria. However, all of the toluene
levels did not exceed the standard. The results revealed
that burning incense significantly elevated the air concentrations
of a number of VOCs, most notably methyl
chloride, benzene, and toluene in the surrounding
environments.found that incense
emissions could increase the indoor benzene concentrations
above urban air background levels of 2–20 μg
m−3, which coincided with the findings of this study.
Visiting temples during peak period (e.g. Chinese lunar
New Year, the first or fifteenth day of each month on
the Chinese lunar calendar) would lead to exposure to
high levels of some VOCs especially for methyl chloride,
benzene, and toluene.