Several studies reported that evaporation of fragrant essential oils in an indoor environment may cause the emission of
secondary organic aerosols (SOAs). However, the tendency of forming SOAs from the use of Chinese herbal oils has not been
reported. This study investigated the formation of SOAs from various Chinese herbal oils when reacting with ozone in a
controlled environment chamber under different test conditions. Lemon oil, a fragrant essential oil, was also tested under the
identical experimental conditions for comparison. The results showed that the formation of SOAs from Chinese herbal oils
was limited, compared with lemon oil. Of the Chinese herbal oils tested, Chinese mulberry and perillae folium oils produced
more SOAs than the other oils. GC/MS analysis of the essential oils demonstrated the presence of SOA precursors, such as dlimonene, in Chinese mulberry and perillae folium oils but not in the other Chinese herbal oils. Compared with the tested
Chinese herbal oils, evaporation of 1 mL lemon oil in the presence of 30 ppb ozone may cause an increase of 6.4 μg/m3
in
indoor PM level in a typical room or office. This study concluded that the use of Chinese herbal oils tested in this study would
result in a lower particle concentration in indoor settings compared with fragrant essential oils.
關聯:
Aerosol and Air Quality Research 11(7), pp.854-859
