VOCs Exposure in Urban Office Microenvironment
Date Issued
2004
Date
2004
Author(s)
Chung, Yuan-You
DOI
zh-TW
Abstract
This study assessed the indoor and outdoor levels of eight VOCs, pentane, butyl acetate, acetone, ethyl acetate, toluene, ethyl benzene, xylene and 1,2,4-trimethylbenzene in three office buildings. The eight VOCs were classified into three groups in terms of their sources, namely the human bioeffluent, the indoor sources and the outdoor sources. The VOCs were sampled by using a 100mg/50mg charcoal tube at flow rate of 200 mL/min for 7 hours, then dissolved in CS2 and analyzed by GC/MS.
The VOCs from the indoor sources, the bioeffluent and the outdoor sources accounted for 9.74%, 39.58% and 50.68% of the total indoor VOCs, respectively. The indoor level of acetone, one of the compounds in human bioeffluent was greater than that of outdoor, once a room was occupied by people. However, the consistent linear relationship between the level and person-hour was not found. The level of ethyl acetate, another compound in human bioeffluent, was significantly associated with the person-hour. For the compounds grouped as the indoor source, their outdoor levels were less. To the group of compounds identified as the outdoor source, especially toluene, the indoor level was significantly associated with the outdoor level (r2 = 0.6829, p < 0.05).
The indoor levels of the compounds including toluene, ethylbenzene, xylene and 1,2,4-trimethylbenzene in the first floor were two to four times higher than those in the fourteenth floor. The levels of these compounds around the buildings facing a main road were two to three times higher than those around the buildings facing a subsidiary road. In addition, these compounds leveled down to one half as a window was open. On the whole exposure concentrations in the studied buildings ranged from 0.30 to 69.13 μg/m3. The total hazard quotient was less than 1 as the risk was estimated according to the exposure scenario at office time.
In conclusion, people working in a room located at the low floors of a building which is close to a main road and has a bad ventilation system as well are likely exposed to a greater level of automobile emission compounds.
Subjects
揮發性有機化合物
室內外
人呼出氣體
暴露量
室內空氣
VOCs
indoor/outdoor
bioeffluent
exposure value?
Type
thesis