Seasonal characteristics and cancer health risk of PM2.5-bound PAHs in residential indoor and outdoor environments in Hsinchu city

• Main Authors: Wen,Yu-Hsien, 温宇賢
• Other Authors: Yang,Tzu-Ting
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/25781844763335669833

碩士 === 元培醫事科技大學 === 環境工程衛生系碩士班 === 104 === The objectives are to understand cancer health risk of PM2.5-bound PAHs of residential indoor and outdoor environments versus season change in Hsinchu. Two personal environment monitors (PEM), with a cut-off aerodynamic diameter of 2.5 m and a sampling flowrate of 10 L/min for 48 hours, collected fine particles on Teflon filters both indoors and outdoors of residence. The sampling periods were the seasons from July 2015 to May 2016. The concentrations of 20 PAHs were determined using the gas chromatography/mass spectrometry technique. The PM2.5 mass concentrations for the indoor and outdoor residences ranged 11.58-21.48 and 13.78-26.96 µg/m3, respectively. The indoor-to-outdoor ratio (I/O ratio) of PM2.5 mass concentrations for the residence had an average value of 0.90, indicated the contributions of indoor PM2.5 mainly came from outdoor. The PM2.5 mass concentrations were in the order spring > autumn > winter > summer for both indoors and outdoors of residence, indicating significant seasonal variation. The PM2.5-bound PAHs concentrations for the indoor and outdoor residences ranged 0.49-1.47 and 0.66-1.72 ng/m3, respectively. The I/O ratio of PM2.5-bound PAHs for the residence had an average value of 0.81 The annual average lifetime excess cancer risk of PM2.5-bound PAHs for indoors and outdoors of residence were 9x10-6 and 11x10-6, respectively, which were higher than the USEPA guideline (10-6). The lifetime excess cancer risk of PM2.5-bound PAHs were in the order winter > autumn > spring > summer for both indoors and outdoors of residence. The experimental results suggested that residents avoided outdoor activities in the autumn and winter seasons to reduce the risk of exposure to PM2.5-bound PAHs.