| 摘要: | 台灣空氣污染控制的執行成果，可藉由環境保護署監測資料顯示出來，包括氮氧化物(NOx)、二氧化硫(SO2)、一氧化碳(CO)、空氣中的懸浮微粒(PM10)和臭氧(O3)都有下降的趨勢。然而對於多環芳香烴碳氫化合物(polycyclic aromatic hydrocarbons, PAHs)並沒有相關的報告。PAHs，是由兩個至七個苯環所組成之碳氫化合物，主要由不完全燃燒或熱解(pyrolysis)反應所形成。空氣中的微粒包含大量無機和有機的物種，其中PAHs更是值得注意的，因為其包含許多潛在的致癌物，更與死亡率和致病率風險的增加相關。我們在中國醫藥大學建立24小時的採樣站，並且從1990年開始到2004年在每年的11月到12月期間進行一個月的採樣。研究的PAH物種包括：pyrene(Pyr), benzo(k)fluoranthene (B(k)F), benzo(a)pyrene (B(a)P), benzo(ghi)perylene(B(ghi)P), dibenzo(a,e)pyrene (DB(a,e)P)。本研究以高液相層析儀(HPLC)，搭配螢光偵測器(fluorescence)進行分析，13分鐘內即可得到高感度並減少廢液產生的良好分析結果。檢量線範圍為Pyr 0.02 ~ 1.30 ng╱ml、B(k)F0.03 ~ 2.67 ng╱ml、B(a)P0.06 ~ 4.83 ng╱ml、B(ghi)P 0.03 ~ 2.39 ng╱ml、DB(ae)P 0.01 ~ 0.71 ng╱ml 且檢量線均達0.995以上。在此研究中，並比較從1900~2004歷年分析的結果進行健康風險評估，以了解民眾居住的健康情形。結果顯示出B(a)P 的濃度雖然在1994年有升高，但是從1990的3.36ng╱m3到2004年的0.45 ng╱m3有下降的趨勢。致癌風險評估方面在以B(a)P為基準的計算下，有4.69E-09降到6.28E-10的趨勢。其他PAH 物種的濃度也有下降的趨勢，其中以B(ghi)P 的降幅最大，由5.92 ng╱m3降到1.54 ng╱m3，其次為B(a)P 由3.36ng╱m3降到0.45 ng╱m3，Pyr 的降幅最小由1.23 ng╱m3降到0.18 ng╱m3。結果顯示歷年來個人風險度的健康風險評估值都在一般民眾可接受的10-6以下，並且以B(a)P╱B(ghi)P的比值來探討污染源的型式則顯示出，研究結果B(a)P╱B(ghi)P都小於0.6，顯示中國醫藥大學週遭大多是以移動性污染源為主。
The air pollution control effort in Taiwan has demonstrated decreasing trends in levels of several air pollutants monitored by Taiwan EPA including NOx, SO2, CO, PM10 and O3. However, no information on the trend of polycyclic aromatic hydrocarbons (PAHs) has been reported.We have a established 24-hour sampling station since 1990 at China Medical University to collect particles matter using high volume air sampler, in November╱December for one month annually until 2004.We used HPLC equipped with fluorescence to measure pyrene (Pyr), benzo(k)fluoranthene (B(k)F), benz(a)pyrene (B(a)P), benzo(ghi)perylene (B(ghi)P) and dibenzo(a,e) pyrene (DB(a,e)P) in the sample extracted with acetonitrile. I measured these PAHs for samples collected in 2004 and past years. Our results showed a decreasing trend for the measured B(a)P concentrations, from 3.36 ng╱m3 in 1999 to 0.45 ng╱m3 in 2004, although there was a rise in 1994. The cancer risk assessed based on B(a)P dropped from 4.69E-09 to 6.28E-10 for the corresponding years. The concentrations for other PAH species were also in decreasing trends. In conclusion, the ambient levels of selected PAHs in the monitored area have all declined measurably in the past decade. This finding is an indication of progress in reducing pollutant emissions, due may primarily to the improvement in automobile control. |
