嘉義地區臭氧成因探討

Abstract

近年來環保署統計，雲嘉南地區超過空氣污染指標PSI次數已超過台中地區，成為在環保署劃定之7個空氣品質管制區中，污染情形僅優於污染重鎮高屏空品區，屬全國第2大污染區。 嘉義地區為一農業鄉鎮。境內工業多以生產民生必需品為主，但近年來卻頻傳高污染事件，所以本研究針對嘉義地區進行分析、探討。 本研究利用1995年~2007年環保署空氣品質資料，分析嘉義地區空氣品質的變化趨勢，統計事件日最常出現風向以瞭解污染主要來向。同時利用逆軌跡模式去分析2001、2002、2003年事件日軌跡線的變化，以了解嘉義地區污染成因。 研究結果顯示嘉義地區空氣品質在2002年開始明顯惡化，從風向統計上來看，事件日發生時最主要以北風為主。以逆軌跡來看，通過六輕的軌跡線在2002年以後，發生次數、超過臭氧小時標準次數、超過臭氧8小時標準次數，均有明顯之增加，而通過台中工業區的軌跡線則沒有太大增量。可見的六輕和嘉義地區空氣品質品的惡化，有直接的關係。

According to the statistics by the Environment Protection Administration (EPA) in recent years, the frequency of PSI(Pollution Standard Index) >100 in Chiayi, Yunlin and Tainan area have already exceeds the frequency in Taichung area. The Chiayi, Yunlin and Tainan area becomes to one of the seriously polluted area, which is merely better than Kaohsiung and Pingtung area. The Chiayi area is an agricultural county, the regional industry is mainly the manufacturing of civil articles. However, the frequency of high ozone episodes is getting higher in recent years. Consequently, this study focused on the air quality in Chiayi area. In this study, we collected the databases from EPA, which is from 1995 to 2007 and analyzed the variation trend of air quality. We also analyzed the wind direction to comprehend the source of air pollutants. In order to comprehend the forming reasons in Chiayi area, we also used the back trajectory model to analyze the ozone episodes in 2001, 2002 and 2003. The result revealed that, the air quality in Chiayi area became worse obviously after 2002. According to the analysis of wind direction, the ozone episodes mainly occurred in north wind condition. The back trajectory analysis reveled that, the trajectory lines passed through sixth Naphtha cracking plants increased obviously. However, the trajectory lines passed through the Taichung industry area were almost changeless. Thus, we concluded that the sixth Naphtha cracking plants has to do with the worsen of the air quality in Chiayi area.