森林環境及室內木質環境中空氣離子濃度之研究

Abstract

空氣負離子（Negative Air Ions, NAIs）可與大氣污染微粒結合而沉降，達到提升環境空氣品質的效果，又由於所帶自由基的高活性，對人類心理及生理上的作用亦可促進睡眠、穩定情緒、改善憂鬱症及多種生理反應機制；然而目前較少有著重在人類活動環境中空氣離子濃度的監測與探討，本研究分別於一年四季的不同時間，測量台北都市休閒環境、溪頭森林環境與室內木、竹質環境的空氣正、負離子濃度及其他環境項目如懸浮微粒、揮發性有機物、甲醛、一氧化碳、二氧化碳、溫度、相對濕度及氣壓，欲作為未來將空氣負離子應用於身心醫療保健的基礎。 結果顯示在夏季時，台北都市休閒環境中不同地點並無明顯差異，而在溪頭森林環境中，不同的林相與地貌所含空氣負離子濃度依序為沿溪處>孟宗竹林>紅檜林>柳杉林>草坪區，且不同季節時主要影響整體空氣負離子濃度的因素不盡相同。另外，木質環境室內空氣負離子濃度在四季依序為夏季與秋季>春季>冬季，且室內濃度顯著大於室外，表示木質環境可提升空氣負離子濃度；又木質環境室內濃度大於竹質環境，但兩者的日變化相似，均為夜晚高於白天；不同季節中主要影響木質環境室內空氣負離子濃度的因素雖略有差異，但可知各季的懸浮微粒（Particulate Matter, PM）與空氣負離子濃度的相關性均不因PM的粒徑大小而有影響。 研究結果亦顯示室內木質環境較台北都市與溪頭森林室外環境更具有可改善人體生、心理狀態的條件，未來欲深入瞭解木質材料對空氣正、負離子的交互反應機制，期望將空氣負離子的效益落實於人類日常活動範圍和居住環境中。

Negative Air Ions (NAIs) may improve the air quality in our environment when they combine with particulate matters due to their electrically charged characteristics. Moreover, with the high reactivity of free radicals, NAIs could also lead to better quality of sleep, emotional stability, reduction in the rate of depression and improvement of many biological response mechanisms. However, little research has been conducted in environments where human spend doing their daily activities. In this study, we measured both of air ion concentrations and other environmental factors in urban Taipei City, forest environments in Xitou area, and indoor environments built by different biological materials such as timber and bamboo. We aim to set a foundation for future application and studies. There was no significant difference in the data collected in summer between experimental sites in urban Taipei City. On the other hand, the annual variation of NAIs concentrations in wooden interior was summer and autumn>spring>winter. Also, the concentrations indoor were significantly greater than outdoor. This suggests that wooden interiors could probably enhance the NAIs concentration inside. Besides, the wooden indoor interior NAIs concentrations were also greater than the bamboo interior. Both of the two indoor environments had similar diurnal variation, as the NAIs concentrations in nighttime were significantly higher than in daytime during all of the four seasons. Last but not the least, the main factors influencing indoor NAIs concentrations in different seasons were slightly different, but the correlations between particulate matter (PM) and NAIs concentration were not affected by the particle size of PM. In conclusion, our study considered that the wooden interior compared to the urban and forest environment has the greatest scenario than both of the urban and forest outdoor environment for human benefits in physiological and psychological health. Further research would focus on the interactional mechanisms of wooden materials to air ions, expecting that the advantages of NAIs could eventually be implemented in daily activities and dwelling environments.