塑化建材在有真菌及濕度的環境生成2-乙基己醇之研究

Abstract

近年來，室內裝潢大量使用塑化建材，可能是病態大樓症候群（sick building syndrome, SBS）的危險因子之一。研究指出添加於塑膠中以增加其柔軟性及使用性的塑化劑，經微生物分解後會產生2-乙基己醇（2-ethyl-1-hexanol, 2-ethylhexanol, 2EH），而相對濕度（relative humidity, RH）為影響化合物自建材逸散及微生物生長的重要變項。因此，本研究之目的為探討塑化建材、真菌及相對濕度間互動產生2-乙基己醇及其他化合物之關係。 研究採用田口氏實驗設計法（Taguchi method），設塑化建材、真菌及相對濕度為變項，每個變項有三個水準，組合成9個試驗組。各組試驗均在20 mL取樣瓶內進行，內置塑化建材，真菌培養於建材，相對濕度則利用飽和鹽類溶液調控。樣品採集於第1天、第4天、第7天、第10天及第14天以polyacrylate纖維進行頂空固相微萃取（headspace solid phase microextraction, HS-SPME），隨後利用GC/FID分析化合物。2-乙基己醇及其他未知化合物則曾先行使用GC/MS定性。實驗數據處理使用Qualitek-4軟體進行變異數分析（ANOVA analysis）。 結果顯示2-乙基己醇僅在有地毯建材的試驗中可測得，且其濃度於14天內無明顯變化；而在壁布建材的試驗中可測得苯甲醛及苯乙酮兩種化合物，其生成量隨時間呈現遞減的趨勢。此三種化合物可在僅有塑化建材的試驗中測得，常於一天達最大量，且非顯著的微生物揮發性有機化合物（microbial volatile organic compounds, MVOCs）。ANOVA分析結果顯示塑化建材對2-乙基己醇、苯甲醛及苯乙酮生成的影響分別為47.71%－85.20%、90.72%－96.33%及90.18%－96.90%，相對濕度和真菌的影響則很小。

塑化建材為影響揮發性有機化合物（volatile organic compounds, VOCs）產生的決定因素，而化合物的物種則隨著建材性質而異。另外建議考慮將本研究的試驗系統及採樣分析方法作為室內建材使用前的快速篩選工具。

Plastics are often used as building materials and likely involving in sick building syndrome (SBS) in recent years. The previous studies proposed that plasticizers added to plastics for imparting flexibility and workability may be degraded to form 2-ethyl-1-hexanol (2-ethylhexanol, 2EH) by microorganisms. And relative humidity (RH) influences chemical emission from building materials and growth of fungi. In that, this study was focused on the yields of 2EH and other prominent compounds in association with plastic building materials, fungi, and RH. Taguchi Method was employed for experimental design to form nine trials where plastic building materials, fungi and RH were parameters and each parameter had three levels. The treatment for each trial was conducted in a 20 mL vial with functions of cultivation of microorganisms on plastic building materials and control of different RH by saturated salt solution. 2EH and other prominent compounds were sampled by headspace solid phase microextraction (HS-SPME) with polyacrylate fiber on days 1, 4, 7, 10 and 14. The samples were analyzed by GC/FID. The qualitative analyses for unidentified compounds were performed using GC/MS. ANOVA analysis was performed using the Qualitek-4 software. The results indicated that 2EH was detected only in the trials having floor covering as a building material in the experimental system and the concentrations of 2EH were not apparently different in 14 days. Two specific compounds, benzaldehyde and acetophenone, but 2EH were found in the trials having wall covering as a building material, and the amount of the two compounds descended in 14 days. The highest amounts for the three compounds usually occurred on the 1st day and no prominent amount could be attributed to microbial volatile organic compounds (MVOCs). The ANOVA analysis demonstrated that plastic building materials were the predominant parameter governing the yield of 2EH, benzaldehyde and acetophenone and the influence percent were 47.71%－85.20%、90.72%－96.33% and 90.18%－96.90%, respectively. Fungi as well as RH had no significant influence on production of the compounds. In conclusion, the plastic building materials are the determinants to yield the volatile organic compounds (VOCs) and the chemical species emitted are dependent on the characteristics of materials. The experimental system used in this study is suggested to be an applicable way for accessing the emission of VOCs from new building materials beforehand.