醫院環境生物氣膠暴露與工作者健康研究

Abstract

本研究針對醫院環境評估工作者健康與室內污染物暴露情形。其中工作者健康情形經由問卷調查得知，室內空氣品質監測項目除真菌及細菌外，尚包含物理性因子（風速、風量、溫度、相對濕度及表面濕度）及化學性因子（懸浮微粒、二氧化碳、一氧化碳、總揮發性有機化合物及甲醛），同時亦收集環境管理及建築體特徵（建築物屋齡、淹水紀錄、整修紀錄、通風換氣方式/設備型態、通風設備故障與清洗紀錄、人口密度及室內盆栽數）等資料。 環境測定結果顯示，空氣中真菌及細菌濃度多符合我國建議值。在菌屬種類方面，Aspergillus sp.（可呼吸性及總濃度）、Candida（可呼吸性濃度）、Paecilomyces（可呼吸性及總濃度）、Penicillium（不可/可呼吸性及總濃度）、Scytalidium（可呼吸性及總濃度）及Trichophyton（可呼吸性濃度）之室內/室外濃度比值均大於1，顯示上述真菌可能具有室內污染源，其中可呼吸性Trichophyton之室內濃度更顯著高於室外 (p=0.0058)。物理性因子部分，醫院平均溫度 (23.06~23.14 ℃) 符合我國與香港、新加坡及英國之建議值，相對濕度 (55.80~63.43 %) 則符合澳洲、加拿大、香港、新加坡及德國之建議值，室內懸浮微粒PM10質量濃度 (14.84~30.42 μg/m3) 則低於香港及新加坡建議值。化學性因子部分，二氧化碳8小時平均值 (690.30~945.24 ppm) 超過我國建議值 (600 ppm)，且其中一家醫院一氧化碳 (6.55 ppm) 及甲醛平均濃度 (0.25 ppm) 均超過我國建議值 (2 ppm；0.1 ppm )，而總揮發性有機化合物平均濃度 (228.67~619.37 ppb) 則低於我國建議值 (3000 ppb)。 進一步利用多變項迴歸模式分析影響院內空氣中真菌及細菌濃度之環境因子時發現，風速較低及建材表面濕度較高可顯著增加不可呼吸性Cladosporium濃度，風速較低及相對濕度較高顯著增加總Cladosporium濃度；相對濕度較高及屋齡較久可顯著增加總Penicillium濃度，增加相對濕度及表面濕度則顯著提高不可呼吸性潮濕性真菌 (Acremonium, Aspergillus versicolor, Cladosporium及Stachybotrys) 濃度。另在風速較低且水漬面積較大之地點不可呼吸性革蘭氏陽性細菌濃度顯著增加。 當以多變項迴歸模式分析影響工作者健康之環境因子時，發現醫院屋齡及A. versicolor與多項呼吸道症狀或疾病達顯著相關，顯示此二項因子對工作者健康最具影響。整體而言，真菌與建築體屋齡對醫院員工健康影響高於細菌、物理性及化學性因子。

This study aims to evaluate the relationship between workers’ health and their exposure to bioaerosol in hospital environment. Hospital workers’ health situation is obtained from questionnaire. Data of indoor quality monitored include biological factors such as fungi and bacteria, physical factors (wind velocity, wind volume, temperature, relative humidity and surface moisture ), chemical factors (particulate matter, carbon dioxide, carbon monoxide, ozone, total volatile organic compound, formaldehyde) and environment management and characteristics of buildings (age of building, record of flood and restoration, ventilation types, record of ventilation equipments breakdown and cleaning, and density of people, potted plants). The environment monitoring result shows that the measured concentrations of fungi and bacteria accords with the suggested figure by Taiwan but exceeds other nations in measured figure contrarily. Secondary, among different fungal flora , the indoor/ outdoor concentration of Aspergillus sp. (total and respiratory concentrations）, Candida (respiratory concentration）, Paecilomyces (total and respiratory concentrations), Penicillium（total and respiratory/non-respiratory concentrations）, Scytalidium（total and respiratory concentrations） and Trichophyton (respiratory concentration) is greater than 1. This demonstrates that the above fungi possibly have potential indoor latent source. Concentration of respiratory Trichophyton indoors exceeds in concentrations outdoors significantly (p=0.0058). As to physical factors, the average temperature (23.06~23.14 ℃) in hospital accords with the suggested figure by Taiwan, Hong Kong, Singapore and England； the relative humidity (55.80~63.43 %) accords with the suggested figure by Australia, Canada, Hong Kong, Singapore and Germany. Yet the indoor PM10 mass concentration (14.84~30.42 μg/m3) is lower than the suggested figure by Hong Kong and Singapore. Finally, as to chemical factors, 8-hour average concentration of carbon dioxide (690.30~945.24 ppm) exceeds the suggested figure in Taiwan (600 ppm). The average concentration of carbon monoxide and formaldehyde are, respectively, 6.55 ppm and 0.25 ppm which exceed the suggested figure in Taiwan (2 ppm；0.1 ppm ). Average concentration of total votatile organic compound (228.67~619.37 ppb) is lower than the suggested figure in Taiwan (3000 ppb). The study analyzes the environmental factors which affects concentrations of fungi and bacteria in air by using multiple regression model. We found that concentration of non-respiratory Cladosporium increased remarkably when the wind velocity is lower and surface moisture is higher on one hand, total concentration of Cladosporium increased remarkably when the wind velocity is lower and relative humidity is higher, on the other. Higher relative humidity and older building contribute to the significant increase of total concentration of Penicillium. Also, higher relative humidity and surface moisture contribute to the significant increase of concentration of non-respiratory humid fungi (Acremonium, Aspergillus versicolor, Cladosporium and Stachybotrys). Lower wind velocity and bigger dampness area contribute to the increase of concentration of non-respiratory Gram positive bacteria. We analyzed those affecting health factors by multiple regression model and have found a significant relationship between age of building, A. versicolor and many respiratory symptoms and diseases, which is saying, these two factors affects hospital workers most markedly. Generally speaking, fungi and the age of building have greater effect on hospital workers’ health than bacteria, physical and chemical factors do.