使用COSMED K5建置本土化成人淋浴呼吸速率評估台灣成人暴露地下水揮發性含氯有機物之健康風險評估

評估地下水污染場址之健康風險時，淋浴時的吸入暴露是重要的揮發性有機物暴露途徑。在計算淋浴時的吸入暴露時，呼吸速率是一項重要的影響參數，然而，現今環保署提供的「土壤及地下水污染場址健康風險評估方法」中，暴露參數大多參考美國環保署所建置的數據，國內目前尚缺乏本土化的呼吸速率參數。本研究使用COSMED K5攜帶式能量代謝系統，實際量測臺灣20-40歲成人的淋浴時呼吸速率，同時亦量測基本身體組成和肺功能，探討影響呼吸速率的因子，並建置本土化的呼吸速率預估公式；另外，再估算全台受含氯揮發性有機物污染的場址周邊成人之健康風險，探討淋浴呼吸速率參數於風險評估中的重要性。本研究受試者平均淋浴時呼吸速率為14.7 m3/day，低於現今環保署土壤及地下水資訊管理系統(SGM系統)中的預設值(24 m3/day)；另外，成人淋浴呼吸速率在性別比較中呈顯著差異，且由相關性分析結果可知，淋浴呼吸速率與體重、體質量指數、骨骼肌、腰臀圍比、基礎代謝率呈顯著相關，表示淋浴呼吸速率受到各項生理指標影響。此外，比較本研究實測值與使用Layton (1993)預估公式預測值，結果顯示使用Layton (1993)預估公式會有低估的情形，建議未來應針對本國人的換氧當量(Ventilatory Quotient, VQ)進行調整。由健康風險的結果顯示，淋浴時吸入暴露為成人暴露到地下水中含氯揮發性有機物的主要暴露途徑，且使用SGM系統預設值所計算出的風險大於使用本研究呼吸速率最大值所算出來的風險，表示若使用SGM系統預設淋浴呼吸速率值計算風險可能會有高估的狀況。本研究利用人體實驗實際量測成人淋浴時呼吸速率，相較於過去的公式預估方式，能夠獲得更準確的成人呼吸速率值，建議未來在污染場址的健康風險評估中，能夠採用本研究實測值進行地下水揮發性有機物的估算，提供受體族群更完整的風險描述。

關鍵字

COSMED K5攜帶式能量代謝系統；淋浴呼吸速率；健康風險

並列摘要

Inhalation exposure during showering is an important exposure route for receptors exposed to volatile organic compounds in the groundwater. When calculating the inhalation exposure during showering, the inhalation rate is a crucial exposure factor. However, the current exposure parameters used in Taiwan are majorly based on those established by the U.S. Environmental Protection Agency; there is still a lack of localized parameters related to the inhalation rate in Taiwan. In this study, a portable gas exchange analyzer (COSMED K5) was employed to measure the inhalation rate for Taiwanese adults aged 20 – 40. The body composition and lung function were also measured to explore the impact factors of inhalation rate. Besides, the localized predictive equation for inhalation rate during showering was developed. The health risk was then conducted to assess the adverse effects of adults living around the contaminated sites and exposed to volatile chlorinated hydrocarbons (VCHs). The results showed that the average inhalation rate during showering was 14.7 m3/day, which is lower than the default value (24 m3/day) in the Soil and Groundwater Management system (SGM system) of Taiwan Environmental Protection Administration. The results also showed that the inhalation rate during showering was significantly different in gender. The correlation analysis showed that the inhalation rate was significantly related to body weight, body mass index, skeletal muscle, waist-hip ratio, and basal metabolic rate, indicating that the inhalation rate is affected by various physiological indicators. Additionally, inhalation rate may be underestimated by using the predictive equation from Layton (1993). This study suggested that the value of the ventilatory quotient (VQ) should be adjusted. Health risk assessment results showed that inhalation exposure during showering was the main route for adults exposed to VCHs in the groundwater. The health risks estimated by default value from SGM system were higher than the risk estimated by the maximum of inhalation rate (IR) of all subjects measured from this study, indicating that using default value from the SGM system may overestimate the risk. The inhalation rates of adults during showering were measured with human trials in this study. Compared with the prediction using formula in the past literature, the results from this study provide relatively actual inhalation rate values. It is also recommended that the inhalation rate measured by COSMED K5 could be employed in the health risk assessment of the contaminated sites in the future.