有害物發生率變動對室內有害物濃度的影響

The Effect of Periodic Varying Contaminant Generation Rate on the Indoor Concentration

張維耕(WEI-KENG CHANG)

指導教授 ： 陳友剛

長榮大學/健康科學學院/職業安全與衛生學系(所)/碩士(2011年)

https://doi.org/10.6833/CJCU.2011.00002

摘要

暴露評估通常都在一恆定刺激的前提下以時量平均暴露近似。但有時峰值暴露有時反而是影響健康的關鍵因素，這時刺激的變動形態對峰值暴露卻有相當大的影響。本研究即在探討週期與脈衝刺激所造成的暴露。以具有變動有害物釋放形態的室內通風做為暴露評估的對象，而室內有害物濃度即做為評估暴露的基準。
　　本研究使用一序列週期矩形刺激模擬不同的刺激形態。使用不同的參數設定，可以產生不同程度週期脈衝乃至恆定的刺激形態。根據均勻混合模式，本研究得到遞迴形式的分析解。當週期趨近於無窮大時，此分析解成為單一脈衝釋放所造成的分析解。
　　在相同的時量平均刺激下，比較週期刺激與穩定刺激所造成峰值暴露計算結果。本研究發現，當系統具有較大的衰減係數時，峰值暴露遠高於時量平均暴露。數個不同強度的刺激序列所造成的暴露也可以相加形成特定刺激形態所造成的暴露。此理論結果可以更進一步應用於毒物學或噪音控制領域中。
　　本研究以暴露艙中以不同形態釋放微粒的通風實驗驗證上述理論。微粒釋放率做為刺激；而懸浮微粒濃度的量測值則做為暴露。實驗結果大致與理論結果一致。

關鍵字

暴露評估 ； 時量平均 ； 室內通風 ； 刺激反應 ； 脈衝

並列摘要

The exposure analysis is usually performed by assuming a constant stimulus to approximate a time-weighted average exposure. While the peak exposure is concerned, the stimulus pattern will become important to the results. This study investigated the effects of periodic and pulsatory stimuli to the exposure. The indoor ventilation with a varying contaminant release rate were used as the object of exposure analysis. The exposure was assessed by the contaminant concentration.

The stimulus was formulated as a series of periodic rectangular function of time. The stimulus can be a periodic pulse, or a constant. An analytic solution in a recurrent form was determined mathematically based on the well-mixing model. When the period became infinite, a solution for a single pulse was also determined.

The peak exposure was determined and compared with that caused by a steady stimulus at the same time-weighted average level. While the system has a large decay coefficient, the peak exposure is much higher than a time-weighted average exposure. The exposure caused by several pulses with various strengths can be summed up to form an exposure caused by any pattern of the stimuli. The theoretical results can also be applied in toxicology and noise control.

Ventilational experiments in an exposure chamber were performed by releasing particles at various patterns. The particle release rate was worked as stimulus, the measured air-borned particle concentration was worked as exposure. The results were fairly consistent with the theoretical studies.

並列關鍵字

exposure analysis ； time-weighted average ； indoor ventilation ； stimulus and response ； pulse

參考文獻

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