目的：本研究主要採橫斷式(cross-sectional study)設計，評估工具機零組件製造業環境噪音及懸浮微粒暴露情形，並探討不同暴露組(噪音暴露、懸浮微粒暴露、噪音與懸浮微粒共同暴露)及不同噪音頻率與高血壓盛行率的關係。
方法：本研究以中台灣地區某工具機零件製造業315名員工為研究族群，在取得廠商及員工同意的前提下進行本研究。我們先進行全場區之現場訪視及基本資料收集。針對噪音平均值≧80 dBA及工作人數較多的作業環境之廠區，我們使用TES-1358八音度音頻分析儀進行8小時時量均能音量測定與頻譜分析。我們依據環境採樣結果對所有勞工進行相似暴露族群的分類，徵求不同區域之個人噪音暴露受試者，進行個人8小時之噪音暴露的量測。我們也依據現場訪視的結果，針對高暴露製程之工作點利用掃描式電移動度分徑儀，進行8小時懸浮微粒粒數濃度之測量；並且徵求不同製程之個人懸浮微粒暴露受試者，進行個人8小時之懸浮微粒質量濃度的量測。本研究同時蒐集員工之個人健康檢查資料及生活習慣問卷以評估可能的干擾因子，並且利用多變項邏輯斯迴歸模式分析不同暴露組及不同噪音頻率與高血壓盛行率的關係。
結果：本研究發現暴露於噪音≧80dBA且工作年資為2-4年的勞工有顯著較高的高血壓盛行率。在噪音頻率與高血壓盛行率方面，我們發現暴露於4KHz≧70dBA且工作年資為2-4年的勞工有顯著高的高血壓盛行率。在懸浮微粒與高血壓盛行率方面，我們發現暴露於粒數濃度≧129000 N/cm3且工作年資為2-4年的勞工有邊際顯著高的高血壓盛行率；我們進一步發現暴露於粒徑11.1-20.6 nm之粒數濃度≧35000N/cm3且工作年資為2-4年的勞工有顯著高的高血壓盛行率。在噪音與粒數濃度共同暴露方面，本研究發現暴露於噪音≧80dBA與粒數濃度≧129000 N/cm3且工作年資為2-4年的勞工有顯著高的高血壓盛行率。在高頻噪音與粒數濃度共同暴露方面，我們發現暴露於2KHz、4KHz或8KHz≧70dBA與粒徑11.1-20.6 nm之粒數濃度≧35000 N/cm3且工作年資為2-4年的勞工有顯著高的高血壓盛行率。
結論：本研究結果顯示工作年資為2-4年的勞工暴露於高頻噪音或奈米級粒徑之粒數濃度與高血壓盛行率有關。噪音與粒數濃度共同暴露沒有協同作用，但是會有些微較高的高血壓盛行率。
Objective: This cross-sectional study was to investigate effects of exposure to noise and/or particulate matter (PM) on the prevalence of hypertension among screw-manufacturing workers
Methods:We recruited a screw-manufacturing company with 315 employees as the study population. The preliminary walk-through survey was performed to identify the work places with noise levels above 80 dBA for conducting frequency analyses during the 8-hour periods. We classified subjects into different similar exposure groups (SEGs) based on the measurements of environmental noise and PM exposure.We used sequential mobility particle sizerto measure the number concentration of PM during the working periods. Volunteers from each of SEGs were recruited to assess individual exposure to noise and PM. Multivariate logistic regressions were conducted to estimate the odds ratio of hypertension related to noise and particulate matter exposure after controlling for potential confounders.
Results: Workers exposed to noise levels≧80 dBA during 2-4 years of employment duration had a significantly higer risk of hypertension. Workers exposed to 4KHz≧70 dBA during 2-4 years of empolyment duration had a significantly higer risk of hypertension. In addition, field workers exposed to PM number concentrations≧129000 N/cm3 during 2-4 years of employment duration had a marginally higer risk of hypertension. Workers exposed to PM(11.1-20.6 nm)number concentration ≧35000N/cm3during 2-4 years of employment duration had a significantly higer risk of hypertension. We also found that co-exposure to noise levels≧80 dBA and PM number concentrations≧129000 N/cm3 during 2-4 years of employment duration had a significantly higer risk of hypertension. In addition, co-exposure to 2KHz、4KHz or 8KHz≧80 dBA and PM(11.1-20.6 nm) number concentrations≧35000 N/cm3 during 2-4 years of employment duration had a significantly higer risk of hypertension.
Conclusion：Our findings revealed that exposure to high-frequency noise or PM with dynamic diameter between 11.1-20.6 nm during 2-4 years of employment duration might be associated with the prevalence of hypertension.There were no interactive effects of co-exposure to noise and PM on the prevalence of hypertension.
