特定職場二甲苯暴露與成人聽覺功能之總體性評估

Xylene exposure on auditory function among adults in selected occupational settings: a systematic review

本研究主要目的為評估二甲苯與二甲苯混合物對在不同作業環境工作下的勞工聽覺之潛在影響。利用網際資料庫（EBSCO以及PubMed）的英文期刊搜索發表的論文進行評估。期刊內容以研究人為主（不包括動物研究），涵蓋期限為三十年（1985-2015）。研究論文包含了同儕審查的論文，病例對照研究，案例分析，以及案例報告。初始搜尋出56件案例。依據研究設計、樣本大小、研究設置、研究日期、以及研究方法，6篇期刊論文被篩選來做更進一步的檢閱。經由詳細的評估，6項研究被取來審查。在有噪音以及無噪音的環境下，研究分為純二甲苯（n=3）與含二甲苯有機溶劑（n=3）二組。整體研究結果顯示，二甲苯與二甲苯混合物加上其他干擾因素（如老化、性別、以及噪音等）對人類聽力的影響程度可由輕微到嚴重足以喪失聽力。雖然，過度的噪音暴露可能影響勞工的聽力。但研究建議，公共衛生機構以及法令單位應多鼓勵關於二甲苯暴露與耳毒性相關的研究。除此之外，長期暴露於二甲苯的個體，應定期進行廣泛的聽力檢查，並實施工業衛生控制，以便早期偵測出聽力的損失。

A review study was conducted to examine potential adverse effects of xylene and xylene mixtures on the auditory system in workers employed in various settings. Utilizing internet-based databases EBSCO and PubMed, we searched peer-reviewed articles focusing on human subjects, published in English language, and spanning a 30 year time period (1985-2015). Studies included peer review full papers, case control studies, and case reports. Animal studies were excluded from the final analysis. Initial search results identified 56 studies. From studies meeting the inclusion criteria, the following data were extracted: publication date, study design, sample size, exposure setting and chemical, assessment method, and outcome. Six journals were retrieved for detailed examination. After detailed examination, six studies were included in the review. Studies were further subdivided into investigations related to xylene only (n=3) and investigations related to xylene mixed with other organic solvents (n=3), with or without the association of noise. As a whole, the results range from moderate associations between xylene or xylene mixtures and hearing, to altered hearing loss due to xylene and other confounders, such as aging, gender, and noise. Exposure to excessive noise, both in and out of the worksite, may contribute to decreased hearing in workers. However, findings suggest public health and medical professionals should be made aware of the future research needs pertaining to hearing dysfunction from occupational xylene exposure. It is recommended xylene-exposed individuals be routinely monitored for signs of auditory impairment; along with the implementation of pertinent industrial hygiene controls.