異氰酸鹽暴露勞工過敏疾病調查與鑑定研究

An Investigation of Hypersensitive Disease and Identification of Workers Exposed to Isocynates

國內異氰酸鹽類列為特化物質共有三種化合物，其中二異氰酸甲苯（Toluene diisocyanate, TDI）是至今被瞭解引起職業性氣喘最多的工業化學物質之一，其揮發性強可經呼吸道、眼睛及皮膚進入勞工體內，因果關係已被確認。然而異氰酸作業場所經常不止使用TDI，故其他種類異氰酸與的致敏情況亦需要了解。本研究綜合為期三年之問卷調查及勞工血樣收集，針對常接觸異氰酸鹽類的勞工，現場進行呼吸道過敏問診及皮膚外觀檢查，挑選自覺有過敏疾病的勞工，完成連續十天工作前後尖峰呼氣流速等氣喘相關測定、四種異氰酸鹽過敏原貼膚試驗，以及TDI及二異氰酸二苯甲烷（Diphenylmethane-4,4-diisocyanate,MDI）兩種異氰酸專一性過敏抗體檢測。調查結果發現來自15家異氰酸作業工廠，578位勞工之問卷訪視資料中，有自覺過敏症狀勞工的統計結果為：呼吸道症狀28.0%、皮膚過敏症狀22.1%及眼睛過敏症狀者13.8%。各種過敏症狀與工作有關的百分率結果分別為：工作相關呼吸道過敏佔該部位過敏的63.6%、工作相關皮膚過敏為65.6%、工作相關眼睛過敏為72.5%；並研判佔全體受訪勞工的2.9%有氣喘症狀的勞工中，有58.8%與工作相關。被詢問過的307位勞工中，有過敏症狀並有配合診斷意願，同時問卷資料完整且完成全部異氰酸鹽相關過敏診斷共有54 人。任一貼膚試驗反應陽性的比率佔受詢問勞工的9.1%（28 人）、血清中抗TDI或MDI 專一性IgE 抗體陽性者，佔受詢問勞工的7.8%（24 人）。連續十天的尖峰呼氣流速在休假與上工期間降低有顯著差異，符合職業性氣喘之診斷原則者共14人，佔受詢問者的4.6%。以上統計分析結果支持上述三種診斷任一種為陽性反應，即與工作有關過敏症狀的有極顯著相關性（p＜0.01），評估可作為異氰酸類職業性過敏鑑定的測試項目。

Among the isocyanates on the list of regulated chemicals, toluene diisocyanate (TDI) is one of the well-known asthma causative compounds. Because of its liquid form and volatile property, the respiratory system is not the only entry route, skin, eyes or other mucous openature are also important for exposure assessment. But in many factories, other isocyanates are also used as bridge agents, which possess the same functional groups. Their sensitizing effects need to be evaluated as well. The identification procedures were conducted in the factories. The methods included: test composed of four kinds of isocyanates and two controls, continuous observation of peak flow for ten days, and specific IgE against TDI and MDI. In this study, questionnaire survey and health examinations of 578 workers from 15 randomly selected plants that used isocyanates as raw materials were conducted. There was a noticeable causative effect of exposure on allergic syndromes of the respiratory system, skin and eyes. The prevalence of self reported symptoms are as follows: 28% exhibited respiratory hypersensitivity, 22.1% showed skin allergic disease, and 13.8% with sensitive eyes. Significant work related hypersensitivity was observed and 63.6%, 65.6%, and 72.5% of the sensitized workers were observed, respectively. Similarly, 2.9 ﹪workers revealed asthmatic symptoms, among them, 58.8% were evaluated to be work related. As for the allergic examination, 307 workers were consulted, and fifty-four allergic persons finished all tests and examinations. Fourteen workers(4.6％)revealed a significant lower peak flow during workdays than days off. The results of patch tests exhibited a 9.1% positive rate, counted by the number of cases showed any positive results among the six tests. A positive rate about 7.8% of IgE antibodies against TDI or MDI was also found, and significantly related to their allergic syndromes. From the statistics, any positive reaction on the above examinations showed significant correlations of their work related syndromes (p<0.01), can support the occupational hypersensitivity of Isocyanates.