耐火磚工廠的勞工粉塵及結晶型游離二氧化矽暴露調查

Survey on the Proc Processes and Dust Exposure in Refractory Brick Manufacturing

根據台灣地區勞工保險給付統計，職業病中以塵肺症為大宗，塵肺症之患者大多因吸入礦物性粉塵所致，而耐火磚工人罹患塵肺症之病例報告高居所有行業之第二位。本研究針對國內某一大耐火磚廠進行其耐火磚製造流程中可呼吸性粉塵與耐火磚礦石原料、產品樣本之採樣及結晶型游離二氧化矽分析，以了解該業勞工粉塵危害情況。研究結果顯示：在原料、成品結晶型游離二氧化矽分析中發現存有石英、鱗矽石、方矽石等不同結晶相，故耐火磚工人除可能石英暴露外，亦有可能暴露於高危害之鱗矽石、方矽石之作業環境下。而針對各常用耐火磚磚種進行結晶型游離二氧化矽含量分析，發現其含量多寡依序為腊石磚＞黏土磚＞高鋁質磚＞模萊石磚＞鎂鉻磚、鎂碳磚。另以直讀式儀器測定耐火磚作業製程之粉塵個數濃度，顯示粉塵數量依序為下料、稱重＞粉碎＞混合攪拌＞成型＞乾燥＞鍛燒。在環境測定方面，由各製程堆積物之結晶型游離二氧化矽分析，推測該工廠空氣中粉塵種類應隸屬法令規範之第二種粉塵；進一步由區域可呼吸性粉塵濃度量測結果得知，其可呼吸性粉塵濃度值介於N.D.〜1.1mg/m3 之間，可知各製程大多低於法令容許濃度標準。

Pneumoconiosis is one of the most occupational diseases compensated from labor insurance in Taiwan. Pneumoconiosis may be caused by exposure to mineral dusts, and its occurrence rate in refractory brick workers is the second highest in all industries. This study is to measure the concentrations of airborne respirable particulates and the contents of crystalline free silica in bulk samples in refractory brick industry. The results indicate that quartz, tridymite and cristobalite are found in the bulk samples and materials. Refractory brick workers may be exposed to tridymite and cristoblite. The contents of free silica in refractory bricks are as following sequences: Pyrophylite brick> fireclay brick> high alumina brick> mullite brick> magnesite-chrome brick and magnesia-varbon brick. The concentrations of airborne particulates in operation processes are as following sequences: proportioning> crushing> mixing> molding> drying> burning. The respirable dust concentrations are between non detectable to 1.1 mg/m3 and all below the regulation of airborne concentrations.