Zhang W C, Zhang Q F, Song Z F
Department of Occupational Health, Fujian Medical University, China.
Biomed Environ Sci. 1997 Dec;10(4):377-86.
Pyrophyllite (H2Al2Si4O22) dust (P-dust) is a mixture of silica (10-40%), different proportions of a luminium oxide (Al2O3), and various metal compounds. People with occupations known to be associated with exposure to P-dust include miners, other industrial workers and persons engaged in artistic carving. Currently, little is known about pyrophyllite pneumoconiosis from P-dust. This study was designed to investigate the hazardous effects of P-dust and to suggest a maximum allowable concentration (MAC) of the dust. This study included four parts: (i) Occupational epidemiology survey in 781 workers from 1 pyrophyllite mine (PM) and four pyrophyllite carving mills (PCM), with a registration rate of 98%. (ii)
Six groups of rats were exposed to different levels of P-dust; the cytotoxicity of P-dust on rat alveolar macrophages (AM) was investigated by determining the potassium content of AM and the activity levels of lactate dehydrogenase (LDH) in AM culture fluid, (iii) Mineralogical analysis of P-dust: The contents of silica (SiO2), aluminum (Al), ferrum (Fe), nickel (Ni), zinc (Zn) and copper (Cu) in both PM-dust and PCM-dust were determined. (iv) Determination of P-dust MAC: Using the life-talbe method, an investigation of the hygiene standard of P-dust was carried out in 625 workers exposed to either PM-dust or PCM-dust, upon whom routine radiographs were performed. The results suggest that the risk of developing pneumoconiosis from pyrophyllite dust is significantly higher for PM workers than for PCM workers. The prevalence rate of PCM-dust pneumoconiosis is significantly higher in men than in women. The content of SiO2 and Al2O3 in the mixture of P-dust is the most important factor in the etiology of pyrophyllitosis. Depending on the different P-dust MAC values, we suggest that 2 mg/m3 and 4 mg/m3 should be considered as the MAC for PM-dust and PCM-dust, respectively, and 3 mg/m3 for P-dust. We believe that establishing different hygiene standards is more accurate even though workers are exposed to the "same" dust.
叶蜡石（H₂Al₂Si₄O₂₂）粉尘（P粉尘）是二氧化硅（10 - 40%）、不同比例的氧化铝（Al₂O₃）以及各种金属化合物的混合物。已知与P粉尘接触相关的职业人群包括矿工、其他产业工人以及从事艺术雕刻的人员。目前，关于因P粉尘导致的叶蜡石尘肺知之甚少。本研究旨在调查P粉尘的危害效应并提出该粉尘的最大允许浓度（MAC）。本研究包括四个部分：（i）对来自1个叶蜡石矿（PM）和4个叶蜡石雕刻厂（PCM）的781名工人进行职业流行病学调查，登记率为98%。（ii）
将六组大鼠暴露于不同水平的P粉尘；通过测定大鼠肺泡巨噬细胞（AM）的钾含量以及AM培养液中乳酸脱氢酶（LDH）的活性水平，研究P粉尘对大鼠肺泡巨噬细胞的细胞毒性，（iii）P粉尘的矿物学分析：测定PM粉尘和PCM粉尘中二氧化硅（SiO₂）、铝（Al）、铁（Fe）、镍（Ni）、锌（Zn）和铜（Cu）的含量。（iv）P粉尘MAC的测定：采用寿命表法，对625名接触PM粉尘或PCM粉尘的工人进行P粉尘卫生标准调查，并对他们进行常规胸部X线检查。结果表明，PM工人因叶蜡石粉尘患尘肺的风险显著高于PCM工人。PCM粉尘尘肺的患病率男性显著高于女性。P粉尘混合物中SiO₂和Al₂O₃的含量是叶蜡石尘肺病因中最重要的因素。根据不同的P粉尘MAC值，我们建议PM粉尘的MAC应考虑为2 mg/m³，PCM粉尘的MAC为4 mg/m³，P粉尘的MAC为3 mg/m³。我们认为，即使工人接触的是“相同”的粉尘，制定不同的卫生标准会更准确。
