[Evaluation of long-term occupational exposure to dust and its effect on health during production of ceramic tiles].

A medical examination has been carried out of 500 workers (290 men and 210 women) of a ceramic plates plant. Also, the measurements of dust concentrations were made at some standard work places . In the materials used for manufacturing the plates crystalline phases and the content of free crystalline silica were determined using the X-ray diffraction method. In the animal experiments the fibrogenic activity of all materials used in the plant was examined and compared to the fibrogenic activity of standard quartz. As a result of the medical examination 64 cases of pneumoconiosis were diagnosed (13% of the subjects). The incidence rate of pneumoconiosis was similar for men and women. The radiological changes characteristic of pneumoconiosis took approximately 24 years of the workers tenure to develop. Type q changes were most frequent (69%), types p and r were observed in 14% of workers (mostly women). In 31% of workers tuberous changes of size B were observed. In 43.8% of the subjects restrictive disorders of ventilation were found. In 30% of workers chronic bronchitis was diagnosed. Dust concentrations at 11 work places were measured using the individual dosimetry method. Total dust concentrations ranged from 0.6 mg/m3 at the electricians posts to 60.1 mg/m3 at the workposts where the furnace truck restorers worked. Dust concentrations exceeded the MACs at 7 workposts. The respirable fraction concentrations ranged from 0.1 mg/m3 to 8.4 mg/m3. During the replacement of asbestos ropes and asbestos board used for insulating the furnace trucks mineral fibres (0.1-0.5 fibre/cm3) were found in the air. The following crystalline phases were determined in the materials: kaolinite, illite, quartz, orthoclase and microline.(ABSTRACT TRUNCATED AT 250 WORDS)