[An annual decrement in the spirometric parameters of those employed in producing refractory materials. A...

Results of a longitudinal study on the yearly decline of two pulmonary parameters are reported. All subjects were workers in a refractory material factory and exposed to dust with low silica content. The study brought about an annual measurement of two spirometric parameters (VC and FEV1) during a 13 year period of follow up on 113 subjects. 56% and 57.5% of them showed annual decreases of VC and FEV1 statistically significant. The trend of the two functional parameters over time was studied both in the whole group of workers and in subgroups obtained from occupational exposure levels, smoking habit, age. The most affected volumetric index was the VC. The 3 risk indicators considered (occupational exposure, smoking habit and age) all negatively influence the VC decrease; however, the effect is statistically significant only for smoking habit. The FEV1 changes with reference to the above mentioned risk indicators are less clear. From the whole group a number of 15 losers were selected.