Lung function in workers refining phosphorus rock to obtain elementary phosphorus.

Elevated levels of phosphoric acid, phosphorus pentoxide, fluorides and coal tar pitch volatiles were present in workplace air of a two-oven industrial refinery. One hundred thirty-one workers prospectively underwent annual pulmonary function testing (forced vital capacity, forced expiratory volume in 1 second, and forced expiratory flow). Regression of these spirometric data, analyzed longitudinally over 3 to 7 years and also cross-sectionally reveals no residual significant effect of industrial exposure after adjusting for the effect of age and smoking. This industrial exposure contributes only weakly and inconsistently to the well-documented reduction of spirometric lung function that occurs from smoking alone. No significant reductions of spirometry occurred in exposed nonsmokers or former smokers.