RESPIRATORY SYMPTOMS AND LUNG-FUNCTION IN ANIMAL FEED WORKERS

In a study among 194 male workers exposed to endotoxin-containing orga nic dust in animal feed mills, lung function was measured by now volum e curves and impedance measurements and respiratory symptoms were reco rded by means of a validated questionnaire. The aims were to detect an d localize airway obstruction caused by fodder dust and endotoxin, and to relate respiratory symptoms to both types of lung function measure ments. Flow volume and impedance parameters were significantly related to present exposure. All impedance parameters, of the spirometric mea sures only FEF(25), were significantly related to cumulative dust or e ndotoxin exposure. The changes in impedance parameters were for overal l increasing resistance at 8 Hz and decreasing reactance at 8 Hz, refl ecting an increase in peripheral airflow obstruction, with increasing exposure. The changes in all lung function parameters were more strong ly related to (cumulative) endotoxin exposure than to inspirable dust exposure. All impedance parameters and FEV(1) showed a good correlatio n with complaints of chronic bronchitis and breathlessness. Impedance measurement of the respiratory system proved to be a useful tool for o bjectively assessing (early) airflow obstruction in workers exposed to inspirable dust and endotoxin and in localizing airflow obstruction.