RESPIRATORY HEALTH-STATUS IN SWINE PRODUCERS RELATES TO ENDOTOXIN EXPOSURE IN THE PRESENCE OF LOW DUST LEVELS

We conducted an assessment of respiratory health status including ques tionnaire and spirographic measurements in 54 male swine producers age 36.3 +/- 11.1 years (mean +/- SD) who worked an average of 10.7 +/- 6 .3 years in the industry and spent 4.7 +/- 2.1 hours per day in the sw ine barns, and we also measured atmospheric contaminants including car bon dioxide, ammonia, total dust, respirable dust, and airborne endoto xin. Mean atmospheric dust contaminant levels were as follows: carbon dioxide, 2632 +/- 807 ppm; ammonia, 11.3 +/- 4.2 ppm; total dust, 2.93 +/- 0.92 mg/ml; respirable dust, 0.13 +/- 0.05 mg/m3; and endotoxin, 11,332 +/- 13,492 endotoxin units/m3. Of these, endotoxin related to f orced vital capacity (P < .05) and endotoxin x hours per day was relat ed to forced vital capacity (P < .05) and to forced expiratory volume in 1 second (P = .06). Respiratory symptoms and lung function studies did not relate to categories of low, medium, and high exposure to resp irable dust. However, categories of endotoxin (available on 46 workers ) related to respiratory symptoms (cough, P = .02; chronic bronchitis, P =.06; and to forced vital capacity, P <.01). These data suggest tha t respiratory health status relates to endotoxin levels but not to dus t level exposures in the presence of low dust levels and indicates tha t control measures should include endotoxin as well as dust control.