EFFECT OF COAL-DUST INHALATION ON PULMONARY IMMUNOLOGICAL RESPONSES

Guinea pigs exposed to a coal dust aerosol (200 mg/m3) for 1 hour per day, 5 days per week for 4 weeks were evaluated for hypersensitivity to coal dust. No evidence of immediate pulmonary sensitivity was obtained from analyses of respiratory rates. To assess the possible activity of coal dust as an adjuvant, the effect of pulmonary coal dust accumulation on the induction of subsequent respiratory hypersensitivity to an unrelated antigen was investigated. Coal-exposed and control guinea pigs were sensitized to the antigen p-azobenzene arsonate ovalbumin (A-OA) by inhalation of protein aerosol. Both groups of guinea pigs developed severe respiratory hypersensitivity to the A-OA antigen. There was no difference between the groups with regard to either the severity of the hypersensitivity responses, the frequency of such responses or the amounts of antibodies to A-OA produced by both groups of animals. In contrast, pulmonary alveolar macrophages isolated from coal-exposed guinea pigs had only one-third the protein-synthesizing ability of macrophages from control animals. Copyright 1979, American Industrial Hygiene Association