Sawmill alveolitis in Sweden.

Short-lasting alveolitis-like symptoms are described in Swedish sawmill workers who are trimming and sorting moldy planks. Precipitating antibodies to Rhizopus antigen are demonstrated by double diffusion analyses in more than 50% of the wood trimmers, who are exposed to greater than 10(6) Rhizopus colony-forming units/m3 (Rcfu/m3). Febrile reactions with muscular pain and malaise occur in 10-20% at peak exposure levels above 10(7) Rcfu/m3. Sawmill workers with repeated acute symptoms have high titres of precipitating antibodies and are mainly non-smokers. The prevalence of this disease in the total Swedish wood trimmer population is estimated at 5-10%. Less typical symptoms from upper and lower airways and a mild, reversible decrement of forced vital capacity over one week's work shift is also suspected to be caused by this airborn mold. The pathogenetic mechanism is assumed to be identical with the wood mold reactions in wood chip burners, where a more complete picture of typical allergic alveolitis is seen. Identification of the cases and preventive measurements seem to have reduced the incidence rate of both these wood mold diseases.