KOTIMAA MH, HUSMAN KH, TERHO EO, MUSTONEN MH. Airborne molds and actinomycetes in the work environment of farmer's lung patients in Finland. Scand J Work Environ Health 10 (1984) 115-1 19. Occurrence of molds and actinomycetes in the breathing zone of farmers during the handling of hay, straw, or grain was studied with the use of an Andersen sampler on 35 farms in Finland. On 24 farms there was a person with recently diagnosed farmer's lung disease, and on 11 farms people were free of the disease. The total spore concentration and the concentrations of the spores of Thermoactinomyces (7) vulgaris, Micropolyspora ( M ) faeni, and Aspergillus ( A ) umbrosus were statistically significantly higher on the farms of patients with farmer's lung than on the disease-free farms. The mean proportions of the spores of thermotolerant and thermophilic microbes were greater on the farms of farmer's lung patients than on the reference farms. T vulgaris was the predominant actinomycete species. Both T vulgaris and A umbrosus were found on all farms of farmer's lung patients, but M faeni on only about half of such farms. The findings match the results of previous microbiological analyses of Finnish moldy hay and serological analyses of Finnish farmer's lung patients. It seems that T vulgaris, not Mfaeni, may be the main causative agent of farmer's lung in Finland. The possible etiologic role of A umbrosus requires further investigation. Because the farmers often failed to identify the moldiness of the plant material in contrast to researchers, it might be possible, through training, to improve farmers' ability to identify moldiness.

A study of sewage workers' exposure to airborne culturable bacteria and inhaled endotoxins was performed at nine waste-water treatment plants that treat mainly industrial effluents. Airborne endotoxins were collected on glass fiber filters and analyzed using a chromogenic limulus assay. Endotoxin concentrations measured in the immediate vicinity of the waste-water treatment process varied from 0.1 to 350 ng/m3. The eight-hour time weighted average concentrations of endotoxin to which workers were exposed exceeded the suggested exposure limit (30 ng/m3 endotoxin) at four of the plants. Air samples of culturable bacteria concentrations varied between 10 and 10(5) colony-forming units/m3. Of the particles carrying culturable bacteria, 88% had an aerodynamic diameter of less than 4.7 microns. The most common genera of airborne gram-negative bacteria were acinetobacter, citrobacter, enterobacter, klebsiella, and pseudomonas. High levels of exposure to bacteria and bacterial endotoxin usually were related to certain phases of the treatment process. The microbiological contamination of air was highest near the inlets where incoming wastewater entered the basins, in the sludge treatment area, and inside the biofilter tower. In these spaces it is necessary to control and reduce exposure to airborne bacteria and endotoxin at wastewater plants.

ABSTRACr A total of 57 subjects who had been exposed to mould dust in the tobacco industry were studied. Their working environment showed exposure to spores of different moulds, and 29 subjects (51 %) showed antibodies against one or more of the microbes. Fifteen (26%) had work related respiratory symptoms. Eight (14%) showed slight radiographic pulmonary fibrosis. Spirometry showed a tendency toward restriction and obstruction, especially in small airways. Diffusion capacity was decreased in 18% of the workers. Three clinical cases of typical allergic alveolitis were also found. All this suggests that exposure of spores of different moulds (especially Aspergillus fumigatus) in the manufacture of tobacco products may induce symptoms and signs relating to extrinsic allergic alveolitis.

KOTIMAA MH, OKSANEN L, KOSKELA P . Feeding and bedding materials as sources of microbial exposure on dairy farms. ScandJ WorkEnvironHealth 1991:17:117-22. Hay, grain, silage, and bedding are the sources of mold dust in agriculture. The aim of the present study was to evaluate the effect of different farming methods on exposure to airborne microbes. The study material comprised 50 silage, 54 hay, 47 grain , and 70 beddin g samples taken on 18 farm s in the beginning , middle, and end of the indoor feeding season. The modified wind-tunnel technique and six-stage impactors were used to determine the number of mesophilic bacteria, xerophilic fungi, mesophilic fungi, thermotolerant fungi, and thermophilic actinomycetesliberated from each material. Baled hay and straw liberated the largest amounts of microbes. Hay, except when dried in storage, liberated great numbers of fungal spores. The proportion of respirable airborne microbe-bearing particles was greatest in the highest concentrations . Theoretically, choosing the best possible alternative work methods could diminish exposure to microbes to onetenth of the present level.

Extrinsic allergic alveolitis in a sawmill worker. A case report. by Terho EO, Husman K, Kotimaa M, Sjöblom T