Wood trimmers are exposed to molds that periodically grow on timber that may induce alveolitis and obstructive lung disease. We have evaluated respiratory symptoms, bronchial reactivity, and lung function in 28 wood trimmers at a Swedish sawmill and in 19 unexposed office workers. Eleven (sero-positive) of the wood trimmers had precipitating antibodies in peripheral blood against one or several molds. The exposure to dust (median 0.26 mg/m3), viable mold spores (median 2950 cfu/m3), viable bacteria (median 370 cfu/m3), airborne endotoxins (range 0.0015-0.0025 microgram/m3), and terpenes (range 0.4-23 mg/m3) was lower than levels that earlier have been reported to affect lung function. The wood trimmers reported an increased prevalence of cough and breathlessness. They also showed signs of a mild obstructive impairment with a tendency to increase bronchial sensitivity to metacholine and decreased FEV1 after 2 days free from exposure. FEV1 decreased more during the working week in the sero-positive workers than among the sero-negative workers, and for the whole group the decrease in FEV1 and MEF25 was correlated to the degree of mold exposure.

To assess the protective effect of exhausts pipe filters or respirators on pulmonary function, 15 workers in a tunnel construction site, truck and loading machine drivers, rock workers, and others were studied. The total and respirable dust, combustible matter in respirable dust, carbon monoxide, nitrogen monoxide and nitrogen dioxide were measured for each subject during entire work shifts. The effect of the exposure on the lung function variables was measured by dynamic spirometry, carbon monoxide single breath technique, and nitrogen single breath wash-out. The exhaust pipe filtering had a protective effect, directly discernible in the drivers on vital capacity and FEV1.0 and for the whole group on FEV% and TLco. The dust respirators had no effect, probably because of the difficulties in correctly using personal protection under the circumstances in the tunnel. In the absence of a true exposure assessment, control measures for diesel exhausts can be tested by medical effect studies. Catalytic particle filters of diesel exhausts are one method of rendering the emissions less irritant, although they will not remove irritant gases. An indicator of diesel exhaust exposure should include the particle fraction of the diesel exhausts, but a discrimination between different sources of organic dust must be possible.

Wood trimmers are periodically exposed to mould and may develop extrinsic allergic alveolitis (EAA). To investigate if there were any signs of EAA in wood trimmers with low exposure, 19 non-smoking wood trimmers underwent bronchoalveolar lavage (BAL), spirometry, and measurement of diffusion capacity (TLco). The group was subdivided into those with (n = 9) and without serological antibodies against mould. In 14 workers the TL,0 was measured both at the beginning and at the end of a week at work. Twenty five healthy non-smokers served as BAL controls and 19 healthy non-smokers as lung function controls. The median exposure of total dust was well below the Swedish threshold value, and the exposure of mould and bacteria was also low. The cell concentrations and the proportions of the various alveolar cells did not differ between the groups. The concentrations of the soluble components albumin, fibronectin, and hyaluronan were, however, significantly increased (p < 0.001 for all) in the workers. No difference was found in lung function between the workers and the controls, and the TLco was not impaired during a week at work. The groups of seropositive and seronegative workers did not differ in any of these parameters. The results are interpreted as a low intensity alveolar inflammation. The presence of precipitating antibodies against mould did not predict any greater risk of developing a more intense inflammation. Analysis of soluble non-cellular BAL components seems to reflect a discrete ongoing

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Objectives-To study whether air contaminants in sawmills can induce acute changes in the upper and lower airways of previously non-exposed subjects. Methods-Nineteen healthy volunteers were examined to find the concentration of interleukin 6 (IL-6) in nasal savage fluid and lung function before and after five hour exposure to dusts and fumes generated in a sawmill where timber from Scots pine was sawed. When exposed, the subjects had respirators with and without a particle filter. Results-The median for daily time weighted average concentration of total dust for subjects with respirators without a filter was 0'13 mg/m3, which was significantly higher than the median of 0-04 mg/im3 for subjects who had respirators with a filter. The median for the concentration of IL-6 in the nasal savage fluid increased after exposure from 0'5 to 5*9 pg/ml in subjects with respirators without a particle filter (P < 0OO5). The increase of the concentration ofIL-6 was significantly correlated with the dust concentration. A decrease in transfer factor of the lung was significantly correlated with daily time weighted average concentrations of terpenes. Conclusion-The findings suggest that healthy volunteers, exposed to air contaminants in a sawmill, show a slight inflammatory reaction. Also, the results of the study indicate the importance of decreasing the concentrations of wood dust in the work environment. (Occup Environ Med 1996;53:586-590)