Twenty-three dust-exposed shacklers in the hanging departments of four poultry slaughter-house plants were examined immediately before work on a Monday morning with a standardized interview, pulmonary function tests (VC and FEV1), and blood sampling for analysis of complement factors. The examinations were repeated immediately after work the same day. Further, the individual breathing zone levels of both total dust and endotoxins were monitored during the whole work-shift. Moreover, spot samples of airborne bacteria and fungi were collected. The mean level of total dust was 6.3 mg/m3 (range 0.4-15.3 mg/m3) and of endotoxins 0.40 micrograms/m3 (range 0.02-1.50 micrograms/m3). Total levels of 4 x 10(5)-4 x 10(6) cfu/m3 of airborne bacteria, mainly coagulase-negative staphylococcal strains, but only 500-4000 cfu/m3 of fungi were found in the hanging departments. An over-shift increase in respiratory symptoms was found, but none of the workers had experienced any symptoms indicating extrinsic allergic alveolitis (EAA) or organic dust toxic syndrome (ODTS). Further, mean over-shift decreases of VC (3.1%) and FEV1 (4.1%) were found, indicating a harmful effect on the bronchi. There were, however, no associations between these over-shift decreases and the individual time-weighted average breathing zone levels of either total dust or of endotoxins. No over-shift change in serum complement factors was observed.