Serum antibodies to Pseudomonas pseudoalcaligenes in metal workers exposed to infected metal-working fluids.

Metal workers exposed to aerosol from metal-working fluid were examined with respect to serum antibody to the lipopolysaccharide (LPS) of Pseudomonas pseudoalcaligenes. During 1 year of observation this species grew at high concentrations in the fluid (approximately 10(8) CFU/ml), and the air surrounding the metal-working machines sometimes contained more than 10(5) CFU/m3. The levels of antibody belonging to the IgG and IgA classes were significantly higher than in blood donors and in workers newly employed. Comparison with employees not working in the machine hall showed a significantly higher IgG, but not IgA, antibody level. For IgM antibody no such difference was found. Among the exposed workers, non-smokers had significantly higher IgG antibody levels than smokers, whereas no such difference was established for IgA and IgM antibodies. In smokers the IgG antibody level seemed to decline in the long-range time, since there was a negative correlation between the time of employment with exposure to metal-working fluids and IgG antibody level. The antibody data indirectly demonstrate that P. pseudoalcaligenes grown in metal-working fluid penetrated the body surface of metal workers to yield an immune response most probably after inhalation of aerosol containing bacteria. In the metal workers this long-term exposure did not lead to any acute or chronic respiratory discomfort.