Pulmonary abnormalities and serum immunoglobulins in facsimile machine repair technicians exposed to butyl methacrylate fume.

Seven repair technicians (RT, site A) repeatedly exposed to facsimile machine fume developed recurring sore throat, fever, lymphadenopathy, chest tightness, dry cough, and dyspnea. The fume concentration was low (0.6 mg/m3 of breathing-zone air) but it contained butyl methacrylate (BMA), a known skin sensitizer. Although chest radiographs were normal, three of the seven RT-A had lung crackles and spirometric abnormalities, and increased serum levels of immunoglobulins IgE or IgM. Symptoms and most other abnormalities improved when exposure to BMA was stopped. We later evaluated workers in two other sites (B and C). Six RT-B had daily contact with BMA fume (0.14 to 0.40 mg/m3 of air) at a field repair depot. Six administrative and six sales staff members (AS-B, SS-B) without regular fume exposure served as controls. All RT-B had elevated serum IgE levels (202+/-69 U/mL [SEM]; normal <41 U/mL). IgE and fume levels were positively correlated (r=0.83). four RT-B had lung crackles, but few symptoms and normal results of spirometry. The crackles cleared 8 weeks after substitution of a BMA-free paper, but IgE levels remained high (201+/-69). The nonexposed AS-B and SS-B had no crackles. Their IgE levels were normal (19+/-4 U/mL [SEM]; p<0.01). The crackles suggest BMA fume might have caused inflammation in terminal airways units. The significance of the IgE elevations is also uncertain since this class of antibodies is usually associated with asthma, not pneumonitis. In view of these uncertainties, BMA was eliminated from the facsimile transceiver process. Follow-up of group C workers (n=32) found no symptoms, lung crackles, or abnormal results of spirometry. However, IgE concentrations were elevated in 15 and remained so for 21 months, perhaps because of continuing exposure to residual low levels of BMA. These findings suggest that BMA-bearing facsimile fume caused increased IgE levels in RT at sites A, B, and C, and might have resulted in permanent lung injury if such exposure had continued.