Inhaled proteins are occupational allergens which cause IgE-mediated occupational asthma (OA) in egg production workers (Ws). Raw and processed egg particles become airborne during processing. To evaluate occupational ambient exposure to aerosolized egg, we quantitated total protein and specific egg allergens: ovalbumin (OVA), ovomucoid (OVOM), & egg lyzozyme (L YS), in air samples taken at a facility with 95 exposed Ws. Aerosol exposures were monitored using 37-mm closed-face cassettes with polyethylene-supported Teflon TM filters and personal sampling pumps, with air flow of 2 lImin., for an 8-hour shift. Filter protein was eluted in PBS, .05% Tween 20, pH 7.4. BCA tests (Pierce) were used to measure total protein; specific allergens were measured by competitive inhibition and sandwich EIAs. The mean values determined for total protein in f.1g/m3 air sample for different jobs/departments were: transfer, 644; breaking, 255; pasteurization, 32; dryer, 91; egg white packaging, 426; egg yolk packaging, 46; sanitation, 9.3. The percent of protein attributable to specific egg allergens also showed variation depending on the area sampled: ovalbumin, 50 - 99%, ovomucoid, 3 - 25%, lysozyme, <.01 - 10%. In stationary paired samples, the mean respirable/ total protein ratio was 322/607 microg/m3. A control referent plant showed a maximum of 41 microg/m3 protein with no detectable specific egg protein. The results indicate that OVA, which comprises 54% of egg protein was the predominant airborne antigen. Air sampling for egg protein can be useful to identify those locations where workers are exposed to high concentrations and where additional controls might be implemented.
The Toxicologist. Society of Toxicology 36th Annual Meeting, March 9-13, 2006, Cincinnati, Ohio