Immunochemical quantitation of an airborne proteolytic enzyme, Esperase, in a consumer products factory

Occupational exposure of dry bleach factory workers to proteolytic enzymes poses a potential health hazard to susceptible workers. A sensitive immunochemical technique has been developed for quantitating exposure of factory workers to Esperase by sampling airborne particles on a fiberglass filter sheet followed by elution and assay for enzyme in a two-site immunoradiometric assay. By this method, 0.05 to 0.1 ng of enzyme (activity 50 KNPU/g) can be quantitated. With this sensitivity, as little as 2 to 4 ng/m3 airborne Esperase could be detected by personal monitors (flow rate of 0.002 m3/min; sampling time of 8 hr) and 0.05-0.1 ng/m3 of airborne Esperase with high volume samplers (flow rate of 1.13 m3/min;sampling time of 8 hr). There were significant day-to-day and site-to-site variations in the airborne Esperase content in the factory. Significant variations were also noted in the quantities of Esperase/m3 in the air inhaled by the workers in the same area on the same day. With this sensitive immunochemical technique and the use of personal monitors, the actual exposure of the worker as he moves about the factory could be measured.