Evaluation of occupational asthma from airborne egg protein exposure in multiple settings.

We previously reported IgE-mediated occupational asthma among workers exposed to airborne egg protein at a plant that produces liquid and dried powdered egg products. To demonstrate that our original observations are generalizable to other facilities that process eggs, and to estimate the prevalence of IgE-mediated occupational asthma among egg-exposed workers, we conducted surveys at two additional plants. We administered a questionnaire to 188 employees to identify workers with symptoms suggestive of occupational asthma. We further evaluated 88 workers with and without symptoms by a clinical examination by a physician blinded to results of other tests, serial peak expiratory flow rate (PEFR) determinations every three hours while awake for one week, and skin prick tests and serum specific IgE levels to extracts of factory egg products, commercial egg test reagents, and egg white protein fractions. Fourteen workers had work-related asthmalike symptoms by questionnaire, a physician diagnosis of occupational asthma, and evidence of IgE-mediated sensitization to one or more egg proteins. Workers exposed exclusively to liquid egg aerosol, as well as workers exposed primarily to dried airborne egg protein, developed occupational asthma. This study replicated our original observations and demonstrated that workers in all areas of liquid and powdered egg production are at risk of developing occupational asthma from exposure to airborne egg proteins.

Investigation of a testicular cancer cluster using a case-control approach.

A case-control methodology was developed and utilized to investigate a reported cluster of testicular cancer among leather workers in New York. Eighteen cases of testicular cancer, including the three index cases, diagnosed from 1974 to 1986 among residents of two counties with substantial leather tanning and finishing establishments made up the case group. Controls (n = 259) consisted of men of similar age who had been diagnosed with cancers of all other sites during the same time period. Reports of usual occupation for cases and controls, obtained from cancer registry reports and death certificates, indicated that cases were much more likely to be leather workers (28%) than controls (7%). After adjustment for age, the relative risk estimate for occupation and testicular cancer was 7.2 (95% Cl: 1.9-27.7). The association was further supported by occupational histories showing similar work environments within the leather industry for five out of six cases known to have been leather workers. Case-control analysis of a reported cluster does not provide independent confirmation of an association between occupational factors and testicular cancer. The methodology, however, can provide a timely way to evaluate the significance of occupational cancer clusters.