The role of atopy in potroom workers' asthma.

A study was performed to clarify a possible role of atopy in the occurrence of acute bronchoconstrictive impairment observed in some workers in a plant using the Alu-Swiss process for the electrolytic extraction of aluminum. Of 227 workers examined the percentage of those with a history of atopy and positive skin tests for common allergens was within the expected range. Six had positive patch test with 2% NaF. Among seven workers with paroxysmal wheezing and dyspnea, of whom three were only light smokers, three had positive skin test with common allergens but only one of them had an increased IgE value. The same worker also had positive patch test for 2% NaF. The average age of workers with paroxysmal wheezing and dyspnea was 32.6 years, and only two had symptoms defined as chronic bronchitis. Although their forced expiratory volumes, with two exceptions, measured at the beginning of work shift were within normal limits, in most of those workers bronchial hyperreactivity was also objectively assessed using nonspecific bronchoprovocative tests with histamine (or metacholine). The results support our previous findings that acute respiratory impairment in some workers is most probably based on bronchial hyperreactivity and not on an allergic mechanism.