Bacillus subtilis Enzymes: a 7-year Clinical, Epidemiological and Immunological Study of an Industrial Allergen

A survey of 1642 workers in a factory producing enzyme washingpowders from 1968 to 1975 has shown that reduction of totaldust and enzyme dust levels, combined with full implementationof the Soap and Detergent Industry Association recommendations,have eliminated detectable respiratory illness.Previous findings,that atopic subjects were more likely than non-atopies to becomeskin prick-test positive (PT+) to a standardized enzyme reagent,have been confirmed. After excluding atopies from such workthe percentage converting to PT+ has steadily fallen. Individualswith only a PT+ have no clinical symptoms and do not react inany way to the working environment. Of all employees workingthroughout this period, 82 per cent (1354 out of 1642 tested)have remained prick-test negative. It is shown that repeatedprick testing with the same allergen does not induce allergicskin reactivity. There is a good correlation between prick-testresults and the results of serological tests for enzyme specificIgE. There is no evidence of any difference in changes in theventilatory capacities of prick-test positive as against prick-testnegative employees, or that positivity alone is a contraindicationto working with these products.Varying degrees of contact orlengths of exposure to enzymes do not produce any statisticallysignificant differences in changes in lung function. The surveydoes not reveal any evidence of longer-term obstructive bronchialdisease. Requests for reprints should be addressed to: Dr C.P. Juniper, Medical Centre, Lever House, Port Sunlight, Merseyside.