Respiratory and ocular symptoms in workers exposed to potassium aluminium-tetrafluoride soldering flux.

Background: Exposure to aluminium compounds, such as fluorides in gaseous and particulate form, places people who work in potrooms at risk for respiratory symptoms. Workers in potrooms, however, also are exposed to a number of other air contaminants. In this study, we present the first report of a dose-response relationship after exposure to potassium aluminium tetrafluoride (KAlF(4)) and the influence of smoking and atopy.

Materials: All workers (308) from an industrial plant that used KAlF as soldering flux were invited to participate in the study. In all, 289 workers participated and 118 employees not exposed to chemicals in their professional work served as an unexposed group.

Methods: In the first step, all subjects answered a questionnaire concerning respiratory symptoms and work history, and participated in a lung function examination. In a second step, all workers who reported work-related complaints from lower respiratory airways were invited to participate in medical examination, methacholine test, screening test of respiratory allergy, and skin prick test against KAlF(4).

Results: The exposed subjects had more symptoms than the unexposed group; dry cough odds ratio (OR): 5.17 (confidence interval 1.79-15.0), stuffy nose: 2.3 (1.25-4.22), nose bleeding: 10.7 (3.26-35.3) and ocular symptoms 5.01 (1.92-13.1) except for chest tightening and wheezing, and shortness of breath. The symptoms appeared in a dose response-like manner although the ORs between high and low exposed were significant for only chest tightening and wheezing, 2.62 (1.30-5.26) and stuffy nose 2.1 (1.22-3.66). Smokers and atopics did not report more frequent work-related symptoms. Smokers were significantly less hyperreactive than non-smokers, indicating a healthy-worker effect. No one showed a positive skin prick test against KAlF(4).

Conclusion: In spite of exposure levels of KAlF(4 )well below the new Swedish threshold limit, value frequent respiratory and ocular symptoms were reported. No evidence of IgE mediated allergy was found.