Occupations
Agents
Aluminium, Chromium, Nickel, Vanadium, Zinc.
Incidence
An epidemiological study in 1995 in young apprenties showed that only 1% of exposed subjects exhibited symptoms after a 5 year follow-up. Incidence is much higher amongst smokers. IgE-dependent mechanism, however irritants play a role. Atopy is an aggravating factor. In addition to the asthmatic risk, there is also a carcinogenic risk (Ni, Cr). In other forms of welding, such as welding tin, cases of asthma caused by zinc chloride have been described. In the case of nickel, its oxides are the cause of the problem; for chromium the hexavalent and trivalent forms are responsible.
Conditions
Sensitization is caused by fumes from the metals, chromium, nickel, cobalt, zinc, aluminium and vanadium. For example, asthma caused by zinc fumes has been reported in galvanization plants. The presence of argon, helium and/or carbon dioxide in the atmosphere gives rise to the production of oxygen free radicals. Vanadium oxide may also cause RADS (Reactive airways dysfunction syndrome or asthma caused by irritants – Brook's syndrome). Deposits of epoxide resins on the metals also increase the risk of work-related respiratory problems.
Symptoms
Severe asthma developing into chronic obstructive bronchopathy. Early and late phase reactions occur.
Diagnostic methods
Skin prick test can be performed, but it is not reliable.
Immunological assay: subject of current research.
Bronchial provocation test (in hospital).