Abstract

Objective-To study the airway response and its mechanism to welding fumes in six
welders with respiratory symptoms.

Methods-Methacholine and welding challenge tests were carried out. The concentration of welding fumes during the exposure test was measured. On two subjects who developed bronchoconstriciton to welding challenge, additional tests were carried out including prick, patch, and inhalation challenges with metal salt solutions.

Results-Three subjects developed immediate bronchial reaction to exposure to welding fume; one to mild steel and stainless steel welding, another to mild steel and galvanised welding, and one only to galvanized welding. They all had a moderate to pronounced degree of non-specific bronchial hyperresponsiveness. The concentration of fumes during welding tests, particularly to galvanised welding, was high. An inhalation challenge test with zinc chloride salt solution in two subjects who reacted to galvanised welding was negative

Conclusions-The airway response to welding in these subjects is non-specific and is due to irritation rather than to sensitisation.

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Comments

SIC with zinc chloride salt solution in two subjects who reacted to galvanised welding was negative zinc chloride 0.3, 0.6, 1.2, 2.5, and 5 mg/ml in saline were used for the specific challenge test. After baseline spirometry was carried out, the subject inhaled saline nebulised for two minutes with a Bennett twin nebuliser at tidal breathing. Spirometry was repeated at one and 10 minutes after nebulisation. The same procedure was repeated starting with the lowest concentration of metal solutions. The inhalation test was discontinued when the highest concentration was reached or the FEVI had fallen by 20%.

2/15/2022