Occupational asthma caused by stainless steel welding fumes: a clinical study

¹ Finnish Institute of Occupational Health, Occupational Medicine, Helsinki, Finland.

^* To whom correspondence should be addressed. E-mail: Timo.Hannu{at}ttl.fi.

	Abstract

The aim of the present study was to describe the cases of OA due to stainless steel welding fumes diagnosed at the Finnish Institute of Occupational Health during the period 1994-2003.

OA was diagnosed according to patient history, lung function examinations, and welding challenge tests with measurements of the FEV₁ and PEF values.

Our series comprised 34 patients, all men, with a mean age of 44.7 years (range 22-57), mainly working as welders. The mean duration of exposure was 22.4 years, and the mean duration of exposure before the onset of respiratory symptoms was 18.0 years. Dyspnoea was the most frequently reported work-related respiratory symptom. During the inhalation challenge tests, the mode of the asthmatic FEV₁/PEF reaction was delayed in 16 (47%) patients, immediate in 9 (26%) patients, and dual (both immediate and delayed) in 9 (26%) patients. In the follow-up assessment six months later, only six patients were considered able to continue performing welding tasks, whereas occupational injury pension was recommended to seven, and measures of vocational rehabilitation to 14 patients.

In most cases, after the diagnosis of OA, the continuation of welding work was not possible.