Medical wastage in shipyard welders: a forty-year historical cohort study.

A 40-year historical cohort study of medical wastage among about 550 shipyard welders and 1100 controls (shipwrights and engine fitters), all employed at the same shipyard, was carried out. The welders left their job 20% more often than the controls; the excess considerably increased with duration of employment. Wastage was particularly due to respiratory, cardiovascular, locomotor and mental disorders. Both welders and controls contributed considerably (about 20%) to permanent work disability. Medical wastage among welders because of respiratory diseases was more than four times higher than among controls, which could not be explained by differential smoking habits alone. The study raises concern about locomotor health hazards for shipyard workers. Moreover, it underscores the need to reduce the large excess risk of respiratory diseases among shipyard welders. The same may be true for welders in other large metal construction plants, e.g. in boiler production.