Risk of lung cancer according to mild steel and stainless steel welding.
OBJECTIVE
Whether the elevated risk of lung cancer observed among welders is caused by welding emissions or by confounding from smoking or asbestos exposure is still not resolved. This question was addressed in a cohort with a long follow-up and quantified estimates of individual exposure to welding fume particulates.


METHODS
Male metal workers employed at least 1 year at one or more Danish stainless or mild steel industrial companies from 1964 through 1984 were enrolled in a cohort. Data on occupational and smoking history were obtained by questionnaire in 1986. Welders in the cohort who started welding in 1960 or later (N=4539) were followed from April 1968 until December 2003, when information on cancer diagnosis was obtained from the Danish Cancer Registry. During the follow-up, 75 cases of primary lung cancer were identified. Lifetime accumulated exposure to welding fume particulates was estimated by combining questionnaire information and more than 1000 welding-process-specific measurements of fume particulates in the Danish welding industry.


RESULTS
The standardized incidence ratio (SIR) for lung cancer was increased among the welders [SIR 1.35, 95% confidence interval (95% CI) 1.06-1.70)]. Among the stainless steel welders, the risk increased significantly with increasing accumulative welding particulate exposure, while no exposure-response relation was found for mild steel welders, even after adjustment for tobacco smoking and asbestos exposure.


CONCLUSIONS
The study corroborates earlier findings that welders have an increased risk of lung cancer. While exposure-response relations indicate carcinogenic effects related to stainless steel welding, it is still unresolved whether the mild steel welding process carries a carcinogenic risk.
Sørensen
Anita Rath
AR
Aarhus University Hospital, Department of Occupational Medicine, Aarhus, Denmark.
Thulstrup
Ane Marie
AM
Hansen
Johnni
J
Ramlau-Hansen
Cecilia Høst
CH
Meersohn
Andrea
A
Skytthe
Axel
A
Bonde
Jens Peter
JP
D000328:Adult; D000395:Air Pollutants, Occupational / Q000032:analysis; D003718:Denmark / Q000453:epidemiology; D006801:Humans; D008175:Lung Neoplasms / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012907:Smoking / Q000453:epidemiology; D013193:Stainless Steel; D013232:Steel; D011795:Surveys and Questionnaires; D014896:Welding
D000395:Air Pollutants, Occupational; D013193:Stainless Steel; D013232:Steel