The smoking habits in Norway appear to have been strongly influenced by social changes and the increasing awareness of the health hazards of smoking. Each cohort's response to these events has depended on the members' age and sex at the time.

Occupational exposure and cancer incidence among workers from an aluminum smelter in western Norway by Rønneberg A, Haldorsen T, Romundstad P, Andersen AThe following articles refer to this text: 2008;34(6) Objectives This study investigated the associations between specific cancers and occupational exposure to polycyclic aromatic hydrocarbons (PAH), asbestos, electromagnetic fields, and heat in a cohort of workers from a Norwegian aluminum smelter. Methods Cancer incidence between 1953 and 1993 was observed for 2647 male short-term workers and 2 cohorts of men with at least 4 years' ernploylnent (2888 production workers and 373 maintenance workers). Standardized incidence ratios (SIR) were calculated from the national male cancer incidence, and associations with cumulative exposure were investigated by stratified analysis. Cumulative exposure in 15-year time windows was used as an alternative dose indicator. Results Investigation of the a priori hypotheses in the production cohort revealed a positive association between bladder cancer and PAH exposure 30 years or more before observation. The results also suggested an association between PAH and pancreatic cancer, although not statistically significant. No association was seen between exposure to PAH and cancers of the lungs or between magnetic field exposure and lymphatic and hematopoietic cancer. In the maintenance cohort there was a positive association between elnployment as an electrician and lymphatic and hematopoietic cancer and a statistically nonsignificant association between PAH and lung cancer. The short-term workers showed a statistically significant excess of lung cancer. C O~~~U S~O~S The results support previous findings of an association between exposure to PAH and bladder cancer.

(Occup Environ Med 1995;52:250-254)

Objective-To investigate associations between exposure to pot emissions (fluorides, sulphur dioxide) and mortality from chronic obstructive lung disease, coal tar pitch volatiles and mortality from diseases related to atherosclerosis, and carbon monoxide and mortality from ischaemic heart disease.Methods-Mortality between 1962 to 1991 was investigated in a cohort of 1085 men hired by a Norwegian aluminium smelter between 1922 and 1975. Associations between cumulative exposure and mortality were investigated through SMR analysis based on national mortality rates; temporal relations were explored by considering exposures only within specific time windows. Circulatory mortality was also investigated by Poisson regression analysis. Results-There were 501 deaths v 471-3 expected in the cohort. The excess was confined to short term workers and did not seem to be associated with exposures in the smelter. Analysis of mortality among the 661 men with at least three years employment showed associations between cumulative exposure to tar 40 years before observation and atherosclerotic mortality (P = 0 03), and between exposure to pot emissions 20-39 years before observation and mortality from chronic obstructive lung disease (P = 0.06). No association was found between exposure to carbon monoxide and mortality from ischaemic heart disease, but cerebrovascular mortality was associated with exposure to pot emissions (P = 0.02). Results for atherosclerotic and cerebrovascular diseases were confirmed through Poisson regression analysis. Conclusions-The data support previous findings of increased mortality from ischaemic heart disease in workers exposed to tar, and some support is also provided for earlier reports of increased respiratory mortality in potroom workers. (Occup Environ Med 1995;52:255-261)

This paper reviews the epidemiologic evidence of cancer risks among workers in aluminum reduction plants with emphasis on associations with specific work areas and exposures. Studies of workers manufacturing carbon products outside the aluminum industry were also reviewed since the work environment is similar to that encountered in the carbon area of aluminum plants. We obtained 22 reports from references cited in earlier reviews, through compact disc literature search 1980-1990, and from the Nordic Aluminum Industry's Secretariat for Health, Environment and Safety. Six reports were excluded because the material was included in later studies or because a critical evaluation was impossible. This left 16 publications from 11 separate studies. Work in potrooms with Söderberg electrolytic cells was associated with increased risk of bladder cancer, and the increase was correlated to duration of tar exposure. There was a suggestion of increased risk of leukemias and pancreatic cancers in potroom workers, and of kidney and brain cancers without any clear association with specific exposures or work areas. Singular results showed associations between lung cancer risk and tar exposure in Söderberg plants, and between lung cancer and work in prebake or carbon plants, but interpretation was limited by inadequate data on smoking and asbestos exposure, and by problems connected with the choice of reference populations in these studies.