Objectives-To investigate the relation between occupational hazards among nickel refinery workers and their exposure to different forms of nickel over time and the interaction between smoking and total exposure to nickel. Methods-The cohort consisted of 379 workers with first employment and at least three years of employment and 4385 workers with at least one year of employment 1946-83. Data on smoking (ever or never) were available for almost 95% of the cohort. Two analyses were used, indirect standardisation from observed and expected numbers and Poisson regression. Results-During the follow up 1953-93, 203 new cases of lung cancer were observed v 68 expected (standardised incidence ratio (SIR) 3*0, 95% confidence interval (95% CI) 2.6-3.4) and 32 cases of nasal cancer were observed v 1-8 expected (SIR 18-0, 95% CI 12-25). The Poisson regression analysis showed an excess risk of lung cancer in association with exposure to soluble forms of nickel, with a threefold increase in relative risk (RR) (P < 0.001) and a multiplicative effect of smoking and exposure to nickel. The RRs were 1 1 (95% CI 0.2-5.1) for exposed workers who had never smoked and 5-1 (95% CI 13-20-5) for exposed workers who smoked. Conclusion-It is not possible to state with certainty which specific nickel compounds are carcinogenic, but a significant excess risk was found for workers exposed to soluble nickel alone or in combination with other forms of nickel. The present study suggests a multiplicative effect of smoking and nickel exposure. (Occup Environ Med 1996;53:708-713)

This paper reports findings from a longitudinal study that evaluated the accumulated effect of three consecutive mass media campaigns using provocative and dissonance arousing appeals to prevent cigarette smoking by adolescents. In the spring of 1992, all eligible adolescents aged 14 and 15 in one intervention county (N = 4898) and one control county (N = 5439) in Norway were included in the study, and were followed until they were 17 and 18 years of age in 1995. Only students who completed questionnaires both in 1992 and 1995 were included in the analyses. Among the non-smokers at baseline, a significantly lower proportion of adolescents of both genders had started to smoke in the intervention county compared to the proportion in the control county. Among those who were smokers at baseline, significantly more girls in the intervention county had stopped smoking than in the control county, while no significant difference between the counties was detected among boys. Our findings suggest that provocative and dissonance arousing appeals that create affective reactions and lead to interpersonal communication should be given more attention in campaigns designed to influence adolescent smoking. However, such appeals may easily produce negative reactions and the normative context should be thoroughly considered when using such appeals in future interventions.

The results of a follow up study of the incidence of cancer and the mortality in a cohort of 454 male workers producing vinyl chloride and polyvinyl chloride are presented. The study population was restricted to employees with more than one year's work experience in the study plant between 1950 and 1969 and the cohort was followed up from 1953 to the end of 1979. Twenty three new cases of cancer were observed compared with 20.2 expected; one case of liver angiosarcoma was found. Five cases of lung cancer were found (2.8 expected) and four cases of malignant melanoma of the skin were observed (0.8 expected). The possibility of a causal relationship between exposure to vinyl chloride and the development of malignant melanomas is discussed.

The results are presented of a study of the overall mortality and the incidence of cancer in male workers producing ferrosilicon and ferrochromium. Although the study included all present and retired workers employed in the factory for more than one year from 1928 until 1977 inclusive, the incidence of cancer in those 976 workers who started work before 1 January 1960 was studied in particular. Both the overall mortality and the incidence ofcancer for all sites were lower than expected when compared with the national expected figures. Nine cases of lung cancer were found in the total population-seven in the ferrochromium subpopulation against expected rates of 3-1 and 1 8 when using national and local expected rates respectively as reference, and less than one expected case when using an internal reference population. A 1 5 O/E ratio was found for prostatic cancer in the whole study population. The results indicate that the increased incidence of lung cancer in the ferrochromium group has a causal relationship to occupational exposure. Perforation of the nasal septum was found in two present ferrochromium workers, and hexavalent chromium was found in the working atmosphere at the ferrochromium arc-furnaces during an industrial hygiene survey carried out in 1975. It is therefore concluded that the raised incidence of lung cancer is partly due to exposure to chromates. The results do not support the suggestion that exposure to chromic compounds entails a cancer hazard similar to that of exposure to hexavalent chromium compounds.Firm epidemiological evidence has been presented showing an association between prolonged inhalation of hexavalent chromium compounds and the development of cancer of the respiratory tract in exposed workers.' Such association has been shown both in workers exposed to dichromates2 3 and in workers exposed to chromium pigments.45 Increased incidence of cancer in the gastrointestinal tract has also been suggested in chromate workers by

ABSTRACr The overall mortality and the incidence of cancer have been studied among male employees at a plant producing calcium carbide. The cohort was defined as all men employed at the plant for at least 18 months in the period 1953 to 1970 and was classified according to 10 occupational categories. The 790 men have been observed from 1953 to 1983 and the incidence of cancer in the cohort has been compared with national incidence rates. A significant excess of colonic cancer (standardised incidence ratio, SIR = 2 09) and of prostatic cancer (SIR = 1.78) was found, and also a slight excess of lung cancer among furnace and maintenance workers (SIR = 1-56). The possible exposure of the workers to polycyclic aromatic hydrocarbons, asbestos, and cadmium is discussed.