A register-based approach has limited value in risk assessment of cellular phone use owing to lack of information on exposure.

Aims: To study the relation between exposure to crystalline silica and silicosis mortality. Although mortality is an important endpoint for regulators, there have been no exposure-response studies for silicosis mortality, because of the relative rareness of silicosis as an underlying cause of death, and the limited availability of quantitative exposure estimates. Methods: Data from six occupational cohorts were pooled with good retrospective exposure data in which 170 deaths from silicosis were reported. Standard life table analyses, nested case-control analyses, and risk assessment were performed. Results: The rate of silicosis mortality in the combined data was 28/100 000 py, increasing in nearly monotonic fashion from 4.7/100 000 for exposure of 0-0.99 mg/m 3

The incidence and prevalence of subjects awarded disability pensions and the prevalence of subjects receiving free medicines because of rheumatoid arthritis were studied in a Finnish cohort of 1026 granite workers hired between 1940 and 1971 and followed up until 31 December 1981. The incidence of awards of disability pensions because of rheumatoid arthritis during 1969-81, the prevalence of rheumatoid arthritis on 31 December 1981, and the prevalence of subjects receiving free medicines for rheumatoid arthritis at the end of 1981 were significantly higher among the granite workers than in the general male population of the same age. Retrospective analysis ofthe records ofall patients with rheumatoid arthritis in the cohort showed a predominance of a severe, serologically positive and erosive form ofrheumatoid arthritis, usually with an age at onset of 50 or over.The possible aetiological or pathophysiological role ofgranite dust in rheumatoid arthritis may be based on the effects of quartz on the immune system.

A mortality study of foundry workers. by Koskela R-S, Hernberg S, Kärävä R, Järvinen E, Nurminen MThe following article refers to this text: 1989;15(4):245-264 Key terms: coronary heart disease; foundry worker; lung cancer; mortality; mortality study; retrospective cohort sutdy; violent death suppl. 1, 73-89. The mortality of foundry workers was studied from a sample of all those men employed in 20 representative iron, steel, and nonferrous foundries for any period of time during 1950 through 1972. A statistical sample of 3,876 men from all those 15,401 workers with at least 3 months' exposure formed the cohort under study. The actual number of person-years of follow-up became 47,160. Total and cause-specific mortality was studied in the entire cohort and in different categories based on exposure time and occupation. The foundry workers' experience was compared to that expected on the basis of the general male population's death rates in Finland, and different categories of the cohort were compared to each other through direct standardization. During the period from 1950 through 1973, there had occurred 224 deaths. The mortality approached the expected value computed from the age-adjusted general male population, the standardized mortality ratio (SMR) being 90 for all foundry workers and 95 for workers in "typical" foundry occupations. The corresponding standard mortality ratios based on the estimated total number of person-years, after the application of corrections for sampling fractions, were 86 and 95, respectively. There was a ,slight shift of the age of death towards younger age groups among the casters, fettlers, and furnace tenders. Mortality from coronary heart disease showed a standardized mortality ratio of 80 for the whole cohort; no significant differences were found for any occupational category. Lung cancer mortality was higher than expected (SMR 150) in the entire cohort; closer analysis revealed that the excess was confined to iron foundries, and especially to molders with more than 5 years of exposure. There were no more violent deaths than expected, not even from work accidents. Because most occupational cohorts have standardized mortality ratios that are well below 90, the present results were interpreted as probably indicating slightly elevated mortality. The most important finding was the concentration of lung cancer among molders in iron foundries.

The mortality and disability of cotton mill workers were studied in five Finnish cotton mills. The population under study comprised all 1065 women exposed to raw cotton dust who had been hired between 1950 and 1971. The minimum exposure period was five years. For the study on disability, the cohort was followed up until the end of 1981. The follow up period for the mortality analysis was from 1950 to 1985. At the end of 1981 the observed number of prevalent disability pensions for respiratory disease was 15, whereas 3 9 were expected (p < 0 01) on the basis of the national figures for women. There were 46 musculoskeletal diseases (27-7 expected, p < 0-01), of which 24 were osteoarthritis (14-5 expected) and 13 rheumatoid arthritis (6-6 expected). The incidence rates of disability pensions were calculated for the period 1969-81. Comparison of incidence rates between cotton mill workers and the Finnish female population showed excessive rates for both respiratory diseases (p < 0 001) and musculoskeletal diseases (p < 0-01), with an excess of new cases of rheumatoid arthritis (p < 0-05). By the end of 1985 the number of person-years was 31 678 and the number of deaths 95. The standardised mortality ratios for the total period of follow up (1950-85) showed no excess for respiratory diseases. Mortality from cardiovascular diseases was also lower than expected. The observed number of tumours was 33, the corresponding expected number 32-0. Thirteen tumours were in the digestive organs (6-6 expected, p < 0-05) and three were lung cancers (19 expected). Five workers had died from renal disease; the expected number was 1-5 (p < 0-05).