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.

Angina pectoris, ECG findings and blood pressure of foundry workers in relation to carbon monoxide exposure. by Hernberg S, Kärävä R, Koskela R-S, Luoma KThe following article refers to this text: 1989;15(4) 2 (1976): supp!. 1, 54--63. A prevalence study on angina pectoris, ECG changes, and blood pressure was carried out with those 1,000 workers (response rate 93.1 0/0) with the longest exposure time (minimum 4.2 years) from a statistical sample of 20 foundries. The history of angina was obt ained from a questionnaire recommended by the World Health Organization, and the ECGs were coded according to the Minnesota code. On the basis of measurements of the concentration of carbon monoxide (CO) in the air, the workers were divided into three occupational exposure groups, one with definite CO exposure, one with slight or occasional CO exposure, and one without CO exposure. Allowance was also made for present and past smoking habits. All comparisons were made on an intrasiudy basis between the different subcategories. The prevalence of angina showed a clear dose-response relationship with regard to CO exposure from either occupation, smoking, or both, but no such trend was found for ECG findings suggestive of CHD. These results may suggest a greater sensitivity in detecting CHD on the part of the angina questionnaire. The systolic and diastolic blood pressures of CO exposed workers were slightly higher than those of other workers when age and smoking habits were taken into consideration. However, exposure to heat was intermixed with exposure to CO. It could be shown that selection based on health had operated in the foundries. Hence, the prevalence found can be considered to be underestimates of the "true" occurrence of cardiac disorders. Nevertheless both angina and "coron:-ry" ECG findings were more prevalent than in other methodologically comparable studies on the general population or industrial workers without toxic exposure.

No abstract

The prevalence of pneumoconiosis, chronic bronchitis, and impaired lung function was studied among those 1,000 foundry workers (response rate 93.1 %) with the longest exposure time (minimum 4.2, mean 17, SD 9 years) from a representative sample of 20 foundries. Pneumoconiosis was diagnosed from 100 X 100 mm radiographs, and the false positives and false negatives were evaluated from normal-size radiographs from alI those with a positive finding and a sample of those with a negative finding. Chronic bronchitis was studied by means of a translation of the MRC Short Questionnarie on Respiratory Symptoms. Forced vital capacity and forced expiratory volume in 1 s were measured with a Vitalograph Single Breath Wedge Spirometer, and the FEV % was calculated from these variables. The subjects were grouped according to smoking habits and dust exposure, which could be fairly welI evaluated from measurements performed in connection with the health survey. AlI comparisons were made between different subcategories. The overalI prevalence of pneumoconiosis was 3.8 0/0, when alIowance had been made for false positive and false negative findings. Most cases were mild. Chronic bronchitis occurred more frequently among those occupied in jobs classified as dusty. Smoking also strongly increased its prevalence; a combination of both exposures produced the strongest effect. The effect of smoking was also evident as an impairment of lung function; however, no such effect of dust expo sure could be shown in this material. Since this was a prevalence study, the selective removai of workers from dusty jobs probably led to underestimates of alI the health effects studied. In spite of the effect of selection excess bronchitis could be demonstrated in workers from dusty environments. Therefore effective dust control must be initiated not only with regard to silica dust but also with respect to total dust.

One hundred and sixty-six middle-aged Finnish men free of clinical coronary heart disease (CHD), but having at least one CHD risk factor, participated in an 18-month controlled exercise intervention study, one-half as an exercising group and the other half as a matched control group; thereafter all 166 followed a partially controlled exercise programme for the next year. These men formed the intervention group for the present follow-up study covering the subsequent 6 years. The reference group for the follow-up comprised 152 men who fulfilled the same inclusion criteria for the original study as the intervention subjects, but who had been excluded from the study for non-medical reasons, mainly because they could not be pair-matched. Mortality statistics were collected, and a postal questionnaire on chest pain symptoms and physical activity was sent to all of the men 8 years after the start of the study. On CHD death and four deaths occurred in the reference group, and one CHD and no other deaths in the intervention group. Severe chest pain possibly suggestive of myocardial infarction was more common in the reference group than in the intervention group, but no difference was found in angina pectoris symptoms. The level of recent physical activity or smoking did not affect the chest pain symptoms independently.