Heart disease mortality among workers exposed to carbon monoxide in New York City.
Case studies in occupational epidemiology. Steenland K, ed. New York: Oxford University Press, 1993 Jan; :21-34
An historical cohort mortality study of bridge and tunnel workers conducted to determine long term effects of exposure to carbon- monoxide (630080) (CO) was described. This study was presented as part of a text book to take the reader through the same steps that the investigator took when conducting the actual study to allow the student to solve the same problems that the investigator solved in the course of the study. To be a member of the cohort workers had to be employed at least 1 day between January 1, 1952 and February 10, 1981. A 97% follow up was achieved for both the bridge and tunnel officers. The percentage of tunnel officers who died was 13%, almost twice that of the 7% reported for bridge officers. The standardized mortality ratio (SMR) for heart disease for tunnel officers was 1.24. Heart disease for tunnel officers was particularly high for arteriosclerotic heart disease (ASHD) with an SMR of 1.35. After 10 yeas of employment the mortality from ASHD increased to 88% over the expected. The results of the study indicated there was an association between CO exposure and ASHD. The overall relative risk of 35% greater than expected was observed in comparing tunnel workers to the population of the United States. When compared to bridge workers directly, the excess risk was 67%.
Risk-factors; Cardiovascular-system-disorders; Toxic-gases; Tunnel-workers; Epidemiology; Humans; Occupational-exposure; Mortality-surveys
Case studies in occupational epidemiology