A RETROSPECTIVE MORTALITY STUDY AMONG CANADIAN PETROLEUM MARKETING AND DISTRIBUTION WORKERS

We conducted a retrospective mortality study among 6672 petroleum mark eting and distribution workers from 226 locations throughout Canada. T hese employees worked for at least 1 year in the marketing distributio n segment from 1964 through 1983 or were annuitants as of 1964. indust rial hygienists assigned hydrocarbon (HC) exposure frequency scores fo r several jobs, departments, and job functions. we computed standardiz ed mortality ratios for the total cohort, HC exposure frequency groups , and tank truck drivers, and we also used Poisson regression techniqu es to model mortality for selected causes of death according to HC exp osure frequency. Results indicate overall mortality below that of the general Canadian population for all marketing distribution workers [St andardized mortality ratio (SMR) = 0.88]. Mortality from aortic aneury sms was significantly elevated in all marketing/distribution workers ( SMR = 1.79) but was due to raised mortality in nonexposed workers (SMR = 2.80). Tank truck drivers showed significantly elevated mortality d ue to leukemia (SMR = 3.35) based on five deaths. The leukemia finding s were not evident in the larger group of marketing distribution worke rs classified as exposed to hydrocarbons (SMR = 1.01). No other cause of death was elevated in truck drivers. The leukemia findings are sugg estive of a possible influence due to exposure to HCs in tank truck dr ivers, although other explanations cannot be ruled out. Other findings of elevated mortality in the marketing distribution group are general ly not statistically significant. These included moderately increased mortality due to multiple myeloma, malignant melanoma, and kidney canc er Small numbers of observed and expected deaths limit concise interpr etations for these diseases.