Plywood Mill Workers' Mortality Patterns 1945-1977 (Revised March 1987)

摘要

A cohort of 2,283 plywood mill workers employed for at least one year between 1945 and 1955 was traced through March 31, 1977. Vital status was determined for 98% of the cohort. The 570 deaths observed were only 74% of the number expected based on comparable U.S. mortality rates. A statistically nonsignificant excess of deaths was observed for the category of lymphatic and hematopoietic cancer excluding leukemia (SMR=156, CI=90-252). Within this category, the excess was greatest for multiple myeloma (SMR=333, 3 deaths observed, 0.9 deaths expected); however, the risk was slightly elevated for all four subgroups of lymphatic and hematopoietic cancer. When analyses of duration of employment and time since first employment (latency) were conducted, the excess mortality due to lymphatic and hematopoietic cancer excluding leukemia was highest after 20 years duration of employment and latency. Based on walk-through surveys in the plywood mills, no known etiologic agents were distinguishable. Plywood workers were potentially exposed to formaldehyde around gluing operations in the mill. However, no deaths due to nasal cancer, which has been associated with exposure to formaldehyde in laboratory animals, were observed in this cohort, although only 0.4 deaths were expected.