A historical cohort study evaluated the mortality experience of 26,561 workers employed in 10
formaldehyde-producing or -using facilities. Approximately 600,000 person-years of follow-up accrued as workers were followed to January 1, 1980. Estimates of historical exposure to
formaldehyde by job were developed by project industrial hygienists using monitoring data available from participating plants, comments from long-term workers, and comprehensive monitoring data specifically collected for this study. Mortality from all causes combined was about as expected [standardized mortality ratio (SMR) = 96] based on mortality rates of the general U.S. population. Significantly fewer deaths occurred from infective and
parasitic diseases (SMR = 51) and from accidents (SMR = 72) than expected.
Cancer overall was not related to
formaldehyde exposure. Workers exposed to
formaldehyde had slight excesses for
Hodgkin's disease and
cancers of the lung and prostate gland, but these excesses were not consistently related to duration of or average, cumulative, or peak
formaldehyde exposure levels. Recent animal studies found
nasal cancer among rats exposed to
formaldehyde, but no excess of this
tumor occurred in this study. Mortality from
brain cancer and
leukemia among these industrial workers was not excessive in contrast to reported excesses among professional groups (e.g., anatomists, embalmers, and pathologists) with exposure to
formaldehyde. Although there was a deficit for
cancer of the buccal cavity and pharynx, mortality from certain subsites, i.e., the nasopharynx and oropharynx, was elevated. These subsites did not, however, show a consistently rising risk with level of exposure. These data provide little evidence that mortality from
cancer is associated with
formaldehyde exposure at levels experienced by workers in this study.