Further Analysis of Cancer Mortality Patterns Among Workers Exposed to Cutting Oil Mists2

Abstract

Workers exposed to cutting oil mists at a single U.S. plant were followed to determine if they experienced unusual death rates for specific cancer sites, which would be indicative of a carcinogenic potential for some or all of the oils used. The study group consisted of 2,485 white males who were employed between 1938 and 1967 and had 5 or more years' employment in jobs exposing them to varying levels of cutting oil mists anytime prior to 1968; 1.137 of these men were engaged in a wide range of metal machining processes that entailed longterm heavy exposure to the mists. Cause-specific mortality patterns among the workers during 1938–67 were compared to death rates in the total U.S. white male population. The usual deficits were seen in mortality for most major disease categories, although total cancer deaths were very close to expectation. Analysis of mortality for each of 15 cancer site categories showed no significant differences between observed and expected deaths for almost all comparisons. However, a twofold risk of cancers of the stomach and large Intestine (combined) was seen after 20 years of follow-up In the subgroup of men with 5 or more years' exposure to cutting oil mists prior to 1938. Deaths from nonmalignant respiratory disease were significantly less than expected. These results suggested that occupational exposure to soluble and nonsoluble cutting oil mists during various metal machining processes does not pose a health hazard in terms of respiratory cancer and fatal nonmalignant respiratory disease but may be associated with certain forms of gastrointestinal cancer.