Mortality among members of a heavy construction equipment operators union with potential exposure to diesel exhaust emissions.

Abstract

A historical prospective mortality study was conducted on a cohort of 34 156 male members of a heavy construction equipment operators union with potential exposure to diesel exhaust emissions. This cohort comprised all individuals who were members of the International Union of Operating Engineers, Locals 3 and 3A, for at least one year between 1 January 1964 and 31 December 1978. The mortality experience of the entire cohort and several subcohorts was compared with that of United States white men, adjusted for age and calendar time. The comparison statistic was the commonly used standardised mortality ratio (SMR). Historical environmental measurements did not exist, but partial work histories were available for some cohort members through the union dispatch computer tapes. An attempt was made to relate mortality experience to the union members' dispatch histories. Overall mortality for the entire cohort and several subgroups was significantly lower than expected. When cause specific mortality was examined, however, the study provided suggestive evidence for the existence of several potential health problems in this cohort. Mortality from liver cancer for the entire cohort was significantly high. Although mortality from lung cancer for the entire cohort was similar to expected, a positive trend by latency was observed for lung cancer. A significant excess of mortality from lung cancer was found among the retirees and the group for whom no dispatch histories were available. Other dispatch groups showed no evidence of lung cancer excess. In addition, the total cohort experienced significant mortality excess from emphysema and accidental deaths.The potential adverse health effects of exposure to diesel exhaust emissions have recently gained considerable attention in the scientific community. This concern is even greater within federal regulatory agencies, partly because of the projected rise in the number of diesel powered cars in this decade. For both medical and economic reasons, it is important to investigate the implications of such a trend to public health.Diesel exhaust emissions consist of a mixture of gases and particles, including carbon monoxide, oxides of nitrogen and sulphur, and particulates, which contain traces of the polycyclic aromatic hydrocarbons.' Exhaust emissions from some current diesel engines contain compounds that are mutagenic and carcinogenic in short term in vitro tests2; the significance of these findings to human health is as yet unknown.Limited epidemiological data on the health consequences of exposure to diesel exhaust emissions are available from a few studies.3-8 These few relevant studies have been summarised in a recent review article.9 The findings from these studies will not be discussed here, except to note that the results cannot rule out a carcinogenic effect on the lung from occupational exposure to diesel engine exhaust.Because of this uncertainty, a historical prospective mortality study of heavy construction equipment workers, many of whom were potentially expo...

A critical review of the relationship between occupational exposure to diesel emissions and lung cancer risk

“…This retrospective, mortality cohort study consisted of 34,156 male Heavy Construction Equipment Operators Union members with at least 12 months of membership between 1964 and 1978 (Wong et al 1985). Overall, 9.8% of the cohort died before 31 December 1978, the end of the follow-up period.…”

Associations between several sites of cancer and ten types of exhaust and combustion products. Results from a case-referent study in Montreal.

“…Among London Transit Authority workers there was no evidence of lung cancer excess (38). Nor did Wong et al (40) find any convincing excess of lung cancer among operators of heavy construction equipment. Howe et al (17) found some excess among Canadian railway workers exposed to diesel exhaust.…”

A 39-year follow-up of the U.K. oil refinery and distribution center studies: results for kidney cancer and leukemia.

“…De Silva (58) measured blood lead levels of gasoline pump attendants in Melbourne and concluded that the levels were lower than the accepted level of concern. Other studies have looked at the effect of diesel exhaust emissions (59,60).…”