Cancer incidence and mortality in aircraft maintenance workers.

A cancer incidence and mortality study was conducted in response to health concerns raised by workers from F-111 aircraft deseal/reseal fuel tank maintenance programs, to determine whether personnel exposed to deseal/reseal had an excess of cancers and mortality. Number of deaths and cancers for individuals involved in F-111 DSRS activities were matched against two Air Force comparison groups. Analyses were weighted to adjust for differences in age, exposure period and rank. Eight hundred seventy-three exposed, 7,577 comparison group one, and 9,408 comparison group two individuals were matched against death and cancer data, with 431 cancers and 431 deaths. Cancer incidence was higher in the exposed group, with marginally significant increases of 40-50% (cancer incidence rate ratio range 1.45-1.62). Exposed group mortality was significantly lower than both comparison groups, likely due to survivor bias in the exposed group (mortality rate ratio range 0.33-0.44). On the balance of probabilities, there is an increased risk of cancer associated with participation in F-111 deseal/reseal activities.