Cancer incidence among 10,211 airline pilots: a Nordic study.
BACKGROUND
Commercial airline pilots are exposed to cosmic radiation and other potentially carcinogenic elements during work and leisure activities.


OBJECTIVE
Work-related factors affect cancer pattern of the pilots.


METHODS
A cohort of 10,051 male and 160 female airline pilots from Denmark, Finland, Iceland, Norway, and Sweden was followed for cancer incidence through the national cancer registries. There were 177,000 person-years at follow-up, 51,000 of them accumulated after 20 yr since the time of first employment. Standardized incidence ratios (SIRs) were defined as ratios of observed over expected numbers of cases based on national cancer incidence rates. Dose-response analyses were done with Poisson regression method.


RESULTS
Among male pilots, there were 466 cases of cancer diagnosed vs. 456 expected. The only significantly increased SIRs concerned skin cancer: melanoma 2.3 (95% CI 1.7-3.0), squamous cell cancer 2.1 (1.7-2.8), and basal cell carcinoma 2.5 (1.9-3.2). The relative risk of skin cancers increased with the time since first employment, the number of flight hours, and the estimated radiation dose. There was an increase in the relative risk of prostate cancer with increasing number of flight hours in long-distance aircraft (p trend 0.01). No increased incidence was found for acute myeloid leukemia or brain cancer which were of interest a priori based on earlier studies.


CONCLUSIONS
This large study, based on reliable cancer incidence data, showed an increased incidence of skin cancer. It did not indicate a marked increase in cancer risk attributable to cosmic radiation although some influence of cosmic radiation on skin cancer cannot be entirely excluded.
Pukkala
Eero
E
Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research, Helsinki, Finland. eero.pukkala@cancer.fi
Aspholm
Rafael
R
Auvinen
Anssi
A
Eliasch
Harald
H
Gundestrup
Maryanne
M
Haldorsen
Tor
T
Hammar
Niklas
N
Hrafnkelsson
Jón
J
Kyyrönen
Pentti
P
Linnersjö
Anette
A
Rafnsson
Vilhjálmur
V
Storm
Hans
H
Tveten
Ulf
U
D000328:Adult; D017677:Age Distribution; D000368:Aged; D000401:Aircraft / Q000706:statistics & numerical data*; D015984:Causality; D015331:Cohort Studies; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology*; D009784:Occupational Diseases / Q000453:epidemiology*; D016273:Occupational Exposure / Q000706:statistics & numerical data; D011471:Prostatic Neoplasms / Q000453:epidemiology; D012306:Risk; D012537:Scandinavian and Nordic Countries / Q000453:epidemiology; D017678:Sex Distribution; D012878:Skin Neoplasms / Q000453:epidemiology; D016526:Workload / Q000706:statistics & numerical data