Environmental Engineering Reference
In-Depth Information
Validated computer models are now available to estimate dosage that take into
account changes in altitude and geographical location during a flight. One of the more
commonly used is CARI-6 that was developed by the FAA Civil Aeromedical Insti-
tute in the US, and is freely available from the FAA via the Internet (www.cami.jccbi.
gov/AAM-600/610/600Radio.html).
A number of studies have been performed that suggest a slightly increased risk
of certain cancers (eg skin cancer: melanoma and basal-cell carcinoma) occurring on
the trunk and limbs, prostrate cancer in pilots, brain cancer, breast cancer and acute
myeloid leukaemia (see Table 4.2). Other cancers have also been reported but not at
significant levels of incidence (eg cancers of the stomach, pancreas, colon, larynx,
rectum and Hodgkin's disease) (Gundestrup and Storm, 1999; Ballard et al, 2000).
Published studies still do not paint a clear picture, and most authors still interpret
their results with great caution. Future studies are underway - in particular, the joint
European cohort mortality study, which aims to standardize study protocol design
across Europe and to provide a pooled analysis from the participating countries. The
combined analysis should be the most powerful to date and provide much needed
important information regarding the occupational cancer risk amongst aircrews
(Blettner et al,
1998).
Ta b l e 4 . 2
Socio-economic status-adjusted relative risks for cancer incidence and
mortality amongst flight personnel
Relative risk (RR)
95% Confidence interval
Amongst male pilots
Mortality from melanoma
1.97
1.02-3.82
Mortality from brain cancer
1.49
0.89-2.20
Incidence of prostrate cancer
1.65
1.19-2.29
Incidence of brain cancer
1.74
0.87-3.30
Amongst female flight attendants
Incidence of all cancers
1.29
0.98-1.70
Incidence of melanoma
1.54
0.83-2.87
Incidence of breast cancer
1.35
1.00-1.83
Source:
Ballard et al, 2000
Legislation relating to in-flight radiation exposure
In 1991 the International Commission on Radiation Protection (ICRP) (ICRP 60,
1991) published the recommendation that natural sources of radiation be classified as
occupational exposures and recommended an occupational annual limit of 20mSv yr
-1
,
compared to a
public limit of 1mSv yr
-1
. Consequently, aircrews are considered to be
one of the most highly exposed occupational groups, although their dosage is still
typically less than half of the ICRP 60 recommended dose (ICRP 60, 1991). The rec-
ommendations of ICRP 60 were incorporated into European legislation, and require-
ments for the protection of aircraft crew are given in Article 42 of the European
