FORCES - Evidence by topic - Back to: The Evidence
AIRLINER CABIN ENVIRONMENT:
CONTAMINANT MEASUREMENTS, HEALTH RISKS,
AND MITIGATION OPTIONS (DOT-P-15-89-5)
PREFACE FROM FORCES
Though the health risks deriving from the exposure to ETS for both passengers and crew turn out
to be ridiculously small, the recommendations are to implement total smoking bans, though some
cosmetic recommendation exists to consider the needs of smokers (at an enormous estimated
expenditure, we may add).
Exposure to cosmic radiation turns out to be 68 times higher than ETS's (6,840% increase compared to
the risks of ETS) only causes the recommendation to "implement exposure management
strategies". Such option is not even considered for exposure to ETS. It is clear that cosmic radiations are not in the political eye (and don't bring any money into the pockets of airlines through savings), thus they do not deserve
radical action.
Notwithstanding the politically correct recommendations, the ridiculously small risk from ETS
exposure was blatantly demonstrated. For this reason, this study was made to disappear. To date
and to the best of our knowledge, there is no mention of it anywhere in government records.
Please note that since smoking bans have been implemented, the air quality in airplanes has
deteriorated dramatically because the filtration system has been de-tuned -- to make more profits
for the airlines -- since the odour of smoke no longer needs to be eliminated. As a result, the
possibility of airborne disease transmission has increased exponentially.
10.1.2 Risk Assessment
The risks faced by cabin crew members and passengers depend on such factors as
frequency of flying, number of years flown, specific routes flown, and, in the case of ETS
exposures, seat locations and prevailing smoking rates. The study conclusions pertaining to
cancer risks are based on specific scenarios relating to number of hours per year in flight, number
of years flown, and, in the case of ETS exposures, proportion of time spent in the smoking
section, boundary region near smoking, and other no-smoking areas. Detailed descriptions of the
scenarios and calculations underlying the risk estimates given herein are provided in Section 7.0
for ETS and in Section 8.0 for cosmic radiation. Estimates for cabin crew members relating to
ETS exposure pertain only to flight attendants and do not include the cockpit crew.
ETS
Estimated lifetime lung cancer risks ascribable to ETS exposure for nonsmoking cabin crew
members flying 960 hours per year on smoking flights for 20 years range from 12 to 15 premature
cancer deaths per 100,000 nonsmoking cabin crew members for domestic flights and from 13 to
17 premature cancer deaths per 100,000 for international flights. The range of estimates was
derived from two different cancer risk models (a phenomenological model and a multistage model)
that assume different durations of exposure.) Applying these risk estimates to the entire U.S.
cabin crew population results in an estimated 0.18 premature lung cancer deaths
per year for domestic flights (that is, approximately 4 premature deaths can be expected every
20 years) and 0.16 premature deaths per year for international flights.
Estimated Lifetime lung cancer risks due to ETS exposure for nonsmoking passengers flying
480 hours per year on smoking flights for 30 years range from 0.3 to 0.8 premature cancer deaths per 100,000 nonsmoking passengers
for domestic flights and from 0.2 to 0.6 premature cancer deaths per 100,000 for international
flights. The range of estimates was derived from the two cancer risk models mentioned above,
and the relatively broad range is due to differences in assumed durations of exposure and the
sensitivity of the multistage model to assumptions concerning the age at which exposure begins.
Estimated lifetime lung cancer risks due to ETS exposure for nonsmoking passengers flying
48 hours per year on smoking flights tor 40 years are approximately 0.1 premature cancer deaths
per 100,000 for both domestic and international flights. Applying these risk estimates to theU.S.
flying population results in an estimated 0.24 premature lung cancer deaths per year for domestic
flights (that is, approximately 10 premature deaths can be expected every 40 years) and 0.12
premature deaths per year for international flights.
In terms of acute effects based on CO concentrations as a proxy for ETS levels, it is
estimated that on one-third of smoking flights about 1 in 8 persons seated in the smoking
section would experience irritation due to ETS exposure. Further, it is estimated that on about
one-third of domestic smoking flights, ETS levels in the smoking section (based on nicotine
concentrations as a proxy ) would be sufficiently high to evoke a marked sensory response in
the eye and nose of an airliner cabin occupant.
Differential effects of ETS and its constituents on such sensitive populations as asthmatics,
children, and persons with ischemic heart disease or other cardiovascular disease could not be
estimated.
Cosmic Radiation
Estimated lifetime cancer risks due to cosmic radiation exposure for cabin crew members
flying 960 hours per year range from 90 to 1,026 premature deaths per 100,000 individuals
flying for 20 years on domestic flight: and from 220 to 512 pramature deaths per 100,000 idivi-
duals flying for 10 years on international flights. The estimates, which
pertain to cockpit crew members as well as cabin crew members, are lowest for relatively short
north-south domestic flights and higher for coast-to-coast flights involving higher altitudes. The
highest estimates are for relatively long, circumpolar international flights which also occur at high
altitudes.
Estimated lifetime cancer risks due to cosmic radiation exposure for passengers flying 480
hours per year range from 45 to 513 premature deaths per 100, 000 individuals flying for 20 years
on domestic flights and from 110 to 256 premature deaths per 100,000 individuals flying for 10
years on international flights. Like the above estimates for cabin crew, the range is governed
largely by flight altitudes and latitudes. Another concern is the effect of cosmic radiation on a
fetus, particularly during the first trimester.
Other Pollutants
The levels of bacteria and fungi measured in the airliner cabin air in this study were found
to be below the levels generally thought to pose risk of illness. Because quantitative
dose-response information on the health risks of biological aerosols was not available, the eval-
uation of the concentration data was performed by placing the prevalence of individual genera
that were identified in rank order, and comparing the prevalence to biological aerosols in other
indoor environments. The levels and general measured in the cabin environment were similar to
or lower than those commonly encountered in indoor environments characterized as "normal."
It was unnecessary to perform a risk assessment for ozone because measured levels on all
monitored flights were well below the current FAA and EPA standards.
10.1.3 Mitigation
Among the methods evaluated for reducing risks due to ETS, a total ban on airliner cabin
smoking would eliminate ETS exposure inairliner cabins and yield the greatest benefit to flight
attendants and nonsmoking passengers. A total ban on smoking on domestic flights is estimated to result
in an annual benefit of approximately 3 million to cabin crew and passengers, based on reduced
mortality risks. In conducting this benefit/cost analysis, reduction in mortality and associated
economic benefits were considered but benefits relating to reduced morbidity were not. Possible
costs related to smokers' inconvenience and discomfort or to displacement of smokers to other
modes of transportation were not considered due to limited data.
Beyond the two-hour ban that reduces ETS exposures on domestic flights by approximately
45 percent, more restrictive bans could be implemented to reduce exposures by as much as 98
percent. Restricting smoking to flights of a 6-hour or greater duration would reduce ETS
exposures by approximately 98 percent. and a restriction for flights of 4 hours or longer would
reduce exposures by about 86 percent. A different type of strategy to curtail smoking, such as
allowing smoking for a 10-minute period every two hours, could reduce average exposures to
ETS by as much as 70 percent. Such a strategy, however, could substantially increase the risks
of health effects from acute exposure during the brief periods when smoking would be allowed.
Two other mitigation measures--increased ventilation and improved filter efficiency--would
reduce ETS exposures by lesser amounts, ranging from 5 to 33 percent. Annual costs of
increased ventilation ( 6 to 50 million), which could reduce ETS exposures by as much as 33
percent, are substantially higher than the benefits ( 0.7 to 1.0 million) that could be calculated
within the constraints of this study. Costs related to improved filter efficiency were not available,
but improved efficiency would provide only a marginal reduction (5 percent) in ETS exposures.
Exposure management is the only viable option for reducing cabin crew member and
passenger exposures to cosmic radiation. In the case of crew members, this strategy would
involve careful scheduling of personnel to avoid persistent exposure to higher cosmic radiation
levels generally associated with high-altitude flights and flight paths toward extreme northern or
southern latitudes.
On aircraft with recirculation, C02 could be removed by sorption on solid adsorbent beds
whose adsorbent capacity for C02 can be regenerated by heating. Increased ventilation could
also bring C02 levels closer to the guidelines specified by ASHRAE. Cost or reliability data for
a sorption system were not available for comparison with costs of additional ventilation.
In view of the low levels observed for ozone and biological aerosols, mitigation strategies
were not assessed for these pollutants.
RECOMMENDATIONS
10.2.1 Actions for Improving Cabin Air Quality
Considerations should be given to a total ban on smoking on all flights departing from or
arriving at U.S. airports as a means of eliminating the ETS risks currently faced by nonsmoking
passengers and nons moking cabin crew members. The estimated benefits of such a strategy
exceed the costs, based on currently available data. In considering this ban, consideration will
need to be given to smokers inconvenience and discomfort, possible economic consequences
of displacement of smokers to alternative transportation modes, and other potential consequences
such as smoker withdrawal symptoms. Possible alternatives include limiting smoking to
longer-duration flights or restricting the time periods when smoking is allowed on flights. In the
latter case, further study would be needed of the potential health effects from acute exposure that
could occur during the limited periods when smoking would be allowed.
Airlines should implement exposure management strategies to reduce risks faced by cabin
crew members, particularly those related to cosmic radiation. Such strategies would include
careful scheduling of personnel, especially those at highest risk, to avoid persistent higher
exposures associated with flight paths at extreme northern/southern latitudes and higher altitudes.
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