Airliner Cabin Environment

Contaminant Measurements... -- Risk Assessment

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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 tothe 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.

10.1.2Risk 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. cabincrew 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 onsmoking 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 ofsmoking flights about 1 in 8 persons seated in thesmoking 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 toevoke 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, whichpertain 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.

10.1.3Mitigation

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 flightattendantsand nonsmoking passengers.A total ban on smoking on domestic flights is estimated to result in an annual benefit of approximately3 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, suchas 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 to50 million), which could reduce ETS exposures by as much as 33 percent, are substantially higher than the benefits ( 0.7 to1.0 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 managementis 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

10.2.1Actions 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 smokersinconvenience 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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