II for more details on this study.) FAA has Taken Action to Address Council Recommendations On Cabin Air Quality, but These Efforts Could Be Improved

The December 2001 Council report on airliner cabin air quality made 10  recommendations about air quality standards for the cabins of commercial  airliners and the need for more information concerning the health effects of  cabin air. In implementing the Council  report recommendations, FAA is attempting to balance the need to conduct  additional research on the healthfulness of cabin air quality with other  research priorities, such as improving passenger safety. Specifically, some in the aviation community  have raised concerns that FAA’s planned actions for implementing the  Council recommendations on cabin air quality, including its research and  surveillance efforts, will not be adequate to answer long-standing questions  about the nature and extent of potential health effects posed by cabin air. According to FAA, the surveillance and research program is to be carried  out in two parts; the first started in December 2003 and the second will  start in December 2004 and end in late 2006 or early 2007. These officials also noted that  a voluntary injury and illness reporting system that it has in place could  capture air quality incidents if it were made mandatory. In addition to citing the need for FAA to  increase the accessibility of health-related information on its Web site, six  of the eight committee members also mentioned that FAA should take  further steps to make health information available to the flying public. Some Technologies Exist for Improving Cabin Air Quality, but There Are Questions About Whether They Should be Required

Several technologies exist today that could improve cabin air quality, but  opinions vary on whether requiring the use of improved technologies in  commercial airliner cabins is warranted. We found one of these  technologies, HEPA filters, is strongly endorsed by cabin air quality and  health experts as providing the best possible protection against one cabin  air problem—the presence of particulates, bacteria, and viruses in  recirculated air. However, some regional jets, which have fewer  than 100 seats, are not equipped with filters, and some older large aircraft  still use less efficient filters. One airline has  plans to retrofit a small number of these aircraft with HEPA filters. Recommendations for Executive Action

To help ensure that FAA’s research and surveillance efforts on airliner cabin  air quality answer critical outstanding questions about the nature and  extent of potential health effects of cabin air quality on passengers and  flight attendants, GAO recommends that the Secretary of Transportation  direct the FAA Administrator to  develop a detailed plan for the research and surveillance efforts,  including key milestones and funding estimates, in accordance with  generally accepted practices for oversight and independence;   appoint a committee of acknowledged experts in the fields of aircraft  ventilation and public health, including representatives of EPA and  NIOSH, to assist in planning and overseeing the research and  surveillance efforts recommended by the National Research Council in  2001;  leverage the findings of international research on airliner cabin air  quality to inform FAA’s surveillance and research efforts; and  report to Congress annually on the progress and findings of the research  and surveillance efforts and funding needs. In order to help improve the healthfulness of cabin air for commercial  aircraft passengers and cabin crews, the FAA Administrator should assess  the costs and benefits of requiring the use of HEPA filters on commercial  aircraft with ventilation systems that recirculate cabin air. (2) What actions has the National Research Council  recommended to improve cabin air quality, and what is the status of those  actions? We also interviewed officials representing the  Federal Aviation Administration (FAA), the World Health Organization  (WHO), the Centers for Disease Control and Prevention (CDC), the  National Institute for Occupational Safety and Health (NIOSH), the  Aerospace Medical Association (AsMA), the Air Transport Association  (ATA), the Association of Flight Attendants (AFA), the International Airline  Passengers Association (IAPA), aircraft and air filter manufacturers, as  well as experts on cabin air quality issues, including members of the  committee that produced the 2001 Council report on cabin air quality. Transmission of Severe Acute Respiratory Syndrome (SARS) on Board Aircraft Is Rare and Associated with Proximity

Aboard aircraft, cabin occupants are confined in close quarters for  extended periods and can be exposed to infectious diseases carried by  other occupants. Does recirculating cabin air increase cabin  occupants’ risk of exposure? National Research Council. National Research Council. U.S. General Accounting Office.
Why GAO Did This Study

Over the years, the traveling public, flight attendants, and the medical community have raised questions about how airliner cabin air quality contributes to health effects, such as upper respiratory infections. Interest in cabin air quality grew in 2003 when a small number of severe acute respiratory syndrome (SARS) infections may have occurred on board aircraft serving areas that were experiencing outbreaks of the disease. In 2001, a National Research Council report on airliner cabin air quality and associated health effects recommended that additional research be done on the potential health effects of cabin air. GAO reviewed what is known about the health effects of cabin air, the status of actions recommended in the 2001 National Research Council report, and whether available technologies should be required to improve cabin air quality.

What GAO Found

Despite a number of studies of the air contaminants that airline passengers and flight attendants are potentially exposed to, little is known about their associated health effects. Reports on airliner cabin air quality published by the National Research Council in 1986 and 2001 concluded that more research was needed to determine the nature and extent of health effects on passengers and cabin crew. Although significant improvements have been made to aircraft ventilation systems, cabin occupants are still exposed to allergens and infectious agents, airflow rates that are lower than those in buildings, and air pressures and humidity levels that are lower than those normally present at or near sea level. The 2001 National Research Council report on airliner cabin air quality made 10 recommendations, 9 of which directed the Federal Aviation Administration (FAA) to collect more data on the potential health effects of cabin air and to review the adequacy of its standards for cabin air quality. FAA has addressed these 9 recommendations to varying degrees as it attempts to balance the need for more research on cabin air with other research priorities (e.g., passenger safety). However, some in the aviation community, including some of the committee members who produced the report on cabin air, do not feel that FAA's planned actions will address these recommendations adequately. For example, most members were concerned that FAA's plan for implementing the report's key recommendations on the need for more comprehensive research on the health effects of cabin air was too limited. FAA plans to address these recommendations in two parts--the first, which started in December 2003, and the second, which will start in December 2004 and end in late 2006 or early 2007. However, FAA lacks a comprehensive plan, including key milestones and funding needs. In addition, most committee members thought that FAA's response to a recommendation for it to improve public access to information on the health risks of flying was inadequate. We also had difficulty accessing this information on FAA's Web site. Several technologies are available today that could improve cabin air quality, (e.g., increasing cabin humidity and pressure or absorbing more cabin odors and gasses); however, opinions vary on whether FAA should require aircraft manufacturers and airlines to use these technologies. GAO found that one available technology, high-efficiency particulate air (HEPA) filtering, was strongly endorsed by cabin air quality and health experts as the best way to protect cabin occupants' health from viruses and bacteria in recirculated cabin air. While FAA does not require the use of these filters, GAO's survey of major U.S. air carriers found that 85 percent of large commercial airliners in their fleets that recirculate cabin air and carry more than 100 passengers already use these filters. However, the use of HEPA filters in smaller commercial aircraft that carry fewer than 100 passengers is much lower. The cost to retrofit the smaller aircraft to accept the HEPA filter, if it were made mandatory, could be expensive.