Frequent fliers often complain about the air quality in flight cabins, but for workers exposed on a regular basis, the air can possibly hurt their health. Engine oil or hydraulic fluid may contaminate the air (“bleed-air contaminants”) supplied to the plane’s cabin during flight, most often during take-off and landing, due to mechanical failure or faulty engine design. Workers who inhale the contaminated air risk adverse health effects and may require treatment for their symptoms.
Dr. Robert Harrison, University of California, San Francisco (UCSF) and his collaborators recently published a guide for health care providers to assist with the diagnosis and treatment of cabin crew exposed to air contaminants aboard their aircraft. The multi-disciplinary team who authored the document called, “Management of Exposure to Aircraft Bleed-Air Contaminants Among Airline Workers,” included members from the Association of Flight Attendants (AFA-CWA), Harvard School of Public Health, and the University of Massachusetts Lowell.
Harrison, a Clinical Professor of Medicine, has practiced at the UCSF Occupational and Environmental Medicine Clinic for almost twenty-five years. He says, “I have treated up to 40 flight attendants and airline cabin crew over the last 15 years who were referred to me by their health care provider, union, or co-worker because of health problems resulting from cabin air exposure.” The new document estimates there are 950 exposure incidents per year for U.S. fleets, or two to three incidents per day.
Passengers may be at risk, according to Harrison, but these guidelines only pertain to airline workers. The team did not have enough information to make passenger recommendations.
During a bleed-air contamination event, crewmembers often report a visible haze and a foul chemical odor—experiencing symptoms within minutes or hours of their exposure. Most frequently they suffer acute respiratory and central nervous system symptoms such as burning eyes, wheeze and cough, shortness of breath, nausea, loss of balance, anxiety, and memory loss. “Crew members who have asthma are probably more likely to have respiratory symptoms,” says Harrison. Aircraft mechanical records may confirm the sources of reported exposure.
The guide recommends that workers with symptoms visit a health care provider within two weeks of exposure. Harrison says, “For most airline cabin crew, symptoms resolve without any permanent health effects. Employees can return to work without restrictions.” Occasionally, symptoms persist. Harrison emphasized the importance of prompt recognition, documentation, and treatment of the exposure. Affected cabin crew may want to bring the medical treatment guidelines when visiting their health care providers to make them aware of the potential health problems that can occur.
Harrison mainly sees flight attendants based out of the San Francisco airport, yet he also treats patients previously evaluated by occupational health care providers around the country, particularly at other NIOSH-funded Education and Research Centers, or at clinics affiliated with the Association of Occupational and Environmental Clinics (AOEC). Frequently, the primary care provider is the first to treat the patient. “The availability and access to occupational health specialists around the country is limited,” says Harrison. “We needed to have a set of medical guidelines that could be useful, not only to occupational health specialists, but to primary care and family medicine providers as well.”
Harrison and his colleagues plan to disseminate the guidelines to a wide audience. They have posted the document on their research project website and on listserves used by occupational health providers and members of the AOEC clinic network organization. They are looking at ways to ensure that primary care providers and family physician are aware of the guidelines as well. Cabin crew will also have links to the guidelines, most likely through the AFA-CWA.
The Federal Aviation Administration Office of Aerospace Medicine provided funding for the project. It is part of a collaborative project between the Occupational Health Research Consortium in Aviation and the Airliner Cabin Environment Research Center of Excellence.
Harrison, R., Murawski, J., McNeely, E., Guerriero, J, Milton, D. (2007). Management of Exposure to Aircraft Bleed-Air Contaminants Among Airline Workers, A Guide for Health Care Providers.