Our health survey data suggest a range of symptoms and outcomes worthy of further investigation. We should note that since our studies were conducted, the FAA and Occupational Safety & Health Administration have been negotiating policies to apply some OSHA standards to cabin crew in flight, pursuant to the Section 829 of the FAA Modernization and Reform Act of 2012. As of this writing (Feb. 2014), OSHA has partial jurisdiction over occupational safety and health of US flight attendants, including hearing conservation, blood-borne pathogen protections, hazard communication, employee access to exposure records, injury/illness recordkeeping and reporting, and whistleblower protections. Some of the health concerns listed above, especially noise-induced hearing loss, may be more effectively addressed as a result of this development.

Conduct ongoing research into the cause(s) of prevalent respiratory symptoms.

The causes of the notably high prevalence of respiratory symptoms (reactive airways, sinusitis or allergies; shortness of breath or reduced lung capacity; other) that were serious enough to necessitate a visit to a medical provider in the last year (Figure 23) should be further studied. It is not clear how much of the chronic bronchitis finding is a function of historical exposure to second-hand smoke on aircraft, and how much is a function of current chemical exposures and infectious agents. The Flight Attendant Medical Research Institute (FAMRI) continues to study and address respiratory health issues among flight attendants, funded by a legal settlement from tobacco companies in 1997.

Develop and test interventions to mitigate fatigue.

The current study offers further evidence that fatigue and sleeping problems are widely experienced among flight attendants. Further data collection about specific causes of fatigue and testing of interventions to mitigate fatigue are both warranted.

Monitor noise exposure and implement hearing conservation programs.

Until late 2013, the OSHA noise standard (29 CFR 1910.95) did not apply to cabin crew, such that noise-induced hearing loss has been not been monitored or protected in the aircraft environment. The findings of our health survey confirm that noise testing and hearing conservation programs are warranted.

Implement a reporting system to document aircraft smoke/fume events.

The FAA, the airlines, and flight crew unions, and independent experts in occupational injury and illness surveillance should work together to design a proactive surveillance system for reporting air contamination events and related injuries and illnesses. This recommendation echoes that from the National Research Council committee report regarding the airliner cabin environment (2002) and, more recently, the 2012 FAA Reauthorization Act (H.R.658, Sec. 320(a)(4)) which calls on the Agency to “develop a systematic reporting standard for smoke and fume events in aircraft cabins.” Both qualitative and quantitative data from our focus groups and health survey provide a starting point in understanding the barriers to reporting and the wide variation between official (BLS) statistics and what flight attendants told us about work-related injuries and illnesses.

Develop and mandate employee education and training regarding bleed air events.

Reporting, and hence improved and expanded information regarding the causes and health impact of bleed air events, would be enhanced by an educational campaign to better enable both flight crew and airline mechanical employees to recognize and document these events.

Conduct additional monitoring to characterize exposure to oil-based bleed air contaminants.

The exposure monitoring aims of the current research were not fully realized due to funding limitations and the failure of the airlines to allow the original protocol of flight attendants taking air samples to go forward. However, this research did establish that the VN sampler is capable of replicating accepted industrial hygiene sampling methods for tricresyl phosphates and capturing (for analysis) levels of contaminants near the method and instrument detection limits. Pilots may be best able to conduct such sampling and record other conditions during the sampling, including the status of the environmental control systems. Such sampling would require FAA and airline involvement in designing the sampling protocols and ensuring that they are carried out as designed.

Commercial airplanes as working environments pose difficult and perhaps unique challenges to exposure monitoring for employee (and passenger) protection using traditional occupational hygiene methods and instruments. The difficulty of monitoring many different aircraft for unpredictable exposures to bleed air contaminants could be addressed by the development and deployment of biomarker tests, including exposure to specific air contaminants (e.g., TCPs) Since data collection in this study took place, potential blood markers for TCPs have shown promise and should be further explored. Further research is also called for to better characterize the nature and toxicity of the chemical constituents of engine oil fumes.

It is notable also that, contrary to concerns expressed by airlines in negotiations over conduct of this research, passengers were overwhelmingly supportive and curious about assessment of cabin air. There were no objections or fears expressed in the course of the 80 samples collected.

Research and develop effective engineering control measures to prevent exposure to smoke/fumes.

Funding should support research and development into engineering, design, and administrative controls for reducing risk of exposure to engine oil contaminants sourced to the ventilation air supplied to the cabin and flight deck. These include:

• Expanding non-bleed options for air supply systems on commercial aircraft, currently limited to the B787;
• Alternative oils with less toxic anti-wear additives;
• Improved engine seal designs to minimize leakage;
• Filtration systems between the bleed air intake and cabin air supply system;
• Improved maintenance practices and more frequent inspections of aging parts;
• On-board sensor systems to ensure that engineering and administrative controls are having their intended effects; and
• Mandatory education and training for flight and cabin crew.

External links for additional information:

Airliner Cabin Environment Research: ACER is a research consortium funded through a Federal Aviation Administration Cooperative Agreement entitled “National Air Transportation Center of Excellence for Research in the Intermodal Transport Environment (RITE). Reports describe ACER member research that relate to onboard exposure to ozone, flame retardants, engine oil fumes, cabin pressure, and disease transmission.

FAA Cabin Safety Subject Index: The US Federal Aviation Administration Cabin Safety Subject Index is a reference guide to federal regulations, FAA orders, advisory circulars, Information for Operators (InFO), Safety Alerts for Operators (SAFO), legal interpretations, and other FAA content related to aircraft cabin safety.

OSHA Flight Attendant/Cabin Crew Members Health and Safety: US Occupational Safety & Health Administration website that outlines regulatory changes in 2013 that led to expansion of OSHA regulations that apply to US flight attendants.