Select Committee on Science and Technology First Report


Thursday 21 June 2007

Members of the Committee present were: Lord Broers (Chairman), Lord Colwyn, Baroness Finlay of Llandaff, Lord Haskel, Lord Paul, Baroness Perry of Southwark, Baroness Platt of Writtle, Baroness Sharp of Guildford, Baroness Wilcox. In attendance were Christopher Johnson (Clerk), Elisa Rubio (Clerk), Dr Cathleen Schulte (Committee Specialist), Dr Michael Glanfield (Specialist Adviser).


Developments and Progress in Research Since 2000—an Overview: Professor Michael Bagshaw

The Committee's report in 2000 stimulated a number of research projects. The WRIGHT Project was commissioned by the World Health Organisation (WHO) and partially funded by the Department for Transport. Through epidemiological studies, pathophysiological studies and interventional studies the project aimed to confirm the association between air travel and venous thromboembolism (VTE), quantify the strength of the association, identify culpable factors in flight environments and identify and evaluate preventive measures.

The main conclusions of the WRIGHT Project were:

  • for healthy passengers the increase in relative risk when flying was in fact lower than when travelling on other forms of transport;
  • "hyper-responders" seemed to react to something in airplanes: if an individual had a risk factor the likelihood of him developing VTE increased dramatically after an 8 hour flight;
  • the longer the flight, including multiple trips, the greater the risk of developing VTE;
  • travelling by air accentuated other VTE risks;
  • immobility was an important factor;
  • there was no difference in the relative risk of VTE if the cabin pressure was reduced; and
  • those who were very short, tall or overweight were at slightly greater risk.

Fifteen organisations from seven European countries participated in the CabinAir project. Questionnaires were sent to the crew of 50 commercial flights and environmental measurements were taken—such as cabin pressure, air and globe temperatures, relative humidity and air velocity. The publication of the full results was imminent but it was suggested that levels of measured air pollutants were similar to other published studies and all levels were below the recommended occupational health limits.

There were other research projects such as the Health Effects of Aircraft Cabin Environment (HEACE), which studied the impact on crew members working in the aircraft environment; the Future Aircraft Cabin Environment (FACE), which focused on comfort parameters inside the aircraft; the Ideal Cabin Environment (ICE), which studied the combined health effects of cabin environmental parameters.

The Committee on Toxicity was reviewing the health effects associated with contaminated cabin air.

Fitness to Fly: Dr Michael Glanfield

The change in passenger demographics meant that the passenger age profile had changed and with it the level of fitness. It was suggested that a significant proportion of serious in-flight medical emergencies were related to existing medical conditions and in most cases the flight environment was an aggravating factor.

The question was raised of whether if was reasonable to allow everybody to fly and whether this was fair on passengers, the airlines or travel insurers. Also, who should take responsibility for the decision on who should be allowed to travel. Perhaps for those passengers with existing medical conditions a separate cabin class or separate flights altogether with a lower cabin altitude could be made available with extra oxygen provided.

It was suggested that at present no single authority was in charge of fitness to fly. Greater liaison should exist between airlines, travel insurers, doctors and passenger interests groups.

New Health Concerns: Raymond Johnston

Three health concerns were highlighted: cabin air, infection and defibrillators. The ICE project—which had completed all its measurements and was analysing data—was unique in that it addressed health and well being. Early results indicated that there was no cause for concern. The Committee on Toxicity was also looking at the health effects of cabin air. Their final statement was expected to be published on 3 July.

With regards to the spread of infection the major concern at present was over pandemic influenza. The world currently stood at stage 3 of the WHO pandemic phases, with sporadic cases of H5N1 in humans, but no confirmed human-to-human transmission. Should the virus mutate, and sustained human-to-human transmission, the precursor to a global pandemic, be identified, there were already national contingency plans in place, which covered aviation.

Anonymous statistics were presented from three airlines, including a charter airline, which showed that the number of survivors of cardiac arrests when defibrillators were used was very low. An airline which carried an average of 4 million passengers a year had 6 cardiac arrests in a four year period. On 3 of those occasions shocks were given using defibrillators. None of the passengers survived. However pooled data and standard protocols were needed from all airlines.

Aviation Psychology: Professor Helen Muir

The longest current direct flights were between 15 to 18 hours covering around 8,000 miles (e.g. New York to Singapore). The question was raised whether on very long journeys (e.g. London to Australia) a quick stop over was enough.

A number of factors should be taken into consideration with the design and configuration of very large transport airframes (VLTA) such as the A380, B747 and the blended wing Boeing (which was at the prototype stage):

  • Seat design and space: it was difficult for one seat to fit all passengers;
  • Location and size of exits;
  • Aisle width: this was largely a comfort issue as it had not been shown to be a factor in emergencies;
  • Distance to toilets;
  • Stairs: in particular internal stairs and how they are not supposed to be used in emergencies;
  • Cabin atmosphere; and
  • Emergency evacuation slides: the height of the upper decks of VLTAs meant there was a risk of vertigo at the top and injury and congestion at the bottom of the slides.

A number of passenger stress factors were mentioned such as claustrophobia and the behaviour of other passengers. Also highlighted as concerns on VLTAs were precautionary evacuations, the spread of fire, cabin crew communications and terrorism.

The Regulatory Framework: Dr Sally Evans

The International Civil Aviation Organisation (ICAO) was a UN organisation based in Montreal. It was charged with coordinating and regulating international air travel by establishing rules of airspace, airplane registration and safety. It had 190 contracting states. ICAO's current interests were cabin air quality, water and food hygiene on board, contingency planning to prevent the spread of disease and medical supplies on board.

The European Aviation Safety Agency (EASA), based in Cologne, was gradually absorbing all functions and activities of the Joint Aviation Authorities (JAA) and would assume competence for pilot licensing (including medicals) and operations and safety of third country aircraft in 2010.

The Civil Aviation Act 2006 gave the CAA the new function of safeguarding the health of persons on board aircraft and therefore the Aviation Health Unit (AHU) had been set up. It provided reference data on aviation health matters and encouraged and monitored research.


A lot of new research had been and was being carried out on VTE, most of which was stimulated by the Committee's original inquiry. Incidence of VTE appeared to be the same in 2007 as it was in 2000. Phase 2 of the WRIGHT project would address the unknowns of phase 1 and would also look at effective interventions. All major airlines had introduced information in their flight magazines and some offered advice on health to passengers over the tannoy system as part of the security briefing before take off. It was noted that 25,000 people died of VTE each year, mainly in hospitals for example following surgery, and the numbers of deaths during or following a flight were tiny in comparison.

Most aircraft accidents were unreported in the media and occurred during take off or landing. The most frequent type of accident occurred when an aircraft overran the runway. Effective evacuation measures were imperative. Some 95 percent of aircraft accidents had survivors.

The UK was at the forefront of the world in dealing with health issues and should be proud of the way the Aviation Health Working Group (AHWG) had brought together the Government, the airlines, manufacturers, unions and health professionals. It provided an interface with the air transport industry and other interested parties on issues relating to aviation health.

The number of UK registered aircraft with HEPA filters had increased as a direct result of the 2000 report. The CAA had responsibility for checking that the filters were maintained regularly as part of the general maintenance schedule. There were regular spot checks.

Nine pilots out of 1,500 members of the Independent Pilots Association had either lost their licenses due to health problems or were under investigation. There were no protocols when dealing with crew who complained of having suffered a contaminated air event. There was agreement that such events did happen, but whether they produced long term ill effects needed to be studied. Symptoms reported were non specific and covered broad spectrum; therefore it would be very difficult to undertake an epidemiological study. Some research projects had measured background cabin air, new studies were needed to measure cabin air during a "fume event", which to date had not yet been achieved. The AHWG was testing measuring devices in conjunction with the Federal Aviation Administration, but the technical challenges of capturing a short-lived "fume event" were still to be solved.

It was noted that during the SARS outbreak the infection was not spread by droplets. It was transferred by people touching infected surfaces. Cross-infection was more likely to occur through direct passenger to passenger contact, either at the airport terminal or during the flight, than as a result of air travel generally.

With regards to emergency medical equipment on board, it was noted that the standards had not changed since 2000. IATA was the body responsible for making recommendations about the equipment on board. Such recommendations were regularly updated. In general, low cost airlines carried only the statutory minimum equipment while big airlines exceeded the minimum requirements.

Participants were:

Andrew Ashbourne, Civil Aviation Division, Department for Transport

Professor Michael Bagshaw, Professor of Aviation Medicine, King's College London

Tim Bamber, NEC Member, British Air Line Pilots Association

Dr Sally Evans, Chief Medical Officer, Civil Aviation Authority

Peter Jackson, Director, Independent Pilots Association

Dr Ray Johnston, Aviation Health Unit, Civil Aviation Authority

Hanna Madalski, Government Advisor, Airbus

Captain Sandy Mitchell, Chairman of Flight Safety Group, British Air Line Pilots Association

Professor Helen Muir, Professor of Aerospace Psychology, Cranfield University

Dr Mark Popplestone, Head of Medical Services, Virgin Atlantic Airways

Sandra Webber, Head of Civil Aviation Division, Department for Transport

Dr Ursula Wells, Policy Research Programme, Department of Health

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