Select Committee on Science and Technology Fifth Report


15 November 2000

By the Select Committee appointed to consider Science and Technology.





1.1 This Report is about the effects on health of travelling by air, a topic which has given rise to much public concern in recent years. Air travel has grown substantially over the last forty years. Every day, millions of people of widely varying ages and states of health travel by air - sometimes for very long distances.

1.2 Medical knowledge has also developed substantially, not least in relation to the links between environmental factors and health. Our Inquiry has examined how far the present arrangements for safeguarding the health of the diverse body of passengers and crew members have kept pace with that developing knowledge.

1.3 We have not found substance in the extreme claims about health risks from air travel. A significant minority have some real fear for their health when flying, and there are those in the media and elsewhere who feed such fears. We encourage people to look at the facts set out in our Report in an open-minded way.

1.4 Although we have found no significant impact of air travel on health for the vast majority of travellers, there are substantial points that need to be addressed for a minority. In addition, we see a general need to improve practices to minimise any risks for the remainder. While the Government, regulators and the industry rightly give absolute priority to air safety, we find them all open to criticism for failing to give sufficient active attention to health. These matters are important now, and will grow in importance as air travel continues to develop.

1.5 We propose improvements not only in the regulatory arrangements but also in the information available to intending air travellers. Like all other human activities, air travel can never be risk free. Most people readily accept substantially greater risks - to both health and physical safety - in respect of other forms of mass transport and, indeed, many other aspects of their daily lives. So that people can make properly informed choices (even if others regard those as the "wrong" choices), risks need to be identified, managed and communicated. The identification, management and communication of health risks in air travel are the main themes of our Report.

1.6 As noted in paragraph 2.15, our Inquiry has ranged over a wide variety of medical, technical and other matters. Chapters 3-9 of this Report are structured to provide a logical route through that inter-related material. We have set out our many findings and recommendations as they arise.

1.7 All our recommendations are repeated below (paragraphs 1.8ff), as are our other main findings (paragraphs 1.48ff). For ease of reference, they are grouped together in a different order from the main text, under appropriate headings, together with a note of the source paragraph.



1.8 Safety is paramount in the airline industry and nobody would wish it otherwise. Our concern is not that health is secondary to safety but that it has been woefully neglected. We welcome the belated acceptance by the Department of the Environment, Transport and the Regions (DETR)[1] that it has the lead within the United Kingdom, and we recommend the Government to ensure that concern for passenger and crew health becomes a firm priority. (Paragraph 8.9)

1.9 There is no international regulatory focus for monitoring and developing practices and procedures on passenger and crew health. We recommend the Government actively to pursue the strong UK interest in passenger and crew health through its international contacts with the Joint Aviation Authorities (JAA), the International Civil Aviation Organisation (ICAO) and other appropriate organisations, and we urge them all actively to promote health. This will both benefit air travellers in other countries and also help to minimise the possible impact of greater attention to health on competition within the international airline industry. (Paragraph 8.10)

1.10 We recommend the United Kingdom and other governments to do everything they can to reduce inertia within the international safety-focused regulatory structures. (Paragraph 8.7)

1.11 We were surprised at the lack of attention - by regulators, airlines and aircrew trade unions - to the health of aircrew. We are aware that there are serious issues of medical confidentiality and job security involved. Nevertheless, we recommend that the present rules, agreements and attitudes regarding the monitoring and recording of the general health of aircrew, over and above their fitness to operate, should be reconsidered urgently. (Paragraph 3.48)

1.12 In the case of pilots, we recommend that, if the authorised medical examiner (AME) finds evidence of significant ill-health not necessarily affecting a pilot's fitness certification, this should be recorded and reported both to the Civil Aviation Authority (CAA) and to the affected person's general practitioner. (Paragraph 3.48)


1.13 The booklets from the Department of Health (DoH), Health Advice for Travellers, and from the Air Transport Users Council (AUC), Flight Plan, should be important sources of health information and advice for intending passengers. As their publishers accept, the current editions fall well short of what is required, and we were pleased to note the plans for appropriate revision. We recommend that priority be given to refining the advice in Flight Plan: "If you have any concerns about your fitness to fly, talk to your doctor before you book your flight", which needs to be made much more specific. (Paragraph 8.48)

1.14 We recommend CAA to revise its Travelling Safely leaflet, at least to cross refer to the revised Health Advice for Travellers and Flight Plan. We also recommend DoH, CAA and AUC to consider whether the combination of their three publications as currently conceived best serves the travelling public's information needs. (Paragraph 8.49)

1.15 We were surprised to learn that the current edition of the DoH book Health Information for Overseas Travel aimed at health professionals did not contain information on medical considerations for travel and on the significance of pre-existing medical conditions, and we were pleased to find that this was being remedied in a revised edition already in preparation. We recommend that DoH monitor the use of the revised Health Information for Overseas Travel to ensure that, with further additions and amendments as necessary, the publication provides the user-friendly authoritative information source that is needed by health professionals. (Paragraph 8.41)


1.16 It is imperative that the current paucity of data on deep vein thrombosis (DVT) be remedied and we recommend that an epidemiological research programme of the case-control type be commissioned by DoH as soon as practicable. (Paragraph 6.25)

1.17 As an interim measure pending the development of more authoritative guidance, we recommend airlines, their agents and others with consumer interests to repackage the summary indicative and precautionary advice on DVT in Box 4, together with the summary information on predisposing and risk factors in Boxes 2 and 3, and make it widely available to the general public. This will enable those who have no access to other advice to make preliminary decisions about their travel and the risk of DVT. (Paragraph 6.29)

1.18 We can understand the airlines' reluctance to accept suggestions that there might be factors specific to the aircraft cabin environment that lead to an increase in the overall risk of DVT. Although any additional risk is likely to be small, it is not in doubt that the risk factors of prolonged immobility and cramped seating are present in aircraft. However, these circumstances are not limited to aircraft and we recommend the Government to consider tackling DVT on a wider travel-related front or, indeed, as a general public health matter. (Paragraph 6.30)

1.19 The term "economy-class syndrome", widely used to refer to flight-related DVT, is misconceived in suggesting that the possibility of DVT need not concern business and first class air travellers - or those using other forms of long-distance transport. We recommend that health professionals and others stop using the seriously misleading term "economy-class syndrome". "Flight-related DVT" or "traveller's thrombosis" would be more appropriate. (Paragraph 6.23)

1.20 In relation to air travel alone, however, and applying the precautionary principle used in other fields where health risks are considered possible but are not well defined or quantified, there are measures which could be taken to improve information and alleviate concerns about flying and DVT, and to encourage preventive activities. We recommend that airlines and their associates reappraise their current practices in relation to not only the provision of information for passengers but also the design of the cabin and cabin service procedures. We also recommend the Government, aviation regulators, trade groups and consumer representatives to consider what action they should take in relation to these points. (Paragraphs 6.31 and 6.32)


1.21 We were pleased to hear about new CAA research into people's size and the reduction in mobility after long flights to ensure that the emergency evacuation requirements are in line with modern circumstances. Given changes over the years in the length of flights and in the sizes, ages and health states of people undertaking them, we recommend that this research be completed urgently. (Paragraph 3.51)

1.22 To facilitate passengers' choice of seating, we recommend CAA to use its current research to develop an unambiguous set of definitions for seat dimensions. The key issues are: the minimum size of seat taking account of health considerations; accommodation of passengers above average size; and proper allowance for seat-space reductions from the seat in front being reclined, material in seat-back pockets and fold-down tables. (Paragraph 6.49)


1.23 For the main purpose of airworthiness certification, JAA currently has no specific cabin air supply requirements for passengers, and the US Federal Aviation Administration (FAA) requirement is seen by manufacturers as, in some cases, impossible or impracticable. Because of the intrinsic importance of the matter and also to clarify matters which cause great public concern, we recommend the Government, CAA and JAA to find a practicable way forward as soon as possible. (Paragraph 3.36)

1.24 JAA's requirement for only fresh air to be supplied to the flight deck reinforces the perception that there is something intrinsically "bad" about re-circulated air. We recommend the Government to urge JAA to reconsider its requirement for ventilation of the flight deck with only fresh air. (Paragraph 5.17)


1.25 Passengers' perception of general cabin air quality is one of the key factors in their assessment of the flight experience as a whole. We recommend that airlines collect, record and use at least some of the basic cabin environment data being continuously monitored, not only to give authoritative substance to their refutation of the common allegations, but also to provide a better basis for public confidence in these matters. Indeed, we are surprised that they do not already do so. (Paragraph 5.49)

1.26 We recommend airlines to carry out simple and inexpensive cabin atmosphere sampling programmes from time to time, and to make provision for spot-sample collection in the case of unusual circumstances. This would be helpful for passengers and staff, and also benefit airlines themselves. (Paragraph 5.50)

1.27 We welcome the ASHRAE[2] work on cabin air quality standards and recommend the industry to support and encourage its timely completion and promulgation. We recommend that, in the light of the outcome, regulators consider extending cabin air quality standards beyond those for carbon dioxide, carbon monoxide and ozone for which they already provide. (Paragraph 5.51)

1.28 We recommend the Government to urge ICAO to upgrade the smoking ban recommendation to a formal requirement on its Member States in relation to all flights. Pending a formal ban, we recommend those airlines which still permit in-flight smoking to complete the ban on a voluntary basis. Where in-flight smoking may still be permitted, we recommend that airlines and their agents should actively make this clear to intending passengers prior to ticket purchase. (Paragraph 4.31)

1.29 To minimise potential health problems when aircraft fly through ozone plumes, we recommend airlines to fit ozone converters to their aircraft used on routes where they may come into contact with such plumes. (Paragraph 4.47)

1.30 The general absence of air nozzles under personal control in newer aircraft reflects airlines' preferred cabin layouts. While we understand that, where fitted, such nozzles deliver the same air as otherwise available, the directed movement of air can provide personal refreshment. The absence of individual air nozzles reduces the personal control passengers have over their flight experience, and we recommend airlines to review and modify their cabin design considerations to include such nozzles. (Paragraph 5.40)


1.31 As part of improved health information for intending passengers, we recommend the Government and airlines to do more to dissuade intending passengers from flying while they are likely to infect others. This could be further reinforced by a reminder that boarding may be denied to those who are obviously infectious. (Paragraph 7.33)

1.32 To reduce cross-infection risks (as well as for general comfort), we recommend airlines to ensure that they have suitable policies for occasions when aircraft with passengers on board have to be held on the ground for extended periods without full ventilation. Such events are rare, so it is all the more important to have in place clear guidelines for action. (Paragraph 7.22)

1.33 We recommend the Government to consider requiring UK airlines and their agents to retain all aircraft passenger information which could be useful in tracing contacts for a minimum of three months after all flights, and that the Government should seek to extend this requirement internationally. We also recommend airlines and their agents to move towards this immediately. (Paragraph 7.40)

1.34 From time to time, airlines and their representative bodies review the passenger data collected for marketing and other analytical purposes. In doing so, we recommend they also consider improving such data (or at least ensuring greater standardisation) to help meet the potential needs of post-flight contact tracing. (Paragraph 7.41)


1.35 Although we do not dispute the design claims for HEPA filters[3], we fail to see how the industry can effectively rebut charges that such filters do not perform as designed when so little attention is given to their performance. We recommend the industry as a whole to review and substantially improve overall in-service performance monitoring of filters. (Paragraph 7.24)

1.36 HEPA filtration is not yet standard. To minimise the risk of cross-infection, we are clear that it should be, and we recommend the Government and regulators to make filtration to best HEPA standards mandatory in re-circulatory systems. In the meantime, we recommend airlines to upgrade all filtration to the best HEPA standards. (Paragraph 7.26)


1.37 It is difficult to see how the principal causes of in-flight cabin noise, engine and air noise, could be substantially reduced at reasonable cost. However, earplugs are useful in reducing annoyance from noise, particularly on overnight flights where passengers are seeking to sleep. We understand that these are routinely offered to first and business class passengers, and we recommend airlines to extend the inexpensive courtesy of offering free earplugs to all passengers. (Paragraph 6.55)

1.38 The British Airline Pilots Association (BALPA) made the point on behalf of pilots that, although cockpit background noise is within acceptable limits, the addition of radio communication noise can cause the noise at the ear to exceed levels at which hearing protection would be required by law if flight-decks were not exempt from the Noise at Work Regulations. As this may have both health and wider safety implications, we recommend CAA and the Health and Safety Executive (HSE) to investigate the matter further. (Paragraph 6.57)


1.39 Noting the inter-relationship between comfort and stress and health, together with the scope for combined adverse effect with other environmental factors, we recommend that, when investigations are conducted into the impact of any particular environmental factor on health or wellbeing, the possibility of combined effects be given appropriate attention. (Paragraph 6.63)

1.40 We recommend airlines to review their arrangements for the timing of refreshments and sleep periods on long-haul flights with jet-lag in mind, and also to advise passengers both at booking and in-flight about appropriate measures to deal with the effects. (Paragraph 6.65)


1.41 Bearing in mind the greater numbers and range of people travelling by air, we recommend the Government to upgrade the required minimum provision by UK carriers for medical emergencies to current "best practice" levels in relation to both crew training and medical emergency kits. The latter should include automatic external defibrillators (AEDs) on at least long-haul aircraft. Furthermore, we recommend CAA to work through JAA to secure similar improvements across Europe. (Paragraph 7.77)

1.42 Contracted ground-based expert medical advice provides not only considerably improved services to passengers but may also save on airline operating costs by reducing the number of medical diversions. We recommend all long-haul airlines to consider engaging such ground-based specialist consultant services. (Paragraph 7.78)


1.43 Our Inquiry has already shown where the major gaps in knowledge are and we recommend the Government to commission research into the following matters as the highest priority:

    (a)  the epidemiology of DVT, by a case-control type study;

    (b)  the demography of air travellers and the types and frequency of travel undertaken;

    (c)  real time monitoring of air quality and other aspects of the cabin environment, with a view to establishing new and clear regulatory minima for passenger cabin ventilation;

    (d)  testing, with the latest non-invasive technology, blood oxygen levels across the whole spectrum of air travellers, to validate conclusions derived from data on young healthy adults;

    (e)  exploration of the ways different aspects of the aircraft cabin environment may interact, particularly on those in less than average health; and

    (f)  extracting maximum value from available and improved medical records of aircrew concerning any long-term effects from exposure to the aircraft cabin environment. (Paragraph 9.3)


1.44 In the market place in which air travel is sold, it is vital that intending passengers are provided with sufficient information to make informed choices. We recommend the Government to require airlines and their agents to provide more information for passengers at the time of booking on:

    (a)  the size of seat that is on offer, using unambiguous standardised definitions;

    (b)  options for pre-booking seats, particularly those with extra leg-room;

    (c)  whether smoking will be permitted on the flight in question;

    (d)  the need for sub-aqua divers to ensure that the effects of any recent diving will not create an additional hazard when they fly;

    (e)  the need for intending passengers to satisfy themselves that they are generally fit to fly - not only for their own health (particularly in relation to DVT) but also for that of others; and

    (f)  in the case of long-haul passengers, measures to deal with the effects of jet-lag. (Paragraph 9.5)

1.45 The importance of fitness to fly needs to be given suitable prominence. We recommend that, at every ticket sale point and in every doctor's surgery, there should be a small display card asking intending passengers, "Are you fit to fly?" To help them find the answer, this could offer a short and user-friendly note of guidance. (Paragraph 9.6)

1.46 Passengers need to be reminded on boarding and in-flight about the simple measures that minimise any risk of flight-related DVT, and of the simple measures to alleviate head pain from pressure changes on take-off and landing. We recommend the Government to require airlines to provide, immediately before take-off, a health briefing comparable to the already required safety briefing, backed up by a standardised card in seat-back pockets. We were pleased that the Minister acknowledged the merits of this. (Paragraph 9.8)


1.47 We recommend airlines to review their systems and procedures for dealing with passenger concerns and complaints so that passengers do not feel that they are being forced to deal with lawyers and insurers from the outset. This review should include considering the case for an independent "ombudsman". (Paragraph 8.60)

1   Abbreviations in this Report are explained at their first mention and also summarised in Appendix 6. Back

2   The American Society of Heating, Refrigerating and Air-Conditioning Engineers is rarely referred to by other than its acronym. Back

3   High efficiency particulate air filters. Back

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