Travel health and safety
Inflight health concerns
Air travel has no impact on the health of the majority of passengers. But before travelling on one of our flights, you may wish to learn more about the possible effects of the following.
Passengers travelling to a destination several time zones away will probably experience jet lag, as the body’s internal circadian clock is only able to reset itself at a rate of about 1 hour per day. For most people, the circadian cycle tends to be slightly longer than 24 hours. That is the reason why most people have fewer problems when flying west (the day is lengthened) than flying east (the day is shortened). The most common symptoms of jet lag are fatigue, headaches, insomnia, and appetite problems.
There is no cure for jet lag, but you can try the following to minimise its effects:
- Jet lag can be worsened by the lack of sleep before the journey, so it is important to get a good night’s rest before your flight.
- If you are on a very short trip (48 hours or less), you may find it more convenient to remain on home time, rather than trying to adjust to local time.
- Eat light meals at the local meal times.
- Avoid caffeinated drinks for 4 hours and alcohol for 2 hours before going to bed to prevent sleep interruptions.
- Try to sleep at the local night time and only have short naps during the day if you are tired.
- For westward travel, late evening exposure to bright light helps delay the onset of sleepiness.
- For eastward travel, early morning exposure to light helps promote sleepiness in the late evening.
Cosmic radiation is a naturally occurring form of ionising radiation that comes from the sun and the galaxies outside the solar system. The earth’s atmosphere and magnetic field substantially shields the earth from cosmic radiation. People travelling in an aircraft may be exposed to more ionising radiation, because the earth’s atmosphere provides less protection from cosmic radiation at the typical cruising altitudes of commercial aircraft. Exposure also increases as the flight path moves further away from the equator. Therefore, the radiation dose will vary between different flights depending on origin, destination, route, flight-level pattern, and solar activity at the time.
Everyone is exposed to background radiation at sea level, which can come from the local environment, food and drink, medical exposure or building materials. In high doses, radiation can be harmful. However, the doses received at flight altitudes are considered very low. Flight crew and frequent flyers get the most additional exposure because of the extra time they spend at cruising altitudes.
Health effects of cosmic radiation
Cancer is the main health concern that has been associated with low-dose ionising radiation. As air travel means having increased exposure to ionising radiation, it follows that there must be some increased risk of developing cancer. The increased risk is however extremely small. Take for example a person who flies roundtrip flights from Hong Kong to New York every two weeks for 20 years. Their risk of death from cancer is between 23.11% and 23.14%. Given that naturally occurring cancer accounts for 23% of deaths in many developed countries, this means their risk is increased around 0.5%, which most people would probably consider acceptable.
Questions have also been raised on the effects of cosmic radiation on pregnancy and the health of the fetus. Based on current knowledge, the limited radiation dose received during occasional air travel during pregnancy poses very little risk to the fetus.
Cosmic radiation on a flight
Radiation dose is measured in milliSieverts (mSv). Most of our flights originate or terminate at low latitudes, so we are more fortunate in this respect than airlines based at higher latitude. An estimate of the radiation dose for a specific flight can be obtained from websites such as this one:
This is an example calculated by computer programmes:
From Hong Kong to New York (in high solar activity year): 0.0688 mSv
From New York to Hong Kong (in high solar activity year): 0.0619 mSv
From Hong Kong to New York (in low solar activity year): 0.0938 mSv
From New York to Hong Kong (in low solar activity year): 0.0817 mSv
Guidelines on radiation dose limits
In general, international agencies involved in radiation protection recommend 20 mSv per year for occupational exposure on commercial air flights (for example pilots and cabin crew), and 1 mSv per year for the general public on commercial air flights (this includes flying when pregnant).
In case of medical emergencies, we have an arrangement with MedAire, Inc. of Phoenix, Arizona to provide MedLink telemedicine service to the cabin crew. MedLink provides advice from doctors of all major specialties round the clock. If a plane has to be diverted for a passenger to receive immediate specialist attention, MedLink has a database of more than 5,000 airports and emergency medical resources worldwide, and will arrange for admission of the passenger and appropriate follow-up.
Our aircraft are equipped with comprehensive medical kits and defibrillators for use by the cabin crew. A small amount of oxygen is also carried on board for emergency use by passengers with breathing difficulties, but if you have known respiratory problems, please notify our reservations office in advance, as extra oxygen may be required. For safety reasons, passengers cannot bring their own oxygen cylinders on board.
Motion sickness is caused by a conflict between the body's sense of vision and its sense of equilibrium and may worsen during turbulence. It can be eased by keeping your eyes fixed on a non-moving object. If you suffer from motion sickness, try to get a window seat, since being able to focus on the ground, sea or horizon can sometimes help. The middle of the aircraft near the wings is also usually preferable. Air sickness bags are available on board. Many over-the-counter preparations are available and we recommend passengers consult their doctor or pharmacist about the appropriate medications to use.
All our flights are non-smoking, so the level of airborne pollutants is far lower than on most city streets. Fresh air is added to recycled air through very fine filters to remove dust, viruses, fungi and bacteria, and is delivered to the top of the cabin and extracted at floor level to carry any particles downwards, away from the breathing zone.
The air within the cabin is of low humidity, but no more so than many parts of the world, particularly desert regions. This does not cause a problem for most passengers, but some do experience slight discomfort from drying of the skin, eyes and nose. Moisturisers, water atomisers and eye drops can usually help. Most passengers who wear contact lenses have no problems inflight, but some do experience discomfort and prefer to wear spectacles instead.
We always put the health and safety of our passengers and employees as a top priority. Therefore, we have a number of procedures in place to ensure our preparedness for any serious outbreak of a communicable disease.
We require medical clearance of all passengers suffering from a communicable disease that pose a direct threat. If a passenger’s condition poses a significant risk to the health and safety of other passengers or crew, they may not be accepted for air travel unless or until the risk has been eliminated. Procedures are also in place to assist cabin crew if they need to deal with passengers onboard who are suspected to have any kind of infection. The guidelines are in line with those established by the World Health Organisation and US Centers for Disease Control and Protection specifically for airline staff and passengers.
The highest standard of cleaning and disinfecting is maintained for our aircraft cabins, seats, galleys and restrooms. Our cleaning procedures follow guidelines issued by various international regulatory and health authorities.
We use HEPA (High Efficiency Particulate Arresters) filtration systems that are capable of filtering 99.999% of dust particles and airborne contaminates, ensuring the highest possible quality of cabin air.
We continue to review and reinforce all health procedures in accordance with guidelines issued by regulatory, industry and health authorities.
We promote public health awareness among our staff, with measures including an influenza vaccination campaign, lectures from prominent experts, and regular updates from our Corporate Medical Department on communicable diseases along with health tips.
Understanding how pressure affects the body in a flight can help you have a more comfortable journey. Passenger flights usually fly at high altitudes, and despite being pressurised, it is not possible to maintain sea-level pressure. Most aircraft maintain a pressure equivalent to 6,000-8,000 feet above sea level. When pressure is reduced, gases expand, with about 20% increase in volume from sea level to 8,000 feet.
Avoid gassy food and drink before the flight
The body contains large amounts of gas, including gases formed in the stomach and intestines during digestion. Expansion of stomach or intestinal gas can lead to discomfort, so it is best to avoid having food and drink that generate gas, such as beans, cabbage, carbonated drinks and beer before your flight.
Swallow and yawn to relieve your ears
The air in the middle ear cavity also expands and contracts with changes in atmospheric pressure. If the pressure is not equal on either side of the eardrum, it will be distended, causing pain or temporary loss of hearing. Middle-ear pressure can usually be equalised by swallowing or yawning, which basically lets air in the middle ear escape through the Eustachian tube into the space behind the nose (nasopharynx). The tube is normally in a collapsed state but can be opened briefly when you swallow or yawn. But as the aircraft descends and the pressure is increased, the relatively lower pressure in the tube tends to keep it collapsed and result in negative pressure in the middle ear, causing discomfort or pain.
Opening of the tube can be aided by swallowing, yawning, performing the Valsalva manoeuvre (closing the mouth, pinching the nostrils closed, and blowing to build up pressure in the mouth and nose) or the Toynbee manoeuvre (closing the mouth, pinching the nostrils closed, and swallowing).
Treat any nasal congestions
Sinuses are air-filled cavities in the bones of the face and skull, and are connected to the nasopharynx by small openings. If these openings are obstructed by nasal congestion, there may be considerable pain on descent. The Valsalva manoeuvre may help, but it is better not to fly with nasal congestion, head colds, hay fever or sinusitis. However, if you must fly, use a decongestant spray before take-off and before the start of the descent to prevent the problem.
Wait after dental treatment
Pain on ascent may also result from the expansion of gas under a new filling, or from a dental cavity or abscess. So it is better not to fly for 24 hours after a dental treatment or if you are suffering from active tooth problems.