Health and Flying 6

Ozone, a variant of oxygen, is highly toxic when inhaled, even in small quantities. It is an irritant to the lungs and can cause severe headaches. It also impairs night vision. The amount of ozone in the air increases above 40 000 ft but during the winter months the low tropopause may mean that there are significant amounts at much lower levels. Fortunately most aircraft effectively break down excess ozone at the compressor stage of cabin air supply through catalytic converters before it enters the cabin. Although present mainly in the stratosphere, ozone is not considered a component in the composition of the atmosphere. Ozone is a very corrosive gas which is toxic to living organisms.

Furnishings and baggage. In case of fire on board an aircraft, some cabin furnishings and plastic or foam upholstery give off poisonous fumes as they are heated. There is also the risk that luggage may contain lethal items which may not have been detected during routine screening. The tragic Saudia Tristar aircraft accident, which killed over 300 people as a result of toxic fumes, is a prime example of this very real danger.

Plastic coated electric wires can be a source of highly toxic fumes when burnt. If the concentration is high enough damage to the central nervous system can occur.

Exhaust gases must be avoided at all times as they contain carbon monoxide. Be especially aware of this when on the apron and while carrying out preflight inspections. The effects and dangers of carbon monoxide have already been discussed.

Acetone and Turpentine, which are both used in aviation, can damage mucous membranes and eyes.

Individuals who have been exposed to any toxic hazard should seek medical assistance as soon as possible from an aviation specialist.

Body Mass Index (BMI)

Body Mass Index is the measure of a person’s weight in relation to a normal standard. The following formula is used to calculate the BMI of an individual.

A BMI of:

Up to 20 for males or up to 19 for females = Underweight.

Between 20 and 25 for males or between 19 and 24 for females = Normal.

Over 25 - 30 inclusive for males and over 24 - 29 for females = Overweight.

Over 30 for males or 29 for females = OBESE.

Thus a male with a height of 1.80 metres and weighing 85 kilograms has a BMI of 26.23 indicating that he is overweight. BMI is also known as The Quetelet Index.

Backache

There are a number of back complaints from which flight crew can suffer. These can range from unspecific back pains to a slipped disk.

Aircrew should be aware of the importance of a good sitting position in flight and the correct setting of the seat lumber support provided. In-flight exercise can help if and most problems can be cured by physiotherapy treatment.

Obesity

Obesity, which tends to be genetic, is the term for an excess of fatty tissue in the body. An individual who is obese is susceptible to:

•Heart attack.

•Hypertension (high blood pressure) with the higher risk of a stroke.

•Hypoxia at lower altitudes than normal.

•General circulation problems.

•Gout (painful inflammation of the joints due to an excess of uric acid).

•Osteoarthritis (wear and tear on the joints).

•Diabetes.

•G-forces.

•Problems with joints and limbs due to weight.

•Decompression sickness (DCS).

•Heavy sweating.

•Chest infections.

•Varicose veins.

•A reduced life expectancy.

Losing Weight

If an individual is overweight or obese there are obvious advantages in losing weight. There is no magic formula or secret dietary method to reduce weight. Any food taken in has to be balanced by the energy output. Any excess is stored in the body as fat. The only practical way to lose weight is to eat less from a balanced diet containing the right mix of carbohydrates, protein and fat.

The use of “crash diets” must be avoided. They are normally ineffective in the long term and may cause dangerous physical and emotional symptoms. The overall objective must be to introduce new habits of eating, with a change in frequency, size and content of meals. On no account should appetite suppressants be taken unless under the direct supervision of an aviation medical specialist.

Exercise

Exercise promotes both mental and physical fitness and a sense of well-being but the amount of exercise required to burn off excess weight is so high that it is not a practical solution to obesity. Those who do take regular exercise can cope with fatigue much better and their resistance to stress is improved. As pilots are required to sit for long periods of time, regular exercise is of particular importance.

To be effective in reducing coronary artery disease, exercise must be regular and sufficient to raise the resting pulse rate by 100% for at least 20 minutes, three times a week.

Playing squash or tennis, swimming, jogging and cycling provide good exercise. Playing a round of golf or walking the dog may be pleasant but provide insufficient exercise to benefit the individual physically.

Flying and Health 6

Health and Flying 6

Nutrition and Food Hygiene

Healthy Diets

A balanced diet is the foundation of good health. A high-carbohydrate/fibre and low-fat diet can reduce the risk of coronary heart disease, stroke, diabetes and certain forms of cancer. Sources of carbohydrates include grains, vegetables, nuts, potatoes and fruits and should make up more than 50% of the calories consumed. The rest should come from lean meats and poultry, fish and low-fat dairy products.

Never miss breakfast - it is the most important meal of the day. Medical authorities state that breakfast should supply about 25% of the daily calorie intake. Never wait until you get on board the aircraft to eat.

Not eating regular meals or fasting can result in low blood sugar (hypoglycaemia) (below about 50 mg per 100 ml of blood).

Its symptoms are:

•Headache.

•Stomach pains.

•Lack of energy.

•Nervousness.

•Shaking.

•Sleepiness.

•Lack of concentration.

•Fainting.

Hypoglycaemia can be relieved in the short term by eating a snack.

REMEMBER: NEVER FLY ON AN EMPTY STOMACH

Vitamins

Vitamins are organic substances your body needs to function properly. They help process other nutrients and form blood cells.

Vitamin pills should not be taken without first seeking an aviation specialist’s advice.

The major sources of vitamins are:

A Fish oils, butter, eggs, margarine, cheese, milk, carrots, tomatoes and fruits.

B1 Wheatgerm, wholegrain cereals, lentils, pork, nuts, yeast and potatoes.

B2 Brewer’s yeast, liver, meat extract, cheese, eggs, peanuts, beef, wholemeal bread, milk and fish.

B3 Bran, wholegrain cereals, lentils, liver, kidney, meat, fish and yeast extract.

B6 Meat, liver, vegetables, wholegrain cereals, and bran.

B12 Meat, liver, eggs and milk.

C Citrus fruits, currants, green vegetables, new potatoes and berries.

DSunlight, oily fish, butter, eggs and margarine.

EWholemeal flour, nuts, wheatgerm, eggs and unrefined vegetable oils.

KVegetables, peas and cereals.

Principal Minerals

Minerals are essential to many vital body processes. The three principle minerals which are critical to the body’s functions are calcium, phosphorus and iron.

Calcium is the most abundant mineral in the body. It helps with the building and maintaining of bones and teeth. Its sources are milk, milk products, dark green leafy vegetables and shellfish.

Phosphorus, the second most abundant mineral, performs more functions than any other mineral and plays a part in nearly every chemical reaction in the body. Its sources are grains, cheese and milk, nuts, meats, poultry, fish, dried peas and beans and egg yolks.

Iron is necessary for the formation of haemoglobin. Its sources are meats, beans, green leafy vegetables, grain products, nuts and shellfish.

Trace Elements

A few elements are present in the body in such small quantities that they are called “trace” elements. However they are essential to health. The most important of these trace elements are iodine, copper, zinc, cobalt, manganese and fluorine.

Trace elements will be obtained from a healthy and balanced diet and supplementary pills should not be taken unless under the direct supervision of an Aviation Medical Specialist.

Incapacitation Due to Food Poisoning

The most common cause of in flight incapacitation is acute Gastroenteritis due to food poisoning or drinking contaminated water. Gastrointestinal disorders represent almost half the causes of incapacitation in flight. The onset of the disorder is usually abrupt and violent. Symptoms include nausea, vomiting, abdominal pain, loss of appetite and diarrhoea which can cause a rapid loss of fluids and lead to dehydration.

An insidious onset is the most dangerous form of this incapacitation. With no obvious symptoms, the pilot is slow to become aware of the critical state into which he/she has entered.

Major Sources of Contaminated Foodstuffs

The major sources of food contamination are from unhygienic food preparation and poor storage methods, undercooked or rancid meats, unwashed salads (or washed in contaminated water), unpeeled fruit and vegetables, seafood and locally made ice cream and mayonnaise.

Actions to BeTaken to Avoid Food or Liquid Contamination

It is prudent for aircrew to take the following precautions when travelling on duty:

•Always eat in a clean environment.

•Avoid eating raw vegetables and fruit unless you can peel them yourself.

•Avoid seafoods - these can harbour powerful poisons without impairing the taste.

Flying and Health 6