Flying and Health — Page 104, Lesson 154

I want to walk you through a new topic now: flying and health, specifically the toxic hazards you can encounter in the aviation environment, and then we'll look at Body Mass Index and backache. Let's start with ozone. Ozone is a variant of oxygen, but don't let that fool you — it is highly toxic when inhaled, even in small quantities. It acts as an irritant to the lungs and can cause severe headaches. It also impairs your night vision, which is obviously critical for flying. The amount of ozone in the air increases above 40,000 feet, but during the winter months the low tropopause may mean there are significant amounts at much lower levels. Fortunately, most aircraft effectively break down excess ozone at the compressor stage of the cabin air supply through catalytic converters before it enters the cabin. Although ozone is present mainly in the stratosphere, it is not considered a component in the composition of the atmosphere. Ozone is a very corrosive gas which is toxic to living organisms. Next, 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 because 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 in earlier chapters. 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. Now let's move to Body Mass Index, or BMI. Body Mass Index is the measure of a person's weight in relation to a normal standard. The formula used to calculate BMI is: BMI equals weight in kilograms divided by height in metres squared. So BMI = Weight in Kilograms divided by (Height in Metres)². Here are the ranges. For males, a BMI up to 20 means underweight; between 20 and 25 is normal; over 25 up to and including 30 is overweight; and over 30 is obese. For females, a BMI up to 19 means underweight; between 19 and 24 is normal; over 24 up to and including 29 is overweight; and over 29 is obese. So for example, 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. Finally, 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.