So how safe are you?
So how safe are you?
In another such instance in the UK, a flight had to be aborted in midair shortly after takeoff when fumes filled the cabin. The immediate suspicion was that it could have been a case of de-icing chemicals getting into the air-conditioning system.
These may be unusual cases of contamination of cabin air by the inadvertent introduction of chemicals. However, they do focus attention on the dangers of being trapped in the skies in a cabin environment where the air quality may leave much to be desired.
These illustrations raise the question: Is there a link between cabin air quality and the comfort and health of passengers and crew? The issue has gained prominence in recent years because of the rapid rise in air travel and the increasing distances traveled by the passengers and the proliferation of airborne diseases as well as exchange of germs over 14 hours from fellow passengers.
An airplane is like a long cigar filled with pressurized air and just enough oxygen to sustain physiological functions. Toxic contamination could very easily upset this delicate equilibrium. Numerous chemicals present in cabin air could influence comfort and health. When combined with other factors such as temperature, humidity, noise, light levels and motion, the result could be more than just a heady cocktail.
In fact, passengers and crew have often reported symptoms such as eye, nose and throat irritation, respiratory distress, headache, fatigue, dizziness and nausea. However, research by government agencies, research groups and airplane manufacturers has not come up with clear-cut and unambiguous associations between cabin air quality and the reported symptoms. For example, a study by the Air Transport Association of America (ATA) and another sponsored by the US Department of Transportation (DOT) have, in fact, shown that air on commercial flights is very clean, with cabin-air microbe counts being smaller than those in "your own house, lower than in the building you work in." But the fears persist and anecdotal evidence keeps mounting.
In fact, the feeling among passengers and crew is that there is "a worrying lack of research and in-flight testing of cabin air quality" and little has been done to improve in-flight air despite the spate of reports of possible on-board contamination. This failure of the airline industry to respond to repeated warnings around the world about cabin fumes hasn’t done much to inspire confidence among the traveling public that their health in the skies is being adequately looked after.
The key cabin air quality parameters in flight are the blood oxygen saturation of crew members and passengers, pressures and rates of change, temperature, air movement, humidity, ventilation rate and concentrations of common pollutants, including carbon monoxide, carbon dioxide, ozone, fuel gases, organophosphates and other chemicals and self-reported health and comfort.
One concern relates to the fact that a large percentage of the air in the cabin is recirculated. In the earlier days, aircraft used to ventilate cabins with fresh air, providing around 20 cubic feet per minute per passenger. But, given the need to curb fuel consumption to reduce costs, airlines have reduced the amount of outside air taken from the engines by recirculating some of the cabin air. In modern aircraft the recirculated air could constitute up to 50 percent of the cabin air, halving the fresh air flow to 10 cubic feet per minute.
One requirement with recirculated air is to have a system of filters to remove bacteria, spores and other harmful agents and contaminants that could come from passengers — through coughing, sneezing or even their movement. These potentially harmful micro-organisms are generally invisible and odorless, so if the filters are not
efficient, the recirculated air could well be infectious and hazardous.
Cabins are routinely disinfected to minimize the risk of insects carrying diseases (such as malaria and dengue fever) being on the flight. While most studies show that the pesticides used do not have adverse human effects, the long-term health effects of repeated exposure to possibly fairly high levels of the pesticides needs to be evaluated.
Temperature does not fluctuate too much in normal aircraft cabin conditions and is considered more a comfort rather than health issue.
Its most obvious effects are in the generation of body odour and the rate of emission of volatile organic compounds (VOCs), which affects pollutant concentration in cabin air. Humidity also affects thermal comfort. In general, temperature affects the rate of dehydration of passengers and crew, with the elderly and infants being the most
susceptible to temperature extremes. One other area of discomfort is related to the sharp changes in temperature that occur between cabin and outside ambient air, when boarding or disembarking.
Low humidity can affect health and comfort, depending on the duration of exposure and other factors like temperature, water ingestion, etc.
Potential problems include drying of the body surface (mucous membranes and skin), dehydration and effects on thermal comfort (feeling cooler at lower RH, especially at higher temperatures). Low humidity also prevents colonization by the fungi and mites. However, allergens have a tendency to adhere to clothing and can collect on
aircraft seats if they are not adequately cleaned.
So, in the final analysis, while the airlines and industry people say the air quality in the cabins up in the skies is safe, passengers and crew often continue to think otherwise. But there are some precautions you can keep in mind the next time you decide to take a flight. Drink water to keep hydrated. If the air feels stuffy or you feel dizzy and nauseous, tell the cabin crew immediately. Ask them to investigate and to also tell the pilot to increase the airflow. If you land up paying a visit to a doctor after a flight, mention the fact to him.