What are hazards and negative effects of flying at high altitudes?

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What are hazards and negative effects of flying at high altitudes?

Postby CaptainMFT » 17 Jun 2016 04:02

High altitude flying is defined as flying above 35,000 ft above sea level. 

Continual flying at higher altitudes as a crew member brings some long term negative effects to our body which we should recognize, realize and understand well. This is something which concerns our body and mind; we have the right to get awareness of all these dangers listed below.


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Hazards of flying at higher altitude discussed in detail below with symptoms and the solution:-



Operation at high altitudes, in excess of 35,000 ft, needs consideration of some specific natural phenomena: 
- High concentrations of ozone. 
- Damaging effects of solar and cosmic radiation. 
- Ultra-violet lights. 
- Low humid atmosphere.. 
- extremely low temperatures. 


What is ozone - O3 and the effects it has on our body?
Ozone could be a variant of oxygen created by the action of solar radiation on high altitude oxygen. 
It is a toxic gas that damages the respiratory organs also known as lungs by irreversibly destroying the elasticity of the lung tissue (emphysema). Little ozone is available within the troposphere however concentrations rise rapidly higher than the tropopause increasing with altitude (greatest concentrations in winter and spring). As the layer is far lower over the poles the risk from the effects of ozone is greatest on trans-polar flights. Thus ozone could be a potential danger between 40,000 and 75,000 ft. 

Symptoms of ozone poisoning are dryness of the nose and throat with irritation causing coughing and a discomfort within the chest. Severe poisoning will cause respiration difficulties, heart strain and occasionally death. Concentration of ozone is more significant than its exposure time. FAA concentration limit is 0.25 parts per million by volume (ppmv) for commercial flights. Ozone is partially destroyed by the high temperatures created within the compressors of jet engines. Aircraft with lower compressor temperatures need catalytic converters and carbon filters to scale back the ozone concentration to an appropriate level. Higher cabin humidity reduces the severity of the symptoms of ozone poisoning. Ozone is sometimes destroyed by the pressurisation process. 


What is radiation and the effects on human body?
Cosmic radiation (from space) and radiation (from sun) become more significant issue at higher altitudes where less has been absorbed by the atmosphere. 
A four hour flight higher than 35,000 foot equates to an equivalent radiation dose as a full chest X-Ray. Cosmic radiation will increase considerably throughout sun storms and periods of high sunspot activity. Radiation carries with it a risk of cancers. Cosmic radiation monitoring instrumentation should be carried on airplane in operation above 49,000 feet. 


What is blue and ultraviolet radiation light and its' risks:-
At altitude the light is way brighter than at sea level. It contains significantly more high energy blue light and ultra violet light than normal. 
This can harm the retina over a period of time. Appropriate sunglasses for defense should be: 

• Impact resistant with thin metal frames. 
• Having smart optical quality, refractive class one. nonprescription sunglasses are classified and controlled by FDA as class one devices. class 1 lenses neutralise distortions and produces no image jumping. 
• Having a luminance transmittance of 10-15%. The luminance transmittance is the quantitative relation of the luminance of a source of light once viewed through a curtain or screen, to the luminance of that source once viewed directly. 
• Meeting filtration standards just like BS2724. A British standard setting out aspects like quality, strength and ultraviolet radiation protection. 
---Photochromic or phototropic sunglasses that vary in darkness and light transmission aren't usually permitted because of their slow response time. 


What are side effects of low humidity on pilots at higher altitudes?
The proportion of water vapour within the air to the amount that it might hold at saturation expressed as a percentage is called the relative humidity. 
At high altitudes the temperature {is terribly|is extremely|is incredibly} low and so the amount of water vapour the air will hold is also very low. Nevertheless, before the air enters the airplane engines the relative humidity might be quite normal, maybe 50%. Once the air is heated to temperatures acceptable for the airplane cabin the capacity of the air to hold vapor is augmented. But the amount of water vapour itself remains constant. This means that relative humidity falls. Pressurisation air could have a relative humidity of as low as 3rd. Relative humidity levels of 40 to 60 minutes are considered comfortable. Low relative humidity will cause a drying of the mucous membranes of the eyes, nose and throat resulting in discomfort. 
Symptoms of ozone poisoning and low humidness are similar. Relative humidities of less than 30 minutes encourage the survival of viruses and bacterium. The effects of low relative humidity are often countered by drinking larger amounts of fluids and avoiding diuretics like tea, coffee and alcohol. 


Hazards and side effects of extremely low temperatures at high altitudes:-
Body heat is generated by the metabolism of oxygen with carbohydrates within the tissues. Very low temperatures need higher level of metabolism. That means higher amounts of oxygen. Thus exposure to extremely low temperatures will increase the susceptibility to hypoxia.
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Good luck,
CaptainMFT.

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