With a thousand-fold rise in commercial airline flights over the North Pole in the last 10 years, exposure to radiation has become a serious concern.
This health news is fact checked.
People who work on commercial airline flights are technically listed as “radiation workers” by the federal government – a classification that includes nuclear plant workers and X-ray technicians.
Exposure to radiation has been shown to increase health risk, according to numerous studies. Space radiation on the ground is very low, but increases significantly with altitude. At 30,000 to 40,000 feet, the typical altitude of a jetliner, exposure on a typical flight is still considered safe – less than a chest X-ray.
Exposure is considerably higher, however, over the Earth’s poles, where the planet’s magnetic field no longer provides any shielding. And with a thousand-fold rise in commercial airline flights over the North Pole in the last 10 years, exposure to radiation has become a serious concern.(https://www.nasa.gov/centers/langley/science/polar-radiation.html)
FAA Advisory circular AC No: 120-61B gives the guidance material on exposure to radiation. Whereas USA federal government categorize crew members as radiation workers, other countries including India does not do the same. The exposure limits are the same as those in the FAA advisory circular. The Indian Atomic Energy Regulation Board limits are given below.
DGCA India recently put out an Operations circular 2/2019 based on the FAA AC.
Recently, a meta-analysis reported an increased incidence of melanoma in pilots and cabin crew, which was possibly due to occupational exposures.1 Cabin crews’ exposure to cosmic radiation was assessed in different studies and always found below the allowed dose limit.2However, the cumulative exposure of pilots and cabin crew to UV radiation, a known risk factor for melanoma, has not been assessed to our knowledge.
Airplane windshields are commonly made of polycarbonate plastic or multilayer composite glass. UV-B (280-320 nm) transmission through both plastic and glass windshields was reported to be less than 1%. However, UV-A (320-380 nm) transmission ranged from 0.41% to 53.5%, with plastic attenuating more UV radiation than glass.3
Intrigued by our findings and the clinical observation of pilots developing melanomas on sun-exposed skin, we measured the amount of UV radiation in airplane cockpits during flight and compared them with measurements performed in tanning beds.
The pathogenic role of UV-A in melanoma is well established. UV-A is capable of causing DNA damage in cell culture5 and in animal models. Pilots flying for 56.6 minutes at 30 000 feet receive the same amount of UV-A carcinogenic effective radiation as that from a 20-minute tanning bed session. These levels could be significantly higher when flying over thick cloud layers and snow fields, which could reflect up to 85% of UV radiation. Airplane windshields do not completely block UV-A radiation and therefore are not enough to protect pilots. UV-A transmission inside airplanes can play a role in pilots’ increased risk of melanoma.
If NASA’s Chris Mertens has his way, weather forecasts and airplane cockpits of the future will include measurements of hazardous radiation in the atmosphere.
Mertens, a senior scientist at NASA’s Langley Research Center in Hampton, Va., is developing a system to predict radiation entering Earth’s atmosphere from space. The goal is to provide high-flying commercial airline passengers and crew with real-time information about the radiation they will be exposed to in flight.
“Aviation occupational radiation exposure currently is not monitored, measured and quantified,” says Mertens. “This will be the first model of its type to do that.”
Better be safe than SORRY.
Try this experiment. Focus your attention on the cross for a while. As you concentrate hard to focus on the cross in the centre, the background slowly begins to disappear.
This could be a possible explanation why crew of AC759 flew over 4 aircrafts at San Fransisco with noticing them.
The Troxler Effect is named after Swiss physician and philosopher Ignaz Paul Vital Troxler (1780-1866). In 1804, Troxler made the discovery that rigidly fixating one’s gaze on some element in the visual field can cause surrounding stationary images to seem to slowly disappear or fade. They are replaced with an experience, the nature of which is determined by the background that the object is on. This is known as filling-in.
The ATC voice recording between the JFK controller and the crew of Kuwaiti 117 is a prime example of learned carelessness or in simple terms bad habit.
Carelessness refers to the lack of awareness during a behaviour that can result in unintentional consequences. The consequences way of carelessness are often undesirable and tend to be mistakes.
The theory of Learned Carelessness offers an explanation why humans take unnecessary risks by omitting safety precautions against better judgment. It is assumed carelessness is learned by means of operant conditioning
Humans are “cognitive misers” (Wickens & Hollands, 2000) which means that they follow the path of the least cognitive resistance. A reduction in effort is positively reinforcing and therefore, increases the likelihood of future shortcuts in the absence of negative consequences.
The underlying motivation is assumed to maximize pleasure while minimizing discomfort. Once learned carelessness has developed it will distort a person’s perception, selection, and interpretation of subsequent information in favour of the monopoly hypothesis. This top-down information processing impairs motivation and capability to detect incidents. The result is unreasonably risky behaviour.
It is mandatory to report the call sign with every transmission in order to be unambiguous and convey the correct meaning of the communication transmission. The requirement to maintain visual separation is imperative and the ATC needs to be 100% sure that the two aircraft that are being separated are the ones with whom the communication is taking place.
Kuwaiti 117, did not report the call sign during the critical phase where the ATC wanted to be 100% sure that there is visual separation between the aircraft. The ATC could have reminded or confirmed with Kuwaiti 117 if the transmission originated from them or some other aircraft. Listening to the workload of the ATC controller, it was not in the best interest to remind every aircraft to follow procedures to ensure safety.
Kuwaiti 117 on the other hand did not get the message loud and clear and as a matter of habit, after JFK ordered Kuwaiti 117 to go around, the crew continued to make the same error. Therefore it is a training issue and also a safety audit issue which has not detected this and flagged the issue. Being relaxed is OK but the bare minimum required is to comply with a set of rules.