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Do crew and passengers, especially those in the window seats, need to slip-slop-slap? (file photo).
A recent video on TikTok has sparked a conversation about whether passengers need to wear sunscreen on flights.
In the footage viewed more than 40,000 times, a former Australian flight attendant known as Kayla warned of the “hidden danger” that most travellers are unaware of.
“The UV up there is so incredibly high … I am religious with putting on sunscreen before a flight and during,” she says in the video captioned: “We need to be on to this.”
The comments range from shock at the news (“Omg, this never even occurred to me!”) to the more humorous (“I might just hop on the plane to tan.”)
So is the advice correct? Do crew and passengers, especially those in the window seats, need to slip-slop-slap?
Ben Liley is an atmospheric scientist at NIWA’s Lauder research station in Central Otago, where studies on ultraviolet radiation have been ongoing for more than 30 years.
In the past, he has collaborated with then-Medical Officer for Air New Zealand, Dr Nicola Emslie, to measure spectral UV in aircraft cockpits. It followed a report in 2015 which said rates of melanoma for flight crew were sometimes 50% higher than the general population. Those findings could not conclusively determine if the high rates were caused by UV exposure during flights or if it occurred on the ground during work or leisure.
Liley told Stuff Travel it is important to recognise the different forms of UV – primarily UVA and UVB.
“Visible light has wavelengths from 700 nanometres (red light) down to 400 nm (violet). Ultraviolet (UV) light from 400 nm down to 315 nm is called UVA, from 315 nm down to 280 nm is UVB, and from 280 nm to 100 nm is UVC,” said Liley.
“The shorter the wavelength, the more damaging, but UVC is entirely blocked in the upper atmosphere so does not reach Earth’s surface, or even aircraft at flight altitude. The main UV hazard is UVB, but UVA can also do harm from prolonged exposure.”
The research involved a UV spectrometer and several electronic UV dosimeter badges on a number of Air New Zealand flights, measuring UV radiation through the different cockpit windows.
What they found is that UV transmission through the windscreen is “nil” thanks to it being heavily laminated, therefore completely blocking both UVA and UVB, but that some of the side windows transmitted UVA above 340 nm.
“The conclusion was that over the course of long flights, there was some increased risk.” Liley added he had heard anecdotally that medical officers at the airline could tell pilots apart from co-pilots by which side of their face was more tanned.
LAWRENCE SMITH/Stuff
Sunscreen brands undergo rigorous testing prior to hitting the shelves, and we can be assured they’re safe – New Zealand Sun Care Initiative says (video published March 2022).
The study did not explore UV in aircraft cabins, but Liley said that ordinary window glass blocks about 95% of erythemal (sun-burning) UV, and aircraft windows can be expected to achieve at least the same.
“The outside UV intensity at flight altitude is higher than at Earth’s surface, and it can be enhanced by reflection off underlying cloud. Just as at Earth’s surface, the erythemal UV intensity is greatest when the sun is overhead and the sun’s rays have a shorter path through the ozone layer.
“Inside the cabin, you might worry more when bright sunlight is pouring in from low sun. Though the UVB content will be low, the UVA can still be high.
“If you are on a long flight and don’t want the shade down, there may be merit in sunscreen, but make sure it is one that blocks UVA.”
Liley also added that “like the flight crew, make sure you use it when you disembark at your sunny destination”.