Window seats may increase radiation exposure during flights, studies reveal

Does a Window Seat on a Flight Expose You to More Radiation? Here’s What Studies Say

Window seats on flights are prized for their stunning views, whether it's city skylines or mountain ranges. However, research suggests that sitting by the window on a daytime flight might expose you to higher levels of radiation. While this might sound alarming, experts assure occasional travellers that the risks are minimal.

Why Does Radiation Exposure Increase During Flights?

Commercial aircraft typically cruise at altitudes between 30,000 and 40,000 feet. At these heights, the Earth's atmosphere—our natural shield against various types of radiation—becomes significantly thinner. This reduced atmospheric protection exposes passengers to higher levels of both ultraviolet (UV) and cosmic radiation.

UV radiation comes directly from the Sun and primarily affects the skin, while cosmic radiation originates from high-energy particles in outer space. Although they are often confused, these two types of radiation are distinct in their effects.

The Window Seat Factor

Cosmic radiation penetrates the aircraft cabin and affects all passengers equally, regardless of their seat. However, window seats pose an additional challenge when it comes to UV radiation. Aircraft windows are designed to block UV-B rays, which cause sunburn, but they allow a significant amount of UV-A rays to pass through. UV-A rays are more insidious, as they penetrate deeper into the skin and are associated with long-term damage, including premature ageing and an increased risk of skin cancer.

At cruising altitude, UV radiation is much stronger than on the ground. A study published in JAMA Dermatology found that sitting in sunlight for just under an hour at 30,000 feet delivers the same dose of UV-A radiation as a 20-minute session in a tanning bed.

Cosmic Radiation: The "Chest X-Ray" Comparison

When people say a flight exposes you to as much radiation as "two chest X-rays," they are referring to cosmic radiation, not UV rays. High-energy cosmic particles interact with the Earth's atmosphere to create secondary radiation, which affects everyone on the plane, regardless of their seat location.

For context, a long-haul intercontinental flight typically exposes passengers to 0.10 to 0.15 millisieverts (mSv) of cosmic radiation. This is roughly equivalent to the dose from a standard diagnostic chest X-ray, which is about 0.1 mSv.

Who Is at Risk?

For occasional travellers, the health health risks from both UV and cosmic radiation are negligible. However, frequent flyers, such as flight crews and business travellers, face higher cumulative exposure. Studies indicate that flight crews, who spend significant time at high altitudes, accumulate greater doses of radiation over their careers. Dermatologists are particularly concerned about the long-term effects of repeated UV-A exposure, which can accelerate skin ageing and increase the risk of skin cancer.

How to Reduce Radiation Exposure

Thankfully, reducing your exposure to UV radiation during a flight is simple:

• Lower the window blind: This is the easiest way to block direct sunlight.
• Choose an aisle seat: Sitting away from the window reduces direct UV exposure.
• Use sunscreen: Apply a broad-spectrum sunscreen (SPF 30 or higher) if you're in a window seat and the sun is shining directly on you.
• Cover up: Wear UV-blocking sunglasses and lightweight, long-sleeved clothing for extra protection.

Final Thoughts

While occasional travellers don't need to worry too much, frequent flyers should consider these precautions to minimise their exposure to UV and cosmic radiation. If you love the view from a window seat, enjoy it—but remember that a little sun protection at 35,000 feet can go a long way.