A warning for these of you who like a window seat on the plane: you could be exposing your self to dangerous UV rays.

According to specialists, dangerous UVA rays can penetrate the glass. Marc Glashofer, MD, a dermatologist at The Dermatology Group tells Condé Nast Traveler that having sunburned need to be worrisome, but not as a great deal as its deadlier counterpart. That is for the reason that there are two varieties of ultraviolet (UV) rays: UVB rays, which lead to sunburn, and UVA rays, which penetrate the skin deeper, potentially causing cancer. Whilst plane windows do a decent job of blocking UVB rays, Glashofer says, they enable the transmission of UVA rays.

According to a current study examining the repercussions of pilots exposed to UV rays, “Airplane windshields are frequently created of polycarbonate plastic or multilayer composite glass. UV-B (280-320 nm) transmission by way of each plastic and glass windshields was reported to be significantly less than a single %. On the other hand, UV-A (320-380 nm) transmission ranged from .41 % to 53.five %, with plastic attenuating far more UV radiation than glass.”

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That similar study located that pilots flying a plane for just a single hour had been exposed to UVA rays equivalent to a 20-minute tanning bed session. And do not let the size of a plane window fool you. Even even though they’re tiny, the hours on a lengthy flight can add up, escalating your danger for skin cancer. So, either pull down the shade or slather on some sunscreen that is at least SPF 30.