As summer approaches, the prospect of feeling the sun on your face may be enticing. It may also send you into hiding.
We hear about UV rays, and the effects of having too much of this radiation exposure.
UVA. UVB. UVC. Sounds like a scenario requiring a bomb shelter. Or a new way of reciting the alphabet.
What is this stuff? If we're going to be out in it -- or trying to steer clear, jumping from the shade of tree to tree beneath a parasol -- we might as well get familiar with our friend and enemy, the UVA ray.
Ultraviolet (UV) radiation makes cell phones, microwaves and X-rays work. You harness UV radio waves when you turn on the lights or listen to the radio.
Ultraviolet radiation emanates from the sun to the Earth in three forms: UVA, UVB, and UVC.
UVC rays and some UVB rays do not reach us, being absorbed into the ozone. But UVA and the remaining UVB rays hit the Earth running and can affect our skin and eyes, with potential for suppressing our immune systems and increasing our risk for cancer.
UVA rays are not as intense as UVB rays but we are exposed to more of them. About 95 percent of the UV radiation hitting the Earth's surface are UVA, and they are 30 to 50 times more abundant than UVB.
UVA rays have a longer wavelength than UVB or UVC. Even though UVB rays are more intense than UVA, the UVA rays themselves penetrate deeper into the middle layer of your skin called the dermis. UVB rays' shorter wavelength reaches only as far as the epidermis, which is the outer layer of your skin.
UVA rays damage skin cells called keratinocytes. UVA may cause skin cancers and contribute to premature wrinkles and skin aging.
Which brings us to tanning beds. Tanning beds use UVA rays. High-pressure sun lamps pour out up to 12 times the amount of UVA rays as we get from the sun.
Tanning bed aficionados have more than double the chance of developing squamous cell carcinoma, and 1.5 times more risk for basal cell carcinoma. And the younger the person in the tanning bed, the greater their risk for melanoma.
This can make you want to pull down your shades and huddle in the dark.