We
all know the sun can damage our skin causing premature aging and even
cancer but most of us don’t know how or why. This article gives a brief
and easy to understand explanation of the sun's UVA and UVB rays and
how they affect our skin.
We all know the sun can damage our skin causing premature aging and even cancer but most of us don’t know how or why.
It can be hard to know what to look for when you need to protect your
skin as it’s easy to get confused about which UV ray does what.
It’s easier to know how to protect yourself if you know what you’re protecting yourself from.
The sun has 2 types of UV, (ultraviolet), rays:
1. UVA
2. UVB
UVA:
Long-wave solar rays of 320-400 nanometers, (billionths of a meter).
You’re almost never safe from exposure to UVA rays as they can go
through windows, light clothing and even your windshield, so if you’re
outside you’re getting exposed to UVA rays.
UVA rays are responsible for aging. They are less likely than UVB to
cause sunburn but UVA penetrates the skin more deeply, causing
wrinkling and leathering of the skin.
Prolonged exposure of UVA cracks and shrinks the collagen and elastin of our skin.
Collagen makes up 75% of our skin and is the fibrous protein of skin,
cartilage, bone, and other connective tissue. Along with elastin, it is
responsible for skin strength and elasticity, and its degradation leads
to wrinkles that accompany aging.
Elastin, is a protein in connective tissue that is elastic and allows
the skin to resume it’s shape after stretching or contracting.
When UVA rays damage these components of our skin it looses strength
and elasticity thus causing wrinkles, sagging, leathery skin and… aging!
If that’s not bad enough studies show that UVA not only exacerbates
UVB's carcinogenic effects but may also directly induce some skin
cancers, including melanomas.
UVB:
Short-wave solar rays of 290-320 nanometers.
UVB rays are more potent than UVA in producing sunburn. Therefore these
rays are considered the main cause of skin cancers, (basal and squamous
cell carcinomas and melanoma).
Sometimes called the "tanning ray", UVB rays stimulate the melanocyte
cell, (located in the bottom layer of the skin), to produce the brown
pigment melanin, producing a suntan as a defense against UV radiation.
So even if it's a cloudy day and you're driving in your car you're
getting exposed to the harmful UV rays of the sun. That's why it's so
important to prtoect your skin with sunscreen and UV protective
clothing at all times, (especially if you're working, playing or
vacationing outside).
