What is The “UV Index,” and Why Should I Care?

    0
    2118

    I was driving earlier this morning through Ontario on my way to Buffalo for a flight, and the sky was clear and cloudless.  It’s a little on the chilly side up there in the Buffalo area (at least it was at 7am when I was on the road), but on the CBC News I heard an anchor talk about a “very high UV index that will make being outside a little on the burny side.”

    What?  I’m going to Dallas right now on a flight, and the UV Index is something that I’ve always just assumed was because we’ve polluted a hole in the ozone, and Nicolas Cage is going to have to deal with aliens like he did in that horrible movie about the sun burning up the Earth.

    So what exactly IS the UV Index, how does it affect us, and why should we care?

    Well, have you ever been sunburned?  How about melanoma?  Ever had a skin cancer scare?  Sun poisoning?  Blisters?  It’s the ultraviolet rays of the sun’s radiation that make our skin the color of a lobster when we’re out in it.  Did you know that overexposure to the sun can cause cataracts?!

    Yeah.  I still love the sun.  That’s probably why I’ll look like a freaking leather catcher’s mitt when I’m 50.

    There are three types of ultraviolet radiation:

    • UVA – makes it through the ozone layer
    • UVB – mostly absorbed by the ozone layer; some does reach the Earth’s surface
    • UVC – completely absorbed by the ozone layer and oxygen

    Our Environmental Protection Agency has quantified the risk of the amount of UV exposure that we get on a certain day.  From the EPA’s website on sun exposure:

    and something a little more helpful, from Wikipedia:

    UV Index Description Media Graphic Color Recommended Protection
    0—2 No danger to the average person Green Wear sunglasses on bright days; use sunscreen if there is snow on the ground, which reflects UV radiation, or if you have particularly fair skin.
    3—5 Little risk of harm from unprotected sun exposure Yellow Wear sunglasses and use sunscreen, cover the body with clothing and a hat, and seek shade around midday when the sun is most intense.
    6—7 High risk of harm from unprotected sun exposure Orange Wear sunglasses and use sunscreen having SPF 15 or higher, cover the body with sun protective clothing and a wide-brim hat, and reduce time in the sun from two hours before to three hours after solar noon (roughly 10:00 AM to 4:00 PM during summer in zones that observe daylight saving time).
    8—10 Very high risk of harm from unprotected sun exposure Red Wear sunscreen, a shirt, sunglasses, and a hat. Do not stay out in the sun for too long.
    11+ Extreme risk of harm from unprotected sun exposure Violet Take all precautions, including: wear sunglasses and use sunscreen, cover the body with a long-sleeve shirt and trousers, wear a very broad hat, and avoid the sun from two hours before to three hours after solar noon.

    I guess that extra four hours a day in the sun over a period of 30 years wasn’t so good for me after all, huh!

    When you’re outside this summer, do yourself a favor, wouldja?  Put on some sunscreen!  I’m certainly not one to advocate for staying out of the sun – it’s my favorite source of light after fire!

    Thanks, Dermis.net and J Grundy!

    Previous articleBurgundy – A New .PSLAB Beiruit Lighting Design Project
    Next articleGlowcamp!