Monday, June 13, 2011

What's The UV Index Where YOU Live?

You may have noticed that I attached a UV Index gadget to the top left of this blog.  (Thanks to Melissa of “Melanoma Sucks” for sharing this).  If you enter your zip code, it’ll take you to the EPA website where it will present your UV index for the day.  Gadgets are cool.
But what exactly is the UV Index?  I consulted the Google-Gurus and found this excerpt from the NOAA and National Weather Service:
The UV Index is a next day forecast of the amount of skin damaging UV radiation expected to reach the earth's surface at the time when the sun is highest in the sky (solar noon). The amount of UV radiation reaching the surface is primarily related to the elevation of the sun in the sky, the amount of ozone in the stratosphere, and the amount of clouds present. The UV Index can range from 0 (when it is night time) to 15 or 16 (in the tropics at high elevations under clear skies). UV radiation is greatest when the sun is highest in the sky and rapidly decreases as the sun approaches the horizon.  The higher the UV Index, the greater the dose rate of skin damaging (and eye damaging) UV radiation. Consequently, the higher the UV Index, the smaller the time it takes before skin damage occurs.

Below is a chart showing the minutes to skin damage chart, depending on the UV Index and how easily you sun burn:

What this basically says is that if you “usually” burn and the UV Index is at “7”, you’ll start seeing sun damage at around 28 minutes.  If you “rarely” burn, then you’d start seeing sun damage at 70 minutes.
Anything that indicates that one should wear sunscreen is a good thing.  The UV Index for Raleigh today was 11+ (that’s as high as they post), so it was definitely a day to wear sunscreen.
What I don’t like about the chart above is the suggestion that it’s okay to wander around in the sun unprotected for the minimum time listed.  I think this gives a false sense of security.  It’s best to simply tell everyone to wear sunscreen despite the UV Index.  Anyone who ventured outside in Raleigh today at noon who might “sometimes” burn probably would not have wanted to be unprotected in the sun for the 30 minutes implied as safe.  It was hot, sunny and not a safe place to be without sun protection.
Below is another chart I found which seems a little better:

This one doesn’t distinguish between skin sensitivity, but it pretty much just says if the UV Index is high, seek protection.  What I don’t like is the recommendation for UV1 or UV12, “No protection required!”  I guess living in the south, I can’t imagine too many days where no protection is required…and if such a day does exist, I’d probably want to keep my shirt on anyhow.
One thing I read on the EPA site is that once the UV Index goes above 6, a UV Alert is issued.  Okay, when I imagine an "alert," I think of an announcement that's important and wide spread.  As I said, the UV Index today was 11+, and yet I saw no evidence of an alert.  I don’t get the daily paper, so it might have been in there.  But I do watch the local news and check out the websites.  Neither had one bit of information about the UV Index short of a link buried deep within other links such as local lake levels and historical hurricane maps.  I emailed one local TV station to ask why they don’t post the UV index…once I hear something, I’ll post their response.  I suspect that they might say that the UV Index is posted for only the noon hour each day (true) and that it’s not a true reflection of the entire day’s sun exposure, therefore they don't report it.  Or they might simply state that, at least in this area, there’s an alert every day in the summer months, so why constantly post it when there’s nothing “new” to report?  I certainly hope the latter is not the case.
The UV Index is not a perfect tool, but again, anything that gets a person to consider the consequences of going into the sun unprotected is a good thing.  So feel free to type in your zip code and determine how strong the “burn” is in your town.  Either way, wear the sunscreen!

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