Sun 1 UV ABC's, ratings, indices, and more

Sun 1 UV ABC's, ratings, indices, and more...

      According to my Dermatology Duchess, a specialist in Transplant and Melanoma  patients,  sun exposure can trigger Graft vs Host Disease ( GvHD ). Protection requires not just  sunscreen, but clothing cover ups  for even a  short  car ride on  sunny day!  (Think newborn baby skin ) Since I will be living with this to some extent for the rest of my born days,  I have been studying  up on Sun Protection.

       My only alternative to become nocturnal, and for me, that is not yet an option.

      Today's post is the first of a multi- part series. There will be plenty of cartoons, and I will intersperse them up with some music posts, a series on the immune system, and any medical updates. This one is a little longish, the rest will be more compact.

     This topic has become much more important to me in the wake of my Stem Cell Transplant, as I am now at great risk of complications that can arise from exposure to the sun. This is not just because I now have new "baby skin",  the chances of kidney failure and vision loss are compounded by my compromised, albeit brand new, immune system.

To get things cooking, today we will lay some ground work and have a look at

* some definitions,
*the Visible Light Spectrum,
*UV  ABCs
*UV Index
*Your Skin Type, your propensity for burning
*SPF ( Sun Protective Factor ) rating for Skin

     If you are in your middle years or beyond, chances are you didn't do much in your youth to protect yourself from sunburns.  We usually started our summers with a burn and peel cycle, but the public consciousness about skin cancer was not as elevated back then as it is now.

There is a lot to cover, or uncover as the case may be, so jump on over

Soundtrack

Here Comes the Sun, Ritchie Havens   Live 1971

High quality audio, from a studio session, don't miss it.

We were so lucky to have heard him at the Beaufort Music Festival 

before he passed over April 13, 2013. 

1955 Saturday Evening Post advertisement

The Coppertone girl was created as an important part of the companies'  brand messaging in 1955. The character was drawn by Pin-up illustrator Joyce Ballantyne, who used her three-year-old daughter Cheri as a model.

When sun is at Zenith, you
lose-your-shadow-in-Hawaii

Hawaii is the only State in the US to experience the Lahaina noon phenomenon, unique to the tropics.

Note shadow directly under sculpture. Must be High Noon in Lahania!

Sunlight

     Sunlight  is composed  radiation that is slightly more than half infrared. At  the zenith, the sun  provides an irradiance of just over 1 kilowatt per square meter at sea level. Of this energy, 527 watts is infrared radiation, 445 watts is visible light, and 32 watts is ultraviolet radiation.

Light, the visible spectrum:

Roy G. Biv, the mnemonic for remembering the visible spectrum.

They Might Be Giants - Roy G Biv Song  Bonus soundtrack, but wait til Richie Havens is done.

red orange yellow blue indigo violet

or vipyor as displayed below...

UV Rays: UltraViolent?

Invisible rays that are part of the energy that comes from the sun

.

Ultraviolet (UV) radiation is part of the electromagnetic spectrum emitted by the sun. Whereas UVC rays (wavelengths of 100-280 nm) are absorbed by the atmospheric ozone, most radiation in the UVA range (315-400 nm) and about 10 % of the UVB rays (280-315 nm) reach the Earth’s surface. Both UVA and UVB are of major importance to human health.

Small amounts of UV are essential for the production of vitamin D in people, yet overexposure may result in acute and chronic health effects on the skin, eye and immune system.

From WHO Site emphasis mine. cbs

UVA radiation may cause premature aging of the skin and skin cancer. It may also cause problems with the eyes and the immune system. So UVA rays  don’t burn, but do penetrate the skin, and are the cause of  cell damage and skin cancer.

ibid

 UVB   radiation causes sunburn  by toasting, darkening and thickening the outermost layer of skin, resulting in redness, peeling, and  possibly cancerous changes in the body’s cells like melanoma and other types of skin cancer. It may also cause problems with the eyes and the immune system. UVB  radiation also comes from special lamps or a laser and is used to treat certain skin conditions such as psoriasis, vitiligo, and skin tumors of cutaneous T-cell lymphoma. 

UVC  Deadly to Humans. In medicine, UVC  comes from special lamps or a laser and is used to kill germs or to help heal wounds, and to treat the same skin conditions that UVB  treatments address. FACT: While glass does block most UVB rays, UVA radiation can get through. Which means that even indoors or in a car with the windows up, you can tan or burn. Tinted windows help some. Don't squint, get the tint.

UV INDEX

      A scale ranging from 0 to 10, used to estimate the risk for sunburn in midday sunlight, with 0 indicating no risk and 10 indicating maximal risk. The UV index is effectively a rough measure of the amount of harmful ultraviolet radiation in the sunlight reaching the Earth's surface at a given location, given the time of year and current atmospheric conditions, expressed in terms of the risks that are associated with exposure to that amount of radiation.

The American Heritage® Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved. 

Ultraviolet Light Index History: 

1992: Environment Canada develops UV index and predictions

1994  US follows suit

2004  World Health Organization standardizes an international UV index with a uniform calculation and color code for print

2005  Australia and US  start posting UV alerts to convey warning to public

UV Index Chart from NOAA, can be found daily

at most weather sites,

Know your Skin type!

Before we started travelling and migrating, this is the way things looked.

The Tropics
See the correlation? Evolution ain't stupid.
source

Here is a practical guide to help you determine your propensity for tanning.

And the time in minutes before you start to burn.

SPF:  Sun Protective Factor three ways -

Geeky, less Geeky, and Simple

The Formula (Geeky)

 from http://www.rheothing.com/2011/06/uv-abosrption-and-sun-protection.html

A cool looking geeky formula that expresses the ratio of UV radiation dose required to produce recognizable redness on skin that has been protected with a sunscreen from the UV B radiation dose required to produce the same degree of redness on unprotected skin using a clinical test  procedure on human skin.

Less Geeky

      Let’s break it down. The SPF number on a bottle of sunscreen is a multiplier. It is an indicator of how long your skin is protected compared to if no sunscreen was used.

SPF tells you how much longer it will take for your skin to begin to redden with the product on than if your skin was unprotected. The percentage of burning UV rays that a product blocks does not increase proportionally with the SPF value. So SPF values indicate a function of skin reddening.

 

Simple

                                SPF 30                 X         10 minutes          =             300 minutes

For example,  say you are  a freckled redhead, a type 1 skin, and it normally takes around 10 minutes before your  unprotected skin starts to burn on a day when the UV index is say 10.

An SPF30+ sunscreen will offer you 30 times that protection for approximately 300 minutes. 

3.3 per cent of UVB rays still reach your skin, which is why its important to combine sunscreen with extra precautions like wearing sunglasses, hats and shirts, and seeking shade.

UNDERSTANDING SPF

source:Dec 02, 2012 1:00 PM by Leigh-Anne Parrish on http://www.sheknows.com.au

Another representation. See out how the SPF flattens out ? Not much difference between SPF 29 and 50

Got it?   

 Think Skin Protection Formula instead of Sun Protection Factor.

But  having said all that,you know what? It is not an exact  science, ,the SPF rating may vary within the batches, people apply it thick and thin, then go swimming or sweat it off, and there are many other variables in the ingrediants so just use you common sense and

And reapply it often. Pay attention to your body, this is not a "no pain no gain" excercise, it is bullet dodging.

Think of it like reefing, and do it when you first think you might need to. You can't use too much, if you are using one that is chemically safe. ( and some is not safe, more on that in a  later post )

RISKS:

I don't want to bum anybody out, but this is something you need to be thinking about...

Skin cancer facts here, and more from the

 American Cancer Society.

According to the American Cancer Society, skin cancer is the most common form of cancer in the United States—an estimated 1 million non melanoma cases are diagnosed annually. The majority of skin cancer cases, up to 90%, are sun-related.

Sources and nore reading

Good Information here

http://www.skincancer.org/skin-cancer-information/skin-cancer-facts#treatment

Can be trusted, in my opinion - from PubMed

http://www.ncbi.nlm.nih.gov/pubmed/11744395

World Health Organization

WHO Intersun program

Sun 2 The Social History and Origins of Tanning coming soon/