Wednesday, June 11, 2008

The latest on sunscreens, sun blocks and sun burn

The link between sun exposure and skin cancer was made all the way back in 1918 by Dr. Norman Paul of Sydney, Australia.

There are components to solar radiation; long wavelength ultraviolet A (UVA) and short wavelength ultraviolet B (UVB). UVA is broken down into UVA and UVA2. For a long time it was thought only UVB caused sun damage to the skin, ie. sunburn.

Research over the past two decades has shown that UVA exposure is the key cause of skin wrinkling and solar damage. This also correlates with a higher incidence of skin cancer. In the early 80’s, it became obvious that sun screens needed to provide a greater degree of protection against UVA rays.

This is what is meant when we speak of “broad spectrum”. It means the sunscreen provides protection against both UVB and UVA.

Generally, I recommend a broad spectrum sunblock with a SPF of 30 or 35. 50 is okay too. Any SPF rating above 50 really doesn’t add much in extra protection but the ingredients are so concentrated they may be irritating to your skin.

What does SPF mean? The initials stand for Sun Protection Factor. If you use a sunscreen with an SPF of 20 it means it would take 20 times longer to get a sunburn than if you had NO sunscreen.

If you get a broad spectrum” sunblock with an SPF of 30-40 or 50, you should have excellent protection. I usually recommend patients liberally apply SPF20 in three coats to exposed areas prior to going out in the sun. You should reapply this every two hours or so.

Today, there are 17 chemical and physical (ie. zinc oxide) screens approved by the FDA.

There are NEW proposed ratings for UVB and UVA protection

Proposed UVB Labeling

  • Low – SPF 2 – 14
  • Medium – SPF 15 – 29
  • High – SPF 30 – 50
  • Highest – SPF 50+

Proposed UVA Labeling

Low - *

Medium - **

High - ***

Highest - ****

Some new changes to occur over the next one to two years:

- Sun protection factor would become sun burn protection factor.

- SPF numbers would be capped at 50 since higher numbers don’t provide any significant added protection.

- Terms such as “sunblock” and “waterproof” would no longer be allowed. “Sunscreen” would replace “sunblock”.

- Sunscreens that maintain their SPF numbers offer 40-80 minutes of total immersion would be labeled “water resistant” and not "waterproof".

- Also, sunscreens would contain a warning that sun exposure increases the risk of skin cancer and aging.

There you have it – just in time for your summer sojourn to the beach or Disney World. One other thing – "gooping" is not only allowed, but recommended

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