Safe Fun in the Sun
Get a Little Sun-For Your Health
It is true that a little bit of sun gives that 'healthy glow' and the essential vitamin D that are bodies need to properly absorb calcium for strong bones as well as muscle health (this includes the heart). What you may not know is that the amount of sun exposure needed to get adequate vitamin D can be as little as 15 minutes depending on skin tone. This can be done walking to the mailbox, back and forth to our cars or across a parking lot. Research is ongoing on what is the proper balance of sun exposure for optimum health and safety.
When It's Too Much
What we do know is that exposure to the point of sunburn is extremely damaging. Repeated, long periods of unprotected sun exposure can lead to sunburn and eventually skin cancer. What many people don't consider is that our eyes need just as much protection. Prolonged sun exposure without proper eyewear to protect against UVA & UVB rays can lead to scarring of the cornea, cataracts in later years.
Ultra Violet Rays
Beyond the few minutes a day needed for vitamin D absorption and metabolism, proper protection from UVR (ultraviolet radiation: UVA & UVB) is a must: sunscreen as well as eyewear.
Some public concern has been expressed regarding the safety of the chemicals used in commercial sunscreens. Studies have been conducted over the past several years with no evidence of any adverse side effects to these chemicals but vast benefits to their protective qualities. What new developments that have come from this ongoing research has been new regulations for sunscreen labeling and testing set forth in 2011.
UVA and UVB differ in quality and effect on the body. UVB makes up about 5% of UVR and is more intense and damaging with a higher risk for causing sunburn and even DNA changes. UVA accounts for 95%, is less likely to cause sunburn but also penetrates the skin much deeper causing the tanning effect and can cause more biological effects.
Cancer Risk
UVR, whether UVA or UVB can cause cell changes and increase cancer risk even is exposure doesn't result in sunburn. This is why so much research has been done on sun exposure and sunscreen protection needed to prevent risk of cell damage.
Not all sunscreens are the same. Sun protection is available in different SPF (Sun Protection Factor), some protect against UVA, some against UVB and those called "broad spectrum" protect against both. New labeling guidelines were established in 2011 that require specific criteria to be met in order to make certain claims of coverage.
The number of SPF correlates to mathematically equated value of the time it takes to produce erythema. In plain English, that means that an SPF of 10 would take 10 times the baseline established by the equation to make your skin red; SPF 20 would take 20 times, SPF 30 would take 30 times and so on.
Broad spectrum is also determined by a formulated test to the wavelength that is blocked. Basically, it's determined by the amount of radiation absorbed and time it takes to darken the skin.
Next is water resistant. This means that the protection keeps it's SPF strength after 40 minutes of water immersion. Very water resistant would call for 80 minutes.
Traits of Ultraviolet Radiation
Characteristics
| UVA
| UVB
|
|---|---|---|
Wavelength
| Longer
| Shorter
|
Penetration
| Dermis (top layer of skin)
| Epidermis (under top layers)
|
%of UVR
| 95
| 5
|
Erythema Potential
| Generally low
| High
|
Effect on Pigment
| 10-20 mins, up to 24 hrs
| 3-7 days after exposure, lasts for weeks
|
Glass Penetration
| Yes
| No
|
Photoaging
| Yes, thinning & aging of skin
| less damaging
|
Immunosuppression/Photocarcinogenesis
| Yes, oxidative stress
| Yes, many areas including DNA damage
|
In A Nutshell
- Broad Spectrum=UVA & UVB protection
- SPF=Sun Protection Factor
- Water Resistant=40 minutes of SPF protection
- Very Water Resistant=80 minutes of SPF protection
- Prolonged unprotected sun exposure=Increased Cancer Risk
References
usnews.com
Medscape.org
American Cancer Society
Lightweight protection!
© 2014 Shawn Holmes
