(Referenced from www.thriveyouth.org)
This discussion wants to debunk some notions which have been established as being irrefutable proof why current sunscreens are the most effective and why the SPF classification can tell you everything about the skincare product.
Imagine these scenarios:
- It is the middle of a hot summer’s day and you are driving around in your air conditioned car. You finish your journey and you notice that your arms and even legs are red and a little bit sore. You will instantly think “I should have put on sunscreen because I have become sunburnt by the nasty UV rays while in my car”
- You sit in the bus and notice that the cloth covered seats that had bright colours, seem to have faded.
- The heavy drapes and curtains you draw on the windows to block out the worst of the days heat seemed to have faded and the polyamide backing appears to be disintegrating.
- Why do women who wear foundation on their face seem to suffer less of melanomas on the face than do men?
The question to ask is why these events happen. Current thought dictates that all these events are occurring because of the UV A and B rays. These are high energy short wavelength beams which penetrate any living matter and cause alterations in skin, fabric, dyes etc. thereby creating serious damage.
All sunscreens must carry a Skin Protection Factor (SPF) which is a theoretical figure to designate the amount of time you may be able to stay in the sun without being sunburnt. The figure is relative to the length of time to get sunburned with the sunscreen on as opposed to not having any on at all. So in theory a sunscreen with an SPF 30 would allow a person to stay in the sun for 30 times longer than with no cream on before being sunburned. So if it takes you 20 minutes before you get sunburned at the peak of the heat of the day, then with the cream on you would theoretically be able to be in the sun for 600 minutes (10 hours). Problem is you perspire and so expose regions to the sun and can burn in those areas.
This does not take into consideration skin types, location of sun exposure (ie near the equator as opposed to near the poles), what time of the day to be exposed, melanin content in the skin etc. Most sunscreens that use an SPF are chemical sunscreens. These types absorb the UV rays through complex reactions with chemicals in the sunscreen. These can be very effective for UV rays although side reactions may lead to by-products which may not be so desirable on the skin.
Firstly we need to understand what these UV rays are. Broadly speaking nature has a very broad spectrum of wavelengths going from the shortest to the longest wavelength as shown below.
(Referenced from http://9-4fordham.wikispaces.com/Electro+Magnetic+Spectrum+and+light)
They range from Gamma rays then X-rays, UV, Visible light, Infrared (IR), Radio wave and Microwave.
So from this you would logically think that the shorter the wavelength the more “penetrating” it would be. Now we need to clarify some perceptions that have been bandied around which theoretically have problems in its logic.
It is a fact that UV rays do not pass through glass (a non-crystalline material) but yet can pass through quartz crystal. So when an object or person is behind a window or glass sheet, UV rays do not reach the target.
So what is it that created that skin burn when you were in that air conditioned car behind the closed window? The answer has to be something with a longer wavelength. Although you can “see” the visible spectrum, which are colours (therefore able to pass through the glass), it does not have enough energy to create damage to the skin. The damaging portion of the spectrum is the Infrared (IR) rays. Infrared easily passes through glass and is what we feel as heat.
The IR wavelength has a frequency which matches the size of the water molecule. It is long enough therefore to spin the water molecules in skin. They rotate faster and faster until they “evaporate” off the skin. So when you are in a car with the air conditioning on the atmosphere is dry, which will dry out the skin quicker.
Once the skin has no more moisture to protect it the skin starts to denature (much like what happens when you boil an egg and the albumen changes form). This denaturing creates what we perceive as pain and burning. After this burning, we have the blistering of the skin which leads to that typical peeling of the skin.
So moisture is very critical to skin. Another example of how water can protect skin is if any acid spills on your skin you will not feel an immediate burning sensation. There is a reaction on the skin which leads to a warming sensation. This heat is due to the reaction between the water molecules in the skin and the acid. When there is no more water to react with the acid, then the skin will start to burn or denature (giving the stinging sensation). So there is enough time to wash most acids (not all) off the skin before any damage is created.
So what should we do to protect our skin from the effects of sun and heat?
There may be some merit to protecting the skin against the action of UV rays but the fundamental thing that the skin has to have is moisture. The skincare cream that is applied needs to have several things in order to be effective.
1. Moisture deficient skin has to have a good replenishment and retention of water in the skin. (I will release an article on differentiating between a “moisturiser” and an “emollient” in the treatment of water poor and/or oil poor skin)
2. The moisturising effect needs to remain for long periods of time which means the water molecules need to be bound to the skin more strongly using a hydrotrope
3. There needs to be reflective materials in the cream so as to “bounce” or reflect the UV and IR waves away from the skin thereby protecting the penetration into the areas where the most damage occurs.
So if you cannot get your hands on an appropriate skincare cream for outdoors find a suitable moisturiser and liberally apply as often as necessary so that the skin does not dry out.
The ideal cream to use would be Australian Melaleuca’s patented Skin Protector Cream which has the appropriate Hydrotropes (water trapping chemicals) and micronised metal oxide compounds needed to reflect the harmful rays. It also contains the emolients and penetrating agents needed to ensure long lasting effects. Contrary to most creams it will be effective even when perspiring heavily, swimming etc. This cream is only removed by washing with a body cleanser. For regular use we also recommend Australian Melaleuca's Hand & Body Lotion which is also a very good moisturiser with very good hydrotropic materials although with no ability to filter out harmful wavelengths from the radiation spectrum.
(Referenced from salmanshaheen.com)