UV Exposure

UV light

UVB and UVA light are very powerful energy and can change a lot of molecules. If it weren’t for the protecting air (less nowadays due to the thinning of the ozone layer), we would all die quickly as the UV alter and kill our cells. Fortunately we still have an ozone layer to give certain protection, otherwise we would have to wear "moon-suits" whenever we went outside.

UVB

UVB -radiation causes the principle changes in the epidermis = burning.  It tends to damage the skin's more superficial epidermal layers.  It plays a key role in the development of skin cancer and a contributory role in tanning and photoageing.

UVB -filters are Cinnamic Acid Esters - Camphor derivatives (PABA = para amino benzoic acids), Benzyl Methane - these filters absorb UVB radiation on the skin and convert it into other forms of radiation.

UVA

UVA -radiation goes deeper into the skin and causes major changes in the dermis.

UVA -radiation is responsible for accelerating the skin aging process by breaking down collagen & elastin tissues.

UVA-filters (mineral filters) are Titanium Dioxide and Zinc Oxide - these pigments reflect radiation and reduce the chance of an allergic skin reaction.

Short-term side effects of sun exposure

The skin becomes red, swollen, tender and painful. Sunburn is an acute inflammatory response. It normally produces a protective effect since most sunburn victims will avoid continued sun exposure, thereby preventing further damage.

Short-term effect of sun exposure is to induce tanning of the skin and thickening the skin, both of which are protective. Tanning involves stimulation of and conversion of pre-formed melanin into melanin that is then distributed through the upper layers of the skin. Melanin quenches UV light and provides significant protection to the skin from further damage by UV light.

Following sun exposure, the upper layers of the skin (the epidermis) show increased thickness. This, again, is a protective mechanism increasing the layers of epidermal cells that need to be penetrated by UV light before the sensitive basal cells can be affected.

Long term side effects of sun exposure

These include photoageing and photocarcinogenesis. The effect is on both the epidermis and the dermis. UVB causes the principle changes in the epidermis and UVA causes the major changes in the dermis.

With increasing photoageing, wrinkles develop, the skin becomes drier and mottled pigmentation develops.

Photocarcinogenesis is extremely complicated. UV light has specific effects on the cellular DNA of the skin cells. It is damage in the DNA that induces mutation within the cell and will allow a malignant clone of the cell to eventually develop into skin cancer.

UV exposure of the skin has a further significant impact on photocarcinogenesis by damaging the epidermal Langerhans cell reducing the immune response in the skin.

Links between sunblock and increase in skin cancer!

" If sunblock prevents burning, it also eliminates the bodies natural defenses against staying in the sun too long."

Since the mid-Seventies melanoma cases have risen by 160 per cent and scientists have been blaming this rise on sunburn. Skin cancer is now the most common form of malignant disease in the World.

There are 40,000 cases of skin cancer each year in this country; 4000 of these cases are melanoma. Malignant melanoma has become the second most common cancer in women under 35 - exceeded only by cervical cancer, according to the Cancer Research Campaign. 18 per cent of cases of melanoma in the UK are found in 15-39 year olds.

It is now well recognised that UV exposure is the major cause of skin cancer, including both melanoma and non-melanoma.

Sun exposure and particularly sunburn before the age of 15 years of age have a significant correlation with the incidence of skin cancer in later years.

Dr Peter Wolf, a biologist from the University of Graz in Germany carried out a controlled experiment with 500 melanoma patients. Wolf found that use of sunscreens at least doubles a person's risk of developing malignant melanoma.

Wolf has an additional concern which is shared by a number of leading professionals, including Drs. Frank and Cedric Garland of the University of California and Dr. Tony Chu of Hammersmith Hospital: the general public mistakenly believes that sunblock not only protects them from sunburn, but also protects them from skin cancer.

The vast majority of sunblocks are tested by their ability to reduce UV-induced erythema, ie controlled induced sunburn that may have no relevance in potential photocarcinogenesis.

The SPF ("sun-protection factor") effectively demonstrates how much more UV exposure is required to induce a minimal erythema dose (MED) to the skin, ie, the dose of UV light that will induce a slight redness of the skin after 24 hours, than would be possible without a sunblock. This means that when using a constant light source, if a MED without protection took five minutes to achieve, then with an SPF15 sunblock it would take some 75 minutes to achieve.

There is now great anxiety that use of high factor sunblocks, determined by their ability to protect against UV erythema, may not protect the skin immune system or the cellular DNA within the skin.

Sunblocks may actually increase the future incidence of skin cancer because the user has a false sense of security that this 'remedy' prevents skin cancer and may be encouraged to engage in more prolonged exposure as a result.

After all, an SPF100 sun lotion only offers 3% more UVB protection than an SPF25 but it is easy to assume from the much bigger number that you will be getting much greater protection. In fact, it is more important to apply enough sun lotion and reapply regularly than choose a high SPF lotion.

Titanium Dioxide

There have been recent suggestions that the use of microscopic particles of Titanium dioxide, also called nano-particles, may increase the formation of free-radicals on the skin. This rumour has come about because isolated nano-particles of Titanium dioxide can react with UV light and oxygen to form free-radicals. However, the form if Titanium dioxide used in Green People sun lotions and creams has been coated with silicates to prevent this happening – in short, it is impossible for it to react with oxygen or indeed any other substance on the skin.

Another concern is that nano-particles may penetrate the skin and thereby enter the body. Again, this is not possible with the form of Titanium dioxide used in Green People sun products as the individual particles clump together during the manufacturing process to form aggregations which are too large to penetrate the skin.

Which sun care product should I choose?

A number of studies in Europe, the UK and the US have shown that sunblocks that give a high level of protection against UV erythema do not fully protect the skin immune system.

It is now obvious that assessment of sunblock and designation of SPF is not sufficient. The use of some blocks could actually increase the risk of skin carcinogenesis rather than decrease it. Allowing users to stay in the sun longer without visible sunburn produces an increased risk of damage to the immune protective system of the skin.

The SPF rating of a sun lotion only tells you the protection it gives against UVB rays. Under new EU legislation, sun lotions must also offer protection against the more damaging UVA rays equal to at least one third of the claimed protection against UVB rays. This can be difficult to achieve using natural UV filters, but Green People’s sun lotions have always provided protection against both UVB and UVA rays and therefore comply with the new EU recommendations.

Naturally derived UV filters, which Green People uses, are preferable. Examples are Titanium Dioxide and Zinc Oxide which are natural pigment substances that work by reflecting the UVA radiation.A recommended group of UVB filters is Cinnamic acid esters,derived from cinnamon acid.

Look for products rich in plants/herb extracts known for their UV protection - like Shea butter and Edelweiss.

Avoid products containing PABA or derivatives of PABA like Padimate-O. Researcher Dr John Knowland from Oxford University reports that the sunscreen material Padimate-O generate free radicals which could attack DNA strands and increase the risk of cancer.

Look out for sun care products rich in natural antioxidants - ex. Avocado Oil - to protect the skin from free radicals. Choose a product rich in moisture binding substances - such as Aloe Vera or Cucumber - to prolong the tan and prevent the skin from drying out and peeling.

SPF15 is normally recommended. There is no need to go to a higher factor. Generally speaking, it can actually have disadvantages. The higher the factor the longer you think it safe to stay in the sun (and therefore still receive too much UV radiation). Furthermore, it can discourage the activation of the skin's own natural defenses against the sun - the skin can in fact become even more vulnerable.

Liberally apply cream to the skin approximately half an hour before going outside. This gives the filters time to work. Be sure to reapply frequently if sun exposure is to continue as otherwise you will not maintain your sun protection. You should be looking at applying an ounce - or a shot-glass full - every time you apply or reapply.

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