What is UV?
Ultraviolet (UV) radiation from the sun is a major cause of skin cancer and accounts for 1.3 million new cases in the USA alone each year. It is classed as a complete carcinogen in that it has the capacity to cause cancer on its own.
Solar UV radiation largely consists of UVB (280-320 nm) and UVA (320-400 nm) wavelengths. UVB radiation has been associated with sunburn, immunosuppression, photoaging, skin cancers and DNA lesions. UVA radiation which represents 95% of the total UV received at ground level, is less energetic than UVB. It has also been associated with immunosuppression, photoaging, and mutagenesis. According to the albino hairless mouse model, both UVB and UVA can be involved in the development of cutaneous cancers including squamous cell carcinomas (SCC) and basal cell carcinomas (BCC). However, the relative efficiency of UVA in inducing these carcinomas is approximately 10,000 times lower than UVB and much higher doses of UVA are required. Both UVA and UVB act by causing programmed cell death [apoptosis] which has been linked to cancer. Thus, ideally, sunscreen products should provide efficient protection against both UVB and UVA radiation.
What is Sunburn?
The natural human sunburn cycle (without the use of any sun lotions or sunscreens) is approximately one week in length (7 days) from start to finish. There are three basic stages or phases. These include Inflammation, New Tissue Formation, and Apoptosis (visible peeling). Inflammation consists of redness and irritation of the skin starting 20-30 minutes from the time of sun exposure. It usually lasts around 2-3 days, but can also last up to 5 or 6 days depending upon UV exposure intensity. New Tissue Formation starts some time after initial exposure and it is complete within one week. Apoptosis is when the top layer of dead skin cells peels off to reveal a new tissue layer beneath. This whole process is complete within approximately 7 days from the time of exposure.
What does Sunscreen do?
It has been shown in scientific studies that sunburn can occur despite the use of sunscreen (15 SPF) during winter months in a mild climate. In addition, sunburn may still occur while wearing stronger sunscreens (30 SPF). Although they may lessen or even eliminate the first phase of redness and inflammation, the second and third phases may not be prevented by wearing sunscreen. Since it is the last phase [Apoptosis] that has been linked to skin cancer, this reflects a potential lack of efficacy of many sunscreens available to the consumer.
What should Sunscreen do?
Moondust Cosmetics has formulated and favourably tested two new sunscreens for their ability to block peeling, or, apoptosis following exposure to solar radiation. The results have been reported in scientific publications. Based on the first formulation, the main active ingredient in our natural suncare products is a preparation of pure zinc oxide in a creme base rather than the microfine form which is currently a popular ingredient of sunscreens. Based on the second formulation, Moondust Natural Sunscreens contain a combination of zinc oxide and melanin. They can be used safely all year round and help to protect against every stage of sunburn.
What is Apoptosis?
Apoptosis (programmed cell death) can occur in response to UV light. This is also known as apoptotic or scientific sunburn. Some people tan by increasing melanin production following sun exposure. The melanin pigment which absorbs UV light is the natural defense system of the human body against sun damage. However, some people do not tan well and experience sunburn instead. This occurs when the unprotected skin cells are actually killed by solar radiation and fall off the surface of the body within a week.