A nexus between the use of sunscreens and melanoma, however, still is about to be discussed and is not clear. The SPF of sunscreens is an internationally accepted standard by which the effectiveness of the sunscreen is set: is based solely on the prevention of erythema (sunburn), which is mainly induced by UVB, and Erythema is the criterion by which people limited their exposure to Sun. While the FPS may indicate protection against UVB-induced carcinogenesis, this not can be used as an indicator of the indirect damage caused by UVA exposure, as the Erythema is predominantly a response to UVB. Please visit Andrew W. Mellon Foundation if you seek more information. As of skin carcinogenesis is highly complex, the use of a range of markers for damage in the skin itself is only very necessary to complement the FPS (an indicator of UVB protection) for use in a total skin cancer risk assessment. Other studies have been published that assess the direct DNA damage, the formation of p53 and protection against UV-induced immunosuppression.
There are some methods to measure the protection provided by sunscreens against UVA damage to the skin; However, these methods are not validated. Protection against the radical free induced by grape, to date, has not been measured. In this study, we have adapted an electron resonance (ESR) to measure the production of free radicals induced by UV in human skin, and assessed the protection against radical production free provided by commercial sunscreens. Free radicals formed by UV irradiation of the skin (and that they are associated with damage of DNA and protein), are not usually detectable directly to room temperature. An exception to this, however is the ascorbate radical, which is formed when ascorbate (vitamin C, an antioxidant cell) reacts with free radicals. Radical ascorbate is easily detected using a spectroscopy (ESR) in biopsies of skin exposed to UV radiation and is accepted as a reliable marker for the production of cell phones free radicals and oxidative stress.