It is a well-known fact that sunscreen is an essential component in everyday lives. Although there are specific theories that state these creams block the sun and one will not be able to absorb high vitamin D, there are others, nevertheless, thinks that applying sunscreen is very important to reduce harmful Ultraviolet radiation from the sunshine to avoid acute diseases such as cancer.
But there have been a significant number of uncertainties when it comes to how to apply and how much to use. Manufacturers produce sunscreen based on a principle that one should apply 2mg/cm2. However, it is not always possible for a person to ask that much and many end up in using very little than that, such as 0.75mg/cm2. According to the researchers from King's College London, the lower application will not significantly protect one from harmful ultra-violet radiation.
To understand how it affects our body, they experimented with two groups of all fair skin participants of both female and male genders. Two groups received UVR exposure differently. One group receive single UVR exposure and were asked to apply higher SPF sunscreen of about 0.75mg to 2mg/cm2, meaning varying thickness, whereas other groups were asked to expose to various exposure conditions.
for the group that was repeatedly exposed to UVR, considerable DNA damage was found on the areas that received no sun protection, even though the UVR dose was very low. Damage was reduced when sunscreen was applied at a thickness of 0.75mg/cm2 and considerably reduced when 2mg/cm2 of sunscreen was applied, even with much higher UVR doses. Five days of exposure to high dose UVR with the sunscreen at 2mg/cm2 showed significantly less damage than just one day's low UVR dose exposure without sunscreen across all samples.
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Therefore, it is not always correct that we should apply how much we want, especially in the case of sunscreens. To avoid dangerous diseases, such as cancer from harmful radiations, one should apply sunscreen as recommended by the manufacturer. Or, one can purchase higher SPF, researchers think that may work too.