Apply a thick layer ensures the effectiveness of sunscreen – Health, education and well-being – Notes

Stockholm, July 28. – People get less than half of the sunscreen that they believe when they use creams or lotions that have this lens, but the problem itself does not. is not the product, but the form and amount that they apply on the skin, say British scientists.

Because of the importance of protecting the skin against the impact of the sun's ultraviolet rays that can cause cancer, researchers at King's College London conducted a study to determine the ## 147 ## 39, efficacy of sunscreens and the damage they can cause in epidermal DNA.

Scientists have found that consumers tend to generally apply sunscreen, that is, a relatively thin layer, and forget to put it on certain areas of the body, such as temples, so that they can not take full advantage of these products.

"The sunscreen provides important protection against the impact of sunlight," says Professor Antony Young, of the Institute of Dermatology at King & # 39; s College London , and states that the study shows that the way it is applied is very important for its effectiveness.

The study involved 16 light-skinned people who were exposed to ultraviolet rays (UVR) to simulate sunlight, to whom sunscreen was applied in various thicknesses, from 0, 75 milligrams (mg) considered typical use, at 2.0 mg, and only small areas of the skin were left unprotected.

Some participants were exposed to UV rays for five consecutive days to mimic the typical conditions that people are exposed to when they go on vacation, but also doses of lightning exposure, varying from low to high. at high, varied.

To end the experiment, the researchers performed biopsies of UV-exposed skin that, for ethical reasons, were at minimal dose in unprotected areas to prevent burns.

The biopsies showed that after repeated UV exposure, epidermal DNA was significantly damaged in unprotected areas, confirming that sunlight can cause burns or damage to the skin. skin.

In fact, a single day of exposure to low doses of UV in an area without sunscreen resulted in more damage to the DNA than a high dose exposure during five days in protected skin with layers of recommended thickness, emphasize the researchers.

The amount applied is very important, because when a relatively thin layer of cream is applied with a sun protection factor (SPF) of 50, it offers at best only 40% of the expected protection , they need.

In an article published in the journal Acta Dermato-Venerology, researchers explain that this is because people are applying less than the amount used by manufacturers in solar filter tests to determine their FPS rating, which is 2.0 mg per square centimeter.

The results of the study reveal that DNA damage was slightly reduced when sunscreen was applied at a thickness of 0.75 mg and decreased considerably when compared to the previous year. a 2.0 mg layer was applied.

In general, the results "demonstrate that public health messages should emphasize a better and greater application of sunscreen for maximum benefit".

Thus, recommend to apply the correct thickness of sunscreen, people should use about 35 milliliters (ml) of blocker for the entire body and distribute it according to the portion of skin to be covered, by example a little more than half a teaspoon (3 ml) for the face and a similar amount for the neck.

The amount should be multiplied by each leg, each arm, for the chest and for the back, suggest that scientists say that it is better to use a higher SPF than necessary because the consumers must apply very little sunscreen.