14 DAY TRIAL // It's summer and most people go on vacation on the beach. Even though it's sunny and warm outside and the sound of the waves is quite pleasant, watch out for the mean ultraviolet radiations. Scientists from the University of Valencia have established that 34% of ultraviolet radiations gets through under beach umbrellas.
José Antonio Martínez-Lozano, co-author of the study and coordinator of the Research Group of Solar Radiation in UV says: “We have proven that irradiance (radiation incidence per unit of surface area) that reaches the ground covered by an umbrella is 34% of the total.” This is the diffused radiation percentage that gets through from the sides of the umbrella. The study published in the journal Photochemistry and Photobiology says that umbrellas only capture the direct flow of radiation coming from the Sun, and most of the time will not protect a person completely.
For this study, the team used an ultraviolet ray sensor that was set on the base of a canvas umbrella, with a radius of 80cm and height of 1.5 meters, painted in blue and white. Martínez-Lozano explains: “The umbrella intercepts the direct radiation that comes from the Sun, but part of the diffused radiation, which makes up approximately 60% of the total, reaches the sensor from the sky not covered by the umbrella.”
The team observed that even if the canvas left only 5% of the radiation unabsorbed, diffused ultraviolet radiation passed through on the sides. By considering every factor (ground, sky and umbrella), scientists managed to simulate real life situations, when people do not always stay under the shade of umbrellas.
Even though the Earth's atmosphere filters a huge part of harmful ultraviolet radiations, specialists do not recommend being exposed directly into the sunlight without some protection. The choice of products is quite large as not only beach umbrellas that can protect the skin; clothes, large hats, sunglasses with UV filters and the very common sun cream are also advised and highly effective. Experts also recommend staying out of the sun between 12 and 4pm (local time).
Moderated ultraviolet is good for the skin as it helps dealing with dermatological problems and boosts the vitamin D3 formation. On the other hand, UV excess can cause melanoma, sunburn, photoaging, DNA damage, weakness of the immune system and several eye problems.