Berlin – In our planetary system, everything revolves around you: the sun shines constantly and with force. In summer, we feel it even more intensely, but at sea, we feel safe from it. What’s up
CLAIM: You don’t get sunburned in the water.
FACTS: UV radiation reaches the body even a meter below the surface of the water. According to experts, 80% of long-wave UVA rays get there, causing premature aging and wrinkling of the skin. 50% of shortwave UVB radiation that typically causes sunburn. You have to dive deeper to prevent dangerous rays from reaching the skin. “At least two meters,” explains dermatologist Reinhard Mrotzek.
If you’re swimming with your head above the waves, you even have to be careful. Like a mirror, the surface of water amplifies UV radiation by 50%. Medical institutes such as the British National Health Service (NHS) warn of the dangerous combination of sun and water: Due to the cooling effect, the skin is often not noticed to burn. Mrotzek advises an intensive sun lotion, and hairstyle is “a good idea”.
CLAIM: The sand also reflects the sun.
EVALUATION: That’s right.
FACTS: Be careful! It is easier to get sunburned not only in the water, but also on the beach. The clear sand reflects light and increases UV radiation by 25%, says Mrotzek, member of the professional association of German dermatologists. Anyone who is unprotected in the sand directly at the water’s edge puts their body in increased danger. The same goes for a visit to a glacier, by the way. The snow there increases solar radiation by up to 90 percent.
If you want to protect your skin from damage, you should definitely avoid the blazing midday sun in summer – between 11 a.m. and 2 p.m. Experts advise being outdoors early in the morning or late afternoon – this is especially true at the water’s edge.
CLAIM: You get a lot of tan after sunburn.
FACTS: “This is total nonsense,” says dermatologist Mrotzek. Sunburn is an inflammation of the skin that looks like a first degree burn or greater. Dermatologists warn of permanent damage if the sun is not protected. According to Mrotzek, a total of 300,000 new cases of skin cancer are expected in Germany in 2020.
The UV Index (UVI) shows how harmful the sun is to the skin in all parts of the world. The World Health Organization (WHO) developed the index with other institutions. The scale goes from 1 to more than 10. The higher the value, the faster the sunburn occurs. In Germany, UVI values of up to 8 are usually reached in summer.
CLAIM: When it’s cool, the sun doesn’t burn as hard.
FACTS: As in water, it is the same on land: coolness does not protect against danger, not even on windy days. Dermatologist Mrotzek: “It doesn’t matter whether it’s hot or cold, UV radiation is the same.”
The deciding factor is the time of year and the day – and therefore the position of the sun. The radiation said to be active for the skin reached a power of nearly 200 milliwatts per square meter on June 21 at noon on a clear day. On a cloudless December 21 at noon, however, it is less than ten milliwatts.
In addition to reflections from the water or snow level, altitude also has an influence on radiation. The effect of the sun increases by 20% at 1000 meters, by approximately 33% at 2000 meters and by 50% at 3000 meters relative to the intensity at sea level.
© dpa-infocom, dpa: 200811-99-132424 / 2