Sun's Sunscreen - New Knowledge: Medicine and Psychology 2

Sun's Sunscreen – New Knowledge: Medicine and Psychology

How long can I stay in the sun with sunscreen?

It depends on the intensity of the sun, the skin type and the sun protection factor (SPF). In a person with very light skin, unprotected skin begins to blush after five to ten minutes in the sun. Theoretically, a sunscreen with a sun protection factor of 50 extends this duration to 250 to 500 minutes. In practice, this period is shorter, among other things, because we usually use too little sunscreen.

What SPF do I need?

A SPF of at least 30 is recommended. A product with SPF 15 leaves about 7% of the UV dose in the skin, with an LSF 30 it is 3.3% and with an SPF of only 1.7%. Whenever the sun protection factor doubles, for example from 15 to 30, means that the UV dose reaching the skin is reduced by half – provided that enough sunscreen is applied.

How much sunscreen should I apply?

Most people are underinflated and therefore fail to achieve the effect that the agent could provide. The rule of the "tea spoon" is an asset: a little less than a teaspoon of sunscreen for the face, neck and each arm. Apply nearly two teaspoons of sunscreen on your stomach, back and legs. When applying a cream, you expect about 10 grams of sunscreen per child and at least 20 grams per adult. As a part is wiped during drying, perspiration or through sand and clothing, you must cream yourself several times a day.

Why should I protect myself in the shade?

Under an umbrella, a person can still capture more than 80% of UV rays, even if the screen is UV-proof. Because the sand reflects about 15% of the sunlight, grass, soil and water about 10% (even 90% snow). In an experiment, people who were not crushed at the lake under the umbrella were eight times more affected by the sun than people with powerful sunscreen.

To what extent do water resistant sunscreens adhere?

This is determined by placing the subjects twice in a hot tub for 20 minutes each. For an agent to be considered water resistant, it must then protect at least 50% more than before. "Extra-water-resistant" means that it fulfills this condition even after four vortex tests. In these tests, however, no account is taken of the fact that the spray water further eliminates the sunscreen. And that, when drying, a large part adheres to the towel. After bathing, cream again, even with impervious products.

Do children need a special sunscreen?

Yes, his skin is more sensitive than that of adults. Up to the sixth month of life, babies should not be exposed to the sun. Dermatologists even recommend that children under three years old should not be exposed to the hot sun. The higher the number of sunburns in childhood, the more the risk of skin cancer increases thereafter. Because of the potentially hormonal effect, advises the American Academy of Pediatricians (AAP) funds containing the oxybenzone active ingredient.

Are sunscreens harmless?

A small study recently revealed the presence of sunscreens in the blood. Concentrations were low but higher than expected. If it is dangerous and if it will now be explored. But it is certain that no sunscreen will damage the skin. Therefore, experts advise on sunscreen. There are two types of sunscreens: Chemical (organic) filters turn ultraviolet rays into low energy radiation. It is proven that they can act as hormones. That they do it really, it's open. Other types are physical (inorganic) filters such as zinc and titanium dioxide. They act like tiny mirrors and reflect light. These products may contain micro or nanoparticles. However, it has been widely proven that these particles do not penetrate the intact skin. In addition, they are much larger than the molecules of the sunscreen chemicals. It is known that some light shielding filters can pass into breast milk at low concentrations. It is therefore advisable for pregnant and lactating women to use physical sunscreens.

Are there natural sunscreens?

40 grams of tomato paste a day, two teaspoons of olive oil, 20 grams of dark chocolate and a quart of green tea, all for at least ten weeks a day. This could be a recipe for a natural sunscreen – but it does not work. Even though medicinal plants, foods, vitamins and minerals have some protective effect against the sun: Before sunburn, neither vitamin E nor turmeric, grape extract, selenium or other natural remedies. First, it takes a lot over a long period. Second, the effect is only modest. The plant extract of the fern Polypodium leucotomos, for example, has a sun protection factor of only two to three. Good sunscreen can not replace natural remedies for now, at best.

How long can a sunscreen be kept?

The expiry date is printed on the package or on a small jar of cream, for example with the indication "12M". This means that: The remedy is valid for 12 months after the first use, if it is properly stored. Sunscreens should not stay in the sun for a long time (or do not freeze in cold weather). You should not use them anymore if they smell or look funny.

Does sunscreen protect against skin cancer?

Only a few older studies are not transferable to more effective sunscreens today. But one thing is certain: sunburn increases the risk of skin cancer – and sunscreens protect against sunburn.

(Editors Tamedia)

Created: 07.07.2019, 18:02