The sun is the source of life on the planet. Its rays provide us with much needed light and heat. However, ultraviolet radiation from the sun is harmful to all living things. To find a balance between beneficial and harmful effects of the sun, meteorologists estimate the ultraviolet index that reflects the degree of its danger.
Ultraviolet radiation from the sun has a range of wavelengths and is divided into three types, two of which reach the Earth’s surface.
The rays almost freely pass through all atmospheric ‘barriers’ and reach the Earth’s surface.
90% of the rays are absorbed by the ozone layer, carbon dioxide and water vapor.
The most dangerous type. It is completely absorbed by stratospheric ozone before reaching the Earth’s surface.
The more ozone, clouds and aerosols the atmosphere has, the less harmful the sun’s effects are. However, those saving factors have a high natural variability. Stratospheric ozone exhibits seasonality with maximum in spring and minimum in autumn. Cloudiness is one of the most unstable weather characteristics. Carbon dioxide levels also change over time.
The UV index shows the amount of UV radiation expected to reach the Earth’s surface. The UV index ranges on a scale of 0 (Low) to 11+ (Extreme).
In mid-latitudes, the UV index reaches unsafe values (6-7) only when the sun is at its maximum elevation (late June — early July). At the equator, the UV index ranges from 9 to 11+ throughout the year.
Small amounts of UV radiation are beneficial to people, play an essential role in the production of melanin, serotonin and vitamin D, and help prevent rickets.
Melanin creates a barrier to protect the skin cells from the harmful effects of the sun. It makes our skin darker and more elastic.
‘Happiness hormone’ serotonin improves our health: it boosts mood and increases overall vitality.
Vitamin D strengthens the immune system, stabilizes blood pressure and prevents rickets.
When tanning, you should remember there is a fine line between beneficial and harmful UV radiation. Excessive tanning is similar to a burn. Ultraviolet radiation damages DNA in skin cells.
The protective system of the body cannot cope with such an aggressive impact. It lowers immunity, damages the retina, accelerates skin ageing and can cause cancer.
Susceptibility to UV radiation depends on skin type. People of European descent are the most sensitive to the sun and need protection when the index reaches 3, while the index of 6 is considered dangerous.
At the same time, the limits for Indonesians and African-Americans stand at 6 and 8, respectively.
Light-skinned people
People with many moles
Children
People living in the mid-latitudes when on vacation in the south
Ice fishing enthusiasts
Skiers and climbers
People with a family history of skin cancer
The idea that the sun is dangerous only in hot and fine weather is a common misconception. You can get a sunburn when it’s cool or cloudy outside.
Clouds, no matter how thick, do not reduce UV radiation to zero. Clouds significantly reduce the risk of getting a sunburn in the mid-latitudes but not in traditional beach holiday destinations. For example, in the tropics, you can get a sunburn in 30 minutes if it is sunny and in a couple of hours if it is cloudy.
Follow these simple rules to protect yourself from the harmful effects of the sun:
Don’t spend much time in the sun around noon
Wear light-colored clothing and wide-brimmed hats
Wear sunscreen
Wear sunglasses
When on the beach, spend as much time in the shade as possible
Sunscreens have varying levels of SPF. Rated on a scale from 2 to 50+, it shows you the amount of solar radiation that breaks through the cream and reaches the skin.
For example, when applying a sunscreen with SPF 15, only 1/15, or 7% of ultraviolet rays will break through the protective film. Only 1/50, or 2% of the rays will affect the skin if you use a sunscreen with SPF 50.
Sunscreen creates a reflective layer on the skin. However, you should know that no sunscreen can reflect 100% of UV rays.
An SPF 15 sunscreen is enough for everyday use, if you spend less than half an hour in the sun. When tanning, you should opt for SPF 30 or more, while light-skinned people should use SPF 50+ sunscreen.
Apply enough sunscreen to cover all exposed skin, including the face, ears and neck. If you plan to stay in the sun for a long time, sunscreen should be applied twice: 30 minutes before leaving home and before hitting the beach.
The recommended amount of sunscreen is stated on the packaging.
You should re-apply your sunscreen after swimming. Water destroys the protective film and increases the amount of ultraviolet radiation by reflecting the sun’s rays. Thus, the risk of getting a sunburn increases when you’re swimming, but you may not feel the burn due to the cooling effect of water.
Re-apply your sunscreen in case of excessive sweating and towelling.
You should remember that even the shade under an umbrella cannot fully protect you on the beach. Sand, water and even grass reflect up to 20% of UV rays, increasing their impact on the skin.
Sunlight reflected from water, snow or sand can cause painful retinal burns. Wear sunglasses with a UV filter to protect your eyes.
The atmospheric ‘filter’ is thinner in the mountains. The UV index increases by 5% with every 100 meters in altitude.
Snow reflects up to 85% of ultraviolet rays. In addition, up to 80% of UV rays reflected by snow are once again reflected by clouds.
Thus, the sun is the most dangerous in the mountains. Protect your face, lower part of the chin and ears even when it’s cloudy.
Apply a wet sponge to the skin to moisten the burn
Apply a burn ointment to the burnt skin
Consult a doctor, if you notice an increase in your body temperature, as you may need to take an antipyretic
If the burn is severe (there are blisters and swelling), seek medical attention
