Excessive UV exposure leads to an increased risk for skin cancer, causes skin aging, suppresses immunity, etc. To estimate the level of UV radiation, a UV index is used: its values range between 0 and ~11. The UV index depends on the time of day and season, location and weather, and their impact depends on the skin type.
UV Index Scale
|low danger, no protection needed||protection needed – stay in shade, wear long-sleeved clothing and hat, use sunscreen cream||extra protection needed – stay indoors during the midday hours; when outside, seek shade. Wear long-sleeved clothing, hat, and apply sunscreen cream|
What You Should Remember
The UV index is usually at its highest from 10 a.m. to 4 p.m. but it depends on the region and time of the year. In Atlanta, the UV index is ~1-3 in winter and 7-11 in summer; the dangerous level of UV radiation is observed from 10 a.m. to 4 p.m.
- Water intensifies UV radiation by 50%, snow – by 85%, altitude – by 16% at every 1,000 metres above sea level.
- Two feet of water lets 50% UVB and 80% UVA through, that’s why one can get sunburned underwater too.
- UV rays penetrate through clouds. Getting sunburn on a cloudy day is possible.
- The higher the UV index and the softer the skin, the greater the need to apply the strongest sun protection as early as possible.
- Sunscreen cream should be used when UV index is above 3.
- Infants are recommended to stay in shade permanently due to skin peculiarities (until 3 years of age, skin melanocytes are not able to produce enough melanin to protect the skin).
There are many questions around vitamin D. Many people believe that kids should stay in the sun to make vitamin D. Yes, it is true that a small amount of UV radiation is necessary for your skin to produce vitamin D, BUT the excessive UV exposure can affect the skin health, eyes, and the immune system. Stay in the sun when the UV index is at a safe level and your child will make enough vitamin D without any health risks.
How to check the UV index
- If you don’t have a UV index report at hand, make a rough estimate by looking at your shadow: if it’s taller than you are, the UV index is considered low.
- Knowledge of the UV index can help one make health-saving choices.
- The information about the UV index can be found on meteorological websites and smartphones. Start the weather application on your phone and read the last line – it’s where the UV index is given.