We've all heard the phrase “a healthy tan”, but there's no such thing. Tanning is the body's attempt to protect itself from damage caused by ultraviolet (UV) radiation. The UV radiation that reaches the Earth's surface is mainly UVA and part of UVB. Nearly half of the daytime total of the most harmful UVB radiation is received between 10 in the morning and 4 p.m.
Even on a cloudy day, UVB radiation can burn you in the sun. As an expert in the field of UV radiation, I'm here to provide you with a comprehensive guide on how much UV light is harmful and how to protect yourself from it. The National Meteorological Services' UV Index predicts the next day's UV radiation levels on a scale of 1 to 11+. This information helps people plan how to protect themselves from the sun.
Current UV Index Forecast (updated daily) provides daily UV index data in map and text form for major cities in the United States. Ultraviolet (UV) radiation is a form of non-ionizing radiation that is emitted from the sun and artificial sources, such as tanning beds. While it has some benefits for people, such as the creation of vitamin D, it can also cause health risks. While UVA and UVB rays differ in the way they affect the skin, both cause damage.
Unprotected exposure to UVA and UVB rays damages the DNA of skin cells and causes genetic defects or mutations that can cause skin cancer and premature aging. UV rays can also cause eye damage, such as cataracts and eyelid cancers. Short-wavelength UVC radiation is the most harmful type of UV radiation. However, it is completely filtered by the atmosphere and does not reach the Earth's surface. Sunscreen garments may have a label that indicates the UV protection factor (UPF) value (the level of protection the garment provides against UV rays from the sun, on a scale of 15 to more than 50).
An obvious but very important way to limit exposure to UV light is to avoid being exposed to direct sunlight outdoors for too long. Just as visible light is made up of different colors that become evident in a rainbow, the UV radiation spectrum is divided into three regions called UVA, UVB and UVC. The United States National Weather Service and the Environmental Protection Agency (EPA) have created the UV Index, which gives you an idea of the intensity of UV light in your area on a given day, on a scale of 1 to 11 or more. In the electromagnetic spectrum, UV light has shorter wavelengths than visible light, so the eyes can't see UV rays, but the skin can feel them. Labels that say “Absorbs UV rays up to 400 nm” or “Meet ANSI UV requirements” mean that the glasses block at least 99% of UV rays. However, light or thin clouds have little effect and can even increase UV levels due to dispersion.
UV rays reach the ground all year round, even on cloudy or foggy days, but the intensity of UV rays can vary depending on many factors. It's important to be aware of your local area's UV Index, as well as take precautions when spending time outdoors in direct sunlight. Wear protective clothing such as hats and sunglasses with labels indicating they block 99% of UV rays. Sunscreen should also be applied liberally and often when spending time outdoors. By following these simple steps, you can protect yourself from harmful levels of ultraviolet radiation.