An Introduction to UV (Ultra Violet)

What Level of UV is Considered Dangerous?

It’s possible to measure the UV rays using specific technology. The WHO has created a UV index where it showcases when UV rays get more dangerous. Sometimes, it’s also considered a good source for Vitamin D but there’s a certain measure for it. Beyond the UV index score 2 is considered harmful for the skin. 

A UV index score between 0 to 2 is considered as minimal danger for an average person. In case the score hikes up to 3 to 5, it is still considered low risk of harm while a score of 6 to 7 is considered moderate risk. However, when the score extends beyond 8 or 10, it possesses high risk of harm from sun exposure without any protection.

Nobody knows the sun like Arizona! Here, the sun is always ready to make itself known, for better or worse. From skin damage to property damage, the desert sun inspires awe – and a little fear. For all but the most durable materials, sunlight can suck the function and flexibility from them. When left in our harsh sunlight, plastics, paints, fabrics and many other materials become brittle, flaky and faded. When we leave ourselves out in the sun, we feel the burn as sun damage contributes to wrinkles and cancer risk.

But what is it about sunlight that can wreck so much havoc? Most people are generally acquainted with the idea of UV radiation, but few know that there are different types of UV that each have different properties.

What is ultraviolet? Ultraviolet radiation is part of the sun’s light spectrum, and is determined by its wavelength. Lightwaves in the visible light spectrum range from the wide wavelengths of red to the short wavelengths of violet. Stretching past the visible spectrum are lightwaves that are longer and shorter, lightwaves longer than visible red are called “infrared” and wavelengths shorter than visible violet are considered “ultraviolet” uv rays.

Ultraviolet (UV) radiation that reaches the Earth is invisible to the naked eye but can be measured with light detecting instruments. Within the designation of UV there are three types: UVA, UVB, and UVC which behave differently from each other, and affect humans in different ways. UVC has the shortest wavelength, but is also the most intense type of UV radiation. UVA has the longest wavelength and accounts for most of the UV that reaches us. All types of UV light can damage human skin and UV exposure to all types should be limited.

The ultraviolet index or UV Index is an international standard measurement of the strength of sunburn-producing ultraviolet radiation at a particular place and time. (Wikipedia)

As stated above, most of the UV radiation that gets through Earth’s atmosphere and reaches us at the surface is UVA. It accounts for about 95% of UV we are exposed to. UVA isn’t blocked by clouds or glass windows, so even on cloudy days we are still encountering UVA, no matter the time of year. Penetrating deeply to the skin’s second layer, UVA causing health effects like wrinkles and aging in the skin.

Modern tanning beds now use UVA radiation, where in the past the more dangerous UVC was used. This means that while tanning will still damage your skin, the risk of developing skin cancer from tanning is far reduced.

If you’ve ever seen plastic deteriorate when left out in the sun, you’ve witnessed the power of UVA. Unless plastics are treated for light resistance, UV radiation has the capability of breaking down their molecular bonds changing their structure and making them faded and brittle.

Although it is only 5% of the UV radiation reaching us from the sun, UVB gives us plenty to worry about. Part of the UV spectrum, UVB rays is the type of UV radiation responsible for sunburns, eye damage and most directly linked as a cause of skin cancer. UVB is more intense than UVA but penetrates our skin more shallowly, mostly affecting the top layer of our skin. When we are overexposed to UVB it begins to damage the very DNA in our skin cells.

Our atmosphere blocks some UVB from getting to Earth’s surface, but the effect of different weather conditions on UV levels can be unpredictable. While some types of cloud cover can reduce UV radiation, other types of clouds can reflect and amplify it. Because UV radiation can be seriously damaging, especially UVB, it is important to limit sun exposure and protect your skin no matter the time of day.

UVC is actually the type of UV radiation with the most potential to harm you. Fortunately for us, UVC from the sun doesn’t penetrate our atmosphere so being outside won’t expose you to UVC. UVC is highly carcinogenic and can cause serious damage to your skin even after brief exposures increasing your risk of skin cancer.

While UVC isn’t part of the light radiation reaching us from the Sun, UVC exposure can still happen at manmade level. Welding torches and mercury vapor lights give off high levels of UVC and people who work around this equipment should wear protective clothing and take precautions to protect their eyes and skin. Older tanning beds also relied on UVC although this method has been updated to use safer (but still skin damaging) UVA instead.

How do you protect yourself from the sun and still enjoy the outdoors? Basic sun protection is a great place to start. Opt for sunscreens that are SPF 30 and above and use UV blocking sunglasses. Take breaks from sun exposure and enjoy the outdoors in the shade.

Exposure to sunlight isn’t just a outdoor problem. Sunlight and UV radiation can penetrate into your home, fading and damaging art and furniture and flooring. Arizona sun also drives up your energy bill in the long, hot summer months.

Stellar Sunscreens can help. Based in Phoenix, Arizona, our company specializes in attractive, energy efficient custom sunscreens that protect you and your home from sun damage. Sunscreens can make your house more comfortable and energy efficient, and our pull-down shades for patio and pool areas can help protect you outdoors as well. Stellar Sunscreens knows Arizona heat, and we tailor our custom window sun protection to be a stylish and durable solution that blocks 90% of sunlight while matching the look and feel of your home. Learn more about when it’s time to invest in custom sunscreens, or contact us today for a FREE estimate for your home.