In this chapter, we are going to explore a tool that can help us answer these questions, improve our relationship with the sun and keep us protected in the process: the UV Index.
What is the UV Index?
The UV Index is a standardized international measurement that indicates the daily strength of UV rays. It was first developed by Canadian scientists in 1992 to help the public understand their daily sun risk. Later, the World Health Organisation and World Meteorological Organisation standardised the measurement in 1994. It’s a spectrum that allows people to understand when protecting themselves means wearing a hat and applying sunscreen versus it’s better to avoid being outside altogether.
What is a UV ray?
UV stands for ultraviolet. It is a type of radiation produced by the sun and artificial sources. Sunlight is the main source of UV, and there are three main types of UV rays it produces UVA, UVB, and UVC.
According to the EPA, the intensity of UV radiation reaching the surface of the earth depends on the angle of the sun in the sky. The sun is at its highest angle at solar noon each day, which is about 12:00 or 13:00, depending on the time zone. Generally, a good rule of thumb is that when the sun is directly overhead and people’s shadows are the shortest, UV radiation is at its highest.
Luckily, the ozone layer shields us from most of the sun’s dangerous UV radiation, making life possible on our planet. But the ozone layer cannot protect us from all harmful radiation. UVA and UVB are the main causes of skin cancer and melanoma symptoms, so in order to stay safe, we also need to learn what we can do to protect our skin.
Don’t we need the sun for vitamin D?
Vitamin D is essential to our health as it helps our body absorb calcium, which supports bone development and other processes in the body. The sun is one of the best sources of vitamin D as the vitamin is notoriously hard to get through food. However, studies have found that it doesn’t take much sun exposure to produce vitamin D. According to a study published by the Journal of the American Academy of Dermatology, even the largest proponents of acquiring vitamin D through sun exposure, advised no more than 10 to 15 minutes of exposure to arms, legs, abdomen, and back, two to three times a week. Furthermore, studies have yet to find that using sunscreen every day leads to vitamin D insufficiency. That’s why the best way to get vitamin D, safely, is through a combination of supplements and food sources.
If we know that the sun is damaging, why do we keep harming ourselves?
There is evidence that reduced sunlight can cause drops in serotonin levels. Serotonin is a chemical in our body that is thought to help regulate mood and happiness. So it only makes sense that letting the sunshine in truly makes us happy humans. And this is precisely why it is so hard to remember that, while the sun is a wonderful thing, it also has very harmful effects we need to pay attention to.
The UV Index
The UV Index makes it easy for us to judge when we are at high risk of experiencing UV damage. The index is on a scale from 0 to 11, with 0 being the lowest risk level and 11 being the highest.
0-2.9: Low-risk level
Low danger for the average person. Wear sunglasses if the sun reflects off the snow and a low SPF for all year round protection, especially if you have fair skin.
3-5.9: Moderate risk level
Moderate risk for sun exposure. You may want to seek shade during the midday hours and wear clothing that covers your body.
6-7.9: High-risk level
This index indicates that the sun rays are dangerous and protective clothing, as well as SPF 30+ cream, is needed. Protect your eyes with sunglasses and seek shade.
8-10.9: Very high-risk level
This level usually occurs on hot summer days. It is recommended to apply sunscreen as well as stay indoors during midday hours and get plenty of hydration.
11+: Extreme risk level
All precautions are needed as this level of radiation indicates health dangers beyond sunburn. Hats, protective clothes, and SPF should be used at all times, be extra sure you re-apply sunscreen every two hours as well.
What can you do?
Remembering to put on sunscreen can be hard enough, so that’s why we wanted to make it as easy as possible for people to check the UV Index on a daily basis. If you open up the SkinVision app, you will notice an icon that says “UV Index” on the home page. If you click it, this will automatically show you the UV risk level for your area at that moment, this way you know the level of precautions you should take when you go outside, without ever having to log onto a browser.
Get into the habit of checking the UV Index before getting ready in the morning. It’s a great way to be more aware of what’s going on in your environment, and use that knowledge to keep you, and the ones you love, protected.