What you need to know about the UV Index.
Slip, Slop, Slap & Slide
The UV Index is a valuable reminder to be careful in the sun. But are you taking as much notice of it as you should?
Environment Canada scientists developed the UV Index in 1992 to inform about the strength of the sun’s UV rays and raise awareness about taking action to protect your health.
It now broadcasts its sun safety message in 26 countries, with the World Meteorological Organization and World Health Organization adopting it in 1994 as the international standard for weather services across the globe.
Why is the UV Index important?
Over-exposure to UVB can cause sunburn, cataracts and potential immune system suppression. UVA penetrates deep into the skin causing damage like wrinkles, discoloration and aging. Sunburn, whether severe or mild, can cause permanent skin damage.
However, contrary to popular belief, you can’t judge UV levels by how hot it is outside. Rather, latitude, ozone, cloud, reflection from surfaces, time of year and time of day all play a role in determining UV levels.
In fact, UV levels can be higher on a cloudy day. And that’s why you should always check the UV Index before you go outside.
Don’t Fry Day: When to be extra careful.
When the UV Index reaches 3, it’s time to make sure you’re being sensible in the sun.
That means you should enact your five-step sun smart plan:
1. Slip on some sun-protective clothing – cover as much skin as possible!
2. Slop on SPF30+ sunscreen – choose one that’s broad spectrum and water-resistant. Remember to put it on around 20 minutes before you head outdoors and reapply every two hours. It’s a great idea to make putting on sunscreen a morning ritual and carry a small bottle with you for regular touch-ups – especially if your family has a history of skin cancer.
3. Slap on a hat – find one that’s large enough to protect your entire face, head, neck and ears – baseball caps don’t count!
4. Seek shade – stay inside, lounge under a large tree or carry your own sun umbrella, just be wary that sometimes UVB radiation reflected from surfaces like water and metal can be far more intense.
5. Slide on some sunglasses – but please check that they comply with national UV protection standards, or you’ll risk serious damage to your vision.
What if you haven’t checked the UV Index today?
A simple way to tell how much UV exposure you’re likely to get is to look for your shadow. If it’s taller than you, your UV exposure will probably be lower. The shorter your shadow, the higher your UV exposure.
The sunshine vitamin, the UV index and you.
Many people are worried about their Vitamin D levels these days, so they’re going out in the sun unprotected to try and beef them up.
However, it’s important to strike a healthy balance between protection and prevention. Yes, you need to get some sun to ensure optimum Vitamin D levels. But on days where the UV Index is 3 or above, you’re in more danger of eye and skin damage and unlikely to develop Vitamin D deficiency.
Positively blazing: The highest UV levels on earth.
The World Health Organization warns against spending any time outside when the UV index tops 12.
But in Bolivia’s Licancabur volcano, a world-record UV index of 43.3 has been detected – similar to the surface radiation on Mars.
Scientists say the high reading is a result of the Andes’ intense tropical sun, high elevation and naturally low ozone levels.
The researchers also think seasonal thunderstorms over the Andes and fires burning in the Amazon could have further depleted protective ozone, along with an atmospheric train of ozone-depleting chemicals streaming north from Antarctica.
They’re keeping a close eye on the volcano to check whether the record index is a one-off event or a sign of things to come.