A high UV index warns of an increased risk of cancer

The UV index indications have been high this summer, meaning more sunburns, skin damage and a higher risk of developing skin cancer. You can find the UV index on your weather app of choice at any time of day using your location.

Here is a guide on how to understand the index, why it’s important to know and what to do during higher levels of UV radiation. The UV index isn’t related to the temperature, so it can be high, even though it may feel cool or it is cloudy.

What is the UV index?

UVI definition: The Ultra-Violet radiation Index (UVI) is a measurement of the amount of ultraviolet radiation in the lower atmosphere. The index begins from zero onwards, and the higher the level of radiation, the worse the damage to the skin and eyes is.

A high UVI also means damage occurs much quicker. UVI categories are:
0-2 low
3-5 moderate
6-7 high
8-10 very high
11+ extreme

For higher levels, avoid exposure completely where possible.

UV and skin, what does UV radiation do?

UV radiation damages skin cells, which can cause ageing, wrinkles, darkening of the skin known as hyperpigmentation, and other more serious effects. It can damage the DNA of skin cells, which is likely what causes skin cancer, and can dehydrate skin, especially when prolonged exposure causes sunburn.

Types of UV and which to look out for:
• UVA rays give off the least energy and contribute to ageing, sun damage and hyperpigmentation.
• UVB give off more energy and are the likely culprits for sunburn. They are also most likely to cause cancer.
• UVC have the highest energy but get blocked by the ozone layer.

Also read: How to protect your children against skin cancer

The effects of the different types:
UVA – minor damage deeper in the skin
UVB – sunburn and cancers on the surface
UVC – more dangerous melanomas, only exposure is typically from man-made sources

There are many kinds of sunscreen, read what dermatologists recommend or ask your dermatologist personally.

Sunscreen, what you should know:

For best protection use broad-spectrum, water-resistant sunscreen that is SPF 50 or higher.

The best practice is to apply a shot glass worth of sunscreen to each exposed area, or 2 grams per square cm of skin.

With spray sunscreen, spray an area for six seconds, or make 3-4 passes.

Reapply every hour or more.

You also need multiple types of protection.

Sunscreen is important, but it should not be your only line of defence. Clothes that provide good coverage, hats, umbrellas and shade are also needed for optimal protection. UV radiation can penetrate through clouds and be reflected from water, so do not think you are safe when it’s cloudy.

Always wear protective clothing and sunscreen when you are outside, check your favourite weather app for the

UV index and avoid sun beds, black lights and arc welding exposure as much as possible.

If you have a concerning, rapidly changing, sensitive or raised mole, see a dermatologist immediately.

Also read: All skin tones are susceptible to sun damage