Just how harmful is UV radiation?

Ultra-violet or UV rays are definitely the bad guys of the radiation family. Unlike sunlight (which you can see and are warm) and infrared rays (which are warm), UV rays can’t be felt or seen – which makes them even more dangerous. In fact, most skin cancers are caused by excessive exposure to UV radiation.

In New Zealand, UV radiation levels are especially high during the ‘daylight savings months’ (September to April), so it’s important to be really vigilant during these months. Even when it’s cool or cloudy outside, you can still get sunburnt – clouds won’t protect you from UV rays.

There are three types of UV radiation from the sun – UVA, UVB and UVC – and all can cause damage to both skin and eyes:

• UVA radiation goes deep into the skin, causing long-term damage such as wrinkles, blotchiness, sagging and skin cancer.
• UVB radiation gets into the top layer of skin and can cause sunburn, skin damage and skin cancer. The ozone layer absorbs most UVB, preventing it from reaching the earth’s surface.
• UVC is the most dangerous type of UV radiation. Ozone and oxygen in the atmosphere absorb all UVC so none reaches the earth’s surface. However, there are other sources of UVC, such as arc welding, which is why workers need to protect themselves.

UV radiation levels fluctuate constantly – they’re affected by the time of day and year, the amount of cloud cover, the altitude, reflection (off water, snow or ice) and your location.
Niwa has handy graphs that predict and measure UVI at several sites around New Zealand here. The measurements include forecast cloud effects and are updated every 15 minutes.

Did you know?

In New Zealand, we not only have some of the highest UV radiation levels in the world, it’s no coincidence that we also have the world’s highest rate of melanoma – the most deadly form of skin cancer.1,2 In fact, seven people a day are diagnosed with melanoma in New Zealand and nearly 500 Kiwis die from skin cancer every year.^3,4

The good news is that most skin cancers, including melanoma, are preventable by simply reducing your exposure to harmful UV rays. Here’s how:

Above: Don't forget too put on your sunscreen especially between 10am-4pm

Don’t forget to slip, slop, slap, wrap … app and map.

Always protect your skin and eyes between at least 10am and 4pm during the ‘daylight saving months’, especially if you’re in the mountains, around snow and ice, or out on the water. And don’t forget to follow the SunSmart guidelines:

• Slip on a shirt or top with long sleeves and a collar – and/or slip into the shade.
• Slop on a broad spectrum, water resistant sunscreen of at least SPF 30 – apply 20 minutes before going outside and reapply every two hours.
• Slap on a wide brimmed hat.
• Wrap around some close fitting, good quality sunglasses.

And we’ve added two more vital points to Sunsmart’s advice. Don’t forget to…

• App – there are some great apps available so you can check the UV levels in your area, such as Sunsmart’s Sun Protection Alert and NIWA’s free uv2Day.
• Map – it’s very hard to spot most skin cancers with the naked eye, so make sure you have a thorough skin check every year by a professional service such as MoleMap.