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UV Radiation – The Facts, The Risks and The Myths

Updated: Aug 20, 2022

Sun lotion UV protection

So here we’re in the season where people in the UK may think about sun protection now. Why is that important? It’s a major risk factor for skin cancer is prolonged exposure to ultraviolet (UV) radiation.

Understanding about UV radiation and how it damages your skin is a major step in learning how to safeguard yourself against skin cancers.

However the best news is that this danger posed by UV radiation can be greatly reduced by YOU! So you can still enjoy the outdoors whilst reducing your skin cancer risk by taking a few simple protective measures.

What is UV radiation? UV light is natural energy produced by the sun. on the electromagnetic spectrum, UV light has shorter wavelength than visible light, so your eyes can’t see it. However, your skin can feel it. Tanning beds emit UV light.

The two types of UV light that contribute to skin cancers are:

  1. Ultraviolet A (UVA) which has a longer wavelength, and this is associated with skin aging.

  2. Ultraviolet B (UVB). This has a shorter wavelength and is associated with skin burning.

What risk does UV light pose?

While UVA and UVB rays differ in how they affect the skin, they both do harm. Unprotected exposure to UVA and UVB damages the DNA in skin cells, producing genetic defects, or mutations, that can lead to skin cancer as well as premature aging. These rays can also cause eye damage, including cataracts, eyelid cancers and melanomas in the eye.

UV radiation is a proven caused of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) which often appear on sun-exposed areas of skin. Fortunately, when discovered early enough, these common forms of skin cancer are almost always curable.

UV light leading to repeated sunburn has proven to play a strong role in developing melanoma – the most dangerous of the three common skin cancers. Research shows that the UV rays that damage skin can also alter a gene that suppresses tumours, raising the risk of sun-damaged skin cells developing into skin cancer. The damage from UV exposure is cumulative and increases your skin cancer risk over time. While your body can repair some of the DNA damage in skin cells, it can’t repair all of it. The unrepaired damage builds up over time and triggers mutations that cause skin cells to multiply rapidly. That can lead to malignant tumours.

The Myths:

1. UV light index is a measure of heat.


UV index measures the intensity of UV radiation from the sun at a location. It’s calculated using the latitude and altitude of that place, time of day, time of year, ground conditions, cloud cover and state of the ozone layer in the atmosphere. Its reported as a from 0 to 11(+), 0 being no sunlight i.e. at night and 11 being extreme radiation, when you can burn in less than 10 minutes.

2. But when the UV index is high, it will be hotter outside.


It may be hotter outside when the UV index is high because UV is higher in the summer and when there are fewer clouds, things that make the temperature rise, too. It could also be that you could be at altitude for example 6,000 feet up with cooler temperatures and a higher UV index. The atmosphere filters out some UV radiation before it hits Earth, and the atmosphere is thinner at higher elevations, making it a less effective filter.

3. If the UV index is low, I won’t get sunburn.

Possibly true

How quickly and easily you burn depends on your skin type. Someone with pale, sensitive skin can burn on a day with a UV index of 1 if they spend a couple of hours outside without sun protection. But on a UV index 2 day, just one step up on the scale, someone with Fitzpatrick Skin type IV* can burn under similar circumstances. Whilst UVB rays cause sunburn and damage to DNA in skin cells, which can lead to skin cancer. Ultraviolet A (UVA) rays can also contribute to sunburn and skin cancer. The amount of UVA that reaches us is much steadier, UVB fluctuates a lot.

How to use the UV Index

So adding it to your daily weather check makes a lot of sense. The same way you might bring an umbrella if it’s going to rain, or stay inside if there is a thunderstorm looming, you can also be prepared for the different levels of UV that you may encounter. You can check your UV forecast, for the day, or by the hour.

Similarly if you know you are at a high risk of developing skin cancer, perhaps with a very pale skin or living at altitude, it can be especially important to avoid exposure during peak UV hours. Using the UV index can help you determine a safer time to be outdoors.

Limitations of UV Index and protect yourself

The bottom line is that everyone needs sun protection during daylight hours all year long, regardless of their skin type or the UV forecast for the day.

Despite the risk factors, you can safely, enjoy the great outdoors by protecting your skin against UV exposure:

  • · Using a broad-spectrum sunscreen,

  • Sun safe clothing such as hats and eyewear.

  • Consider a UV window film for your home and car.

Make it a way of life….. Protect yourself every day, even when it’s cloudy. Avoid indoor tanning entirely.

*Fitzpatrick scale is the system classifies skin type according to the amount of pigment your skin has and your skin's reaction to sun exposure. 1 being low pigment and therefore burning easily and VI being the most darkly pigmented skin, and having a lower risk of skin cancer from sun exposure.


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