UV Exposure Risks: Sunburn, Skin Ageing and Eyes

Sunburn

Sunburn is the quickest sign that your skin has had too much UV. The WHO lists sunburn, DNA damage and immune suppression as the acute effects of UV on skin.

The NHS describes what it looks like. Skin may feel hot, sore or painful, and it may flake or peel, usually a few days after the burn, and severe sunburn can cause blisters. On white skin sunburn is usually red or pink. On black or brown skin the colour change may be hard to notice, so the heat and soreness are the better clues (NHS).

Sunburn usually gets better within 7 days, according to the NHS. Severe sunburn can lead to heat exhaustion and heatstroke, which the NHS calls very serious. It advises seeking urgent help for blistering or swelling, a very high temperature, dizziness, sickness, headache or muscle cramps, and for any sunburn in a baby or young child.

If you do burn, the NHS suggests getting out of the sun, cooling the skin with a cool shower, bath or damp towel, applying aftersun or unperfumed moisturiser, drinking water and keeping the area covered from direct sun until it heals. It advises against petroleum jelly, ice, popping blisters and peeling skin.

The longer-term part is the one people forget. The NHS says that getting sunburnt can increase your risk of skin cancer. The Skin Cancer Foundation reports that a person’s risk of melanoma doubles on average after more than five sunburns.

Skin ageing

UV is not only about burning. The WHO lists premature skin ageing among the chronic effects of UV exposure, next to skin cancer (WHO).

The Skin Cancer Foundation estimates that 80 percent of visible skin ageing in Caucasian women is caused by the sun. It also reports that people who use sunscreen of SPF 15 or higher every day show 24 percent less skin ageing than those who do not (Skin Cancer Foundation). These figures come from research on specific groups, so read them as an indication of scale, not a prediction for your own skin.

Skin cancer

The WHO names three main skin cancers linked to UV: melanoma, squamous cell carcinoma and basal cell carcinoma. It reports that in 2020 more than 1.5 million skin cancers were diagnosed worldwide and more than 120,000 deaths were associated with them (WHO).

The NHS says ultraviolet light is the most common cause of both melanoma and non-melanoma skin cancer, and that it comes from the sun and from sunbeds. The Skin Cancer Foundation cites a UK study that attributes about 86 percent of melanomas to UV radiation from the sun.

One afternoon outside is not the whole story. Risk builds with exposure over time, which is why sun exposure and sunburn history show up in the risk factors below, and why your everyday habits matter more than any single day. If you are worried about a mole or a change in your skin, a healthcare professional is the right person to ask.

Eye damage

Your eyes burn too. The WHO describes photokeratitis and photoconjunctivitis as reversible but painful, and lists cataracts, pterygium and cancers in and around the eye among the chronic effects. It adds that UV exposure may be involved in age-related macular degeneration (WHO).

On the scale of the problem, the WHO says about 15 million people worldwide are blind from cataracts and that some 10% of these cases may be due to UV exposure.

Who is at higher risk

Anyone can be harmed by UV, but some people face more risk. The NHS lists these risk factors for skin cancer:

• pale skin that burns easily in the sun
• red, fair or blonde hair, or blue or green eyes
• a large number of freckles or moles
• a history of skin cancer in your family, or having had skin cancer before
• a lot of sun exposure and a lot of sunburn in the past
• frequent sunbed use
• older age (both NHS pages say skin cancer is more common in older people, but younger people can also get it)

The same NHS pages say that if you have black or brown skin your chance of getting skin cancer is lower, but you can still get it.

Children. The WHO says childhood sunburn increases the risk of skin cancer later in life, and that more UV can reach and damage a child’s retina.

High altitude. Thinner air absorbs less UV. The US EPA states that UV intensity increases about 6% per kilometre of elevation above sea level (US EPA).

UV on cloudy days

A grey sky is not a safeguard. The WHO says UV levels can be high even with cloud cover. Cancer Council Australia notes that UV can stay strong on cool or cloudy days and recommends checking the UV index rather than relying on the weather (source).

The EPA’s model shows why: even a fully overcast sky passes about 31% of UV, and broken cloud passes 73% (US EPA).

The practical rule is the one from the UV index explainer: the WHO says sun protection measures should be used when the UV index reaches 3 or above, whatever the sky looks like. UV GO shows you the forecast index for each hour, so you do not have to guess.

For the practical side, read how to protect yourself from UV. UV GO gives general guidance, and your own skin and health history are best discussed with a healthcare professional.