The link between sun exposure and skin cancer is well known, but some of the things we do to guard against sunburn may increase our risk of damage from ultraviolet light. Here, experts debunk the sun safety myths too many of us believe in . . .
Myth 1: Swim in a T-shirt to stay safe
Wearing a T-shirt in the water might sound sensible, and is safer than exposing bare skin, but be aware that once it’s wet, a damp shirt allows more UV light to penetrate than a dry one.
‘Wet clothing raises the risk of burning by decreasing the materials’ UV absorption,’ explains Professor Paul Banwell, a plastic surgeon and skin cancer expert at the Banwell Clinic in East Grinstead, West Sussex, and lead plastic surgeon for the NHS Sussex Community Dermatology Service.
Wearing a T-shirt in the water might sound sensible, and is safer than exposing bare skin, but be aware that once it’s wet, a damp shirt allows more UV light to penetrate than a dry one. A stock photo is used above [File photo]
‘Wetting a T-shirt reduces its UPF (ultraviolet protection factor, a universal rating system that measures the sun-blocking effectivness of clothing) by over 55 per cent.’
A wet white T-shirt has a UPF rating of just 3, whereas the UPF of a typical dry white T-shirt is around 7.
A black or dark blue T-shirt will have a UPF score of 10 compared to the 7 of a dry white T-shirt, and more tightly-woven fabrics such as Lycra and polyester will have a higher score independent of colour, Professor Banwell says. Lycra has a UPF of over 50.
‘Darker colours are more effective at blocking light than light-coloured fabrics, as darker colours absorb and dissipate the ultraviolet rays,’ he adds.
‘People are often a lot more relaxed about sunscreen application when the weather is overcast and clouds are more prominent than the sun,’ says Dr Daniel Glass, a consultant dermatologist and lead clinician for skin cancer at London North West Healthcare NHS Trust and The Dermatology Clinic in London [File photo]
‘White T-shirts are more comfortable to wear [as they reflect rather than absorb heat] but people must be aware of the lesser UPF.’
‘Similarly, “vintage” clothing will score poorly because older fabrics allow more penetration of UV rays,’ he explains.
‘Tightly-woven, dark fabrics offer the best protection — even if they might not be the most comfortable in the heat.’
‘Ideally in the water you should wear UV-protected swimwear and avoid swimming in the hottest part of the day — usually 11am to 3pm.’
2: I don’t need cream if it’s cloudy
‘People are often a lot more relaxed about sunscreen application when the weather is overcast and clouds are more prominent than the sun,’ says Dr Daniel Glass, a consultant dermatologist and lead clinician for skin cancer at London North West Healthcare NHS Trust and The Dermatology Clinic in London.
‘However, what they fail to realise is that 80 per cent of the sun’s rays can pass through clouds, according to the Skin Cancer Foundation.’
Not only can you burn when it’s cloudy — you might get an even worse sunburn as you’ve neglected to protect yourself, he warns.
2. A ‘base tan’ will protect my skin
Already having a bit of a tan before going in the sun — perhaps from a sunbed — is thought by some to be a form of protection from burning.
But according to Dawn Davis, a dermatology expert at the Mayo Clinic in the U.S., there is no such thing as a ‘safe’ base tan.
‘If you get a base tan simply to go on holiday, what you’re doing is pre-emptively giving yourself skin damage before — instead of later.’
You can still burn on top of a tan. And using fake tan won’t improve your body’s ability to protect itself from the sun, says Andrew Wright, a professor of dermatology at the University of Bradford.
Already having a bit of a tan before going in the sun — perhaps from a sunbed — is thought by some to be a form of protection from burning. But according to Dawn Davis, a dermatology expert at the Mayo Clinic in the U.S., there is no such thing as a ‘safe’ base tan [File photo]
‘Some products contain an SPF rating which may allow minimal protection, but this should not be relied on for continued protection. There is no safe way to sit in the sun without proper protection.’
4: Contacts will protect my eyes
Prolonged exposure of the eyes to UV has been linked to cataracts, macular degeneration and some types of eye cancer.
But contact lenses will only guard the eyes from the sun if they are specifically designed to absorb UV, reducing the amount of radiation that reaches the surface of the eye.
This type of contact lens also protects the eye from the radiation that creeps in from above or around the sides of sunglasses.
‘The problem is that in wearing even these UV lenses, people may forget that the periocular skin — the skin around the eyes such as on the eyelid — isn’t protected,’ explains Dr Jeff Kwartz, a consultant ophthalmologist at the Royal Bolton Hospital in Greater Manchester.
Contact lenses will only guard the eyes from the sun if they are specifically designed to absorb UV, reducing the amount of radiation that reaches the surface of the eye [File photo]
‘This skin around the eye is one of the most common places for cancers such as basal cell carcinoma — the most common form of skin cancer.
‘So if you do wear these lenses, still wear sunglasses and delicately apply sunscreen to this area around the eye. And remember, the smaller the sunglasses, the less protection they provide.’
When selecting sunglasses, don’t presume darker ones will provide better protection. The level of UV protection is not determined by the tint, says Dr Kwartz.
‘Sunglasses don’t need to be dark or expensive,’ says Dr Kwartz. ‘What they need is to conform to agreed standards.’
Look out for a CE (European Community Standard), BS EN ISO 12312-1(British Standard) or UV400 markings and choose a pair that offers 80 per cent light reduction.
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5: Hats give great protection
Not all hats give adequate protection from the sun, explains Dr John Ashworth, lead NHS consultant dermatologist in Warrington and of dermatologist.co.uk.
‘To test if they do, hold your hat up to the sky,’ he advises. ‘If you can’t see the sun through it, it means it is thick enough to block out its rays.’
And avoid baseball hats, as they don’t protect the ears — another common area for skin cancers.
Find a broad-brimmed style that covers the scalp, upper ears and back of the neck, which are easily damaged.
‘Remember, a hat may offer 100 per cent protection from above but half of sun exposure enters from the side and under the hat due to reflected UV light, so apply sunscreen,’ says Dr Ashworth.
6: I’m safe if I stay in the shade
A common error that many make is believing that they cannot burn in the shade, says Dr Glass.
‘However, this is far from the truth as you can burn even when under a tree or parasol due to UV radiation reflected off nearby surfaces.
‘It is important to understand that it’s not necessarily the visible sunlight that damages your skin, but the UV radiation.
‘Even though we cannot see or feel them, UV rays reflect off benign surfaces such as sand, water, and even snow, which means that you can still get sunburnt even in the shade.’
So you need to wear the same kind of protection in the shade as you would if you were sitting in the sun.
A common error that many make is believing that they cannot burn in the shade, says Dr Glass. ‘However, this is far from the truth as you can burn even when under a tree or parasol due to UV radiation reflected off nearby surfaces’, he says [File photo]
7: Waterproof sunscreen lasts
A sunscreen is considered ‘water-resistant’ if it retains its sun protection properties following just two 20-minute intervals (40 minutes total) of moderate activity in water.
However, this doesn’t take into account the impact of drying, and up to 85 per cent of a product can be removed by drying off with a towel, according to the British Association of Dermatologists.
And the water itself has an effect: a 2018 study by Which? found that protection offered by popular water-resistant sunscreens plummets in conditions that replicate the sea and fast-moving water.
On a hot day, you are likely to spend much more time than this in the water so you should reapply every time after swimming, if you’re sweating a lot, or after any vigorous activity.
A sunscreen is considered ‘water-resistant’ if it retains its sun protection properties following just two 20-minute intervals (40 minutes total) of moderate activity in water [File photo]
8: Once-a-day cream keeps you covered
A product that provides all-day sun protection in one application sounds very tempting.
But as Good Health revealed last week, it may be risky to rely on them for all day coverage.
Dr Ashworth explains: ‘Most people don’t apply enough sunscreen or they miss difficult-to-reach sections such as the back.
‘More significantly, factors such as drying oneself with a towel can reduce the impact of the cream. Sweating can also wash the sunscreen away.’
The average adult needs at least six full teaspoons of sunscreen — half each arm, one for the face, neck and ears and just over one teaspoon to each leg, and the back and front of the body.