Most confused about UVA and UVB rays

Sunscreen should protect against both
  • Deborah Condon

While most people are aware of the importance of protecting their skin from the sun's rays, over half of Irish people do not know the difference between UVA and UVB radiation, a new survey has found.

There are many different types of rays present in sunlight, however the rays that are most damaging to human skin are called ultraviolet (UV) rays. There are two basic types of ultraviolet rays that reach the earth's surface - UVA and UVB.

UVA makes up most of the UV that reaches the earth surface. It affects the deeper layer of the skin causing premature skin ageing, eye damage and skin cancer.

UVB is mostly absorbed by the ozone layer and other substances before it reaches the earth's surface and it tends to damage the skin's more superficial layers. However, it causes sunburn and is the major cause of skin cancer, including the most deadly form of the disease, malignant melanoma.

In the past, sunscreen products were more successful at blocking UVB rays than UVA rays.

A survey of almost 1,000 people conducted on behalf of McCabe's Pharmacy has found that 51% did not know the difference between UVA and UVB. Furthermore, just 12% knew that UVA rays age the skin and UVB rays burn it, while almost 21% incorrectly thought it was the other way around.

Just over 15% said they ‘vaguely' knew the difference.

According to Dr Nicola Ralph, a consultant dermatologist at the Blackrock Clinic in Dublin, UVB is most intense in Ireland between May and October, however UVA radiation is present all year round.

"Technically, the only month in Ireland when UV radiation is not strong enough to cause sun damage to the skin is January. Therefore I advise sunscreen to be worn to sun-exposed sites all year round, especially on the face, ears and backs of the hands throughout the winter," Dr Ralph advised.

When choosing a sunscreen, the sun protection factor (SPF) indicates the level of protection against UVB. Sunscreen with a minimum of SPF 30 is recommended, but when exposed to direct sunlight, SPF 50 is recommended.

UVA protection is indicated by the star rating on a bottle, from zero to five. A minimum of four stars is advised.

Sunscreen should not be applied to babies until they are at least six months old. Prior to this, infants should be kept in the shade and dressed in light clothing.

"Ideally, introduce the idea of applying sunscreen regularly to children from a young age so that they associate it with a routine and are less against having it applied as they grow older. Avoid having children in direct sun between 10am and 2pm especially when UV radiation is most intense," Dr Ralph said.

Meanwhile, according to Lisa Byrne, a superintendent pharmacist at McCabe's Pharmacy, anyone using old sunscreen should check it has not expired. She suggested stickering bottles with the date of first use, as these products usually expire within one or two years of opening.

"I've seen so many cases where parents haven't done this and then they or their child ends up sunburnt. As well as using a broad-spectrum sunscreen that protects skin from UVA and UVB rays, use wide-brimmed hats, sunglasses and sun-protective clothing to avoid sunburn," Ms Byrne said.

Sunscreen should be applied 20 to 30 minutes before sun exposure and reapplied at least every two to three hours. Bathing suit straps should be lifted up and sunscreen applied underneath as they are bound to move around.

"If you do fall victim to sunburn, use refrigerated after-sun moisturisers while skin is damp from taking a short cold shower. Drink plenty of water. Stay out of the sun until the swelling has reduced, and wear loose-fitting clothes that won't anger the burn," Ms Byrne added.

Medical attention should be sought if sunburn leads to infections, severe blistering, or if the person experiences a fever, chills or dizziness.

The survey was carried out in May 2019.


Discussions on this topic are now closed.