Differences Between UVA and UVB Rays

UVA and UVB rays are behind skin photoageing and damaged skin cells. But... what is the difference between them? In today’s post, we answer this question and also explain which factors increase ultraviolet radiation. Keep reading!Ultraviolet (UV) radiation is the sun’s radiation that reaches the earth, havingthe ability to penetrate all layers of the skin, which can become harmful to health, as UV rays damage the DNA of our skin cells. The sun is not the only source of ultraviolet radiation. Likewise,sunlamps and tanning bedsare also othersources of this type of radiation.According toa reportfrom the AECC Observatory (Spanish Association Against Cancer):“Skin carcinomas in Spainhave an incidence rate of47 cases per 100,000 inhabitants in 2020, with an upward trend”. They also add that “melanoma has a much lower incidence rate: 12 cases per 100,000 inhabitants”.

Factors that increase the intensity of UV rays

• Areas at higher altitude receive more ultraviolet rays.
• The Equator line.The farther from the Equator line, the lower the exposureto solar radiation.
• Between 12:00 and 16:00is when there isgreater ultraviolet radiation.
• Radiation is more intense inthespring and summermonths.
• The effect of cloudsin relation to ultraviolet rays can vary. They canact as a barrier as well as increase exposure to this radiation. That is why our advice is toapplysunscreenseven on cloudy days.
• UV rays bounce off certain surfaces,such as water, sand, grass, snow and even street paving.

What are UVA rays?

UVA rays (Long-Wave Ultraviolet A Rays)damage cell DNA,age the skin and cause the appearance of dark spots. In addition, the vast majority of sunlamps and tanning beds emit high amounts of UVA rays, which are linked to the risk of skin cancer. This radiation accounts for95% of ultraviolet raysand canpenetrate as far as the dermis layerof our skin.

What are UVB rays?

UVB radiation(Short-Wave Ultraviolet B Rays) is somewhatmore powerful than UVA rays. These are the rays that mainlycause sunburn. In addition,this type of ray is associated with most skin cancers. This type of ultraviolet ray accounts for5% of the radiationthat reaches the atmosphere, but it onlyaffects the epidermis, the outermost layer of the skin. Capacity of UVA and UVB rays. Image from Fundación Piel Sana (Spanish Academy of Dermatology and Venereology).

Differences between UVA and UVB rays

Although in the previous sections we have seen the differences between UVA and UVB rays, in the following table we show them in summary form:

UVA | UVB

Long wave. | Short wave.

Lower energy. | Higher energy.

Accounts for 95% of the radiation that reaches the earth. | They make up only 5% of the ultraviolet rays that penetrate the atmosphere.

Promotes ageing and the appearance of dark spots on the skin. | Causes sun-induced burns.

They penetrate as far as the dermis. | They do not go beyond the epidermis.

Less closely linked to cases of skin cancer. | More strongly linked to cases of skin cancer.

Would you like to know how to protect your skin type from ultraviolet radiation?AtFarmaciasdirectwe have a wide catalogue and a team of pharmacists who will offer youfree adviceon which products to use this summer, so that your skin is fully protected.