Ultraviolet radiation UVA, UVB, SPF protection—what does it mean?

Ultraviolet radiation (UV radiation) is a major cause of skin cancer and has led to an increase in skin cancer diagnoses in dermatology practices in recent years. In the Netherlands we are even in the top 5 of European countries with the highest number of skin cancer cases. It is worrying that not only older people, but also children are affected by this disease.

As dermatologists, we emphasize the importance of good sun protection. But what does it actually mean to protect your skin against the sun and what are the specific aspects of ultraviolet A (UVA), ultraviolet B (UVB) and SPF sun protection? Understanding these terms and how they work can help us take better care of our skin and minimize the risks of harmful sun rays.

Different ultraviolet rays – UVA and UVB

First of all, the light from the sun consists of a number of elements: Ultraviolet A (UVA), Ultraviolet B (UVB), visible light and infrared (IR).

For more: sunrays

UVA rays are present with relatively equal intensity during all daylight hours throughout the year, and can penetrate clouds and glass. These UVA rays make up the largest part of the ultraviolet radiation, so more than UVB.

UVA is 30 to 50 times more frequent than UVB light

Although the intensity of UVA rays is less than UVB, it penetrates deeper into the skin, even into the dermis (dermis). Free radicals are formed in the dermis by UVA rays. This causes damage to elastin and collagen fibers in the dermis, which provide the elasticity of the skin and skin fibroblasts. Skin fibroblasts are responsible, among other things, for the synthesis of collagen and elastin

In the long term, UVA rays can lead to skin aging such as wrinkles, fine lines, skin discolorations and even skin cancer. Tanning beds can, varying in strength, emit up to 12 x more UVA rays than the sun. In the skin, it gives a quick tan, which is short-lived. People who regularly visit tanning salons may be 2.5x more likely to develop squamous cell carcinoma. 1.5x More likely to develop basal cell carcinoma. According to a recent study, first exposure to tanning beds in childhood increases melanoma risk by 75 percent.

UVA – A FOR AGING OF THE SKIN

UVB rays

UVB penetrates into the superficial epidermis and is responsible for our vitamin D production. So for a slow and longer lasting tan. Too much UVB causes redness, sunburn and eventually also skin aging and skin cancer. Unlike UVA, UVB does not penetrate glass. Unlike UVA, UVB radiation can be up to 1000x stronger than UVA rays and does not penetrate glass to cause damage to our hereditary material, DNA.VB. The damage can disrupt the genes that control normal cell division. The damage can increase over the years, resulting in cancer.

UVB – B FOR BURN

SPF – Sun Protection Factor

SPF is correlated with UVB rays and not UVA. The higher the SPF value, the more UVB is blocked and UVA rays are passed through. An SPF 30 blocks 97% UVB, SPF50 – 98% and SPF100 – 99% not available in Europe against UVB rays.

SPF ≠ UVA

In short: In the Netherlands, UVA rays are present all year round during daylight and UVB is strongest during the spring and summer period. In the spring and summer period SPF30 possibly combined with day cream UVA filter

More about: Sunscreen

New: visible light protection for Asians and dark skin

For people with dark and Asian skin, extra protection against visible light is important due to specific characteristics of their skin. While visible light does not cause direct damage to the skin, it can cause indirect damage through the formation of free radicals. Free radicals are unstable molecules that can lead to oxidative stress and cell damage, which can ultimately contribute to skin aging and pigment problems.

An important aspect is that dark and Asian skin types contain more melanin than lighter skin types. Melanin is the natural pigment that protects the skin from the harmful effects of ultraviolet (UV) radiation. While melanin is effective against UV radiation, it offers less protection against visible light. Because of this, people with darker or Asian skin may be more susceptible to damage caused by visible light.