What is UV radiation?

Ultraviolet radiation, also known as UV radiation, is a form of electromagnetic radiation that comes from the sun. This radiation is invisible to the human eye because its wavelengths are shorter than those of visible light.

The UV spectrum is divided into three main categories: UVA, UVB and UVC, which have different properties.

UVA radiation

UVA radiation is a form of electromagnetic radiation that comes from the sun. It is part of the broad spectrum of solar radiation, together with UVB and UVC radiation. UVA radiation has longer wavelengths and is less energetic than UVB and UVC radiation.

UVA radiation penetrates deep into the skin and can even pass through glass. It is present all year round, regardless of the season. Although UVA radiation causes less direct damage to the skin than UVB radiation, prolonged exposure can lead to premature skin ageing, wrinkles, pigmentation problems and can contribute to the risk of skin cancer.

It is important to protect yourself from UVA radiation by using sunscreen that offers broad spectrum protection, wearing clothing that covers your skin and wearing sunglasses that block UVA radiation.

UVB radiation

UVB radiation is a form of electromagnetic radiation that comes from the sun. It is part of the broad spectrum of solar radiation, along with UVA and UVC radiation. UVB radiation has shorter wavelengths and is slightly more energetic than UVA radiation.

UVB radiation is strongest between 10 a.m. and 4 p.m., especially during the summer months. It has less penetrating power than UVA radiation and does not penetrate as deeply into the skin. UVB radiation is the main cause of sunburn and plays a major role in the development of skin cancer.

Although UVB radiation does not penetrate as deeply as UVA radiation, it can damage the upper layers of the skin and damage the DNA in skin cells. This can lead to burning, redness, rashes and, in severe cases, blistering.

UVC radiation

UVC radiation is also a form of electromagnetic radiation, but unlike UVA and UVB radiation, UVC radiation does not usually reach the Earth's surface. UVC radiation is mainly absorbed by the ozone layer and the atmosphere, blocking most of it before it reaches the ground.

UVC radiation has the shortest wavelengths and is the most energetic of the three types of ultraviolet radiation. It is often used in laboratories and medical settings for disinfection and sterilisation purposes due to its ability to kill or inactivate microorganisms, such as bacteria and viruses.

Sunscreen and UV radiation

Sunscreen plays an essential role in protecting our skin from harmful UV radiation. There are two important aspects to consider when choosing an effective sunscreen: the sun protection factor (SPF) and the protection against UVA radiation.

The sun protection factor (SPF) is a measure of how well a sunscreen protects against UVB radiation. UVB radiation is responsible for sunburn and plays an important role in the development of skin cancer. The SPF value on a sunscreen indicates how long you can stay protected with the cream before your skin starts to burn compared to unprotected skin. For example, a sunscreen with SPF 30 means that you can stay in the sun 30 times longer before you burn than if you did not use sunscreen. It is important to remember that higher SPF values do not always offer proportionally higher protection, so an SPF of 30 blocks approximately 97% of UVB rays, while an SPF of 50 blocks approximately 98%.

In addition to SPF, it is also important to check whether a sunscreen offers protection against UVA radiation. UVA rays are less intense than UVB rays, but they penetrate deeper into the skin and are present all year round, even on cloudy days. Prolonged exposure to UVA rays can lead to premature skin ageing and may contribute to the risk of skin cancer. To check whether a sunscreen offers protection against UVA radiation, look for labels or symbols such as the UVA logo (a circle with 'UVA' inside) or the term 'broad spectrum'. Broad spectrum means that the sunscreen protects against both UVB and UVA radiation.

It is important to apply sunscreen regularly, especially after swimming, sweating or drying yourself with a towel. It is also essential to take other protective measures, such as wearing protective clothing, avoiding the sun during peak hours and wearing sunglasses (or a hat) to protect your eyes.