Sunlight has positive effects on health as, among other things, it helps to stimulate the production of vitamin D, to control some chronic skin disorders (such as psoriasis) and causes a feeling of well-being. However, exposure to solar radiation also has negative consequences for the skin as it can lead to burns, wrinkles, ageing, allergic reactions and even skin cancers.
For this reason, it is important to protect our skin by following a series of basic recommendations and using an appropriate sunscreen. The sun is capable of emitting radiation of different lengths, including ultraviolet (UV) radiation.
Ultraviolet (UV) light is invisible to the human eye, but it is the light that can have the greatest effect on our skin. There are three types of UV radiation, which are classified according to wavelength:
UVB radiation (short wave) is very energetic and is responsible for making us red when we are exposed to the sun. The powerful radiation passes through the most superficial layer of the skin, that is, the epidermis and the tan more quickly. However, it has a high capacity to produce skin cancers.
In this sense, if the dose of UVB radiation is higher and stronger, the skin becomes red and inflamed, leading to sunburn. This is a serious alarm signal sent by skin cells. Therefore, over time, it can lead to chronic skin conditions and even the development of cancer. Photoprotectors protect us against this type of radiation.
On the other hand, UVA radiation (long waves) penetrates deeper into our dermis “where they produce the tan”. A priori, natural UVA rays (not artificial ones through the use of tanning beds) do not cause burns.
However, they can damage the connective tissue under the epidermis, causing the skin to lose its tone and leading to reactions such as wrinkles or premature skin ageing. Furthermore, recent research highlights that being exposed to a high concentration of UVA can also contribute to the development of skin cancer.
Firstly, the skin is able to protect itself naturally against the first impacts of solar radiation. The epidermis thickens and blocks UV light. Melanocytes (pigment-producing cells) increase the amount of melanin, which darkens the skin and leads to tanning. This provides some natural protection.
However, it is important to follow some recommendations to protect the skin from the harmful effects of radiation such as avoiding exposure to the sun too long, using clothes that cover the skin, wearing glasses that protect our eyes and, above all, using some type of cream, protector and sunscreen.
At this point it is important to establish the differences between sunscreen and sunblock, two types of products used to protect the skin from solar radiation, so that you know which is best to purchase in each case.
When buying a sunscreen it is important to read the label. It is recommended to use products with a broad spectrum protection (against UVA and UVB rays) and with a sun protection factor (SPF) value of 30 or higher, as indicated by the American Cancer Society.
The sun protection factor (SPF) indicates the level of protection the product has against UVB rays. A higher number indicates a better ability to absorb this harmful radiation, although there is no sunscreen with total protection. By using these products you will avoid the appearance of sunburn or redness on your skin.
On the other hand, it is advisable to choose products whose label verifies that they are “broad-spectrum” since they will filter out UVA and UVB rays. Everyone should use this type of protection, especially when doing outdoor activities where the skin is very exposed to the sun.