Ultraviolet (UV) radiation is divided into three types: UVA, UVB, and UVC. On Earth, only UVA and UVB rays reach the surface. Over 80% of UVA rays are absorbed by the surface of the epidermis, while the remaining small percentage can penetrate into the dermis. This small fraction is responsible for photodermatitis, skin aging, various skin conditions, and ultimately, skin cancer.
To achieve full protection against both UVB and UVA rays, it is essential to use broad-spectrum sunscreens. Additionally, they should be water-resistant and have an SPF of 30 or higher. It is also crucial to reapply sunscreen regularly over the entire body, including the face, neck, and ears. During summer, this should be done at least every 2 hours. However, if you swim or sweat heavily, reapplication should occur as soon as you dry off.
Under normal conditions in Greece, the UV index can reach 10 or 11, which indicates extremely strong radiation and, therefore, the need for immediate sun protection. The effects of UVB radiation are cumulative, and tanning does not provide protection. Even if you are tanned or have dark skin, UVA penetrates deeply. People who work outdoors or sailors often have many deep wrinkles due to prolonged UVA exposure.
Reflected surfaces such as water, white walls, sand, or concrete can reflect a large portion of harmful radiation, so shade alone is not sufficient. Sunscreen should be applied even when in the shade. UV radiation is also stronger when there are no clouds.
The sunscreen product must protect not only from one type of radiation (cheap creams only protect against UVB), but also from UVA and UVB. It is known that UVA causes irreparable damage. This is because it constitutes 90% of UV solar radiation and penetrates deeper into the skin.
Myths and truths about sunscreen.
Myth: A high UV index alone is enough for effective sun protection.
Truth: To protect yourself from the sun’s radiation, you need to apply a sufficient amount of sunscreen to all areas of your body exposed to the sun. It is important to apply it 30 minutes before sun exposure and reapply every two hours.
Myth: Sunscreen is only necessary in the summer.
Truth: Sunscreen protection is essential year-round, for any sun exposure and during all activities. This is because 80% of UVA radiation reaches the skin even on cloudy days, and 75% of sun-induced skin damage occurs when we are not at the beach.
Myth: Time is the only factor responsible for skin aging.
Truth: The sun is worse than time when it comes to skin aging, as 80% of visible skin aging is caused by UV radiation. Its effect on the skin is significant, destroying elastin and causing visible signs of aging such as spots, discoloration, wrinkles, and dehydration.
Myth: Sunscreen alone is enough to protect you from the sun.
Truth: Sunscreen alone is not enough. Even with sunscreen, the sun can worsen signs of aging, wrinkles, and sunspots.