Ultraviolet rays (UV) account for only a small part of the sun's rays, but this is the main cause of skin damage. Exposure to ultraviolet rays can damage the DNA in skin cells, increase the risk of skin cancer, and accelerate signs of aging, such as fine lines, deep wrinkles and dark spots.
There are three types of ultraviolet rays: UVA, UVB and UVC. Let's take a look at their differences and how they affect the appearance and health of the skin.
UVA light is not absorbed by the ozone layer and can penetrate the human dermis, which is the deepest layer of the skin. UVA rays have many effects on the skin, including immediate redness and darkening of the skin, the formation of fine lines, wrinkles and age spots. UVA also plays a minor role in the development of skin cancer because it causes the formation of free radicals in the skin.
UVA radiation can penetrate glass (windows), which is why doctors and dermatologists recommend wearing sunscreen every day even if you don’t go outdoors every day.
Remember, UVA = aging!
UVB is another form of ultraviolet light. Unlike UVA rays, not all UVB rays can reach the earth because some rays are absorbed by the ozone layer. Because UVB rays are shorter and have a higher frequency, they are more harmful to the skin when they penetrate the epidermis (the top layer of the skin). UVB radiation can cause sunburn and delayed tanning. It plays a major role in the development of all types of skin cancers that cause DNA damage to skin cells and the immune system. UVB is also important in the synthesis of vitamin D3.
Remember, UVB = severe burns!
UVC rays are too short to pass through the earth’s atmosphere. Although UVC is the most dangerous form of ultraviolet radiation, it is completely absorbed by the ozone layer and usually does not cause skin cancer. Of course, at any given time and place, the amount of UV rays on the skin depends on many factors, including time of day, time of year, altitude, and cloud cover. You can refer to the UV index ranging from 1 to 11+ to see the intensity of UV rays in this area. A higher number means more UV exposure and a higher risk of sunburn and skin damage.
Recently,265nm 275nm UVC light strips has came into the public's attatention due to the breakout of the coronavirus. But it shoud be noted that it is harmful for human skin and eyes.
What can I do to protect myself?
Sunlight is not the enemy, but the inevitable ultraviolet radiation that we must learn to control. Many people like to be active outdoors on a sunny afternoon. On such days, when we venture to enjoy nature, we can protect our skin in the following ways: 1. Hovering in the shaded area 2.Wear sunscreen on exposed areas of the skin (minimum SPF is 30, reapply every 1-2 hours) 3. Wear light protective clothing (wide-brimmed hat, sunglasses, breathable long-sleeved shirt, etc.). For daily protection, use sunscreen to moisturize the face, neck and chest. Using these measures to minimize exposure to ultraviolet radiation is one of the best measures you can take on your skin to slow down the signs of aging and prevent skin cancer.