Usually, I walk my dog after 6:30 in the morning, around 7 o’clock, when I return to the entrance of the residential area, I encounter a group of parents taking their children to school. Sometimes, I see some parents wearing cloaks, covering their faces, with only their eyes and mouths exposed. I think this level of sun protection is a bit excessive. If we protect ourselves from the sun with such high standards in the morning, in plain areas, and for short periods of time, how can people in other places even go outside at noon? In the morning, there is no need to be so afraid of sun exposure. Firstly, the morning sunlight is not particularly intense. The “Merck Manual” states: “The most effective method to prevent sun damage is to avoid direct exposure to strong light. Avoid exposure to bright sunlight at noon. Ultraviolet rays are not particularly intense before 10 a.m. and after 4 p.m.”
Secondly, our skin has a natural defense mechanism. “When exposed to ultraviolet rays, the skin undergoes certain changes to prevent damage. The epidermis (the outermost layer of the skin) thickens to block ultraviolet rays. Melanocytes (skin cells that produce pigment) produce more melanin (a brown pigment that darkens the skin), resulting in a suntan. Melanin can absorb the energy of ultraviolet rays, helping to prevent light from damaging skin cells and penetrating deep into the tissues. Therefore, tanned skin provides some natural protection when exposed to ultraviolet radiation in the future.” Moreover, appropriate sunlight exposure is necessary for health, as the absorption and metabolism of calcium require vitamin D (VD). VD primarily comes from the skin and needs to be converted into active VD3 after exposure to sunlight (medium-wave ultraviolet light).
People are paying more and more attention to sun protection, not only for health reasons but mainly for skin whitening. Exposure to sunlight can cause permanent skin aging. Skin damage caused by long-term exposure to sunlight is called photoaging. Exposure to ultraviolet rays can cause fine lines and wrinkles, irregular pigmentation, large areas of freckle-like spots (known as age spots), yellowing of the skin, and rough skin texture. Experts say, “UVA is present in all seasons and all weather conditions. Therefore, from the perspective of preventing photoaging, sun protection is not seasonal. UVA can penetrate glass and enter indoor spaces, so sun protection is also necessary indoors and in enclosed vehicles.” In 2019, an article in the American magazine “Outside” stated, “Current American guidelines on sun exposure are unhealthy and unscientific. The American Academy of Dermatology takes a zero-tolerance attitude towards sun exposure. The academy advises people to protect their skin from the sun every day, even on cloudy days. In the United States, fewer than 3 people per 100,000 die from skin cancer each year. For every one person who dies from skin cancer, over 100 people die from cardiovascular disease. Melanoma, a deadly form of skin cancer, is much rarer, accounting for only 1% to 3% of newly diagnosed skin cancers. What is confusing is that outdoor workers have only half the risk of developing melanoma compared to indoor workers. Overall, people with tanned skin have a lower risk of illness.”