In summer, with the increase of ultraviolet radiation, the public's awareness of sun protection rises, and there are more sun protection "equipment" on the streets and alleys: sun protection clothes, sun hats, sun umbrellas... Many people also carry sunscreen with them and apply it at any time. However, the confusion about sun protection also arises - should we protect ourselves from the sun on cloudy days? Do you need sunscreen indoors? Is a higher SPF value for sunscreen better? Some people even fall into "sun protection anxiety", wrapping themselves up layer by layer when going out, but worrying about affecting vitamin absorption. How to strike a balance between resisting harm and embracing health in sun protection? Recently, the reporter interviewed Shi Chunrui, the chief physician of the Department of Dermatology and Venereology at the First Hospital of Lanzhou University, to listen to her detailed explanation of sun protection techniques. Be wary of UV damage. Sunscreen is not exclusive to summer. When it comes to sun protection, many people's first reaction is that they are afraid of getting tanned or sunburned in summer. However, in Shi Chunrui's view, the core of sun protection is to resist the "invisible damage" of UV rays. Ultraviolet radiation is an electromagnetic radiation with higher energy than visible light in sunlight, and the main causes of skin light damage are UVA (long wave ultraviolet) and UVB (medium wave ultraviolet). Shi Chunrui introduced that UVA has strong penetration and is prone to skin aging, while UVB is the "culprit" that causes sunburn. The potential harm of ultraviolet radiation to the skin is widespread. UVA is like a 'chronic killer' that can penetrate deep into the skin, quietly damaging collagen. Over time, wrinkles, pigmentation, and skin sagging will come knocking on the door; UVB is like an 'acute assassin', which can make the skin red and painful in the short term, and in severe cases, cause blisters and peeling. Repeated sunburn can also increase the risk of skin cancer. ”Shi Chunrui said. It is worth noting that sun protection is not exclusive to summer or sunny days. In winter, the intensity of UVA can reach 50% to 80% of that in summer, and coupled with cold and dry weather, the skin barrier function may be damaged, making it more susceptible to UV damage. ”Shi Chunrui pointed out that even on cloudy days, we cannot take it lightly. Clouds can only block some ultraviolet rays. Although it is not easy to get sunburned, it will unconsciously accelerate skin aging. Due to the strong penetrating power of UVA, even if staying indoors, it may be "attacked" by ultraviolet rays. Ordinary transparent glass almost completely blocks UVB, but can only block 30% to 70% of UVA, which means that long-term close work or study by the window will still be exposed to a considerable amount of UVA, and sun protection work still needs to be done. ”Shi Chunrui emphasized that the damage caused by ultraviolet rays is cumulative, therefore, sun protection is a "mandatory course" throughout the year and day. There are multiple ways to choose sun protection, and the key is to use it correctly. There are various types of sun protection products on the market, how should one choose? In fact, sun protection is not just about applying sunscreen, one must choose the right method and use the right method. Shi Chunrui said that a more reliable combination is "physical shielding+sunscreen", and then flexibly adjust according to specific scenarios. Physical shading, commonly known as "hard sunscreen", usually uses clothing, hats, umbrellas, sunglasses, etc. to block light and protect the skin. They can provide immediate protection, with a UPF value (UV protection factor) exceeding 50, which can block over 98% of UV rays, and the protective effect is not affected by sweat or friction. ”Shi Chunrui suggests that infants, young children, and people with easily allergic skin should prioritize using this method. "There is no chemical irritation, and it is more skin friendly." Although physical shielding is good, it is not perfect. For wrinkles and edge areas of the skin, such as the nose and neck, physical shading is easy to miss. When used in combination with sunscreen, the effect is better, "said Shi Chunrui. Sunscreen is divided into physical sunscreen and chemical sunscreen. The former works by reflecting and scattering ultraviolet rays, while the latter reduces damage to the skin by absorbing ultraviolet rays and converting them into heat energy. So, what are the advantages and disadvantages of chemical sunscreen and physical sunscreen? Physical sunscreen is like covering the skin with a layer of 'reflective mirror', which can be applied immediately and is suitable for sensitive skin. The disadvantage is that it has a thick texture and may turn white if applied too much. "Shi Chunrui said that chemical sunscreen has a light and thin texture, like a 'sponge' that absorbs ultraviolet rays, but it needs to be applied about 30 minutes before going out to wait for it to adhere to the skin before it can take effect. It is suitable for oily skin that is afraid of acne. When choosing sunscreen, it is common to see the outer packaging displaying SPF (UVB protection) and PA (UVA protection) values. Many people are confused about whether higher values are better? In fact, there is no need to blindly pursue high multiples. "Shi Chunrui gave an example. SPF30 can block about 96% of UVB, and SPF50 can block about 98%, which is not a typical linear increase. A high SPF value (greater than 50) may also increase the burden on the skin, induce acne or allergies. Choosing SPF30+or PA++for daily commuting is enough. In terms of usage and dosage, Shi Chunrui suggests that firstly, the dosage should be sufficient. Apply to the face, referring to the size of a 1 yuan coin, about 2 milligrams per square centimeter. Do not miss blind spots such as the neck, behind the ears, and on the back of the hand; Secondly, apply chemical sunscreen in advance. It is best to apply it 20 to 30 minutes before going out; Thirdly, it is recommended to reapply regularly and engage in outdoor activities, with an average reapplication every 2 hours; Fourthly, the order is correct. Applying sunscreen is usually the last step in skincare and the first step before makeup. For new types of sunscreen products such as sunscreen spray and sunscreen stick, because the protection is weaker than cream, she suggested that they be used as makeup. In fact, sun protection is important, but it is not necessarily better to cover it too tightly. Excessive sun protection may lead to new health problems. Long term use of high SPF sunscreen may cause skin allergies and acne. ”Shi Chunrui reminds that excessive sun protection may also lead to vitamin D deficiency. "90% of vitamin D in the human body is synthesized through UV radiation on the skin, and excessive sun protection can block this pathway, leading to a significant decrease in vitamin D levels and affecting calcium absorption. Young people may also experience decreased bone density, nighttime cramps, or lower back pain. ”In addition, vitamin D is involved in regulating the hair follicle cycle, and its deficiency may also lead to resting phase hair loss and emotional disorders. Excessive sun protection is equivalent to splashing shower water and children out together. "In response, Shi Chunrui gave the suggestion of" safe sun exposure ", choosing from 6am to 10am or 4pm to 5pm, when the UV is weak, exposing the arms and legs for 10 to 20 minutes." Eating deep-sea fish, egg yolks, animal liver, etc. can also supplement vitamin D. "Balancing sun protection and health, special groups need to be" tailored "- infants and young children have delicate skin. For babies under 6 months old, try not to expose themselves to the sun and use sunshades or baby stroller covers when going out. Children's first choice is pure physical sunscreen, SPF30+, which can be avoided around the eyes when applying. Pregnant women should try to avoid using chemical sunscreens containing oxybenzone, retinol palmitate, etc. Pure physical sunscreens are safer. In addition, pregnant women with high incidence of melasma during pregnancy need to strengthen UVA protection, choose PA+++sunscreen, and use physical shielding measures such as sun hats and masks. Sensitive and acne prone skin should be covered with physical sunscreen as much as possible, and mild physical sunscreen can be used in combination. Avoid using chemical sunscreen or sunscreen containing alcohol, acne causing ingredients, and other substances. During the acute phase of dermatitis, hard sunscreen is mainly used, and sunscreen is used again during the recovery period. The skin barrier and repair ability of the elderly population are weaker, and sun protection requires more attention. It is recommended to choose physical sunscreen to reduce skin irritation, wear gloves and wide brimmed hats frequently when going out, and focus on protecting areas such as the head, neck, and back of the hand that are prone to sun spots. Avoiding sun protection misconceptions and repairing sun damage in a timely manner is far more than imagined. In addition to "no need for sun protection on cloudy days" and "high magnification sunscreen is more reassuring", there are also these common things in daily life: "For example, some people think that 'applying sunscreen once for a day' is wrong. ”Shi Chunrui emphasized that outdoor sunscreen should be reapplied every 2 hours. After sweating or wiping, it should be reapplied immediately. "Otherwise, sweat will wash away the sunscreen, which is equivalent to no protection. When swimming, waterproof sunscreen is preferred." "Some people hastily apply sunscreen before going out. In fact, only pure physical sunscreen can take effect immediately after application. Chemical sunscreen usually takes 15 to 30 minutes to be absorbed by the skin. Applying it in advance can reduce the loss caused by sweat washing. ”She said. Some people are also struggling with whether to remove their makeup with sunscreen. ”Shi Chunrui said that using amino acid facial cleanser can basically clean ordinary sunscreen, and after washing, you can observe whether the water droplets can spread evenly; Waterproof products need to be removed with makeup remover oil, otherwise residue can cause closed mouth and irritation. "If you are really worried, you can choose products with oil-free formulas and non acne labels." With the arrival of summer, many parents choose to take their children to high-altitude areas for tourism and summer vacation, and their sun protection measures also need to be upgraded. For every 1000 meters increase in altitude, the intensity of ultraviolet radiation increases by about 10%. Coupled with thin air, it is easy to get sunburned and peel. "Shi Chunrui suggests that the public can wear dark sunscreen when going to areas with high altitude and strong ultraviolet radiation. Sunscreen should be selected with SPF50+and PA+++. Apply enough sunscreen 30 minutes before going out and reapply in a timely manner. If conditions permit, avoid strong light periods and move out in shaded areas such as trees and buildings to reduce direct exposure. If you get sunburned, don't panic! ”Shi Chunrui reminds that when you first get sunburned, you can rinse with cold water for 10 minutes, apply aloe vera gel externally, but do not use ice to avoid skin irritation. Starting from the second day, apply a thick layer of non-alcoholic moisturizer. Be careful not to tear it when peeling, let it fall off naturally. You can also take anti-inflammatory and repair products such as centella asiatica. "If blisters, fever, or headache occur, it may be severe sunburn, seek medical attention immediately." "In short, sunscreen is not about building a high wall to block sunlight, but about blocking it and exposing it to the sun. ”Shi Chunrui summarized that scientific sun protection requires continuous protection throughout the year, with physical shielding as the main focus, sunscreen to detect leaks and make up for deficiencies, and flexible adjustments for special groups. Only by avoiding excessive anxiety and taking chances can we maintain good health while taking care of our skin