With the advent of unblocking, there are more opportunities to go out, and it is summer, so sun protection is indispensable. But sunscreen is more than just applying sunscreen, there are many things that need attention.
Many skin-related cancers are related to sun exposure, so sunscreen not only prevents darkening, but also prevents skin cancer. But just rubbing sunscreen is not enough, because sunscreen can’t protect the skin completely, so the following sun protection items must be paid attention to:
1. An umbrella can provide shade, but this color is the best
Under the big sun, many people will hold umbrellas. Zhu Bailing, director of the Heatstroke Prevention Center of the General Hospital of the Tri-Services General Hospital, cited a 2013 study in the medical journal “JAMA Dermatology” and pointed out that as long as you hold a parasol, you can cover 77% to 99%. The ultraviolet rays are quite effective sun protection methods.
Zhu Bailing pointed out that the darker the color of the umbrella, the better the UV protection effect. Generally, umbrellas can block 77% of ultraviolet rays, and black umbrellas can prevent 90%. If it is a special umbrella for sunshade, the anti-UV effect can reach 99%. Although the dark umbrella absorbs heat and the surface of the umbrella itself has a high temperature, the temperature under the umbrella is actually not high because of its good light isolation effect, which has a good cooling effect.
“Kang Jian” has also tested the anti-ultraviolet effects of umbrellas of different materials in the past, and found that if the general material is thin and transparent, the shielding rate is usually relatively poor.
Liang Jinyuan, manager of the National Fair Inspection Laboratory at the time, explained that due to the characteristics of the fabric itself, some materials have limited effects even if they are processed with anti-ultraviolet rays. For example, fabrics with low density, easy light transmission, or thin fabrics are easily penetrated by ultraviolet rays.
Dermatologist Zhao Zhaoming pointed out that some umbrellas use silver glue on the inner layer of the umbrella. Although it shields the ultraviolet rays from above, it may also reflect the light on the ground and increase the chance of tanning. The most effective parasol should be The inner layer is black or dark, and the outer layer is coated with silver glue for better sun protection.
2. Keep sunscreen even when driving
Sitting in the car, although the windshield blocks UVB, UVA will still shoot into the car. In 2010, the American Journal of Dermatology investigated the effect of the position in the car on skin-related cancers, and found that sitting on the left side of the car is more likely to develop skin cancer than the right side. Therefore, in the car (especially driving), it is also recommended to wear clothing to cover the skin, and it is also recommended to put on a heat shield or color film that can block UVA.
3. Clothing selection is very important
In addition to sunscreen, clothing is the most important sunscreen. As Estee Williams, assistant professor of dermatology at Mount Sinai Medical Center, pointed out, clothing and sunscreen can achieve the best sun protection effect. However, clothes are not casually worn to have a protective effect. According to the recommendations of the Skin Cancer Foundation, in addition to covering the skin as much as possible, the following points should also be paid attention to:
‧ New clothes will have better sun protection effect after washing: After washing clothes, the fiber will shrink, so it can provide better sun protection effect.
‧ The darker or brighter the color, the better: Darker or brighter clothing can absorb ultraviolet rays and prevent ultraviolet rays from directly penetrating the skin.
‧Purchase clothing with sun protection effect: The sun protection factor of clothing is UPF, which is the test method standard for clothing UV protection proposed by Australia in 1996. It is divided into 3 levels. The higher the value, the stronger the UV resistance.
According to the National Standards (CNS) of the Bureau of Standards, Metrology and Inspections of the Ministry of Economic Affairs as follows:
Grade A: UPF 40～50+: The rate of ultraviolet light penetrating clothes is less than 2.5%
Class B: UPF 25～39: The rate of ultraviolet light penetrating clothing is 2.6～4.1%
Class C: UPF 15～24: The rate of ultraviolet light penetrating clothing is 4.2～6.7%
Generally speaking, the UPF of a simple, unprocessed T-shirt does not exceed 15, but research by the Skin Cancer Foundation has found that the UPF needs at least 30 to protect enough. Therefore, some clothing manufacturers will add some substances to the fabric to increase the sun protection effect.
Lin Jihong, deputy director of the inspection team of the Textile Research Institute, pointed out that there are two main types of sunscreen clothing, one is tightly woven, and the other is processing. The limit of service life and washing times; the other is to add titanium dioxide or silicon oxide at the beginning of spinning, but because the temperature during spinning is very high, these chemicals are prone to failure due to high temperature, so this technology is more difficult high.
Although China currently has CNS standards to classify these sunscreen clothing, Lin Jihong said that because sunscreen is not a necessary function of clothing, there are currently no regulations to regulate related products.
‧ Tighter fabrics have good sun protection: fabrics with higher weave density or heavier fabrics used in the clothes themselves have better sun protection effects, such as polyester fiber, lycra, nylon, denim, khaki, silk, wool, etc. . Others, such as cotton, linen, and rayon, have poor sun protection effects.
If you want to see whether the clothes can be sun-proof, just put the clothes under the light. If the light can pass through the clothes, it means that the weave or the fabric may be too thin and the sun-proof effect is limited.
‧ Loose clothing is better than tight-fitting: loose-fitting clothing has a good sun protection effect. If it is too tight, the clothes will be pulled during activities, the fibers will become thin, and the sun protection effect will be reduced.
‧ Moisture level: If the clothes are damp due to sweating, it will reduce the ability to disperse ultraviolet rays, and it will stick to the body, reducing the sun protection effect.
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