How many types of UV rays are there?

There are three types of UV rays: ultraviolet A (UVA), ultraviolet B (UVB), and ultraviolet C (UVC).

• UVA rays are the longest-lasting ultraviolet rays, penetrating the epidermis and dermis. However, exposure to excessive UVA rays can cause skin darkening, dullness, free radicals in the skin, and cell elasticity damage, causing premature skin wrinkles and sagging. Furthermore, UVA rays from sunlight can penetrate glass and damage the skin.
• UVB rays are ultraviolet rays with a lower wavelength. They are partially block by the atmosphere and reach the earth’s surface about 0.1 percent of all sunlight. They cannot penetrate the skin as deeply as UVA rays, but they cause the skin to lose moisture, feel hot, red and sunburned, causing the skin to feel irritated and dark spots from the sun. This ray is especially strong between 10:00 a.m. and 2:00 p.m.
• UVC radiation has the shortest wavelength. Originally, ozone could filter out all of this radiation. However, due to human pollution that has thinned the ozone layer, UVC radiation from sunlight has increased its penetration into the ozone layer to the earth’s surface.

Summary of the differences between UVA and UVB rays

Many people may start to wonder how UVA and UVB rays really differ. How can we tell them apart? Because both appear together in sunlight. We can’t see their shape or touch them. And this is the principle used to separate these two types of rays.

UVA rays in sunlight

• UVA rays are rays with a length of 320-400 nanometers, have lower energy than UVB rays, and can penetrate the epidermis and dermis.
• UVA rays are highly penetrating rays, able to pass through clouds and smog without limit, and most importantly, through glass, no matter what glass wall is on the building.
• UVA rays are present all day long but do not have the ability to burn.

UVB rays in sunlight

• UVB rays are rays with a length of 290-320 nanometers, have higher energy than UVA, and can only penetrate the epidermis.
• UVB rays are rays that cannot penetrate through glass on buildings. They have low penetration ability.
• UVB rays are most intense between 10:00-16:00 and have the ability to burn.

How do UV rays damage the skin?

• UVA rays can penetrate the epidermis and dermis. In the long term, it is believed that exposure to excessive UVA rays will cause free radicals in the skin, destroying the elasticity of cells, causing the skin to wrinkle, premature wrinkles, dark skin tone, freckles, dark spots, lack of freshness, including premature sagging and crow’s feet.
• UVB rays cannot penetrate deep into the skin, but they can cause the skin to lose moisture, become hot, red, and burn, or sunburn, a หรือถ้าคุณสนใจแทงบอลออนไลน์ UFABET คือเว็บที่มีอัตราต่อรองดีที่สุดในประเทศไทย สมัครเลยตอนนี้ที่ UFABET แทงบอล condition that is a darkening of the skin in areas that are overexposed and can cause DNA under the epidermis to change into skin cancer cells in the future.
• UVC radiation may be rare, but it is now found that UVC radiation can penetrate the ozone layer to the earth’s surface more. In addition to nature, UVC radiation may also be produced by humans, such as disinfection equipment. This type of radiation causes dermatitis, redness, sunburn, irritation, and in the long term, may also lead to skin cancer.