It is said that it is best not to expose yourself to UV rays for the sake of your skin, but many people do not know the specific effects of UV rays. Excessive exposure to UV rays can have negative effects, but moderate sun exposure is important for maintaining health.

In this article, we will introduce the changes that occur in the body when exposed to ultraviolet rays. We will also explain how to protect your body from UV rays, so please refer to it.

Are there different types of UV rays? The amount of UV rays changes depending on the season

Even though the term "ultraviolet light" simply refers to it, there are multiple types. Here we will explain the types of UV rays and their effects.


● There are 3 types of UV rays

•UV-A
• UV-B
• UV-C

There are three types of ultraviolet light: UV-C does not reach the ground because it is blocked by the ozone layer that covers the earth. There are two types of UV-A and UV-B that reach the ground.

UV-A is a wavelength that reaches deep into the skin, the dermal layer. UV-A damages the components that maintain skin firmness and elasticity, causing wrinkles and sagging. The amount of UV-A is said to be 20 times that of UV-B.

Changes in the skin caused by UV-A occur slowly and are difficult to notice compared to UV-B. You will need to take daily measures to avoid the situation where you realize that your skin is aging.

On the other hand, UV-B is a type of ultraviolet light that affects the shallow layers of the skin. UV-B causes inflammation on the skin surface, causing redness and hot flashes. It also stimulates melanocytes, which produce dark pigments, and can cause age spots and freckles.

Approximately 10% of the ultraviolet radiation that reaches the ground is UV-B. Even in small amounts, UV-B can damage the genetic tissue of skin cells and cause skin cancer.

【reference】
“Ultraviolet rays environmental health manual 2020” (Environment Agency)
https://www.env.go.jp/content/900410651.pdf


● Which season and time of day are you most likely to be affected by UV rays?

UV-A becomes stronger from May to August, and UV-B becomes stronger from June to September. When we think of ultraviolet rays, we think of summer, but ultraviolet rays are present all year round. Even in January, there is one-fifth as much UV-B and one-half as much UV-A as in summer, so sun protection is essential.

The amount of UV rays also varies depending on the time of day. In the summer, about 70% of UV rays hit between 10 a.m. and 2 p.m. Therefore, if you want to avoid UV rays, it is best to go out in the morning or evening.

【reference】
“Basic knowledge about ultraviolet rays” (Japan Cosmetic Industry Association JCiA)
https://www.jcia.org/user/public/uv/knowledge

Effects of ultraviolet rays on the body and skin

Exposure to UV rays puts a strain on your skin, but not being exposed to UV rays at all is also a problem. Ultraviolet rays promote the production of vitamin D, an important nutrient in the body. You can live a healthy life by getting adequate exposure to UV rays.


● Effects that occur on the body and skin immediately after exposure to ultraviolet rays

Exposure to UV rays for a long period of time causes redness on the skin. The redness caused by sunburn is a phenomenon called "sunburn."

It occurs when cells are damaged and blood flow increases in the skin. Sunburn begins several hours after exposure to UV rays and peaks 8 to 24 hours later. It usually disappears after 2-3 days.

Also, "suntan" is the darkening of the skin caused by sun exposure. Melanin pigment is thought to be produced to protect the skin from damage by absorbing and scattering harmful ultraviolet rays. Suntan usually appears a few days after exposure to UV rays and disappears within a few weeks to months.

The following symptoms may occur if you are exposed to too much UV rays.


Blisters
Water seeps out from blood vessels dilated due to inflammation, accumulates under the thin layer of the epidermis, and swells.

decreased immunity
The body's ability to eliminate abnormal cells, bacteria, and viruses that occur in the body decreases.

keratitis
Damage to corneal cells can cause a foreign body sensation, redness, and severe pain.

[Source] “Ultraviolet Environmental Health Manual 2020” (Environment Agency)
https://www.env.go.jp/content/900410650.pdf


● Effects of long-term exposure to UV rays on the body and skin

Continued exposure to UV rays over many years can damage your skin, causing age spots, wrinkles, and sagging skin.

Furthermore, exposure to UV rays can cause benign tumors (seborrheic keratosis) and malignant tumors (skin cancer). Seborrheic keratosis is a condition that is sometimes called ``senile warts,'' and is characterized by the appearance of slightly raised mole-like lesions.

There are various types of skin cancer, including melanoma, basal cell carcinoma, and squamous cell carcinoma. Basically, it can be found in a visible place, so it can be discovered immediately. Some cases can be completely cured with early treatment, so if you are concerned, please visit a clinic as soon as possible.

Prolonged exposure to UV rays can also affect your eyes. The following are examples of symptoms caused by continued exposure to UV rays.


cataract
A disease in which the crystalline lens becomes cloudy, making it difficult to see. It is caused by the oxidation of proteins within the lens cells due to damage from ultraviolet rays.

pterygium
A disease in which the white tissue of the eye grows toward the black side. It is believed that chronic irritation is the cause.

[Source] “Ultraviolet Environmental Health Manual 2020” (Environment Agency)
https://www.env.go.jp/content/900410650.pdf

How to protect yourself from UV rays

Here we will show you how to protect yourself from UV rays. People who want to maintain beautiful skin should try multiple methods.


●Do not expose bare skin to the sun

Physically cover your skin and avoid exposing it to UV rays. Wearing fabrics with tight weaves or stitches will be more effective. However, in the summer, it is important to choose materials that are breathable. Wearing clothes that do not allow wind to pass through will prevent body heat from escaping and increase the risk of heat stroke.

Additionally, using parasols and hats that block UV rays will be even more effective. Some products are labeled as ``UV protection ○%'', so we recommend using that number as a guide when choosing a product.


●Wear sunglasses

Proper use of glasses that block UV rays can reduce eye exposure by 90%.

When choosing sunglasses, choose ones that are the right size for you. Ultraviolet rays not only reflect from above but also from below and behind, affecting the eyes. Therefore, it is important to choose a product that is a certain size and fits your face.


●Use sunscreen during the day

UV rays are present all year round, so be sure to apply sunscreen every day. It is also important to choose the appropriate sunscreen depending on the purpose.

There are "SPF" and "PA" units to express the function of sunscreen. SPF is an indicator for UV-B protection, and PA is an indicator for UV-A protection. The higher the number and the more + signs there are, the better the UV protection effect.

If you are going to be outdoors for long periods of time, such as mountain climbing or swimming at the beach, choose one with an SPF of 30 or higher and a PA of +++ or higher. If you are commuting to work or taking a walk, you can expect sun protection even with products with lesser functionality.

Recently, highly water-resistant sunscreens have also appeared. Water resistance is expressed by the number of stars, and there are two types: ★ (1 star) and ★★ (2 stars). If you are going to be immersed in water, such as at the beach or in an outdoor pool, choose a product with ★★ UV water resistance.

However, the disadvantage of using sunscreen is that very little vitamin D is produced. If you're concerned about vitamin D deficiency, it's a good idea to apply sunscreen only to your face and leave your hands and feet in the sun.

[Source] “Ultraviolet Environmental Health Manual 2020” (Environment Agency)
https://www.env.go.jp/content/900410650.pdf

Understand the effects of ultraviolet rays and live a healthy life

In this article, we have explained in detail the effects of ultraviolet rays on the body. Excessive exposure to UV rays can cause redness and pigmentation. You need to be careful because long-term exposure to it can cause aging, such as age spots and wrinkles.

However, exposure to UV rays stimulates the production of vitamin D, which is necessary for the body. Vitamin D is an important nutrient for leading a lively daily life. Therefore, it is important to avoid excessive UV protection and to expose yourself to sunlight in moderation.

Article supervision

Director of Original Beauty Clinic GINZA
Mr. Reiji Sato
Original Beauty Clinic GINZA

Graduated from Keio University Faculty of Commerce/Tokyo Medical and Dental University Faculty of Medicine.
After working as the director of a clinic in the Tokyo metropolitan area, she opened Original Beauty Clinic GINZA.
I work hard every day to become a ``family beauty doctor'' that everyone trusts.

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