What is sun protection factor and how is the skin affected by ultraviolet radiation?
Posted by Ivatherm
Spending time outdoors doing your favorite physical activities is an excellent way to maintain a healthy lifestyle, reduce stress, and get the vitamin D your body needs. However, too much sun exposure can have negative effects on the body.
The immediate danger of exposure to ultraviolet rays is sunburn, as these damage cells and blood vessels. With repeated sun damage, the skin becomes dry, discolored, and pigmentation spots and wrinkles can appear – two signs of skin aging.
However, the most serious threat of prolonged sun exposure is skin cancer. Specialists believe that almost all types of skin cancer can be avoided by preventing sun exposure.
In this article, we discuss the negative effects of ultraviolet radiation on the skin, the sun protection factor and its role in protecting the skin, the problems that can arise from prolonged sun exposure, and the most effective prevention methods.
Table of Contents
What is ultraviolet radiation?
Ultraviolet (UV) radiation is part of the natural energy produced by the sun. On the electromagnetic spectrum, UV light has shorter wavelengths than visible light, so human eyes cannot see ultraviolet rays, but the skin can feel them.
Ultraviolet rays are divided into three types: UVA, UVB, and UVC. In the UV spectrum, there are two types of rays that can damage DNA in skin cells and increase the risk of developing skin cancer:
UVA rays have a longer wavelength and are associated with skin aging. UVA rays, although less intense than UVB, penetrate deeper into the skin. The shortest wavelengths of UVA rays contribute to sunburn. UVA rays represent approximately 95% of the ultraviolet radiation that reaches the Earth. These rays maintain the same strength level during daylight hours, throughout the year, meaning that throughout life, all people are exposed to a high level of UVA rays.
UVB rays play, according to research, a key role in the development of skin cancer. UVB rays penetrate the outer layers of the skin, and overexposure leads to skin tanning, sunburn, and, in severe cases, blisters. The intensity of UVB rays fluctuates, but they can affect the skin throughout the year, especially at high altitudes.
As for UVC rays, people are not exposed to them, as the Earth's ozone layer blocks this type of ray.
The degree of skin damage depends on the intensity of the ultraviolet rays and the period during which the body was exposed to the sun without protection.
Effects of ultraviolet rays on the skin
Ultraviolet radiation is the main cause of the development of two common types of skin cancer: basal cell carcinoma and squamous cell carcinoma. Cancerous tumors appear predominantly on sun-exposed skin areas. If discovered early and with proper treatment, both types of cancer can be cured.
At the same time, exposure to ultraviolet rays that cause sunburn plays an important role in the development of the most dangerous type of skin cancer: melanoma.
Exposure to ultraviolet rays can also cause other health problems:
Sunburn – usually appears a few hours after too much exposure to ultraviolet light (from the sun or artificial sources, such as tanning lamps);
Premature skin aging – approximately 90% of visible skin changes, commonly attributed to the natural aging process, are caused by the sun;
Eye problems – cataracts, an ophthalmological condition that causes progressive vision loss due to loss of lens transparency, pterygium, an overgrowth that originates from the conjunctiva and invades the cornea, macular degeneration, which involves the deterioration of the macula due to retinal aging, are just some of the eye problems that can be caused by prolonged exposure to ultraviolet rays;
Weakening of the immune system – scientists have discovered that overexposure to UV radiation can suppress the proper functioning of the immune system and the skin's natural defenses.
Some people are more sensitive to the harmful effects of ultraviolet radiation. For example, people with light skin are more prone to sunburn and to developing different types of cancer.
Damage caused by exposure to ultraviolet rays is cumulative and increases, over time, the risk of skin cancer. Although the body can repair some of the damaged skin cells, the process cannot cover all of them. This accelerated cycle of cell destruction and repair, combined with UV action on DNA, can favor mutations and the appearance of cancer.
Protection against UV rays is important all year round, not just in summer. UV rays are also present on cloudy and cool days, reflecting off various surfaces, such as water, cement, sand, and snow.
Ultraviolet rays and vitamin D
The skin naturally produces vitamin D when exposed to UV rays from the sun. Natural vitamin D production depends on several factors: from age and skin color to the intensity of sunlight.
Therefore, the best way to get enough vitamin D is through sunlight, but it is important to take measures to protect the skin. Specialists recommend sun exposure for 15 to 20 minutes in the afternoon, when ultraviolet rays are not as strong, and the body can absorb the light.
What is the sun protection factor (SPF)?
Cosmetic products that offer sun protection indicate on their label a sun protection factor (SPF) number, to denote the level of protection against UVB rays, and also the mention "broad-spectrum coverage," which means they contain ingredients that can protect the skin from UVA rays.
The value of the sun protection factor indicates the degree of protection against ultraviolet rays, taking into account the time it takes for UVB rays to "break through" sun protection and cause skin redness, compared to the time it takes when there is no sun protection.
As an indicator of sun exposure time, the sun protection factor reduces the speed of sunburn by as many times as its value indicates. Thus, using a product with SPF 30 would make it 30 times harder for the skin to redden than if no sun protection were applied.
The SPF value is calculated by dividing the dose of solar radiation needed to cause sunburn when the skin is protected by the dose needed to cause sunburn when there is no sun protection.
Products with SPF 15 block 93% of UVB rays, those with SPF 30 filter 97%, and those with SPF 50 provide 98% protection.
Types of sun protection factor
Products with sun protection factor include active ingredients that reduce the risk of the sun's UV radiation reaching the skin. These are of two types:
physical sun protection ingredients (mineral filters) – block and scatter rays before they penetrate the skin;
chemical sun protection ingredients (organic filters) – absorb UV rays before they damage the skin.
Mineral filters are extremely effective and are increasingly appreciated, especially by those who practice outdoor activities, are exposed to solar radiation, and prefer high protection, not considering the aesthetic aspect as much (mineral filters can leave white marks). Women, in particular, avoid going out with white marks on their face and choose sun protection creams with organic filters.
Also, mineral filters, as well as some organic filters, act as an occlusive film on the skin's surface and can be comedogenic (i.e., they clog pores and cause acne outbreaks). This happens especially in people with oily skin, acne-prone skin, or acne. Fortunately, for these individuals, products with mineral and/or organic filters have appeared that are non-comedogenic and anti-shine. Look for light, dry-touch products.
Chemical (organic) filters are also effective. It is preferable to combine several filters in low concentrations rather than 1-2 filters in high concentrations. There are combinations that act synergistically and enhance each other.
Both types of filters, mineral and organic, have been tested as safe and effective. In fact, many sun protection products contain both types of ingredients.
Skin types and appropriate protection
In addition to the intensity of ultraviolet rays, there are a number of other factors that influence the amount of solar energy a person is exposed to, including:
skin type;
amount of sunscreen applied;
frequency of reapplication.
Specialized cells called melanocytes produce the pigment melanin, which, in addition to determining skin, hair, and eye color, partially protects DNA from harmful UV radiation. The amount of melanin that skin, hair, and eyes can produce is primarily determined by genetic factors.
It is recommended that the sun protection factor be chosen according to skin type, taking into account how ultraviolet rays can affect cellular DNA:
very fair skin – there is a high risk of damage from sun rays because the melanin content is low;
fair skin – it absorbs more solar energy than dark skin;
darker skin – it is also susceptible to the harmful effects of ultraviolet rays, but to a lesser extent, because it contains more melanin, one of the biological absorbers of UV light.
Thus, people with fair skin are more likely to absorb more solar energy than those with dark skin, under the same conditions. The amount of sunscreen applied also influences the amount of solar radiation absorbed, as more sunscreen results in less absorption of solar energy. The fairer the skin, the higher the sun protection factor should be.
The amount of sunscreen cream is also essential for good protection. Specialists recommend applying 2g/cm² of product to the skin. For simplification, the fingertip method should be used. Apply an amount of cream, as much as squeezed from the tube, starting from the base of the phalanx to the fingertip, which is 0.5g for a man and 0.4g for a woman. Two fingertips of cream should be applied to each of the 11 body segments. The 11 segments are:
face and neck;
right arm;
left arm;
upper back;
lower back;
upper torso;
lower torso;
right thigh;
left thigh;
right lower leg and foot;
left lower leg and foot.
Despite this, doctors claim that people use much less, half or even a quarter of the necessary amount.
A pragmatic approach would be to use half of the above quantities, meaning only one fingertip, but reapply one fingertip every 30 minutes.
The frequency of reapplication also depends on the exposure time, especially if you engage in sports activities involving abundant sweating or contact with water.
The Sunlight range from Ivatherm protects skin cells from the mutagenic effects of ultraviolet radiation:
Sunlight Mineral Very high sun protection SPF50+ instantly protects the skin against UVA and UVB radiation, because mineral filters form a total protective screen on the skin that reflects sunlight and prevents it from penetrating the skin.
Sunlight Mat Tinted Dry Touch Fluid SPF50+ is a very high sun protection cream for sensitive combination or oily skin. It protects skin cells from the mutagenic effects of UVA and UVB radiation.
Sunlight Milk for face and body SPF50+ provides very high, immediate and long-term sun protection for sensitive skin exposed to the harmful action of solar radiation, prevents premature aging and hyperpigmentation, and protects the skin from sunburn.
On the other hand, if an SPF product effectively blocks UVB rays, this does not guarantee protection against UVA rays. Therefore, it is necessary to apply broad-spectrum products. Broad-spectrum creams and lotions block UVA rays in the same proportion that SPF blocks UVB rays. UVA protection is indicated on the label with a circle surrounding the letters UVA.
In this context, the level of UVA protection must increase proportionally with the SPF value indicating UVB protection. For example, products with an SPF below 15 cannot offer broad-spectrum protection.
Sun protection factor products are ideally applied 30 minutes before sun exposure. Subsequently, every two hours or more often – depending on certain activities – reapplication is necessary.
Activities that can increase the need for applying sun protection factor products include:
swimming;
skiing or other high-altitude activities, because the protective layer of the atmosphere is thinner, meaning fewer UV rays are filtered;
any activity that increases the level of perspiration.
Methods of prevention against sun damage
In addition to applying sun protection factor products and avoiding sun exposure during peak hours, there are other effective ways to prevent damage caused by ultraviolet rays:
Choosing appropriate clothing
Long-sleeved shirts, as well as long pants and skirts, can provide protection against UV rays. Also, darker clothing items can offer more protection than light-colored ones. Additionally, there are clothing items, certified according to international standards, that offer UV protection.
Choosing suitable clothing accessories
To ensure high protection against ultraviolet rays, it is recommended to wear wide-brimmed hats. Fabrics such as canvas protect the skin from UV rays while allowing it to breathe. On the other hand, straw hats, which allow sunlight to pass through, are not recommended.
Also, sunglasses protect the eyes from ultraviolet rays and reduce the risk of developing eye problems. Sunglasses that block both UVA and UVB rays offer the best protection.
Seeking shade
The risk of developing skin cancer and other problems associated with sun exposure is lower if ultraviolet rays are blocked. Sheltering in the shade, under an umbrella or a tree, is one of the most effective solutions. However, using sunscreen products, protective clothing (long-sleeved shirts, long pants, scarves, wide-brimmed hats), and sunglasses is necessary even in the shade.
Both in the warm season and in cold seasons, protecting the skin from ultraviolet rays is a necessity. For the skin to fulfill its role of protecting the body from harmful environmental factors, it must remain healthy. Therefore, avoiding sun exposure – one of the main risk factors for the development of skin diseases – is an essential measure for protecting the skin.
Echipa Ivatherm
Conținutul IvaStories este creat de echipa Ivatherm, brand romanesc de dermatocosmetice fondat de Dr. Rucsandra Hurezeanu. Produsele Ivatherm sunt formulate cu Apă Termală Herculane și sunt testate dermatologic, recomandate de medici specialiști.
What is sun protection factor and how is the skin affected by ultraviolet radiation?
Spending time outdoors doing your favorite physical activities is an excellent way to maintain a healthy lifestyle, reduce stress, and get the vitamin D your body needs. However, too much sun exposure can have negative effects on the body.
The immediate danger of exposure to ultraviolet rays is sunburn, as these damage cells and blood vessels. With repeated sun damage, the skin becomes dry, discolored, and pigmentation spots and wrinkles can appear – two signs of skin aging.
However, the most serious threat of prolonged sun exposure is skin cancer. Specialists believe that almost all types of skin cancer can be avoided by preventing sun exposure.
In this article, we discuss the negative effects of ultraviolet radiation on the skin, the sun protection factor and its role in protecting the skin, the problems that can arise from prolonged sun exposure, and the most effective prevention methods.
Table of Contents
What is ultraviolet radiation?
Ultraviolet (UV) radiation is part of the natural energy produced by the sun. On the electromagnetic spectrum, UV light has shorter wavelengths than visible light, so human eyes cannot see ultraviolet rays, but the skin can feel them.
Ultraviolet rays are divided into three types: UVA, UVB, and UVC. In the UV spectrum, there are two types of rays that can damage DNA in skin cells and increase the risk of developing skin cancer:
As for UVC rays, people are not exposed to them, as the Earth's ozone layer blocks this type of ray.
The degree of skin damage depends on the intensity of the ultraviolet rays and the period during which the body was exposed to the sun without protection.
Effects of ultraviolet rays on the skin
Ultraviolet radiation is the main cause of the development of two common types of skin cancer: basal cell carcinoma and squamous cell carcinoma. Cancerous tumors appear predominantly on sun-exposed skin areas. If discovered early and with proper treatment, both types of cancer can be cured.
At the same time, exposure to ultraviolet rays that cause sunburn plays an important role in the development of the most dangerous type of skin cancer: melanoma.
Exposure to ultraviolet rays can also cause other health problems:
Some people are more sensitive to the harmful effects of ultraviolet radiation. For example, people with light skin are more prone to sunburn and to developing different types of cancer.
Damage caused by exposure to ultraviolet rays is cumulative and increases, over time, the risk of skin cancer. Although the body can repair some of the damaged skin cells, the process cannot cover all of them. This accelerated cycle of cell destruction and repair, combined with UV action on DNA, can favor mutations and the appearance of cancer.
Protection against UV rays is important all year round, not just in summer. UV rays are also present on cloudy and cool days, reflecting off various surfaces, such as water, cement, sand, and snow.
Ultraviolet rays and vitamin D
The skin naturally produces vitamin D when exposed to UV rays from the sun. Natural vitamin D production depends on several factors: from age and skin color to the intensity of sunlight.
Therefore, the best way to get enough vitamin D is through sunlight, but it is important to take measures to protect the skin. Specialists recommend sun exposure for 15 to 20 minutes in the afternoon, when ultraviolet rays are not as strong, and the body can absorb the light.
What is the sun protection factor (SPF)?
Cosmetic products that offer sun protection indicate on their label a sun protection factor (SPF) number, to denote the level of protection against UVB rays, and also the mention "broad-spectrum coverage," which means they contain ingredients that can protect the skin from UVA rays.
The value of the sun protection factor indicates the degree of protection against ultraviolet rays, taking into account the time it takes for UVB rays to "break through" sun protection and cause skin redness, compared to the time it takes when there is no sun protection.
As an indicator of sun exposure time, the sun protection factor reduces the speed of sunburn by as many times as its value indicates. Thus, using a product with SPF 30 would make it 30 times harder for the skin to redden than if no sun protection were applied.
The SPF value is calculated by dividing the dose of solar radiation needed to cause sunburn when the skin is protected by the dose needed to cause sunburn when there is no sun protection.
Products with SPF 15 block 93% of UVB rays, those with SPF 30 filter 97%, and those with SPF 50 provide 98% protection.
Types of sun protection factor
Products with sun protection factor include active ingredients that reduce the risk of the sun's UV radiation reaching the skin. These are of two types:
Mineral filters are extremely effective and are increasingly appreciated, especially by those who practice outdoor activities, are exposed to solar radiation, and prefer high protection, not considering the aesthetic aspect as much (mineral filters can leave white marks). Women, in particular, avoid going out with white marks on their face and choose sun protection creams with organic filters.
Also, mineral filters, as well as some organic filters, act as an occlusive film on the skin's surface and can be comedogenic (i.e., they clog pores and cause acne outbreaks). This happens especially in people with oily skin, acne-prone skin, or acne. Fortunately, for these individuals, products with mineral and/or organic filters have appeared that are non-comedogenic and anti-shine. Look for light, dry-touch products.
Chemical (organic) filters are also effective. It is preferable to combine several filters in low concentrations rather than 1-2 filters in high concentrations. There are combinations that act synergistically and enhance each other.
Both types of filters, mineral and organic, have been tested as safe and effective. In fact, many sun protection products contain both types of ingredients.
Skin types and appropriate protection
In addition to the intensity of ultraviolet rays, there are a number of other factors that influence the amount of solar energy a person is exposed to, including:
Specialized cells called melanocytes produce the pigment melanin, which, in addition to determining skin, hair, and eye color, partially protects DNA from harmful UV radiation. The amount of melanin that skin, hair, and eyes can produce is primarily determined by genetic factors.
It is recommended that the sun protection factor be chosen according to skin type, taking into account how ultraviolet rays can affect cellular DNA:
Thus, people with fair skin are more likely to absorb more solar energy than those with dark skin, under the same conditions. The amount of sunscreen applied also influences the amount of solar radiation absorbed, as more sunscreen results in less absorption of solar energy. The fairer the skin, the higher the sun protection factor should be.
The amount of sunscreen cream is also essential for good protection. Specialists recommend applying 2g/cm² of product to the skin. For simplification, the fingertip method should be used. Apply an amount of cream, as much as squeezed from the tube, starting from the base of the phalanx to the fingertip, which is 0.5g for a man and 0.4g for a woman. Two fingertips of cream should be applied to each of the 11 body segments. The 11 segments are:
Despite this, doctors claim that people use much less, half or even a quarter of the necessary amount.
A pragmatic approach would be to use half of the above quantities, meaning only one fingertip, but reapply one fingertip every 30 minutes.
The frequency of reapplication also depends on the exposure time, especially if you engage in sports activities involving abundant sweating or contact with water.
On the other hand, if an SPF product effectively blocks UVB rays, this does not guarantee protection against UVA rays. Therefore, it is necessary to apply broad-spectrum products. Broad-spectrum creams and lotions block UVA rays in the same proportion that SPF blocks UVB rays. UVA protection is indicated on the label with a circle surrounding the letters UVA.
In this context, the level of UVA protection must increase proportionally with the SPF value indicating UVB protection. For example, products with an SPF below 15 cannot offer broad-spectrum protection.
Sun protection factor products are ideally applied 30 minutes before sun exposure. Subsequently, every two hours or more often – depending on certain activities – reapplication is necessary.
Activities that can increase the need for applying sun protection factor products include:
Methods of prevention against sun damage
In addition to applying sun protection factor products and avoiding sun exposure during peak hours, there are other effective ways to prevent damage caused by ultraviolet rays:
Choosing appropriate clothing
Long-sleeved shirts, as well as long pants and skirts, can provide protection against UV rays. Also, darker clothing items can offer more protection than light-colored ones. Additionally, there are clothing items, certified according to international standards, that offer UV protection.
Choosing suitable clothing accessories
To ensure high protection against ultraviolet rays, it is recommended to wear wide-brimmed hats. Fabrics such as canvas protect the skin from UV rays while allowing it to breathe. On the other hand, straw hats, which allow sunlight to pass through, are not recommended.
Also, sunglasses protect the eyes from ultraviolet rays and reduce the risk of developing eye problems. Sunglasses that block both UVA and UVB rays offer the best protection.
Seeking shade
The risk of developing skin cancer and other problems associated with sun exposure is lower if ultraviolet rays are blocked. Sheltering in the shade, under an umbrella or a tree, is one of the most effective solutions. However, using sunscreen products, protective clothing (long-sleeved shirts, long pants, scarves, wide-brimmed hats), and sunglasses is necessary even in the shade.
Both in the warm season and in cold seasons, protecting the skin from ultraviolet rays is a necessity. For the skin to fulfill its role of protecting the body from harmful environmental factors, it must remain healthy. Therefore, avoiding sun exposure – one of the main risk factors for the development of skin diseases – is an essential measure for protecting the skin.
Echipa Ivatherm
Conținutul IvaStories este creat de echipa Ivatherm, brand romanesc de dermatocosmetice fondat de Dr. Rucsandra Hurezeanu. Produsele Ivatherm sunt formulate cu Apă Termală Herculane și sunt testate dermatologic, recomandate de medici specialiști.