Why effective sun protection is so important
The incidence of skin cancer has increased dramatically. Over the past two decades, the number of deaths from skin cancer in Germany has risen by approximately 55%, and the number of inpatients with skin cancer has increased by as much as 75% (1).
The increase in non-melanoma skin cancer is particularly worrying. Among workers in agriculture, forestry, and horticulture, non-melanoma skin cancer is now the most common reported occupational disease, which is why prevention is a top priority (2).
In addition to the risk of skin cancer, intense sunlight also leads to premature skin aging. Visible signs of this include pigment spots and wrinkles, which are caused by the damaging effects of the sun on the skin's structure.
Why is the incidence of skin cancer increasing?
There are several reasons that could play a role in why the incidence of skin cancer is increasing:
- Demographic change: People are living longer and spending more time in the sun throughout their lives. With age, cumulative UV exposure increases, increasing the risk of skin cancer.
- Travel habits: More and more people are spending their holidays in sunny regions, even in winter. This increased UV exposure can increase the risk of skin cancer.
- Improved screening: Advances in medical diagnostics mean that skin cancer is detected earlier and more frequently.
- Climate change: Experts suspect that climate change is contributing to the increase in skin cancer. Changes in the ozone layer lead to increased UV exposure. A warmer climate also causes people to spend more time outdoors, further increasing UV exposure (3).
Distinction: UVA and UVB radiation
Sun protection is primarily concerned with protection against ultraviolet radiation (UV radiation). UV radiation, like visible light and the infrared range, belongs to the electromagnetic spectrum of solar radiation. The UV range encompasses the electromagnetic wavelengths from 100 to 400 nanometers (nm).
A distinction is made between UVA, UVB and UVC radiation (3):
- UVC radiation: UVC radiation is particularly energetic and covers wavelengths below 280 nm. However, this radiation is filtered out by the ozone layer of the Earth's atmosphere and does not reach the Earth's surface.
- UVB radiation: UVB radiation has a wavelength range of 280 to 315 nm. About 5% of the UV radiation that reaches the Earth is UVB.
- UVA radiation: This includes wavelengths from 315 to 400 nm. UVA radiation accounts for about 95% of the UV radiation that reaches the Earth's surface.
How does UV radiation damage our skin?
Both UVA and UVB rays can damage our skin. Effective sunscreen must therefore be effective against both types of radiation.
UVB radiation
UVB radiation is more energetic than UVA radiation, but due to its shorter wavelength, it only penetrates the epidermis. UVB radiation can cause direct damage to the DNA of skin cells by triggering changes in their DNA structure. If this damage is not repaired, it can lead to the development of skin cancer in the long term.
In addition to epithelial cells, the epidermis also contains pigment-producing cells, so-called melanocytes. Exposure to UVB radiation stimulates melanocytes to produce pigment, i.e., melanin. The increased melanin content improves the skin's natural protection against UV radiation. The resulting tanning of the skin is therefore a protective mechanism.
UVA radiation
UVA radiation penetrates deeper into the skin and can cause indirect damage by generating free radicals and thus oxidative stress . Free radicals are highly reactive particles that can attack other molecules in the environment. This can lead to damage to proteins, fats, or DNA, for example. UVB rays also contribute to the development of oxidative stress in the skin, although to a lesser extent than UVA rays.
UVA rays play an important role in the skin aging process. The resulting oxidative stress in the dermis leads, among other things, to damage to collagen and elastic connective tissue fibers, causing the skin to increasingly lose its firmness and elasticity, becoming sagging and wrinkled. Oxidative stress also promotes hyperpigmentation and thus the formation of dark spots.
DNA can also be attacked by free radicals, so UVA rays also increase the risk of skin cancer.
sunburn
Sunburn occurs when the skin is exposed to excessive amounts of UV radiation, especially UVB radiation, within a short period of time. This causes a burn, which can be accompanied by redness, pain, swelling, and, in severe cases, blistering. Sunburn therefore represents severe skin damage.
Sun damage sustained during childhood and adolescence can significantly increase the risk of developing skin cancer later in life. Repeated sunburns and excessive sun exposure during early years can cause cumulative DNA damage, which can lead to skin cancer later in life.
Further harmful effects
In addition to skin damage, UV radiation can also cause other health problems:
- Eye damage: Long-term UV exposure can lead to the development of cataracts, a clouding of the lens of the eye.
- Immunosuppression: UV radiation can weaken the immune system, reducing the body's defenses against infections and diseases. This also increases the risk of skin cancer (3).
How does skin cancer develop?
Skin cancer develops due to DNA damage in skin cells, leading to degeneration and uncontrolled proliferation of these cells. In addition to UV radiation, which can come from the sun or artificial UV sources such as tanning beds, genetic predisposition, environmental toxins (e.g., arsenic), ionizing radiation (e.g., X-rays), or phototoxic substances that sensitize the skin to UV radiation also play a role in the development of skin cancer.
Depending on which cell type in the skin is affected, different forms of skin cancer occur:
- Melanoma: Melanoma affects the pigment-producing melanocytes. Melanomas are particularly dangerous and can metastasize quickly.
- Non-melanoma skin cancer : These include basal cell carcinoma and squamous cell carcinoma. Non-melanoma skin cancer is more common but less aggressive than melanoma.
Elements of effective sun protection
The most important pillars of effective sun protection are:
- Self-protection of the skin
- Avoid strong UV radiation
- Sun protection clothing
- sunscreen
- Skin cancer prevention
In the following, we will go into the individual points in more detail and explain what you should pay particular attention to.
Natural sun protection for the skin
UV sensitivity can vary greatly from person to person. To better assess UV sensitivity, skin types are divided into six different types. The natural protection time refers to how long you can stay in the sun without getting sunburned.
The following skin types are distinguished (4):
- Skin type I: Very fair skin, often with freckles, reddish or reddish-blonde hair, blue or green eyes. Self-protection time: approximately 5 to 10 minutes. Sunburns easily and tans almost never.
- Skin type II: Light skin, blonde to brown hair, blue, green, or gray eyes. Self-protection time: approximately 10 to 20 minutes. Frequently sunburns and tans only moderately.
- Skin type III: Light brown skin, dark blonde or brown hair, gray or brown eyes. Self-protection time: approximately 20 to 30 minutes. Tans faster than skin type II and burns less frequently.
- Skin type IV: Olive-colored skin, dark brown hair, brown eyes. Self-protection time: approximately 30 to 40 minutes. Rarely gets sunburned and tans quickly.
- Skin types V and VI: These skin types include dark-skinned individuals. A tanning effect is only visible in extreme sunlight. Sunburn almost never occurs. The natural protection time can last for over an hour.
In addition to genetically determined UV sensitivity, there are other factors that influence the skin's resistance. These include, among others, acclimatization to the sun, i.e., whether the skin already has a certain tan. This extends the natural protection time, albeit only slightly.
Furthermore, supplying the skin with micronutrients is also extremely important. If the skin lacks important vital nutrients, metabolic processes and repair mechanisms cannot function properly. Read our articles "Beauty from Within: Nutrients for Skin, Hair & Nails" and "Natural Sun Protection from Within " for more information.
Avoid intense sunlight
The intensity of UV radiation varies throughout the day. Around midday, when the sun is at its zenith, UV radiation reaches its maximum intensity. Dermatologists therefore recommend avoiding sun exposure between 11 a.m. and 3 p.m. During this time, you should preferably stay indoors or in well-protected shady areas.
What does the UV index mean?
To compare UV radiation intensity, there is the so-called UV index. This is internationally valid and provides information about the current intensity of UV radiation at a specific location.
The UV index is indicated on an open-ended scale. The higher the number, the greater the UV radiation intensity and the faster you will suffer sunburn if your skin is unprotected. Protective measures are recommended starting at a UV index of 3.
In Germany, values of 8 to 9 are reached in summer, and even up to 11 in mountainous areas. At the equator, values of 12 and higher can occur. You can find the current UV index using weather apps or on the websites of weather services. During the day, the UV index is highest between 11 a.m. and 3 p.m.
Reflective surfaces such as sand, water and snow can significantly increase the UV index locally, so you should be especially careful in such situations, such as on a beach or skiing holiday.
Influence of clouds and shadows?
Many people neglect sun protection when it's cloudy or in the shade. However, this is not recommended, as UV intensity can still be high. For example, in the shade, you are still exposed to up to 50% of UV radiation due to the reflection of ambient radiation.
Light cloud cover also barely reduces the UV index. It can even increase the UV index due to additional scattered radiation. A dense cloud cover, on the other hand, can block up to 90% of UV radiation (5).
Sun protection clothing
The best protection against UV radiation is achieved through clothing. A hat and sunglasses protect the sensitive areas of the scalp and eyes.
Simple, thinner clothing, such as a long-sleeved T-shirt, corresponds to a protection factor of approximately 20. Heavier clothing has a correspondingly higher protection factor of 50 and above. Unlike sunscreen, the protection provided by clothing is immediate, consistent, and lasting (3).
For particularly good protection, there are also special UV-protective clothing made of tightly woven fabrics. UV-protective clothing is a good choice in the summer, especially for children, who are more sensitive to UV radiation than adults.
sunscreen
In addition to the measures mentioned above, the use of sunscreen is also a key component of sun protection for the skin. Below, we explain how to compare the protective effects of different products and what to consider when using sunscreen.
To ensure effective protection, it's important that the sunscreen used protects against UVA and UVB radiation. However, people often only pay attention to the sun protection factor. This information isn't sufficient to assess UV protection.
What is meant by sun protection factor?
The sun protection factor (SPF) indicates how well a sunscreen protects the skin from UVB rays. The SPF does not provide any information about UVA protection. The specified value indicates how much longer you can stay in the sun with the sunscreen without getting sunburned compared to unprotected skin.
For example, an SPF of 30 means you can theoretically stay in the sun 30 times longer before getting sunburned. However, it's important to note that actual protection depends on several factors, such as the intensity of the sun's rays, your skin type, and the amount of sunscreen applied.
It's also important to note that the sun protection factor only applies once a day. This means that applying sunscreen multiple times won't extend the protection. For example, if you have a natural protection factor of 10 minutes and apply a product with SPF 20, you can stay in the sun for 200 minutes that day, regardless of whether you apply more sunscreen.
How is protection against UVA rays indicated?
According to EU regulations, UVA protection should be at least one-third of UVB protection. This is indicated by the "UVA seal" on the packaging, which consists of a circle containing the letters "UVA."
Another classification is the PA (Protection Grade of UVA) system, developed in Japan. The PA system uses a plus sign to indicate the level of protection. The rating ranges from PA+ for basic protection against UVA rays to PA++++ for very high protection.
How often should you reapply cream?
Sweating, contact with water, dirt, or rubbing your face can all remove sunscreen. In such cases, you should reapply it several times to maintain your existing protection.
Is “waterproof sunscreen” really waterproof?
Sunscreens are considered "waterproof" if they still provide at least 50% of the declared protection after rinsing. Even waterproof sunscreens must be reapplied after swimming to maintain their protection.
How much sunscreen should you apply?
You shouldn't skimp on sunscreen. A minimum of 30 ml or 3 to 4 tablespoons is recommended for the entire body. Only by applying a sufficient amount of product can the stated level of protection be guaranteed.
Early detection of skin cancer
In Germany, it is recommended that anyone over the age of 35 undergo a skin cancer screening every two years. This screening is covered by statutory health insurance and includes a thorough examination of the entire skin by a dermatologist. Screening may also be beneficial at a younger age, however, not all insurance companies cover it.
People with a higher risk of skin cancer, for example due to a family history, frequent sun exposure or a large number of moles, should be examined more frequently and should discuss this individually with their doctor.
Do you need UV protection indoors?
In general, UV protection is significantly less necessary indoors than outdoors, as window glass blocks most UVB radiation. However, UVA rays can penetrate ordinary window glass and affect the skin.
In certain situations, it may be advisable to take UV protection measures indoors as well. These situations include long car journeys or prolonged exposure to large windows, especially in direct sunlight. It's also a good idea to apply sunscreen if you work in a brightly lit office.
Conclusion – Effective sun protection has many aspects
Protecting your skin from UV radiation is important and should not be taken lightly, as sun damage can accumulate and often only becomes apparent many years later. Effective sun protection goes far beyond simply applying sunscreen and includes measures such as avoiding intense sunlight, wearing protective clothing, and regular skin cancer screening.
Sources
- Number of inpatient skin cancer treatments increased by 75% within 20 years. Federal Statistical Office [Internet]. [Accessed on: June 28, 2024].
- Skin cancer cases expected to double by 2030. Leipzig University Hospital [Internet]. [Accessed on: June 28, 2024].
- Health guideline: Prevention of skin cancer. Oncology Guideline Program [Internet]. Status February 2022 [accessed on: June 28, 2024].
- The different skin types. Federal Office for Radiation Protection [Internet]. [Accessed on: June 28, 2024].
- Factors of UV exposure. Federal Ministry for Climate Protection, Environment, Energy, Mobility, Innovation and Technology [Internet]. [Accessed on: June 28, 2024].
