UV radiation improves mood, changes skin color and aids in curing some dermatological diseases. Still, it has more bad than good sides. What types of UV do we recognize and what is their positive and negative impact on skin? How to shield ourselves against UV rays?
Types of UV radiation
There are three types of UV rays distinguished: UVA, UVB and UVC.
- UVA radiation constitutes 95% of the entire UV rays that reach the Earth. Its intensity remains unchanged no matter the season or cloudiness. UVA rays are able to penetrate clouds, glass and human epidermis. This is the very radiation that affects the epidermis layer and reaches the cells of the dermis. UVA radiation has a negative impact on skin condition: it accelerates skin aging and might cause skin cancer.
- UVB rays constitute the remaining 5% of the entire UV radiation. Its intensity is the highest during the summer, especially when the solar irradiation is the strongest. Contrary to UVA rays, UVB rays are blocked by glass and clouds, but they are able to penetrate skin (through epidermis). It’s responsible for tanning, cause pain after tanning, sunburns and skin cancer. Both types of radiation are emitted by solarium bed lamps.
- UVC radiation doesn’t affect skin because it’s almost entirely absorbed by the ozone layer.
Positive impact of UV rays on skin
Solar radiation synthesizes vitamin D3 that is responsible for stimulating immunological system, proper muscle functioning as well as healthy teeth and bones. Sunbathing (only with sunscreen) can soothe some types of allergies and skin diseases such as psoriasis, atopic dermatitis or acne. Moreover, sun improves mood and helps to fight back depression.
Negative impact of UV rays on skin
UV radiation and skin photo-aging
Sadly, UV radiation might do more harm than good to skin. After all, sun is the main factor of skin aging. It’s believed that if it wasn’t for the sunlight, the signs of aging would appear in a considerably more advanced age.
UVA radiation is responsible for free radicals appearance, which lead to skin photo-aging. Because of UVA rays, fibroblast disappear and this significantly slows down collagen production and weaken elastin fibers (both proteins are responsible for maintaining skin density, firmness and elasticity). As a consequence, skin gets flabby, features more furrows and wrinkles.
UV radiation and sunburns
Sunburns, also called solar erythema are the consequence of overexposure to the sun. They appear already within a few hours of being in contact with too much solar radiation and are always accompanied with pain, stinging sensation and redness. When the situation gets serious, solar erythema might lead to fever, chills, nausea and vomit.
An effective way to deal with these ailments is application of cold dressings and covering body with cooling aftercare products. Highly recommended products are those which are based on moisturising and soothing substances such as aloe, allantoin and panthenol. What might be surprising, dairy products such as cream or natural yogurt are good at dealing with and healing solar erythema. Still, despite being healed, skin might remain affected by sun-induced discolorations.
UV and skin cancer
The most dangerous consequence of excessive UV rays exposure is skin cancer. Keeping your body exposed to the sun for too long might contribute to causing moles and actinic keratosis that sometimes transforms into skin cancer.
How to protect skin against UV rays?
The basic protection against the sun is offered by sunscreens; the level of protection should match skin phototype and frequency of sun exposure. Body should be exposed to the sun gradually. To clarify, you should start with the highest filter and spending little time outdoors to extend this period and slowly reducing the level of SPF. The sunscreen should be reapplied every two hours or after leaving water.
Additionally, you must avoid getting a tan during the strongest solar irradiation period, which takes place between 12:00 AM and 3:00 PM. In the summer try to wear sheer clothing made of natural fabric, protect your head and put on sunglasses. Also, don’t forget to apply lipsticks, powders and foundations containing SPF. They will help you slow down the unwanted process of face skin photo-aging.