It’s difficult to know what to think about sun exposure, isn’t it? On the one hand, we’re told to cover up and not expose ourselves in the hottest part of the day and to wear SPF at all times… but at the same time, we do need to feel the sun on our skin, to keep it, as well as the rest of us, healthy. So, how should we approach the sun? SOPHYTO’s bioesthetician Ishtar Magally has the facts…

On the Bright Side

The sun is indispensable for life on Earth and provides several health benefits.

Positive physiological effects of sunlight:

• Stimulates the synthesis of vitamin D, which prevents rickets and osteoporosis.
• Improves circulation, by dilating blood vessels.
• Beneficial in the treatment of some dermatosis (skin disorders).
• Acts as an antidepressant, stimulates the production of specific neurotransmitters which are responsible for our state of mind.

However, the sun does emit radiation, which can have negative affects on our bodies. The most common negative effects are solar erythema (redness/irritation) sunstroke, allergies (rashes), photo-ageing (also known as actinic aging), eye diseases, a compromised immune system and, in very extreme cases, skin cancer.

The different types of radiation:

• Infrared light (calorific effect): Infrared light penetrates the hypodermis (subcutaneous tissue) and causes dilation of blood vessels.

• Visible light (luminous effect): the only type of radiation that the human eye can see. Visible light can penetrate the dermis.

• Ultraviolet light (biological effect): The electromagnetic waves of Ultraviolet light have frequencies higher than those that humans identify as violet color, hence their name. Ultraviolet light is made up of UVA, UVB and UVC wavelengths:
• UVA rays are known as The Tanning Rays (UVA is the dominant tanning radiation). They are the least damaging UV rays, they rarely cause erythema. UVA radiation is not absorbed by the ozone layer and 30% to 50% of these rays can reach the dermal layer of the skin. UVA rays are responsible for photo-ageing and studies indicate they can initiate the development of skin cancers of the epidermis (basal and squamous cell cancer).
• UVB rays are partially absorbed by the ozone layer and generate more energy than UVA rays. Their intensity is greatly influenced by time of the day, season and location. UVB rays are at their peak between 10 AM and 4 PM (Daylight saving time). They are especially intense at high altitudes and on reflective surfaces such as snow, which bounces back up to 85% of the rays. UVB radiation penetrates the epidermis, contributes to tanning and stimulates the body into producing Vitamin D. However, overexposure to UVB radiation can cause sunburn, photo-aging and several forms of skin cancer (melanoma, squamous cell cancer and basal cell carcinoma).
• UVC are the most dangerous UV rays but they do not reach the Earth’s surface as they are completely absorbed by the ozone layer (at present - however, the ozone layer is depleting by 0.5% every year due to the accumulation of CFCs, chlorofluorocarbons). UVC rays do have powerful antibacterial properties (an artificial form is still being used in sterilizers).

Solar radiation can be extremely detrimental if we don’t take the preventative measures to protect our skin - the most important of these being daily sunscreen application. However, there are sunscreens and sunscreens - some natural, some chemical, some physical, some preferable, some not so much… In Ishtar’s next installment, she’ll be discussing the merits of different types of sun protection available, so check back with us soon for that.