The Sun

Effects of the Sun

The sun makes life on earth possible, but it can also have harmful effects – especially without sufficient protection.

Immediate effects

Immediate pigmentation

The first colour-related effect of exposure to the sun is known as “immediate pigmentation”, or a colouring that appears during exposure and disappears within 2 hours. Caused by UVA and visible light, immediate pigmentation does not protect against sunburn.

Persistent pigment darkening  (PPD)

PPD appears during exposure and remains for up to several days. It is not protective.

Delayed effects

Sunburn 

If you don’t protect yourself from high doses of UV rays, these rays will start penetrating the layers of the skin. Eventually, blood vessels below the skin's surface will expand and leak fluids, causing inflammation and redness. Sunburn normally first appears 2–6 hours after the start of exposure, reaches its maximum intensity within 24–36 hours and disappears after 3–5 days.

Tanning (delayed pigmentation)

Tanning starts 3–5 days after exposure, when special skin cells called melanocytes start synthesising melanin, the body’s natural tanning pigment. Melanin is then transfered to neighbouring cells called keratinocyces, which are the main cell type in the epidermis, or upper layer of your skin. Unlike immediate pigmentation, actual tanning does help protect against the harmful effects of UV radiation. Tanning fades progressively, but remember that people with a natural suntan also need to apply sunscreen, as a tan does not provide sufficient protection from UV exposure.

Long Term effects 

Skin aging

Sun exposure plays a major role in the skin’s aging process. Up to 90% of all visible signs of aging can be attributed to the harmful effects of sun exposure. 

Skin cancer (malignant melanoma)

Skin cancer, or malignant melanoma, appears to be caused by damage to the DNA structure of skin cells that are exposed to the sun – with just 5% of all carcinomas occurring on areas of the skin that are not exposed. Damage to these skin cells leads to the growth of degenerated cells that in turn result in cancer. In Europe, skin cancer is far more prevalent in the north, where people’s skin tends to contain less pigmentation.

Accidental effects

Solar intolerances

The most common type of sun-induced skin eruption is the benign summer light eruption (BSLE). Particularly common among young women, BSLE appears as small, itchy papules on the throat, upper chest and back of the forearms. The condition appears within hours after intense sun exposure and disappears within a few days.