UVC Radiation

Taking these in reverse order, UVC has the shortest wavelength and although it is potentially very harmful to our skin, it is completely filtered out by the earth’s atmosphere and so does not affect us.

UVB Radiation

UVB radiation is the one that causes the appearance of a tan after sun exposure. It does this by stimulating the formation of the pigment ‘melanin’ in the deeper layers of the skin and activates it’s movement to the outer skin layers. Here it acts as an antioxidant and skin protector – it is in fact part of our natural defence against sun damage.

UVB radiation also causes thickening of the outer layers of the skin, and if exposure is taken to excess is what causes sun-burn. This should be avoided at all costs, particularly by children, as it is thought that sun-burn in early years may lead to an increased risk of skin cancer later in life.

UVA Radiation

UVA radiation is potentially the most damaging form as it penetrates deeper into the skin. In the deep basal layers of the skin UVA can damage the DNA that makes up the blueprint of each cell, and can result in mutated cells that no longer reproduce properly. This in turn may be a primary cause of some skin cancers, although they may take years or even decades to manifest themselves.

UVA also damages structures made from or containing collagen and elastin and this is one of the main causes of wrinkles and premature ageing in skin that is often exposed to sunlight.

General Advice

The general advice given to adults who are going to be exposed to sunlight can be summed up in the now famous Australian adage of ‘Slip, Slop, Slap’ – Slip on a Shirt, Slop on a Hat, Slap on some Sun-cream. Clearly, all three of these actions are designed to reduce exposure to sunlight and therefore minimise the risks involved.

Further advice is to avoid exposure to the sun when it as its strongest – between mid-day and three in the afternoon. When you think about it, this is the traditional time when many Mediterranean countries have lunch followed by a Siesta – both taken indoors thereby avoiding the worst effects of the sun.

SPF, an abbreviation for sun-protection factor, is a number such as 15, 30, or 50 that indicates how long a topical sunscreen remains effective on the skin. A user can determine the duration of effectiveness simply by multiplying the SPF by the length of time it takes for him or her to suffer a burn without sunscreen.

Basal Cell Carcinoma  is a common form of skin cancer with almost 1 million cases each year in America. Treatment includes a procedure to remove the cancer, typically by cutting out the affected area or treating with a topical chemotherapy. If left untreated, the cancer will continue to grow. Individuals who have been diagnosed with basal cell carcinoma need sun protection to minimize UV exposure.

Bottom line – the sun is our friend.  We need it and it is wonderful for our spirits and our health. Enjoy it but safely and in moderation.