Why should one protect one's skin from the sun?
It is vital to protect skin and eyes from the damaging effect of the sun because exposure to ultraviolet radiation contributes to ageing skin and is the main cause of skin cancer. Some people may need to take particular care because of photosensitivity.
No matter what the weather, or what you are doing, cover up! Take particular care in summer – between September and May in New Zealand – especially between 11 am and 4 pm. Make sure your children are protected as well as yourself.
You should also be careful to protect your skin if you are at high altitude in any season, particularly when in the snow because it reflects extra ultraviolet radiation onto your skin.
The maps below demonstrate the variation in ultraviolet radiation according to the time of day and cloudiness in mid-summer, and the variation according to the time of year. The 15-minute and 30-minute burn times are also shown.
Data collected at Waikato Hospital 1989
In recent years, publication of the Global Solar Ultraviolet Index has become the standard way to determine the risk of sunburn.
How should one protect oneself?
- Wear closely-woven covering clothing. Choose long sleeves, long trousers, or a long skirt.
- Look out for clothing with a label stating its UPF (protection factor) is greater than 40. Tests have shown sun clothing blocks ultraviolet radiation very effectively (much better than sunscreens). However, normal fabrics are also protective.
- Put on a broad-brimmed hat.
- Try to keep in the shade or carry an umbrella.
- Apply a sunscreen to all uncovered skin before you go out.
- Consider taking an oral supplement that offers photoprotection, such as Polypodium leucotomas or nicotinamide.
A little sun exposure is necessary for the production of vitamin D, which is essential to balance calcium levels and to make strong bones. However, regular use of sunscreens does not result in vitamin D deficiency in Australasia.