Some sun exposure - below the level of sunburn - can be beneficial through helping your body create vitamin D and promoting feelings of general well being. However, excessive sun exposure is associated with:
- skin cancer
- photosensitive rashes
- aggravation of existing conditions such as rosacea and eczema
- premature skin ageing.
The risk of sunburn is increased when, in addition to direct exposure from the sun, Ultra Violet (UV) radiation is also reflected. For example, the sun is reflected from water when swimming, and from white sand or snow. The risk is also greater at higher altitudes when there is less protection from the earth's atmosphere.
Effects of UV Radiation
Excessive exposure to UV radiation, particularly from a young age, is the main cause of melanoma and non-melanoma skin cancers. UV exposure that has caused sunburn is most harmful, but frequent non-burning exposures are also damaging.
UV is transmitted in three wavelengths; UVA, UVB and UVC. UVC does not penetrate the earth's atmosphere but you still need to protect your skin against UVA and UVB.
UVB is the form of UV radiation most responsible for sunburn and has strong links to malignant melanoma and basal cell carcinoma. UVB protection in sunscreen helps prevent sunburn.
UVA is the form of UV radiation that affects the skins elastin, leading to premature skin ageing and sun-induced skin damage. UVA protection in a sunscreen helps defend the skin against photo ageing.
Sunscreens are products combining several ingredients that help prevent the sun's UV radiation from damaging your skin. In the UK, sunscreens are labelled with an ‘SPF’, this stands for ‘sun protection factor’ and it shows the level of protection against UVB, not the protection against UVA.
SPFs are categorised as providing low to very high protection, this is intended to make the SPF number easier to understand. The table below illustrates this:
|Level of Protection||SPF Numbers|
|Low protection||SPF 6 and 10|
|Medium protection||SPF 15, 20 and 25|
|High protection||SPF 30 and 50|
|Very high protection||SPF 50+|
In the UK, the UVA star rating ranges from 0 to 5 and indicates the percentage of UVA radiation absorbed by the sunscreen in comparison to UVB, in other words the ratio between the level of protection afforded by the UVA protection and the UVB protection. It is therefore advisable to choose a ‘broad spectrum’ sunscreen with high SPF as well as a UVA rating of 4 or 5 stars.
The following people should take extra care to avoid UV skin damage:
- babies and children
- fair skinned people
- people with red or fair hair
- people with light coloured eyes
- people with lots of freckles or moles
- anyone with a previous history of sunburn
- anyone that has used sun beds
- anyone with a personal or family history of skin cancer
- anyone with certain medical conditions such as albinism, or those that are immunocompromised
- anyone taking drugs which may increase photosensitivity, such as tetracyclines (including doxycycline), oral hypoglycaemic drugs and diuretics.
The safest way to enjoy the sun and protect your skin from sunburn is to use a combination of shade, clothing and sunscreen:
- seek shelter; avoid sun exposure between 11am and 3pm when sun is typically stronger
- cover up using clothing such as wide brimmed hat and long sleeved tops, closed weaved fabrics may offer better sun protection
- use sunscreen properly (see below)
- wear sunglasses with wraparound lenses or wide arms with the CE Mark and European Standard EN 1836:2005.
- babies under 6 months of age should be kept out of direct strong sunlight
- infants and children should be well protected at all times
- extra care is required for those with fair skin, light coloured eyes, fair or red hair, freckles or moles.
Additionally, The British Association of Dermatologists recommends that you tell your doctor about any changes to a mole. If your GP is concerned they should refer you to a Consultant Dermatologist (on the GMC register of specialists).
Most people apply less than half of the amount of sun screen required to provide the level of protection indicated on the packaging and areas of skin are commonly missed. Use a sunscreen of at least SPF 15 (UVB protection) and 4 stars (UVA protection); the brand of sunscreen makes no difference so long as it has these properties.
- Apply sunscreens generously; it takes at least six full teaspoons (approximately 36 grams) to cover the body of an average adult, this is over half a teaspoon of sunscreen to each arm and the face/neck (including ears), and over one teaspoon to each leg, front of body and back of body. This is the amount used when products are tested for their SPF (it equates to 2 mg /cm²).
- Apply sunscreen to ALL sun exposed areas.
- Get the timing right: sunscreen needs to be applied 20 - 30 minutes before sun exposure.
- Reapply after washing or being in water; even water resistant sunscreen needs to be reapplied after being in water.
- Sunscreen should be applied and allowed to absorb before application of insect repellents, moisturisers and make-up.
- Store sunscreen out of the heat and check the expiry date.
Remember, sunscreen alone does not offer full protection and should be used in combination with clothing and shade.
Note: Some sun protection products offer 8+ hours of protection from one application. Once-a-day sun protectors do not account for poor application or removal through sweating, showering or swimming. Consequently, if a section of skin is accidentally missed during the initial application or sunscreen is accidentally removed the skin may be subjected to unsafe sun exposure.
- Cancer Research UK offer a variety of free resources on sun, UV and cancer.