Sunsense: Protecting Yourself from Ultraviolet Radiation
Where does UVR come from?
Ultraviolet radiation (UVR) is produced by the sun and by some artificial sources. The human eye cannot see it. Solar UVR which could reach the earth's surface is subdivided into two types. These are UVB and the less energetic UVA. Some people are also exposed to UVR at work, as a medical treatment or by using sunbeds.
Is UVR harmful?
The main source of human exposure to UVR is the sun. UVR can damage DNA in cells on the surface of the body. UVR causes the skin to burn. The skin may react to UVR exposure by tanning. It can increase the risk of developing skin cancer (melanoma, squamous cell skin cancer and basal cell cancer). Intense UVR exposure can inflame the eyes. Long-term exposure may cause cataracts. These effects can take many years to develop so overexposure now may increase risks in later life. UVR causes skin ageing and, in many people, troublesome photosensitivity rashes. It may also affect the immune system in the skin, although the consequences of this are not certain yet. The incidence of skin cancer is rising. There are now about 40,000 new cases and nearly 2,000 deaths from skin cancer in the UK each year.
Surely, sunlight can be beneficial to health too?
Exposing the skin to UVR produces vitamin D. This benefit only needs the amount of outdoor exposure people get as part of daily life. It may be more important for health in dark-skinned people with vitamin D deficient diets. Many people 'feel better' out in the sunshine. You can keep these benefits of sunshine without increasing the health risks by following our Sunsense Guide below.
Are some types of UVR less harmful?
We do know that UVB is the main cause of sunburn. UVA is thought to cause skin ageing. We do not yet know enough to say which types of UVR cause cancer. The International Agency for Research on Cancer, which is part of the World Health Organization, classifies all UVR as carcinogenic (cancer-causing) to experimental animals.
Is sunburn dangerous?
Although there is limited evidence whether sunburn directly causes cancer, sunburn is a sign that the skin has been damaged. Your risk of melanoma (the main cause of death from skin cancer) is related, among other things, to the number of times you have had intense exposure to UVR. Such exposures may be particularly damaging in children, although skin cancers usually develop in adult life.
I have a suntan, does that protect me?
A suntan is a sign that the skin has already been exposed to UVR and is trying to protect itself from further harm. People with naturally dark or tanned skin can still suffer sunburn. A suntan only offers modest protection against further exposure.
Who is most at risk of UVR damage?
UVR damage occurs most easily in fair-skinned people and others who burn easily in the sun. Even dark-skinned people can get sunburnt. Everyone is at risk from UVR damage to the eyes.
How does UVR damage the eyes?
One-off intense exposure (as in snow blindness) can cause intense inflammation in the eye. High levels of exposure over a long time may increase your risk of a number of eye diseases including cataract.
Are there any other effects of UVR?
UVR can affect the immune system. The long-term consequences of this are not known. Some people find that cold sores are reactivated after exposure to UVR.
Why is it so important to protect children?
Children have many years ahead of them. Their skin needs to be protected from damage when they are young. This may help to reduce their risks of cancer and eye disease in adult life. Children cannot be expected to take responsibility for sun protection themselves. Carers of children have a responsibility to protect the skin and eyes of their young charges.
Are sunbeds safe?
Sunbeds emit UVR. Sunbeds cause tanning and can cause sunburn. There is no evidence to suggest that any type of sunbed is less harmful than natural sun exposure. The HPA discourages the use of sunbeds for cosmetic tanning. Sunbeds should never be used by anyone under 18 years of age. If you are over 18 years of age and wish to use a sunbed then use a facility that provides guidance to users. Limit your use of the sunbed - don't have repeated sessions to build up a quick tan before a summer holiday.
How can I enjoy the sunshine without the risks of UVR?
The first line of defence is to know your skin type and keep alert for weather reports predicting that the global solar UV index will be 3 or more which can damage sensitive skin. This will let you plan adequate protection to be out and about on days when sunlight could damage your skin or eyes. A solar index of 6 or more is considered high.
Know your skin type
Which of the following best describes your skin's reaction to sun exposure?
a. White skin that always sunburns easily, never or minimally suntansb. White skin that sunburns and suntans moderately
c. White skin that sunburns minimally and suntans easily to a mid-brown colour
d. Brown skin that rarely sunburns and suntans well
e. Dark brown or black skin that almost never sunburns
| Global solar UV index | Approximate time for sunburn to begin in skin type a |
|---|---|
| 1 | sunburn unlikely |
| 2 | 1 hour |
| 3 | 50 minutes |
| 4 | 40 minutes |
| 5 | 30 minutes |
| 6 | 25 minutes |
| 7 | 20 minutes |
| 8 or more | less than 20 minutes |
The next line of defence is to protect the skin and eyes by seeking shade or wearing clothing, wide brimmed hats and wrap-around sunglasses. The best clothing is loose fitting with a close weave. The third line of defence is sunblock or broad-band sunscreen (at least SPF 15). It should be used generously and applied frequently to areas that cannot be shaded from the sun with clothing. If used correctly, sunscreens will prevent sunburn. However, if you use them in order to stay out longer in the sun, you may partially or entirely lose the benefits in terms of protection from UVR exposure.
The final line of defence is early detection of skin cancer. Remember the signs of early melanoma and check yourself and your family.
You should consult a doctor if you develop a major sign or a number of minor signs of melanoma
Major signs of malignant melanoma
- A mole with three or more shades of brown and black.
- An existing mole getting bigger or developing an irregular outline.
- A new mole growing quickly (months) in an adult.
Minor signs of malignant melanoma
- A mole that is larger than the blunt end of a pencil.
- A mole becoming inflamed or developing a reddish edge.
- A mole that develops bleeding, oozing or crusting.
- A mole starting to feel different (e.g. itching or painful).
Ten ways to minimise UVR-induced skin and eye damage: the HPA sunsense guide
- Take sensible precautions to avoid sunburn, particularly in children.
- Remember that a suntan offers only modest protection against further exposure. It is not an indication of good health.
- Limit unprotected personal exposure to solar radiation, particularly during the four hours around midday, even in the UK.
- Seek shade, but remember sunburn can occur even when in partial shade or when cloudy.
- Remember that overexposure of skin and eyes can occur while swimming and is more likely when there is a high level of reflected UVR, such as from snow and sand.
- Wear suitable head wear, such as a wide-brimmed hat, to reduce exposure to the face, eyes, head and neck.
- Cover skin with clothing giving good protection - examples are long-sleeved shirts and loose clothing with a close weave.
- Sunglasses should exclude both direct and peripheral exposure of the eye to UVR, i.e. be of a wrap around design.
- Apply sunblocks, or broad-band sunscreens with high sun protection factors (at least SPF 15) to exposed skin. Apply generously and reapply frequently, especially after activities that remove them, such as swimming or towelling.
- Remember that certain individuals have abnormal skin responses to UVR and may need medical help. Certain prescribed drugs, medicines, foods, cosmetics and plant materials can also make people more sensitive to sunlight.
Where has this advice come from?
This advice is based on a report by the National Radiological Protection Board (NRPB) expert Advisory Group on Non-Ionising Radiation (AGNIR). NRPB was an independent body that was set up by the Government in 1970 to provide advice on protection from radiation. In April 2005 NRPB merged with the Health Protection Agency (HPA) and now forms the Radiation Protection Division of the HPA. The AGNIR consists of UK experts who have reviewed all the science. The report considers what is known about the health effects of UVR and how you can protect against them.
The Sun Protection Factor (SPF) is the ratio of the UVR exposure to produce minimal reddening of the skin on a site protected by sunscreen to the UVR exposure to produce a comparable reddening on unprotected skin. An SPF of 10 would reduce exposure to 10% of that of unprotected skin.
March 2004
(revised May 2006)
Last reviewed: 7 December 2007