Ultraviolet Radiation: Solar Radiation and Human Health
Too much sun is dangerous
Sunlight, an essential prerequisite for life, may be extremely dangerous to human health. Excessive exposure to the sun is known to be associated with increased risks of various skin cancers, cataracts and other eye diseases, as well as accelerated skin ageing. It may also adversely affect people's ability to resist infectious diseases, and compromise the effectiveness of vaccination programmes.
Sunlight is electromagnetic energy, which is propagated by electromagnetic waves. Healthwise, the most important parts of the sunlight electromagnetic spectrum are: ultraviolet radiation ( UV ), invisible to the eye; visible light that allows us to see; and infrared radiation , which is our main source of heat but is also invisible. Excessive exposures to them poses particular risks to health.
Skin
Excessive UV exposure results in a number of chronic skin changes. These include various skin cancers of which melanoma is the most life-threatening; an increased number of moles ( benign abnormalities of melanocytes) and a range of other alterations arising from UV damage to keratinocytes and blood vessels. UV damage to fibrous tissue is often described as "photoageing". Photoageing makes people look older because their skin loses its tightness and so sags or wrinkles.
- United Nations Environment Programme (UNEP) has estimated that more than 2 million nonmelanoma skin cancers and 200,000 malignant melanomas occur globally each year.
- In the event of a 10% decrease in stratospheric ozone, an additional 300,000 nonmelanoma and 4,500 melanoma skin cancers could be expected worldwide.
- Caucasians have a higher risk of skin cancer because of the relative lack of skin pigmentation.
- The worldwide incidence of malignant melanoma continues to increase, and is strongly related to frequency of recreational exposure to the sun and to history of sunburn.
- There is evidence that risk of melanoma is also related to intermittent exposure to UV, especially in childhood, and to exposure to sunlamps. However, the latter results are still preliminary.
Eye
UV exposure of the eye depends on many factors: ground reflection, the degree of brightness in the sky leading to activation of the squint reflex, the amount of atmospheric refection, and the use of eyewear.
- The acute effects of UV on the eye include the development of photokeratitis and photoconjunctivitis, which are like sunburn of the delicate skin-like tissue on the surface of the eyeball (cornea) and eyelids. While painful, they are reversible, easily prevented by protective eyewear and have not been associated with any long-term damage.
- Chronic effects include the possible development of pterygium (a white or cream coloured opaque growth attached to the cornea), squamous cell cancer of the conjunctiva (scaly or plate-like malignancy) and cataracts.
- Some 20 million people worldwide are currently blind as a result of cataracts. Of these, WHO estimates that as many as 20% may be due to UV exposure. Experts believe that each 1% sustained decrease in stratospheric ozone would result in an increase of 0.5% in the number of cataracts caused by solar UV.
- Direct viewing of the sun and other extremely bright objects can also seriously damage the very sensitive part of the retina called the yellow spot, fovea or macula leutea. When cells of the fovea are destroyed, people can no longer view fine detail. This is a serious visual impairment making it impossible to read, sew, watch TV, recognise faces, drive a vehicle or do any task which requires recognition of fine details.
Immune system
UV also appears to alter immune response by changing the activity and distribution of the cells responsible for triggering these responses. A number of studies indicate that UV exposures at environmental levels suppress immune responses in both rodents and humans. In rodents, this immune suppression results in enhanced susceptibility to certain infectious diseases with skin involvement, and some systemic infections. Mechanisms associated with UV-induced immunosuppression and host defence that protect against infectious agents are similar in rodents and humans. It is therefore reasonable to assume that UV exposure may enhance the risk of infection and decrease the effectiveness of vaccines in humans. Additional research is necessary to substantiate this.
Thermal effects
Heating of tissues in the human body is the principal effect of infrared radiation. Excessive infrared radiation can result in heat strokes and other similar reactions particularly in elderly, infirm or very young individuals. At moderate levels of exposure, the warmth experienced from being in the sun is relaxing and restorative.
Protective measures
Methods for personal protection from solar UV exposure include adequate clothing, hats and the proper use of sunscreens to protect UV-exposed skin. For eye protection, UV absorbing sunglasses are needed.
Changes in behavior could minimize solar UV exposure. These include staying out of the sun, either indoors or in shaded areas, during the four-hour period around solar noon when UV levels are at their highest. During summer, when daylight saving time is in effect, solar noon in most of Europe is at 14.00 hours (2 p.m.); in the UK and countries with a similar longitude, it is at 13.00 hours (1 p.m.).
Broad-spectrum sunscreens should be used when other means of protection are not feasible, and then to reduce exposure rather than lengthen the period of exposure. While topical applications of sunscreen are preferred for absorbing UVB, some preparations do not absorb the longer wavelength UVA effectively. Moreover, some preparations have been found to contain ingredients that are mutagenic in sunlight. People using sunscreens should use those with a high sun protection factor (SPF) and be aware that they are to protect from the sun and not for tanning purposes.
The reflective properties of the ground have an influence on UV exposure. Most natural surfaces such as grass, soil and water reflect less than 10% of incident UV. However, fresh snow reflects nearly 80% while sand reflects 10-25%, significantly increasing UV exposure for skiers and bathers.
Global Solar UV Index
The Global Solar UV Index is an important tool developed through the work of the WHO INTERSUN Project to assist local authorities in giving guidance on the degree of protection to be used on any given day. It provides an estimate of the maximum solar UV exposure at the Earth's surface. While the intensity of UV reaching the ground varies during the day, it reaches a maximum, when there is no cloud cover, around mid-day. It is generally presented as a forecast of the maximum amount of skin-damaging UV expected to reach the Earth's surface at solar noon. The values of the Index range from zero upward and the higher the Index number, the greater the likelihood of skin and eye damaging exposure to UV, and the less time it takes for damage to occur.
In the most extreme environments close to the equator, summer-time values can range up to 20. During a European summer the Index is generally not more than about 8, but can be higher, especially at beach resorts. The following descriptions are usually associated with various values of the Index: Low UV exposure - 1 and 2; Moderate exposure - 3 and 4; High exposure - 5 and 6; Very high exposure - 7 and 8; Extreme exposure - greater than 9.
Recommendations on the description, calculation, and dissemination of the Global Solar UV Index were made in 1995 by WHO, the World Meteorological Organization (WMO), the United Nations Environment Programme (UNEP) and the International Commission on Non-Ionizing Radiation Protection (ICNIRP). National authorities throughout the world now use the Global Solar UV Index. These international organizations recommended that:
- The Global Solar UV Index should be used as a vehicle to raise public awareness of the potential harm of excessive UV exposure and to alert people about the need to adopt protective measures. This is especially important given the continuing decrease in stratospheric ozone and subsequent increase in UV intensities that cause increasingly severe UV-induced health effects;
- National governments should be encouraged to use the Global Solar UV Index as part of their public awareness and educational programmes;
- The news media should be encouraged to report the Global Solar UV Index with their daily weather information, so that people begin to accept this as something they need to know in addition to the news and weather.
Multiple UV indices
There has been a proliferation of indices in various countries, especially in Europe, that provide different measures of the levels of UV to which people are exposed from the sun. These UV indices may be promoted by some sun-screen or cosmetic manufacturers for commercial purposes or by local authorities unaware that there has been widespread acceptance of an international agreement on the use of the Global Solar UV Index. Using the standardized Global Solar UV Index at the same time as other UV indices may, however, lead to public confusion about the important health messages related to different Global Solar UV Index values. The purpose of the Global Solar UV Index is to provide uniform information to the public about daily UV exposure levels so that consistent messages can be provided on what protective measures are necessary with various index values.
INTERSUN - the Global UV Project
The consequences of increased UV exposure were a major topic for discussion at the United Nations Conference on the Environment and Development, held in Rio de Janeiro in 1992. Agenda 21, adopted by the Conference, recommended as a matter of urgency that research be undertaken on the health effects of UV exposure and that appropriate measures be taken to mitigate them. Further to this recommendation the Global UV Project "INTERSUN" was launched in 1993.
The objectives of INTERSUN are to:
- Collaborate with specialist agencies to implement key research related to human health and environmental effects from UV exposure;
- Develop reliable predictions of health and environmental consequences of changes in UV exposure with stratospheric ozone depletion;
- Develop practical ways of monitoring change in UV-induced health effects over time in relation to environmental and behavioral change; and
- Provide practical advice and information to national authorities on health and environmental effects of UV exposure; Means of efficiently disseminating this information, particularly through use of a Global Solar UV Index; Measures to protect the general public, workers and the environment against the adverse effects of increased UV exposure.
- INTERSUN is a collaborative project between WHO, UNEP, the International Agency for Cancer Research (IARC), the International Commission on Non-ionizing Radiation Protection (ICNIRP), the World Meteorological Organization (WMO) and national authorities in the WHO Member States.
Ultraviolet radiation and health
What is UV radiation?
Everyone is exposed to UV radiation from the sun and an increasing number of people are exposed to artificial sources used in industry, commerce and recreation. Emissions from the sun include visible light, heat and UV radiation.
The UV region covers the wavelength range 100-400 nm and is divided into three bands:
- UVA (315-400 nm)
- UVB (280-315 nm)
- UVC (100-280 nm).
As sunlight passes through the atmosphere, all UVC and approximately 90% of UVB radiation is absorbed by ozone, water vapour, oxygen and carbon dioxide. UVA radiation is less affected by the atmosphere. Therefore, the UV radiation reaching the Earth's surface is largely composed of UVA with a small UVB component.
Environmental factors that influence the UV level
- Sun height-the higher the sun in the sky, the higher the UV radiation level. Thus UV radiation varies with time of day and time of year, with maximum levels occurring when the sun is at its maximum elevation, at around midday (solar noon) during the summer months.
- Latitude-the closer the equator, the higher the UV radiation levels.
- Cloud cover- UV radiation levels are highest under cloudless skies. Even with cloud cover, UV radiation levels can be high due to the scattering of UV radiation by water molecules and fine particles in the atmosphere.
- Altitude-at higher altitudes, a thinner atmosphere filters less UV radiation. With every 1000 metres increase in altitude, UV levels increase by 10% to 12%.
- Ozone-ozone absorbs some of the UV radiation that would otherwise reach the Earth's surface. Ozone levels vary over the year and even across the day.
- Ground reflection-UV radiation is reflected or scattered to varying extents by different surfaces, e.g. snow can reflect as much as 80% of UV radiation, dry beach sand about 15%, and sea foam about 25%.
|
 |
Ozone depletion and UV-related health effects
Depletion of the ozone layer is likely to aggravate existing health effects caused by exposure to UV radiation, as stratospheric ozone is a particularly effective UV radiation absorber. As the ozone layer becomes thinner, the protective filter provided by the atmosphere is progressively reduced. Consequently, human beings and the environment are exposed to higher UV radiation levels, and especially higher UVB levels that have the greatest impact on human health, animals, marine organisms and plant life.
Computational models predict that a 10% decrease in stratospheric ozone could cause an additional 300,000 non-melanoma and 4500 melanoma skin cancers and between 1.6 and 1.75 million more cases of cataracts worldwide every year. |
|
Ultraviolet Radiation: Global Solar UV Index
An educational tool to reduce risks of skin cancer and cataract
Everyone is exposed to ultraviolet (UV) radiation from the sun. Small amounts of UV radiation are beneficial to people, and play an essential role in the production of vitamin D. However, overexposure to UV radiation is responsible for two major public health problems: skin cancer and cataract.
UV radiation
Emissions from the sun include light, heat and UV radiation. UV radiation reaching the Earth's surface is largely composed of UVA with a small UVB component. UV radiation levels are influenced by:
- Sun elevation: the higher the sun in the sky, the higher the UV radiation level.
- Thus UV radiation levels vary with time of day and time of year.
- Latitude: the closer to equatorial regions, the higher the UV radiation levels.
- Cloud cover: UV radiation levels are highest under cloudless skies but even with cloud cover, they can be high.
- Altitude: at higher altitudes, a thinner atmosphere absorbs less UV radiation.Ozone: ozone absorbs some of the UV radiation that would otherwise reach the Earth's surface.
- Ground reflection: grass, soil and water reflect less than 10% of UV radiation; fresh snow reflects as much as 80%; dry beach sand about 15% and sea foam about 25%.
Sun elevation: the higher the sun in the sky, the higher the UV radiation level. Thus UV radiation levels vary with time of day and time of year.Latitude: the closer to equatorial regions, the higher the UV radiation levels.Cloud cover: UV radiation levels are highest under cloudless skies but even with cloud cover, they can be high. Altitude: at higher altitudes, a thinner atmosphere absorbs less UV radiation.Ozone: ozone absorbs some of the UV radiation that would otherwise reach the Earth's surface. Ground reflection: grass, soil and water reflect less than 10% of UV radiation; fresh snow reflects as much as 80%; dry beach sand about 15% and sea foam about 25%.
As UV radiation can neither be seen nor felt, it is important to provide a tool to raise awareness of the problem and alert people on a daily basis to take prompt, appropriate, protective action.
The Global Solar UV Index (UVI)
The UVI is a simple measure of the UV radiation level at the Earth's surface. It has been designed to indicate the potential for adverse health effects and to encourage people to protect themselves. The values of the Index range from zero upward and the higher the Index value, the greater the potential for damage to the skin and eye, and the less time it takes for harm to occur.
While the levels of UV radiation vary during the day, they reach a maximum around mid-day. The UVI is usually presented as a forecast of the maximum amount of UV radiation expected to reach the Earth's surface at solar noon. In countries close to the equator, the UVI can reach up to 20. Summer-time values in Northern latitudes rarely exceed 8.
An internationally harmonized UV index
The UVI was developed through an international effort by WHO in collaboration with the United Nations Environment Programme (UNEP), the World Meteorological Organization (WMO), the International Commission on Non-Ionizing Radiation Protection (ICNIRP), and the German Federal Office for Radiation Protection. Since its initial publication in 1995, many countries have been using the UVI to promote sun protection along with the weather forecast in newspapers, TV and radio. However, most people have not fully understood its meaning or usefulness, and UVI reporting and associated protection messages differed greatly between countries, creating confusion.
INTERSUN, WHO's Global UV project, has developed and introduced an internationally agreed communication concept to ensure uniformity of sun protection messages, to facilitate the delivery of a simple and relevant message and to improve its use as an educational tool. The concept is published in a WHO booklet Global Solar UV Index: a Practical Guide. The following harmonized exposure categories and colours are associated with various values of the UVI:
| Category |
UVI range |
Colour |
Low
Moderate
High
Very high
Extreme
|
0 to 2
3 to 5
6 to 7
8 to 10
= 11
|
Green
Yellow
Orange
Red
Purple
|
A standard graphic presentation of the UVI promotes consistency in reporting and improves people's understanding of the problem. The graphics package can be downloaded from the web site of INTERSUN, the Global UV Project, at http://www.who.int.uv/.
Summary of major health concerns
Exposure to the sun is known to be associated with different types of skin cancer, accelerated skin ageing, cataract and other eye diseases. There is also evidence that UV radiation reduces the effectiveness of the immune system.
Skin
Between 2 and 3 million non-melanoma skin cancers and over 130,000 malignant melanomas occur globally each year. A changing lifestyle and sun-seeking behaviour are responsible for much of the increase in skin cancers. In particular, frequent sun exposure and sunburn in childhood appear to set the stage for high rates of melanoma later in life. Depletion of the ozone layer, which provides a protective filter against UV radiation, may further aggravate the problem. Other chronic skin changes due to UV radiation include injuries to skin cells, blood vessels and fibrous tissue, better known as skin ageing.
Eye
Acute effects of UV radiation on the eye include photokeratitis, an inflammation of the cornea and iris, and photoconjunctivitis, an inflammation of the conjunctiva, the membrane that lines the inside of the eyelids. Long-term effects of UV radiation exposure of the eye may include the development of pterygium (white or creamy opaque growth attached to the cornea), and squamous cell cancer of the conjunctiva. Some 16 million people worldwide are currently blind as a result of cataracts; of these, WHO estimates that as many as 20% may be due to UV radiation exposure.
Immune system
The immune system is vulnerable to modification by environmental agents such as UV radiation, which appears to diminish the effectiveness of the immune system by changing the activity and distribution of the cells responsible for triggering immune responses. A number of studies indicate that environmental levels of UV radiation can suppress immune responses in both rodents and humans. In rodents, this immune suppression results in enhanced susceptibility to certain infectious diseases. It is therefore reasonable to suspect that exposure to UV radiation may enhance the risk of infection and decrease the effectiveness of vaccines in humans. However, additional research is necessary to substantiate this.
Vulnerable groups
Vulnerable groups Children are particularly sensitive to UV radiation and require special protection. More than 90% of non-melanoma skin cancers occur in fair skinned people who tend to burn. However, even though the incidence of skin cancer is lower in dark skinned people they are nevertheless susceptible to the damaging effects of UV radiation, especially to the effects on the eye and immune system.
Protective measures
Simple precautions will prevent both short-term and long-term damage of UV radiation exposure, while still making the time spent outdoors enjoyable. Sun protection is important in all settings, in particular at all outdoor recreation sites such as beaches and sports centres.
The basic sun protection messages
- Limit exposure during midday hours.
- Seek shade.
- Wear protective clothing.Wear a broad brimmed hat to protect the eyes, face and neck.
- Protect the eyes with wrap-around-design sunglasses or sunglasses with side panels.
- Use and reapply broad-spectrum sunscreen of sun protection factor (SPF) 15+ liberally.
- Protect babies and young children.
Staying out of the sun, either indoors or in shaded areas, during the four hour period around solar noon when UV radiation levels are highest is an effective means of protection. It should be combined with using clothing, hats and sunglasses. Sunscreen should be applied to parts of the body that remain exposed, like the face and hands. However, sunscreen represents a last line of defence, and should never be used to prolong the duration of sun exposure.
Some common myths:
| False |
True |
| A sun tan is healthy. |
A tan results from your body defending itself against further damage from UV radiation. |
| A tan protects you from the sun. |
A dark tan on white skin only offers an SPF of about 4. |
| You can't get sunburnt on a cloudy day. |
Up to 80% of solar UV radiation can penetrate light cloud cover. Haze in the atmosphere can even increase UV radiation exposure. |
| You can't get sunburnt while in the water. |
Water offers only minimal protection from UV radiation, and reflections from water can enhance your UV radiation exposure. |
| UV radiation during the winter is not dangerous. |
UV radiation is generally lower during the winter months, but snow reflection can double your overall exposure, especially at high altitude. |
| Sunscreens protect me so I can sunbathe much longer. |
Sunscreens are not intended to increase sun exposure time but to increase protection during unavoidable exposure. The protection they afford depends critically on their correct application. |
| If you take regular breaks during sunbathing you won't get sunburnt. |
UV radiation exposure is cumulative during the day. |
| If you don't feel the hot rays of the sun you won't get sunburnt. |
Sunburn is caused by UV radiation which cannot be felt. Most of the heating is caused by the sun's visible and infrared radiation and not by UV radiation. |
INTERSUN
INTERSUN, the Global UV project, is a collaborative project between WHO, UNEP, WMO, the International Agency on Cancer Research (IARC) and ICNIRP that aims to reduce the burden of disease resulting from exposure to UV radiation. The project assesses and quantifies health risks, and develops an appropriate response through guidelines, recommendations and information dissemination. Beyond its scientific objectives, INTERSUN provides guidance to national authorities and other agencies about effective sun awareness programmes. These address different target audiences such as occupationally exposed people, tourists, school children and the general public. For further information on INTERSUN refer to our web site: www.who.int/peh-uv
Sunbeds, tanning and UV exposure
The desire to acquire a tan for fashion or cosmetic purposes has led to a large increase in the use of artificial tanning sunbeds in, mostly, developed countries. Use of sunbeds for tanning continues to increase in popularity, especially among young women.
Sunbeds used in solariums, and sun tanning lamps, are artificial tanning devices that claim to offer an effective, quick and harmless alternative to natural sunlight. However, there is growing evidence that the ultraviolet (UV) radiation emitted by the lamps used in solariums may damage the skin and increase the risk of developing skin cancer.
Some 132 000 cases of malignant melanoma (the most fatal kind of skin cancer) and over two million cases of other skin cancers occur worldwide each year. One in every three cancers diagnosed worldwide is a skin cancer. Most skin cancers are attributable to over-exposure to natural UV radiation. A fact sheet indicating the adverse health consequences from natural (i.e., sun) UV exposure issued by the World Health Organization (WHO) can be found at the link to the right.
This fact sheet is the complement of the above, providing information on artificial sources of UV. Primary among these artificial sources is sunbeds, and this fact sheet looks at the health consequences of sunbed usage and how they can be managed. Information for this fact sheet comes from WHO sponsored meetings and workshops, recent scientific literature, reviews by WHO Member States and the recommendations of international NGOs.
Protecting children from ultraviolet radiation
Children are in a dynamic state of growth, and are therefore more susceptible to environmental threats than adults. Many vital functions such as the immune system are not fully developed at birth, and unsafe environments may interfere with their normal development. But most environmental hazards are preventable: reducing exposure is the most effective way of protecting children's health.
Ultraviolet radiation and ozone depletion
Ultraviolet (UV) radiation is one component of solar radiation. It is progressively filtered as sunlight passes through the atmosphere, in particular by the ozone layer.
As the ozone layer is depleted, the protective filter activity of the atmosphere is reduced and more UV radiation, in particular the more harmful UVB, reaches the Earth's surface. In the year 2000, the ozone hole over the Antarctic reached its biggest size ever covering 11.4 million square miles - an area more than three times the size of the United States. For the first time it also stretched over populated areas exposing local residents to extreme levels of solar UV radiation. Local authorities warned residents in Southern Chile that they could sunburn in less than seven minutes and should avoid spending time outdoors in the middle of the day.
Sustained ozone depletion and enhanced levels of UV radiation on Earth will aggravate UV effects on the human skin, eyes and immune system. Children are at especially high risk of suffering damage from exposure to UV radiation.
Health effects of sun exposure: a global concern
UV radiation causes sunburn and skin cancer and accelerates skin ageing. Overexposure to UV radiation can lead to inflammations of the cornea and the conjunctiva in the eye, and causes or accelerates cataract development. A health issue of growing concern is that UV radiation can reduce the effectiveness of the human immune system. Consequently, sun exposure may enhance the risk of infection and could limit the efficacy of immunization against disease. Both of these act against the health of poor and vulnerable groups, especially children of the developing world, as many developing countries are located close to the equator and hence exposed to very high levels of UV radiation.
Skin cancer has become the focus of intervention campaigns in Australia, Europe and North America. Many believe that only fair-skinned people need to be concerned about overexposure to the sun. Although it is true that darker skin has more protective pigment, the skin is still susceptible to the damaging effects of UV radiation. The incidence of skin cancers is lower in dark-skinned people, nevertheless skin cancers occur and are often detected at a later, more dangerous stage. The risk of other UV-related health effects, such as eye damage, premature ageing of the skin, and immunosuppression is independent of skin type. For example, a 10% decrease in total stratospheric ozone is predicted to result in between 1.6 and 1.75 million additional cases of cataract per year worldwide .
Skin cancer incidence on the rise
Between 2 and 3 million non-melanoma skin cancers and approximately 132,000 malignant melanomas occur globally each year. With a sustained 10% decrease in stratospheric ozone, an additional 300,000 non-melanoma and 4,500 melanoma skin cancers could be expected world-wide, according to UNEP estimates. Currently, one in five North Americans and one in two Australians will develop some form of skin cancer in their lifetime.
People's behaviour in the sun is the main cause for the rise in skin cancer rates in recent decades. An increase in popular outdoor activities and changed sunbathing habits often result in excessive UV exposure. Many people consider intensive sunbathing to be normal and unfortunately, even many children and their parents perceive a suntan as a symbol of attractiveness and good health. However, a suntan is merely a sign of UV damage and represents the skin's defence to prevent further harm.
Children require special protection
The United Nations Convention on the Rights of the Child states that children, including all developmental stages from conception to age 18, have the right to enjoyment of the highest attainable standard of health and to a safe environment. Children require special protection as they are at a higher risk of suffering damage from exposure to UV radiation than adults, in particular:
- A child's skin is thinner and more sensitive and even a short time outdoors in the midday sun can result in serious burns.
- Epidemiological studies demonstrate that frequent sun exposure and sunburn in childhood set the stage for high rates of melanoma later in life.
- Children have more time to develop diseases with long latency, more years of life to be lost and more suffering to be endured as a result of impaired health. Increased life expectancy further adds to people's risk of developing skin cancers and cataracts.
- Children are more exposed to the sun. Estimates suggest that up to 80 per cent of a person's lifetime exposure to UV is received before the age of 18 .
- Children love playing outdoors but usually are not aware of the harmful effects of UV radiation.
Caring for children in the sun
According to an Australian study, four out of five cases of skin cancer are preventable by sensible behaviour. Encouraging children to take simple precautions will prevent both short-term and long-term damage while still allowing them to enjoy the time they spend outdoors. Parents should serve as role models, and it is their responsibility to ensure that their children are protected adequately. Always keep infants of less than 12 months in the shade and make sure your children:
- Cover up with protective clothing, a hat and sunglasses.
- Apply broad-spectrum sunscreen of SPF 15+.
- Limit their time in the midday sun.
- Seek shade.
- Avoid sunlamps and tanning parlours.
Shade, clothing and hats provide the best protection for children -- applying sunscreen becomes necessary on those parts of the body that remain exposed like the face and hands. Sunscreen should never be used to prolong the duration of sun exposure.
Sun protection is relevant in all settings
Sun protection is not only necessary on the beach or at the swimming pool but applies to all outdoor settings. In many situations sunburn arises because people do not realize the need for protection. Children can be exposed to intense sunlight on the balcony at home, on weekend trips or a visit to the zoo, during breaks at kindergarten or school, and during outdoor sporting activities.
Particular attention should be paid in the mountains, as UV levels increase by approximately 8 per cent with every 1000 meters altitude. Although UV radiation is most intense under cloudless skies it may be high even on an overcast day. Many surfaces such as snow, sand and water reflect the sun's rays and add to the overall UV exposure.
Sun protection programmes can make a difference
Sun protection programmes to raise awareness and achieve changes in life-style is urgently needed to slow down and eventually reverse the trend towards more and more skin cancers. An effective campaign can have an enormous impact on public health: the regular use of sunscreen with sun protection factor 15 or higher up to the age of 18 could decrease the frequency of skin cancer in Australia by more than 70 per cent. Beyond the health benefits, effective education programmes can significantly decrease costs in the health system and strengthen the economy. Current prevention campaigns in Australia invest approximately US$ 0.08 per person per year, while the direct costs of skin cancer treatment have been estimated at US$ 5.70 per head of the population during the same period of time.
WHO's Activities to promote children's sun protection
INTERSUN Project
INTERSUN, WHO's Global UV Project aims to reduce the burden of disease resulting from exposure to UV radiation. The programme encourages and evaluates research to fill gaps in scientific knowledge, assesses and quantifies health risks, and develops an appropriate response through guidelines, recommendations and information dissemination. Beyond its scientific objectives, INTERSUN provides guidance to national authorities and other agencies about effective sun awareness programmes. These address different target audiences such as occupationally exposed people, tourists, school children and the general public. The programme is working towards the development of a framework for children's sun protection education that comprises an educational package as well as recommendations on best practices.
Global Solar UV Index
The UV Index (UVI) was developed by WHO, the United Nations Environment Programme, and the World Meteorological Organization as part of an international effort to raise public awareness of the risks of sun exposure. It is a simple measure of the intensity of the sun's ultraviolet rays at the earth's surface, and in many countries is presented as part of the weather forecast. INTERSUN promotes the harmonized use of the UVI, and advises governments to employ this educational tool in their health promotion programmes. WHO encourages dissemination channels such as the media and tourism industry to publish the UVI forecast and promote sun protection messages.
Global School Health Initiative
WHO's Global School Health Initiative seeks to mobilize and strengthen health promotion and education activities to improve the health of students, school personnel, families and other members of the community. Schools are vitally important settings to promote sun protection, and play a significant role in increasing awareness and changing behaviour among children and the people taking care of them. As part of the WHO Information Series on School Health, INTERSUN is preparing a document that will describe the essential steps in setting up a school initiative on sun protection.
Task Force for the Protection of Children's Environmental Health
In response to new knowledge about the special vulnerability of children and to growing concerns about the health impact of unsafe environments, WHO set up a Task Force for the Protection of Children's Environmental Health in July 1999. Its objectives are to raise the awareness of member states and the general public, to assist countries in mitigating the effects of environmental threats and to develop methodologies for risk assessment and the dissemination of information. Protecting children from harmful ultraviolet radiation is one of the topics covered by the Task Force's activities.
| Panel: (we are currently updating names of the doctors/dermatologists participating in this panel) |
Acknowledgments
We acknowledge National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) of National Institutes of Health for the above content. Contributors include Robert Katz, M.D., Rockville, MD; Larry Miller, M.D., Chevy Chase, MD; Alan Moshell, M.D., NIAMS, NIH; Gary Peck, M.D., Washington Hospital Center, Washington, DC; and Maria Turner, M.D., National Cancer Institute, NIH.
top
