世界衛生組織的新報告「全球因陽光紫外線而造成的疾病負擔」，是有史以來第一份針對紫外線帶來的健康負擔，所進行的全球性系統分析研究。該報告調查了9種因紫外線過度曝曬而有害健康的疾病。其中造成最重大疾病負擔的主要3種疾病，包括了皮膚惡性黑色素瘤、發生在不同皮膚細胞層的非黑色素瘤皮膚癌──鱗狀細胞癌，以及基底細胞癌（basal cell carcinomas）。
Up to 60,000 cancer deaths a year worldwide are caused by too much exposure to ultraviolet radiation from the Sun, the World Health Organization says in a new report. Simple prevention measures can avert much of this illness and death, the world health agency advises.
The most serious consequence of excess ultraviolet radiation (UVR) is malignant melanoma, which has high cure rates only if detected early. Up to 90 percent of the global burden of disease from melanoma and other skin cancers are estimated to be due to UVR exposure.
"This global assessment of the health risks of UV radiation provides a good basis for public health action. We all need some sun, but too much sun can be dangerous - and even deadly," said Dr. Maria Neira, director for public health and the environment at the World Health Organization.
The new World Health Organization (WHO) report is the first-ever systematic examination of the global health burden due to ultraviolet radiation. The report, "Global Burden of Disease of Solar Ultraviolet Radiation," investigates nine adverse health outcomes from excess exposure to ultraviolet radiation. The main three, which cause the greatest burden of disease, are cutaneous malignant melanomas, and non-melanoma skin cancers developing in different cell layers of the skin - squamous cell carcinomas and basal cell carcinomas.
In addition, ultraviolet radiation causes three eye problems - cortical cataracts, or eye lens opacities; pterygium, a fleshy growth on the surface of the eye; and rare squamous cell carcinomas of the eye. The report notes that ultraviolet radiation does have beneficial effects, mainly in the production of vitamin D following skin exposure to the UVB, the shorter wavelength component of UVR. Adequate vitamin D prevents the development of bone diseases such as rickets, osteomalacia and osteoporosis.
In most cases minimal casual exposure to ultraviolet radiation should be sufficient to maintain vitamin D levels at a range that avoids these health problems. The dangers are much greater from over-exposure to the sun's radiation, the world health agency says.
A few easy-to-implement sun safety measures could prevent much of the cancer and other death and disease burden due to UV radiation, Dr. Neira says.
- Limit time in the midday sun.
- Use shade wisely: seek shade when UV rays are most intense.
- Wear protective clothing including hats and sunglasses.
- Use a broad-spectrum sunscreen of sun protection factor 15+.
- Avoid sunlamps and tanning parlours; for youth under the age of 18, WHO recommends that they do not use them at all.
- Know the UV index: when the UV Index predicts radiation levels of 3 (moderate) or above sun safety practices should be taken.
- Protect children from the sun.