UN health agency issues guide on reducing risk of skin cancer, cataract from sun exposure

Wearing protective clothing and sunglasses, and avoiding the sun at midday can reduce the risk of skin cancer and cataracts by up to 70 per cent, the United Nations World Health Organization (WHO) says in new guidelines released in an effort to help reduce the risk of such illnesses.

The publication is based on the Global Solar Ultra Violet Index which WHO developed in 1997 in collaboration with several other agencies, to measure UV radiation levels at the Earth's surface and to indicate the potential for skin damage, thereby alerting people to take appropriate protective actions.

In the new booklet, "Global Solar UV Index - A Practical Guide," UVI values are grouped into exposure categories of low, moderate, high, very high and extreme with corresponding colour codes. Simple icons indicate the appropriate sun protective behaviour.

The guide also provides basic facts about UV radiation exposure, its determinants and health effects, the use of the UVI, and options for public education messages for different target audiences and settings.

According to WHO, 2 million to 3 million non-melanoma skin cancers and at least 132,000 malignant melanomas occur globally each year. There has also been a significant increase in the incidence of skin cancers since the 1970s.

“A changing lifestyle and sun-seeking behaviour are responsible for much of the increase in skin cancers,” the UN agency said. “Depletion of the ozone layer, which provides a protective filter against UV radiation, aggravates the problem.”

Sun exposure may also be responsible for more than 2 million cases worldwide of blindness due to cataract. Furthermore, UV radiation may impair immune functions that could enhance the risk of infections and limit the efficacy of vaccination programmes.