Daniela Estrada
SANTIAGO, Jan 9 2007 (IPS) – The hole in the ozone layer over Antarctica, where the ozone thins out every southern hemisphere springtime, is recovering for the time being, but all regions in Chile will receive extremely high levels of ultraviolet radiation this month.
The ozone layer is found all round the earth at an altitude of about 15 to 30 kilometres, and protects living things from the sun s harmful ultraviolet (UV) rays.
Every year, between September and November, the ozone layer thins out in a large area that includes the southern parts of Argentina and Chile, where UV radiation increases by 25 percent.
According to the National Oceanic and Atmospheric Administration (NOAA) of the National Aeronautics and Space Administration (NASA), the ozone hole grew to an average size of 27.5 million square kilometres from Sept. 21-30, 2006, making it the biggest hole in history and posing a serious risk to the population.
But the dean of the Faculty of Science at the state University of Chile, Raúl Morales, explained to IPS that when the Antarctic ozone hole begins to shrink, health risks to people living in Argentina, Australia, Chile and New Zealand are at their height.
In November, December and January, masses of ozone drift from areas near the Tropic of Capricorn towards the South Pole, in order to fill in the depleted zone (over Antarctica), the expert said.
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While the ozone hole only affects the southernmost part of Chile, this dilution effect has an impact on every region of the country, Morales said.
According to the latest report from the Chilean Meteorological Office, the ozone hole was indeed filled in by Dec. 9, but in January and February, with clear skies nearly every day, UV radiation will reach its highest levels very high and extreme.
It is therefore recommended that people take every possible precaution during their holidays, that is, avoid exposure to the sun between 10 a.m. and 4 p.m., cover up, and use sunblock cream and sunglasses with UV filters, Morales said.
People who work outdoors farmers and fisherfolk must be especially careful, as well as those spending the summer in the countryside, the mountains or on the coast, since water, sand and snow reflect UV radiation and accentuate its effects.
I believe we need to develop a culture of solar protection. In Chile, there has always been a sun-tanning culture, particularly among young women, which is very harmful to the skin, said the expert.
Apart from skin cancer, prolonged exposure to UV rays can cause eye damage, such as cataracts, and infections, because it weakens the immune system. UV-B radiation is the most dangerous, and its effects are cumulative.
Nancy Ortiz, of the non-governmental National Cancer Corporation (CONAC), told IPS that the incidence of malignant skin tumours has doubled in Chile in the last 10 years, and skin cancer is the most prevalent type of cancer in the country.
An estimated 10 out of every 100,000 Chileans now have skin cancer, and the number of sufferers is rising.
So CONAC and the Physics Department of the state University of Santiago created a National UV Measurement Network in 2001, which provides daily information on UV indices throughout the country.
In 2002, CONAC established a national network of solmáforos , devices looking rather like traffic lights located in beach resorts and public promenades which give instant, on-the-spot colour-coded measurements of UV radiation. (The term combines the Spanish words for sun sol and stoplight semaforo ).
In late 2006, CONAC launched a vigorous awareness-raising campaign, aimed primarily at children. Among other efforts, a photo-sensitive bracelet was put on sale which signals when the sun is dangerous for the skin.
According to Ortiz, the bracelet has been so successful in Chile that orders are now being received from other countries in Latin America, and from Europe and the United States.
In March 2006, law 20,096 was passed to implement the Montreal Protocol, signed and ratified by Chile in 1990.
This 1987 convention, signed by 184 countries, is designed to allow the ozone layer to recover its normal thickness by gradually eliminating the use of chlorofluorocarbons (CFCs) and about a hundred other ozone-depleting chemicals.
These chemical substances, particularly CFCs present in refrigerators, freezers and air-conditioners, destroy the ozone layer and the natural protection it affords.
The law, which according to both Morales and Ortiz was late in arriving, also calls for awareness-raising on preventive health measures. For example, it states that the media must include information about UV radiation levels in weather reports, which they are now doing.
In Morales view, Chileans are becoming more aware of the problem. But he said the key was to educate children and young people about the environment in primary and secondary schools, which is only just beginning to happen.
Environmental education involves forming good habits. That s why it s important that all this knowledge should be taught systematically by teachers to their students, especially during August and September, he said.
We absorb practically our whole lifetime dose of solar radiation between the ages of two and 18, because that s when we have the most free time to be outdoors in the sunshine. The exception is those who work out-of-doors. As adults, we are protected from the sun in our offices and homes, Morales explained.
Alfonso, 59, works as a truck driver in Santiago, which obliges him to spend the better part of the day on the street and in the sun. He told IPS that he was aware of the dangers of UV radiation, and used sunscreen lotion every day.
Carolina Arredonda, a 28-year-old computer engineer, also said she knew the risks involved when she sunbathes, and therefore uses a sunblock cream which protects against UV rays. Morales said that the latest research indicates that the ozone layer is recovering, and that if countries stop using ozone-depleting chemicals, it may be restored to normal levels in 50 to 70 years time.
