Sunday, 1 April 2012

Now the sun is less dangerous

25 years ago with the 1987 Montreal Protocol, the international community for the first time decided to take joint action to address a serious environmental problem: the "gap" in the ozone layer, which allowed carcinogenic ultraviolet radiation from the sun to reach Earth in large quantities, endangering human health. Now these efforts seem to have produced results. It seems not only that the ozone layer is recovering steadily, but finally this recovery is accompanied by a significant reduction of the dangerous solar radiation. The good news, which proves that when we want we can do something for the environment, comes from Greek researchers, who warn: if the sun really has become less dangerous, this does not mean that we should stop being cautious.

"Finally, some good news coming from Greece!". This comment by a prominent German scientist has multiple meanings. Besides the fact that good news coming from Greece is rare these days, even more rare is the good news concerning the state of our planet. A scientific study of Greek origin, however, proved that such good news is not impossible.
Greek researchers, headed by academician Christos Zeferos, proved for the first time in decades that the recovery of the ozone layer in the atmosphere, observed in recent years, is finally accompanied by the desired result: a reduction of the carcinogenic ultraviolet Β (UVB).
This does not mean, however, that you should run outside and "burn" under the spring sun. On the one hand, although the reduction is significant and likely to continue in the coming decades, it has not yet reached the desired levels. On the other hand, as Christos Zeferos warns, sunrays have always had their hidden dangers for human health. "This good news should not calm us down", he stresses. "We can enjoy the sun, but with caution."
Remarkable radiation reduction
Since 2007 UVB rays have decreased by 2 percent. "This is a huge percentage for such a short period of time. We checked this with accurate measurements in Canada, Europe and Japan," says the academician. Conversely, the ultraviolet rays Α (UVA), which are not absorbed by the ozone layer continue to increase, because the sun gets brighter. UVB rays cause sunburn and other forms of skin cancer, while UVA rays affect the subcutaneous tissue and may alter the structure of collagen and elastin fibres in the skin and thus accelerate its aging.
Although we must be careful with these hazards, Academician Zeferos stresses that we should not lose our common sense. “Over protection and fear of UVB rays lead to the opposite extreme. We should not hide from the beneficial sun exposure, which produces vitamin D”, he says. "Unfortunately, the lack of vitamin D, observed in the countries of northern Europe has started to occur in Greece as well. This is a serious problem due to the use of sunscreens with high protection factor."
International action success
Scientists in the '70s discovered that ozone layer depletion in the stratosphere is due to the use of chlorofluorocarbons (CFCs) in sprays and refrigerators. The official response was delayed slightly, mainly due to opposition from businesses. The Montreal Protocol, which prohibits the use of CFCs and other ozone depleting substances, was finally signed in 1987, initially with some doubts. Quickly, however, mass participation followed (it was signed by all UN member states and not only), and it is considered particularly successful.
"If the Montreal Protocol had not been adopted we would have been required to work outdoors at night and sleep during the day", noted academician Zerefos. "This happened in Punta Arenas, Chile. They noticed that during recess the skin of students was getting red within a few minutes. Then the mayor closed the schools until the ozone "hole" moved away from the area and people avoided going outside during the day."

The ozone layer and climate change
The other good news from the study conducted by academic Zeferos and his associates is that the recovery of the ozone layer is progressing well. As he explains, the conversion process started being visible in 2000, but until recently experts did not know whether it would continue. Last year, the scientific community got worried when a study (again conducted by the academician and his team) found that in the winter of 2011 there was serious depletion of the ozone layer (about 20-25 percent) in the northern hemisphere from Canada to Siberia. Greek researchers found that it was a consequence of the greenhouse effect, which keeps the heat in the lower atmosphere, causing the upper layers to cool. This has disastrous consequences for the ozone layer. "This was an isolated case, an unusual winter, among many other winters", noted the academician. "This shows, however, that the ozone layer is influenced by climate change."
This is the unpredictable factor that clouds the otherwise bright future of the ozone layer. Based on current data and, if current trends continue, it is estimated that in about three decades, the ozone layer, and with it, the ultraviolet rays Β, will return to the satisfactory levels of the 1980s. "We're on our way towards recovery, but with all the hazards arising from climate change”, emphasizes Christos Zerefos. "Our fears are not to have more frequent events like the one in the winter of 2011 in the northern hemisphere due to the greenhouse effect. Climate change is one of the main hazards and people should know that the ozone layer has begun to recover, but the sun is still dangerous, especially for those who work outdoors."

Safe sunbathing
The UV index indicates how dangerous ultraviolet solar radiation is. Measurements and predictions for different regions of Greece are carried out by the National Network for measuring ultraviolet solar radiation ( During certain seasons and times the value of the UV index in Greece can increase significantly, so special caution is advised. As the sun gets close to the horizon, the lower the index and hence the danger of ultraviolet rays is greater.
Exposure to ultraviolet rays can lead to immediate and chronic health problems of the skin, eyes and immune system. Immediate effects of these rays are the burning of the skin and photokeratitis (inflammation of the cornea of ​​the eye). Chronic effects include cancer and premature skin aging, cataract and various diseases of the cornea of ​​the eye. Contrary to the skin, which absorbs ultraviolet rays and produces melanin, the eyes do not have this ability.
In order to protect your skin, use sunscreen with UVB and UVA rays filters. When sunbathing for the first time during the season sun protection factor 15 is recommended for adults and 20 for children, with particular emphasis on very young children and babies. "We recommend a reasonable protection. Do not use protection factor 50, even for children. They can enjoy the sun until 11 o’clock in the morning and after 4 o’clock in the afternoon, with a reasonable sun protection factor," says academician Zeferos.
In order to achieve the right sun protection factor effect for adults the correct amount of sunscreen is about 30-40 gr. (i.e. a handful!). The sunscreen should be applied before sun exposure and applied once again after coming out of the water.
In order to protect your eyes use sunglasses with UVA and UVB filters. The use of sunglasses is particularly important in children.

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