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Sunshine through the Ozone Hole |
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By Sandra Guijarro Vilela*
The residents of Punta Arenas, in the extreme south of Latin America, are learning to coexist with the ozone hole and the fear of ultraviolet radiation, though they complain about the sensationalism surrounding the matter.
PUNTA ARENAS, Chile - The hole in the ozone layer is not a pleasant topic for the 120,000 inhabitants of Punta Arenas, the southernmost city of Chile and of South America. Stigmatized as residents of a ''martyr city,'' the local people complain about the alarmist attitudes arising from their proximity to the threat of unfiltered radiation from the Sun.
In the early 1990s, sensationalist publications began to flourish stating that the residents of Punta Arenas were being burned alive and that local sheep flocks were going blind from the Sun's radiation, all of which proved false. Scientists found that the affected animals suffered from an eye infection.
Also in the 1990s, a Japanese group launched a project to photograph - over a number of years - a panorama of the city to show how ultraviolet radiation would reduce the trees to ashes. But they went home disappointed because no such thing occurred.
Ozone is a gas found 15 to 50 km above the Earth's surface and serves to filter out the Sun's harmful ultraviolet rays. As a result of the emission of certain contaminants by human activity, this protective layer has become thinner, though especially in a 25 million square km area over Antarctica, an area that extends over Punta Arenas.
A group of researchers from the University of Chile and from the US-based Johns Hopkins University discovered last year - contrary to what had long been assumed - that the hole in the ozone layer poses a greater health threat to the residents of Santiago, in central Chile, than to the population of Punta Arenas.
According to the scientific team's research, the incidence of skin cancer is much greater in the capital than in the southern city.
The residents of the extreme south, despite receiving more unfiltered solar radiation, are less affected because they do not expose as much skin to the Sun's rays. The region's cold temperatures mean that people are less likely to be found outside with bare heads or arms.
Another element in their favor is the location of the city with respect to the Sun. In Punta Arenas, solar radiation reaches the Earth's surface at a much more acute angle - and is therefore less intense - than in Santiago, located 2,200 km to the north.
Nevertheless, Punta Arenas is the only city in Chile where the media provide a daily report on ultraviolet radiation levels. When there is a yellow alert, there is a moderate level of UV radiation, but an orange or red alert means dangerous levels.
In spite of the warnings, the people of Punta Arenas do not seem to make much effort to protect themselves from the otherwise much-feared UV rays during the Southern Hemisphere spring season, when the cyclical phenomenon of the ozone hole is at its peak – in September and October.
''A minority uses sunscreen, but most people have not taken to heart the potential severity of the problem and have not changed their habits. But studies show that skin cancer rates have not risen here,'' says Juan Ursich, director of National Television in Punta Arenas.
A survey conducted here last year by the National University of Chile's dermatology department found that 64 percent of the respondents had never used a sun blocking cream, and that 41.5 percent had never used sunglasses.
''That proves the population here is not panicking like it was reported they were. We are preventing skin cancer through massive campaigns throughout the country, because not only those who live in the south run the risk of receiving excessive UV radiation,'' said Juan Honeyman, head of the university's dermatology department.
The people of Punta Arenas are proud to have ''the cleanest air in the world'' and many are nostalgic for the prosperity of the city, having heard stories of times before the construction of the Panama Canal, when the port saw much more shipping traffic.
The residents of the zone are largely the descendants of the indigenous Kaweshka, Selk’nams, Yámanas and Aonikenk, and of the European pioneers who arrived in the 19th century to populate what is known as Patagonia. Today, topping the list of immigrants are people from Croatia, then Spain, Switzerland, France, Britain, Italy, Germany and Greece.
Due to the hostile and windy climate - in October winds of 120 km/hour were recorded - life in Punta Arenas takes place indoors, in colorful homes that are heated. This reality has been ''lucky twist of fate'' for the city's residents, given the threat of the ozone hole, say scientists.
Claudio Casiccia, director of the Ozone and UV Radiation Laboratory at the University of Magallanes (Magellan), said ozone-related problems have been limited this year.
The thickness of the ozone layer in the ozone ''hole'' in September measured 210 Dobson Units (DU – how much ozone is found in a standard column of air), and 240 in October. In contrast, the layer was just 170 DU the same time last year. The lower limit - at which it does not pose a threat to human health - is 220 DU.
Though the ozone hole this year was three million square km smaller than last year's, it has lasted longer.
''People hear that this year the hole is smaller and they immediately think that the atmosphere is recovering. False. If it is lasting longer we are losing more and more ozone. The thinning of the ozone layer has not diminished, but is increasingly worse,'' said Bendric Magas, a professor of engineering at the University of Magallanes.
The Institute of Political Ecology, a local non-governmental organization, filed a petition in late October stating that Chile should be declared a ''vulnerable country'' because of the thinning ozone layer over the Antarctic region, and accused the government of ''negligence'' in handling the problem.
The group proposed that Chile request resources from the Multilateral Fund of the Montreal Protocol, an international accord that commits governments to reduce emissions of ozone-destroying gases, such as CFCs (chlorofluorocarbons).
The activists want to see more research of the phenomenon and to develop related health campaigns and educational programs for the Chilean public.
Many wonder if the loss of ozone will go on indefinitely, in spite of efforts like those stipulated under the Montreal Protocol. For the University of Chile's Cabrera, ''there has to come a time when this situation will turn around.''
Ozone expert Casiccia, meanwhile, predicts that the phenomenon will continue to worsen until 2010, and then will gradually improve, and the ozone hole could disappear by 2050.
''But the world must adopt the necessary measures if we are going to stop what is occurring to the ozone layer today,'' he pointed out.
* Sandra Guijarro Vilela is a journalist and Tierramérica contributor.
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