By Stephen Leahy, IPS-Tierramerica.

Countries in the Southern Hemisphere are exposed to high ultra violet (UV) radiation during spring when the Antarctic ozone hole opens. Higher UV levels are linked to increases in skin cancer, cataracts and eye lesions, and other diseases. However governments can help the ozone layer to recover by reducing and eliminating the use of ozone depleting chemicals.

Skin cancer, eye lesions and other infections are on the rise, a reminder that the Antarctic ozone hole continues to be a serious problem, especially for southern Argentina and Chile, where ultraviolet radiation during the spring months increases 25%.

The ozone layer covers the entire planet at an altitude of between 15 and 30 km, and protects living organisms from the sun’s harmful rays.

According to the US National Oceanic and Atmospheric Administration (NOAA), the dramatic thinning of the ozone layer over the Antarctic – an annual phenomenon – sprawled to an average of 29.5 million square km on 21 September to 30 September.

“This year’s Antarctic ozone ‘hole’ is the largest on record,” said Achim Steiner, executive director of the United Nations Environment Programme (UNEP).

“Governments need to reduce and shut down the remaining sources of ozone-depleting chemicals,” Steiner said in a statement.

The rates of sunburn increase during the southern hemisphere springtime, when the Antarctic ozone hole is large enough to extend over the city of Punta Arenas at the southern tip of Chile, according to studies conducted by Chile’s Universidad de Magallanes.

Diagnoses of malignant melanoma, a deadly form of skin cancer, have doubled in recent years, leading Chilean health authorities to recommend avoiding direct exposure to the sun between 11:00 am and 5:00 pm this time of year, and especially to protect children.

“Worldwide, the increases in melanoma are alarming. It is among the fastest rising forms of cancer,” says Edward De Fabo, an ultraviolet (UV) radiation and skin cancer researcher at George Washington University, in Washington, DC.

“It used to be rare in young people, but we see increasing cases of melanoma in people under 25 years of age,” De Fabo told Tierramerica in an interview.

Rising rates of sunburn have also been linked to higher levels of UV reaching the Earth’s surface. Direct adverse effects of higher UV levels will be increases in skin cancer and increases in cataracts and lesions in the eye, said Frank de Gruijl, a research scientist at the University Hospital of Utrecht in the Netherlands.

“There are good reasons to suspect increases in herpes simplex virus infections and other infectious diseases as well,” de Gruijl told Tierramerica.

Higher levels of ultraviolet B rays (the most harmful) have been linked to the suppression of immune systems in humans, he said.

Animals and plants are also affected by the seasonal expansion of the ozone hole.

Argentine scientists have found extensive DNA damage to plants in Tierra del Fuego National Park, and Australian scientists have documented reductions of phytoplankton up to 65% in southern ocean waters.

A bulletin on this year’s ozone depletion, by the Australian Environment Department’s Antarctic Division, reports that an area of the far South Atlantic known as the breadbasket of Antarctica was exposed to three to six times the normal amount of UV radiation in October.

Global UV levels have been rising for the past 25 years and it is not known how fast they will continue to increase, nor for how long, said De Fabo. “Ozone-depleting chemicals are going to be in the atmosphere for hundreds of years,” he added.

The ozone was “virtually gone” in the atmospheric layer 12 to 20 km above the earth’s surface.

Worldwide, levels of UV radiation are on average five to 10% higher than pre-1980 levels, and will remain that way for another decade or more.

These levels vary greatly, depending on location and time of year. Countries closest to the equator have the highest UV exposure but southern Argentina and Chile experience very high levels of UV – 25% higher – during the spring, when the Antarctic ozone hole opens.

Atmospheric scientists recently announced that the ozone layer is beginning to recover and would be back to pre-1980 levels by 2050.

De Fabo points out that the projected recovery, which has been pushed back several times before, is dependent on full compliance with the 1997 Montreal Protocol, which sets targets for phasing out production and consumption of ozone-depleting substances.

These chemicals include halogenated hydrocarbons – which contain chlorine or bromide – known for their role in breaking down the three-oxygen ozone molecule.

Representatives from nearly 200 countries met on 30 October-3 November in New Delhi to track progress on the goals of the Protocol, which “has been incredibly successful up till now, but there is much left to do,” UNEP spokesman Michael Williams told Tierramerica from New Delhi.

Other issues discussed at the meeting were the illegal trade in banned chlorofluorocarbons (CFCs), the continued use of methyl bromide in the United States, and the fact that replacement chemicals (like hydrochlorofluorocarbons, HCFCs, and hydrofluorocarbons, or HFCs) worsens the other global atmospheric problem – global warming – by contributing to greenhouse gas emissions.

(Originally published by Latin American newspapers that are part of the Tierramerica network. Tierramerica is a specialised news service produced by IPS with the backing of the United Nations Development Programme and the United Nations Environment Programme)

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