'Ozone-related deaths to increase in next 60 years'

Climate change may be worse for the lungs, as ozone pollution-related deaths are likely to increase in certain regions in the next 60 years, scientists have warned.

Researchers have predicted that certain countries such as Belgium, France, Spain and Portugal may witness an increase in ozone pollution deaths between 10 and 14 per cent during the period.

However, Nordic and Baltic countries are expected to see a drop in such deaths, they said at the European Respiratory Society's Annual Congress in Amsterdam, LiveScience reported.

Ozone is a two-faced gas. High in the stratosphere, it forms a protective layer that blocks ultraviolet radiation, which is potentially harmful to life, keeping it from reaching the surface of the planet.

This happens at roughly 12.4 miles (20 km) above the Earth's surface. Closer to the surface of the planet, ozone is a pollutant that can act as a greenhouse gas, trapping energy and warming the planet.

Breathing ozone can also cause health problems, including chest pain, coughing, throat irritation and congestion, said the researchers. It can aggravate conditions like bronchitis, emphysema, and asthma, as well as reduce lung function and inflame the linings of the lungs, and repeated exposure to ozone may permanently scar lung tissue, they said.

The researchers led by Bertil Forsberg at Umea University of Sweden made the ozone-related death projections as part of work the Climate-TRAP project to prepare for the changing public health needs expected to accompany human-caused climate change.

They used two emissions scenarios, one for high growth, the other moderate and two climate models to simulate how future ozone levels would be affected by climate change.

Scientists worried as Arctic has record ozone loss

Image released by NASA shows Ozone at about 20 km altitude, near the peak of the ozone layer in the lower stratosphere - AFP

An ozone hole five times the size of California opened over the Arctic this spring, matching ozone loss over Antarctica for the first time on record, scientists said on Sunday.

Formed by a deep chill over the North Pole, the unprecedented hole at one point shifted over eastern Europe, Russia and Mongolia, exposing populations to higher, but unsustained, levels of ultra-violet light.

Ozone, a molecule of oxygen, forms in the stratosphere, filtering out ultraviolet rays that damage vegetation and can cause skin cancer and cataracts.

The shield comes under seasonal attack in both polar regions in the local winter-spring.

Part of the source comes from man-made chlorine-based compounds, once widely used in refrigerants and consumer aerosols, that are being phased out under the UN's Montreal Protocol.

But the loss itself is driven by deep cold, which causes water vapour and molecules of nitric acid to condense into clouds in the lower stratosphere.

These clouds in turn become a ‘bed’ where atmospheric chlorine molecules convert into reactive compounds that gobble up ozone.

Ozone loss over the Antarctic is traditionally much bigger than over the Arctic because of the far colder temperatures there.

In the Arctic, records have until now suggested that the loss, while variable, is far more limited.

Satellite measurements conducted in the 2010-2011 Arctic winter-spring found ozone badly depleted at a height of between 15 and 23 kilometres (9.3 and 14.3 miles).

The biggest loss of more than 80 per cent occurred between 18 and 20 kms (11.25 and 12.5 miles).

"For the first time, sufficient loss occurred to be reasonably be described as an Arctic ozone hole," says the study, appearing in the British science journal Nature.

The trigger was the polar vortex, a large-scale cyclone that forms every winter in the Arctic stratosphere but which last winter was born in extremely cold conditions, Gloria Manney, of the Jet Propulsion Laboratory in California, told the media in email.

"The ozone destruction began in January, then accelerated in late February and March, so that ozone values in the polar vortex region were much lower than usual from early March through late April, after which the polar vortex dissipated.

"Especially low total column ozone values (below 250 Dobson Units) were observed for about 27 days in March and early April.

"The maximum area with values below 250 Dobson Units was about two million square kilometres (772,000 square miles), roughly five times the area of Germany or California."

This was similar in size to ozone loss in Antarctica in the mid-1980s.

In April, the vortex shifted over more densely populated parts of Russia, Mongolia and eastern Europe for about two weeks.

Measurements on the ground showed ‘unusually high values’ of ultra-violet, although human exposure was not constant as the vortex shifted location daily before eventually fading, said Manney.

The study, published by the journal Nature, challenges conventional thinking about the Arctic's susceptibility to ozone holes. This thinking is based on only a few decades of satellite observations.

Stratospheric temperatures in the Arctic have been extraordinarily varied in the past decade, the paper notes. Four out of the last 10 years have been amongst the warmest in the past 32 years, and two are the coldest.

In the stratosphere, ozone is protective. At ground level, where it is produced in a reaction between traffic exhaust and sunlight, it is a dangerous irritant for the airways.