Alarm over ozone layer depletion

Ozone depletion has raised the level of ultraviolet (UV) radiation, increasing health hazards for humans and plants all over the world, said a senior official of the UAE Meteorology Department.

The UAE, which is continuously monitoring the ozone layer over the country since 1998, has been contributing to the international efforts under the Montreal Protocol for the protection of ozone.

Sheikha Mowza Ali Hamad Al Mualla, Director of the UAE Meteorology Department at the Ministry of Communications, said international efforts are aimed at drawing the attention of the world to the continuous depletion of ozone in the atmosphere.

The world today is marking the International Day for the Preservation of the Ozone Layer, under a resolution of the UN General Assembly. World meteorological organisations commemorate this day through national meteorological services.

"Ozone layer protects humans and other living beings from harmful effects of the UV radiation from sun. Persistent decrease in ozone amounts, especially in the middle and polar latitudes, is a dangerous trend that has to be reserved," she said.

Concern over stratospheric ozone depletion has led to speculation about the effects of increased exposure to UV radiation on human health. This has led to an enhanced level of research on the effects, she added.

"The effects of UV radiation are more insidious and detrimental to the eye than were suspected previously," she said, noting that research on animals and fish has shown that premature aging of the lens or cataract has long been associated with UV radiation.

"In the light of new findings, the researchers suggest that practitioners should not hesitate to prescribe UV filters for sun glasses," she said.

Ozone is a simple composition of oxygen and resides around the globe at a strategic level where it absorbs ultraviolet radiation.

The ozone damaging gases, generally known as CFCs (chloroflorocarbons), are mostly being released from the developed and heavily industrialised countries. These gases are playing a leading role in lowering the ozone concentrations around the globe, she explained.

Sheikha Mowza said the world is getting increasingly conscious about the use of substances which are considered damaging to ozone. The UAE is also a signatory of the Montreal Convention and the Vienna agreement which stipulate a ban on materials contributing to ozone depletion by 2005.

Scientists say since the late 1970s, much of the protective layer of stratospheric ozone above Antarctica has disappeared, creating an ozone hole that now measures about nine million square miles. This hole actually allows the lethal UV radiation to stream through the earth's atmosphere.

"The ozone hole is a drastic example of man-made chemical instability. There is also a substantial risk of an ozone hole development in the higher latitudes of the northern hemisphere," she warned.

The seriousness of this global problem, said the director, has been recognised by all the nations of the world and international agreements have been signed and enacted to halt production of CFCs and halos (chlorine, bromine, iodine compounds) since the beginning of 1986.

According to the recent scientific findings and observations of the International Panel on Climate Change (IPCC) Working Groups, the total combined abundance of ozone-depleting compounds in the lower atmosphere peaked in about 1994. "It is now slowly declining," he added.

She said the springtime Antarctic ozone hole continues to grow unabated but the rate of decline in stratospheric ozone at mid latitude has slowed down.

Sheikha Mowza said that even though significant depletion of ozone has not yet been feared over the tropical belt, the ozone concentrations have to be kept under watch through regular and systematic monitoring.

The distribution of ozone over the emirates is in salutary condition and the UAE Ozone Observatory, located inside the Met Department, has continuously been monitoring it.

Khalid Masood Zaidi, a senior meteorologist at the ozone observatory, said the regular study has observed that the maximum concentration of ozone molecules is between 24 to 26 kilometres above the UAE.

However, most of the ozone in tropical atmosphere is seen between 16 to 38 kilometres.

He said the observatory, which is a member of the Canada-based World Ozone and Ultraviolet Radiation Data Centre, has been producing valuable scientific date on ozone and the damaging UV radiation.

The observatory also compiles a monthly report that is distributed among 18 different departments and organisations for research, he said. The maximum UV radiation in the UAE is recorded in the month of June and drops to its minimum in December, according to the met department.