London: A vast blanket of pollution stretching across South Asia is cutting down sunlight by 10 per cent over India, damaging agriculture, modifying rainfall patterns and putting hundreds of thousands of people at risk, a new study revealed on August 11.

The startling findings by scientists working with the UN Environment Programme (UNEP) indicate that the spectacular economic growth seen in this part of the world in the past decade may soon falter as a result of the "Asian Brown Haze".

Research carried out in India indicated that the haze might be reducing the winter rice harvests by as much as 10 per cent, the 53-page UNEP report said.

"Acids in the haze may, by falling as acid rain, have the potential to damage crops and trees. Ash falling on leaves can aggravate the impacts of reduced sunlight on Earth's surface. The pollution that is forming the haze could be leading to several hundreds of thousands of premature deaths as a result of higher levels of respiratory diseases," it said.

Results from seven cities in India alone, including Delhi, Mumbai, Ahmedabad and Kolkata, estimate that some kind of air pollutions were annually responsible for 24,000 pre-mature deaths in early 1990s. "By the mid-1990s they resulted in an estimated 37,000 premature fatalities," the report said.

"The haze has cut down sunlight over India by 10 per cent (so far) - a huge amount. As a repercussion the North West of India is drying up," Prof V Ramanathan of Scripps Institute of Oceanography (US), a key member of the UNEP Scientific Panel, which produced the report, said when asked specifically about the impact of haze over India.

Stating that sunlight was going down every year, Prof Ramanathan said "we are still in an early stage of understanding of the impact of the haze. If our initial model stimulation regarding rainfall reduction is correct then it raises the question of sustainability".

Asked whether the current drought in most part of India after over a decade of good monsoon was owing to the haze, he said it was too early to reach a conclusion. "If the drought persists for about four to five years, then we should start suspecting that it may be (because of the haze)," he said.

"India, China and Indonesia are the worst affected owing to their population density, economic growth and depleting forest cover," Prof Ramanathan said.

He said the preliminary results of the haze indicate that the build up of the haze, a mass of ash, acids, aerosols and other particles, was disrupting weather systems, including rainfall and wind patterns and triggering droughts in Western parts of the Asian Continent.

"The concern is that the regional and global impacts of the haze are set to intensify over the next 30 years as the population of the Asian region rises to an estimated five billion people," he said.

The UNEP Scientific Panel, which has produced the new report, consists of leading academics in the field and include Ramanathan, Nobel Laureate Paul Crutzen of the Max-Planck Institute for Chemistry in Germany and A P Mitra of the National Physical Laboratory in India.

Klaus Toepfer, Executive Director of UNEP, told a press conference in London where the report was launched, that action was needed to have a better understanding of the scientific complexities of the phenomenon as well as measures to reduce the haze.

PTI