Delhi turns on giant air freshener to control pollution

London, March 16 : Reports indicate that India has switched on its first public air purifier in the city of New Delhi as part of an experiment that could help other smog-choked cities in emerging countries.

According to a report in the Telegraph, the unit, which is plugged in on a traffic-clogged street of central Delhi, is part of a pilot that could lead to more being installed in other areas of the city, ranked the world's fourth most polluted by the World Health Organisation (WHO).

The maker of the seven-ton machine, Italy's Systemlife, claims that the box-like structure can purify 10,000 cubic metres of air every hour, scrubbing out pollutants such as carbon dioxide (CO2) and nitrogen oxide.

"It is the first such project in India and if it works then we would acquire a number of them and place them at strategic locations," said P.K. Sharma, the health chief of the New Delhi Municipal Council.

He said that a state environmental agency will monitor the performance of the machine, which costs about 25 million rupees and works like a vacuum cleaner, sucking in air and releasing it purified form from a roof vent.

Sharma said that the purifier would be tested for three months at the site, which is drawing curious onlookers.

The electricity-driven unit, installed free of cost, uses a five-stage filtering process including electrodes to remove health-threatening solid and gaseous pollutants.

"Almost all Indian cities and especially New Delhi needs them," said Ritika Modi, director of the Indian partner company of Systemlife.

The Italian company has installed similar public purifiers at 26 locations in Spain, six in Switzerland and seven in Italian cities, including in the capital Rome, according to a statement issued by the firm.

Environmentalists said that they could only give a thumbs-up to the machine after the tests were over, which will include an examination of the filters by the Italian firm after three weeks of operations.

"We have to examine the variation in air quality, but this can be done only after we analyse the readouts," said Vivek Chattopadhyaya, an air analyst with the Centre for Science and Environment, an environmental research and lobby group.

In November last year, the city government vowed to enforce a single standard for industrial and residential pollution as part of plans to tighten air quality rules.