Faulty samplers and data fudging hamper India's air pollution fight

The World Health Organisation recently declared Delhi the world's most polluted city

PUBLISHED : Wednesday, 22 October, 2014, 4:02am
UPDATED : Wednesday, 22 October, 2014, 6:33pm


India is changing the way it maps pollution, with an update to its air quality index. In its initial phase, eight pollutants will be tracked in 46 cities with populations exceeding a million people. After five years, the rest of the country will slowly be brought into the system.

At the launch, the minister for environment and forests, Prakash Javadekar, said it wouldn't be "business as usual'' anymore. The move couldn't have come a moment sooner.

Five months ago, the World Health Organisation declared Delhi to be the worst polluted city on earth. In a study spanning 1,600 cities across 91 countries, the organisation used India's own officially released data to show the city had the world's highest annual average concentration of microscopic airborne particles known as PM2.5.

These extremely fine particles of less than 2.5 micrometres in diametre are linked with increased rates of chronic bronchitis, lung cancer and heart disease as they penetrate deep into the lungs and pass into the bloodstream. Delhi's annual PM2.5 reading was 153 compared to London's 16. Indian officials contested the study's finding but agreed Delhi was as bad as Beijing, although the latter's PM2.5 reading was only 56.

In fact, Delhi's air quality may be even worse. The Economic Times reports that the central pollution control board compared some India-made PM2.5 samplers with international ones a couple of years ago.

A manufacturer of samplers, Rakesh Agarwal of Envirotech, candidly said: "There was a 100 per cent difference in readings.''

While some instruments leaked air from the sides, others evaluated a lower-than-stipulated volume of air. Agarwal explained the implications: "If I expect the air input to be 20 litres per minute, but get just 16 litres, my PM2.5 count will be lower.''

If this is how PM2.5 is measured, Delhi's PM2.5 score is likely to be worse.

The Economic Times notes while the Indian government hasn't set standards for these instruments, it makes it mandatory for manufacturing companies to adhere to the US Environment Protection Agency specifications. It doesn't check if these samplers comply with those standards.

Users of these faulty instruments then fudge this flawed data. Since the early 1990s, industrial units have had to install air quality measuring units and send the data to the appropriate state pollution control boards. If emissions peak, the industrial unit may be shut down. So industries fabricate 90 per cent of the data "by changing the calibration of their machines, or by injecting clean air into the intakes or by placing CM units [instruments] away from the plant and in a nearby wood or between trees''.

The Economic Times says 30 years after legislating the Air Act, India has no monitoring protocols. Air quality standards are not set according to zones such as residential and industrial areas. The entire country has one standard. All is fine as long as industries' emissions do not push the overall air quality score above that standard.

The whole system - from faulty instruments and data fudging to lack of policing - allows industries to pollute and get away with it.

Will the newly launched index improve air quality? It seems unlikely.