The long awaited Revised National Ambient Air Quality Standards, the first uniform health-based standards in India, have been notified by the Union Ministry for Environment and Forests, which will have a telling effect on the public health in the country, especially in the bustling cities in the country.

The standards have brought two new deadly pollutants – PM 2.5 and ozone - - within the ambit of regulation. Both of these have begun to raise their ugly heads in the cities. Delhi, particularly, has already begun to experience ozone pollution. However, while the proposed air quality norms had suggested a standard of 90 microgramme per cubic metre for ozone, the notified standard (eight hourly) is 100 microgramme per cubic metre. For PM 2.5, the standard has been fixed at what had been proposed – 40 microgramme per cubic metre.

The standard for nitrogen oxide (NOx) has been made more stringent: from the existing 60 microgramme per cubic metre, it has been tightened down to 40 microgramme per cubic metre. Standards for short duration -- just one to a few hours – have been set to reduce peak exposure to some deadly gases like ozone and carbon monoxide. Normally, nearly all pollutants have time average standards for a year and a day or for 24 hours. Additionally shorter duration standards of an hour or few hours will help avert immediate impacts of peak levels on people with respiratory and cardiac problems during smoggy days.

In some cases, tighter standards for ‘sensitive areas’ have been notified. Several major agricultural crops are very sensitive to air pollutants. Therefore, a tighter air quality standard is now in place for forests and natural vegetation.

Meanwhile, the Centre for Science and Environment (CSE),which fought hard for this much needed regulation, has welcomed the newly notified Revised National Ambient Air Quality Standards.

“CSE has been demanding these norms, proposals for which have been languishing with the ministry for over three years. It has been a long and protracted battle, and we have fought very hard for them,” said Anumita Roychoudhury, associate director, CSE and head of its Right to Clean Air Campaign.

She added, “With pollution levels going up in almost every Indian city, this was urgently needed to raise the bar of protection for public health.”

What is most important is that India will now have – for the first time – a uniform health-based standard. Says Roychoudhury, “We will now discontinue the old practice of setting air quality standards for different land use classes like residential and industrial and keeping the standards lenient for the industrial areas. The government has finally attached priority to health over protecting industrial interests.”