Calcutta began the week as a polluted city but will end it as a critically polluted city.

The new standards for air quality announced by the environment ministry on Wednesday have pushed Calcutta firmly into the hall of shame, with the toxic count of at least two major pollutants being 1.5 times higher than the permissible limit.

New Delhi: Fifteen years after they were first notified, the environment ministry on Wednesday released new and tougher air quality norms under which residential and industrial areas will have the same standards.

New Delhi, Nov. 18: India has revised standards for air quality for the first time in 15 years in a move that environmental experts say will overnight tar more cities and localities across the country as polluted beyond limits.

The Centre on Wednesday announced that both industrial and residential areas will not have different standards for air quality norms. In a major move to bring down the air pollution levels, the Centre unveiled tougher new air quality norms. The revised guidelines have added five more hazardous chemicals in the list of the National Ambient Air Quality Standards (NAAQS) for monitoring.

The Ministry of Environment and Forests (MoEF) has notified the Revised National Ambient Air Quality Standards (NAAQS), 2009, which provide a legal framework for control of air pollution and protection of public health. The revised norms have come 15 years after the Central Pollution Control Board (CPCB) had notified the previously existing NAAQS in 1994.