New air quality standards in India

For the first time in 15 years India has revised its air quality standards. The new standards were notified by the environment ministry in November, and have lowered maximum limits for health damaging pollutants such as sulphur dioxide, nitrogen dioxide and PM10, and introduced new limits for pollutants left out earlier, including ozone, PM2.5, arsenic, nickel, benzene and polyaromatic hydrocarbons (as benzo(a)pyrene).

Another change is that there will now be uniform standards for residential, industrial and rural areas limits, thus ending the practice of providing less stringent limits for industrial zones.

More cities are now likely to find themselves exceeding the limits. Data from the Central Pollution Control Board suggests that, even under old standards, two-thirds of 120 cities whose air quality is monitored by the board have higher than permissible levels of particulate matter. An analysis by the non-government group Centre for Science and Environment (CSE) has shown that in 80 per cent of the 120 cities the value of at least one pollutant exceeds the annual average limit imposed under the new standards.

CSE welcomed the new standards as the first uniform health-based air quality standards in India. “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 of CSE and head of its Right to Clean Air Campaign.

The annnual mean standard for nitrogen dioxide (NO2) has been strengthened from 60 to 40 micrograms per cubic metre (µg/m3) and a 1-hour mean limit of 200 µg/m3 has been introduced.

For ozone, the new limits are 100 and 180 µg/m3 respectively as 8-hour and 1-hour mean values, and for fine particles (PM2.5) the new limits are set at 40 µg/m3 as annual mean and 60 µg/m3 as daily (24-hour) mean.

Some of the new standards are aligned with recommendations from the World Health Organization (WHO), while others – such as those for fine particles – are much less stringent.

Christer Ågren

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