india

Updated: Nov 04, 2019 02:15 IST

India needs to have a regional emission inventory of air pollution sources for quick response once the air quality starts to deteriorate, according to experts who pointed out that such a database would help developing localised graded response action plans (GRAP) that would be much more effective than one for an area as large as the National Capital Region (NCR).

As of now, the Union ministry of earth sciences releases air pollution emission inventory for states and regions based on the inputs such as the number of industries, cases of farm fires, and vehicles registration, received from the various state pollution control boards.

According to the ministry’s inventory report for 2018, road dust was the biggest source of particulate matter in air pollution, contributing between 36.6% and 65.9% to the overall pollution levels in different areas over the course of a year. The second was transport, whose contribution was 17.9% to 39.5%, followed by biomass burning (including stubble burning), which contributed 5 to 10%.

However, during peak air pollution months of mid-October to mid-November, the contribution of biomass burning (including stubble burning) increases to 39.5%, according to the ministry’s emission inventory for 2018. In 2019, the contribution of stubble burning to overall pollution load in northern India rose to 44% on October 30, according to System of Air Quality and Weather Forecasting and Research (SAFAR).

Apart from the ministry, the Central Pollution Control Board (CPCB), the Indian Institute of Technology, Kanpur, The Energy and Resources Institute (TERI) and Urbanemissions have come out with emission inventory reports for different periods.

“Most of these emission inventory studies present a big picture, but that makes it difficult for agencies to initiate action at the local level,” said Chandra Bhushan, former deputy director of Centre for Science and Environment. “If we really want to take action, we need to know about the sources of emission in localities in towns such as Karnal, Rohtak, Delhi, Patiala, and so on, which contribute to the overall pollution load in the region.”

Other than Delhi-NCR, the pollution levels in these towns were high on Sunday. CPCB’s pollution data for the last five years shows air pollution levels in tier-2 and tier-3 cities was rising at a much faster pace than in metros such as New Delhi, and that they would be the next big air pollution hot spots.

Bhushan said that if local pollution authorities know what contributes most to the air pollution it would be able to take immediate action once the pollution level starts rising.

“That is the way forward to deal with air pollution,” said a CPCB official, who asked not to be named as he is not authorised to speak to the media.

“Building local emission inventory is a scientific work and needs a lot of money. Once we have that, we can have localised GRAPs,” he said.

Even according to earth sciences ministry, maintaining an emission inventory is a scientific way to identify aggregated local source contribution and their region-specific spatial distribution within a confined boundary. “It is a more effective tool to identify hot spots and plan control measures,” said Gufran Beig, project director, System of Air Quality and Weather Forecasting and Research (SAFAR).

Beig said the satellite data on air pollution can help to prepare such localised emission inventories that can help track how emissions change over a long period of time.

“From air monitoring, we know which areas in a town have high air pollution but the emission inventory can help in identifying the sources for the same. And once authorities tackle these sources effectively air pollution levels could be brought down,” he said.

Among cities that use local emission inventory to control pollution and future planning, are Beijing in China and California in United States.



While in Beijing the inventory is used to close down specific industries in localities when the pollution rises, the California Air Resources Board website says the inventory is an “important tool” to keep emissions under control and plan infrastructure in a “green” way.