Kolkata, Jan 30 (IANS): Official ambient air quality monitoring has shown 61 percent increase in particulate matter in four years from 2010 to 2013, a Centre For Science and Environment study said here on Saturday.

"Kolkata is in the grip of rising air pollution and multi pollutant crisis. Official ambient air quality monitoring has shown 61 percent increase in particulate matter in four years from 2010-2013. The levels exceed standards by 2.7 times. The nitrogen dioxide levels exceed by close to two times," said Anumita Roychowdhury of CSE.

In addition, the organisation's exposure monitoring in the city (done during last week of January) provides clinching evidence of alarming dose that an average person in Kolkata breathes on a daily basis in different parts of the city, she said.

"This is two to three times higher than the ambient level recorded by official monitors," said Roychowdhury, executive director, research and advocacy, CSE.

She said the analysis reveals the direct exposure to toxic fumes is very high in the city.

CSE has analysed the data from the official ambient monitoring reported by the Central Pollution Control Board and West Bengal State Pollution Control Board.

"Official monitoring shows that particulate levels (PM10) in 78 percent cities of Bengal exceed the standards. All cities exceed the Nitrogen dioxide standard," she said.