With worst AQI, Kolkata becomes India's most polluted metro

Since last Thursday, crossing the levels registered in the national capital, Kolkata has been recording the worst PM 2.5 count in the country, making itself the most polluted and 'unhealthy' metro city in the country.

In last few days, the average PM 2.5 count in Kolkata's air roamed between 300-380 when the count in Delhi was between 220-310.

Meanwhile, the situation in the city of joy became partially better on Monday as the website of National Air Quality Index showed that overall atmospheric Particulate Matter 2.5 (PM 2.5) count at Rabindra Bharati University (RBU), one of the two AQI recording stations of West Bengal Pollution Control Board (WBPCB) in the city, stood at 327 (very poor) at 6 pm.

WBPCB's another AQI station at Victoria Memorial in central Kolkata's Maidan area recorded a PM 2.5 count of 235 (poor) at the same time while according to an AQI recorder installed at US Consulate in city's Jawaharlal Nehru Road area, the PM 2.5 count in the late evening was 187 (unhealthy).

Environmentalists claimed that a heavy air pollution occurred due to the smoke from busted firecrackers during Kali Puja, Diwali and Chhath Puja, which was responsible for such 'unhealthy' air quality of the city as the vehicle count in Kolkata is barely a fourth of Delhi.

"We saw how honourable Supreme Court's order to burst firecrackers during Diwali between 8-10 pm. was devastated in and around Kolkata as police and administration failed to take adequate steps to stop the use of firecrackers after the court given deadline," a city based environment activist told IBNS.

"Government has to take more action and general people have to follow the court and pollution control board's guidelines to avoid such hazardous situation in Kolkata in future," the environmentalist added.

What is Air Quality Index (AQI)?

According to the Air Now, a New York based provider of public national air quality information and real-time AQI conditions for over 400 cities across the United States, the Air Quality Index (AQI) is an index for reporting daily air quality. It tells people how clean or polluted the local air is, and what associated health effects might be a concern for them. The AQI focuses on health effects you may experience within a few hours or days after breathing polluted air. Think of the AQI as a yardstick that runs from 0 to 500. The higher the AQI value, the greater the level of air pollution and the greater the health concern. 

Particulate Matter 2.5:

According to the New York State Department of Health, fine particulate matter (PM 2.5) is an air pollutant that is a concern for people's health when levels in air are high. PM 2.5 are tiny particles in the air that reduce visibility and cause the air to appear hazy when levels are elevated. Outdoor PM 2.5 levels are most likely to be elevated on days with little or no wind or air mixing.

(Reporting by Deepayan Sinha)