Air quality in Kolkata dips to ‘very unhealthy’ category

Air quality in Kolkata has started dipping with a drop in temperature as AQI levels ranged between 204 and 290 since Thursday, 14 November.

The AQI level range between 201 and 300 comes under the “purple” or “very unhealthy” category. It involves health warnings of conditions where the entire population in a city is more likely to be affected.

The level is just above the worst AQI level between 301 and 500, which comes under the “maroon” or “hazardous” category involving more serious health effects on the entire population.

Kolkata’s AQI quality remained good before the Diwali and Kali Puja because of the winds of Cyclone Dana.

However, it started deteriorating sharply from the night before Diwali or Kali Puja because of the unbridled bursting of firecrackers. Similar bursting of firecrackers during the Chhath Puja aggravated the deterioration further.

According to green-technologist and environmental activist Somendra Mohan Ghosh the basic flaw lies in the fact that the Indian air quality standards are more lenient compared to the World Health Organisation's (WHO) guidelines.

“The permissible limits under the Indian National Ambient Air Quality Standards (NAAQS) for particulate matters like PM2.5 and PM10 as well as other items like nitrogen dioxide, ozone, carbon monoxide and sulphur dioxide is much more lenient than those permissible under WHO guidelines,” said Ghosh.

“Exposure to air pollution above WHO guidelines can lead to respiratory problems like asthma or COPD, cardiovascular diseases, lung cancer, neurological damage and premature mortality,” Ghosh pointed out.

According to him, there is an urgent necessity to revise NAAQS aligning with the WHO guidelines.

“At that same time there should be stricter emission controls, promotion of clean energy resources and implementation of effective waste management. What is equally necessary is enhancing public awareness and education,” said Ghosh.

Meanwhile, Delhi-NCR's air quality remained severely poor for the third consecutive day, with the national Capital's Air Quality Index (AQI) reaching a severe level of 409 early on Friday morning and the readings being above the 300 mark in neighbouring cities in Haryana and Uttar Pradesh.

According to the Central Pollution Control Board (CPCB), the region continues to suffer from hazardous pollution levels as winter approaches, with many of the cities in Delhi's neighbourhood registering dangerously high AQI values.