It's not just the Indian national capital which is reeling under air pollution, Kolkata "surpasses" New Delhi many a times during October to January when it comes to poor air quality, a resource conservation specialist said.
According to Rajeev Sharma, Resource Conservation Specialist, Embassy of the US, New Delhi, there is a very short window when the air quality in Kolkata is at its best.
"Our data showed that between January 2014 to June 2016 (in these years), there is a very small time in Kolkata when the air is breathable (as per US Environmental Protection Agency)," Sharma said here at "Kolkata's Air Quality -- Navigating Solutions" workshop at the American Centre in collaboration with the Global Change Programme of Jadavpur University and banglanatak.com.
The US embassy and consulates' air quality monitors measure airborne fine particulate matter (commonly referred to as PM 2.5 because they are less than or equal to 2.5 microns in diameter) on the compounds of the embassy and consulates.
The air quality data collected by the US mission in India is translated into actionable information by the US Environmental Protection Agency's (EPA) NowCast algorithm. This algorithm converts raw PM 2.5 readings into an air quality index (AQI) value that can help inform health-related decisions.
Expanding on the trend, Sharma said towards September to January, Kolkata "defeats" and "surpasses" Delhi "many a times" each year in AQI.
"As per US EPA, in June, July, August and towards the end of September, that is the best time period, when the air is breathable, best air after that the air quality goes into the unhealthy area," Sharma said.