Gurugram’s winter pollution in 2019 just as bad as 2018, shows data
Despite perceptions that Gurugram had a cleaner winter in 2019 as compared to 2018, an analysis of the city’s daily Air Quality Index (AQI) readings reveals that pollution levels have remained more or less the same. December, with an average 31-day index reading of 265, was in the ‘poor’ category, as per the Central Pollution Control Board’s (CPCB) daily AQI bulletin data. December saw zero days of ‘severe’ air, four days of ‘poor’ air, 10 days of moderate air, and 17 days of ‘very poor’ air.
This was only a marginal decrease from December 2018, when the city saw nine days of ‘poor’ air quality, seven days of ‘moderate’ air quality, eight days of ‘very poor’ air quality and two days of ‘severe’ air quality(while Gurugram remained absent from the AQI bulletin on four days). The city’s average 27-day day AQI reading in December 2018 was 274, also in the ‘poor’ category.
Marginal change in air quality
The city has recently also seen two spells of favourable air quality in November, which is unusual for this time of the year, thanks to meteorological conditions, such as unexpected rainfall and high wind speeds. Officials and some experts, too, maintained that Gurugram is experiencing a ‘cleaner’ winter than it did last year. However, a similar comparison of the Air Quality Index (AQI) data (for November 2018 and 2019) shows that the improvement is only marginal.
An analysis of AQI data for November 2018 shows that the city recorded an average 30-day AQI reading of 283, which is just marginally more than what it recorded this year, i.e. 278. November this year recorded six days of ‘severe’ air, six days of ‘very poor’, eight days of ‘moderate’, eight days of ‘poor’, and just two days of ‘satisfactory’ air quality. During the same month in 2018, Gurugram recorded mostly ‘very poor’ and ‘poor’ air days, at 12 each, while witnessing one day of ‘severe’ and only four days of ‘moderate’ air.
Deterioration between October and November
Going back even earlier, air quality in the city deteriorated by 1.3 times between October and November in 2019. While November recorded an average 30-day AQI reading of 278, in October the city had recorded a reading of 207, as per the air quality monitoring data available with the Haryana State Pollution Control Board (HSPCB). Since July 2019, when the city recorded an average AQI reading of 50 (satisfactory), air quality has deteriorated by 5.5 times.
Explaining these numbers, Sachin Panwar, a city-based air quality scientist, said, “Last year, the air quality had stabilised in the ‘very poor’ to ‘poor’ categories once temperatures began to fall, but this year, the pollution levels are fluctuating more. The highs are higher, while the lows, which create the impression of a cleaner period of air quality, are lower. Taken together for the month, though, the improvement isn’t remarkable even with favourable weather.”
A scientist at the CPCB’s air quality lab in Delhi explained that the late retreating monsoon has had a major role to play in bringing about favourable weather events. Both the CPCB and HSPCB officials did not provide specific responses to HT’s analysis of the AQI data, saying they would need to examine it before commenting.