New in October: Good air days on a trot

NOIDA/GHAZIABAD: October AQI scales aren't usually in the green.
In a typical year, those living in NCR start pulling out their air purifiers as the AQI begins veering towards yellow, then orange, and finally in the red.
Not this time. Days of downpour have had a cleansing effect at a time norm-ally marked as the beginning of the annual winter pollution season.
Data shows that Ghaziabad and Greater Noida have recorded four 'good' air days - when the 24-hour average air quality index (AQI) is up to 50 - for four days in a row.
From October 7 to 10, the AQI in Ghaziabad was in this order: 44, 26, 14 and 19.
The same for Greater Noida was 49, 43, 23 and 26.
In Noida, three out of the four days were 'good'. The city's AQI was 50 on October 7, 48 on October 8, and 49 on October 10. The index slipped into the 'satisfactory' category on October 9, when it was 55.
Officials of the UP Pollution Control Board admitted it was unusual for NCR cities to breathe in clean air during this time of the year, when pollutants are normally suspended in the air due to colder temperatures and other weather conditions, resulting in a dome of toxic smog.
"On Saturday (October 8), Ghaziabad's AQI was even better than Shillong, which records the most number of 'good' air days in the country. The AQI was 28 in Shillong while it was 26 in Ghaziabad," an official said.
Comparison with the last few years is also an indication of the anomaly that this is. Since 2018, most of the 'good' air days were limited to the monsoon season and the month of October never recorded these on a trot.
This year, Ghaziabad has seen eight 'good' air days - half of which were before October and an equal amount over the past few days. In Greater Noida, four of the total nine 'good' air days this year fell in October. In Noida, the October count is three out of six days.
In 2021, Ghaziabad saw a total of five 'good' air days, Greater Noida recorded seven, and Noida, six. None of these were consecutive days of AQI less than 50 in October.
Similarly, in 2020, the monsoon that came on the back of pandemic lockdowns pushed up the number of 'good' air days to 13 in Ghaziabad, 16 in Greater Noida and 20 in Noida. Again, none of these were straight days of AQI less than/equal to 50 in October.
The AQI trend remained the same in 2019 and 2018.
Ghaziabad has four pollution monitoring stations. In Greater Noida, there are two monitoring stations and Noida has four.