Delhi breathes easier: 10-month AQI data shows relative improvement air quality

Oct 31, 2023

New Delhi [India], October 31 : The daily average air quality in Delhi, for the 10-month period between January - October 2023, registers its best index as compared to the corresponding period during the last 6 years (barring the COVID affected 2020), thus establishing a continual trend of relative improvement in air quality of Delhi-NCR, the Ministry of Environment said in a statement on Tuesday.
The daily average AQI for Delhi during the above-noted period during the current year has been recorded as 172 against 187 in 2022, 179 in 2021, 156 in 2020, 193 in 2019, and 201 in 2018 respectively, during the corresponding period, the statement said.
AQI levels are greatly impacted by the levels of rainfall/ precipitation and wind speed which are prime facilitators for dispersal of the pollutants/emissions. Effective dispersal is a must for good air quality, even if there is a control/reduction in the quantum of emissions from all the primary sources in the region, added the statement.
Delhi recorded a single day scant rainfall of only 5.4 mm in the month of October 2023 as against 6 and 7 days of rainfall during the months of October 2022 and October 2021, with a cumulative rainfall of approximately 129 and 123 mm respectively during the month.
The average wind speed during the month of October 2023 was also relatively slower and spells of absolute "still" conditions were also witnessed during the month.
Despite this heavy rainfall deficit and low wind speeds, the daily average AQI during the month of October 2023 at 219 has only been slightly higher than the daily average AQI of 210 during October 2022, read the statement further.
Delhi has also witnessed the highest number of days (206) with "Good" to "Moderate" air quality (Daily Average AQI<200) during January - October 2023 as compared to the corresponding period in the previous years (barring the COVID-affected 2020).
"Good" to "Moderate" air quality days during this period in the previous years were only 160 in 2022, 197 in 2021, 175 in 2019, and 157 in 2018 respectively. This period in 2023 has also witnessed a remarkable reduction in daily avg. PM2.5 and PM10 concentrations over the last 6 years.
The period from January-October in 2023 recorded a daily average PM2.5 concentration of about 75 ugm/m3 as against ranging from 81-95 ugm/m3 during the corresponding periods from 2017 to 2022 (barring the COVID affected 2020).
Likewise, the daily average PM10 concentration in Delhi has been about 173 ugm/m3, which is much lower than a range of 182-220 ugm/m3 during the corresponding periods from 2017 to 2022 (barring the COVID affected 2020), mentioned the official statement.
In the wake of highly unfavorable meteorological and climatic conditions prevailing around this point of time, measures under GRAP Stage-II were invoked proactively on 21.10.2023 so as to intensify the preventive measures towards endeavouring delayed invoking of Stage-III of the GRAP as much as possible. GRAP Stage-III in previous years was invoked in the last week of October which has not been the case during 2023, said the statement.
The Commission once again urges the stakeholders to effectively implement all directions and guidelines related to the abatement of air pollution, particularly under the schedule of the GRAP and the citizens to follow the Citizen Charter in our joint pursuit for better air quality.