New Delhi, Oct 26 Levels of major air pollutants in the capital during October this year have remained lower compared to most previous years, with data compiled on a dashboard by a private Delhi-based think tank showing a decline in concentrations of particulate matter, nitrogen dioxide and ozone this year.
The public-access dashboard, tabulating Central Pollution Control Board (CPCB) and Commission for Air Quality Management (CAQM) data on various air pollution parameters, has been prepared by Envirocatalysts.
The data, based on averages recorded till October 25 this year against full-month averages for 2015-2025, showed that the average PM2.5 concentration stood at 67 micrograms per cubic metre (µg/m³) in October 2026, compared with 108 µg/m³ in October last year and 147 µg/m³ in 2016 — the highest during the period under observation.
The data showed that average PM2.5 concentration in Delhi stood at 111 µg/m³ in 2024, 103 µg/m³ in 2023, 105 µg/m³ in 2022, 75 µg/m³ in 2021, 133 µg/m³ in 2020, 123 µg/m³ in 2019, 134 µg/m³ in 2018, 115 µg/m³ in 2017, and 121 µg/m³ in 2015 — all of which are higher than this year’s reading.
PM10 levels also registered a decline this year, with the average concentration recorded at 172 µg/m³, as compared to 217 µg/m³ in 2025 and 345 µg/m³ in 2016.
Nitrogen dioxide (NO2) levels averaged 36 µg/m³ in October till date, lower than 48 µg/m³ in 2025 and 79 µg/m³ in 2016, according to the data.
Ozone concentrations stood at 55 µg/m³, compared with 78 µg/m³ last year and 101 µg/m³ in 2015. However, the October average was marginally higher than the 54 µg/m³ recorded in 2023 and 2021.
Carbon monoxide (CO) levels averaged 1.80 milligrams per cubic metre (mg/m³), the same as in 2025 and lower than 2.10 mg/m³ in 2024 and 4.70 mg/m³ in 2016.
The data showed that concentrations of all five pollutants till October 25 this year were lower than their October averages in 2020, when PM2.5 stood at 133 µg/m³, PM10 at 284 µg/m³, NO2 at 59 µg/m³, ozone at 81 µg/m³ and CO at 2.30 mg/m³.
The figures provide a comparison of pollution levels during October, although meteorological conditions, including wind speed, temperature, humidity and rainfall, also influence pollutant concentration and their dispersion.
Despite the decline in the recorded averages, particulate pollution remains a concern. The PM2.5 and PM10 averages of 67 µg/m³ and 172 µg/m³, respectively, were above India’s annual National Ambient Air Quality Standards of 40 µg/m³ and 60 µg/m³, respectively.
As per national standards, the 24-hour limits for PM2.5 and PM10 are 60 µg/m³ and 100 µg/m³, respectively. However, a monthly or period average cannot be directly compared with a 24-hour standard to determine the number of days on which pollution limits were breached.
Fine particulate matter, or PM2.5, can penetrate deep into the lungs and is associated with respiratory and cardiovascular problems, according to experts. PM10 can irritate the airways and aggravate conditions such as asthma.
Nitrogen dioxide, largely associated with combustion sources such as vehicles and industrial activity, can inflame the airways and worsen respiratory conditions. Ground-level ozone can also cause breathing difficulties and reduced lung function.
Carbon monoxide reduces the blood’s capacity to carry oxygen and can affect the heart and brain at elevated concentrations.
The comparative data comes amid lingering concerns over Delhi’s air quality as the city enters its peak pollution season, when unfavourable meteorological conditions can trap pollutants close to the ground and lead to pollution spikes.
(PTI News)
