Varanasi Witnesses 72 Per Cent Pollution Reduction with India's National Clean Air Programme

Similarly, for PM10, data across five years was available for 46 cities. Of these, 24 cities saw an improvement in PM10 levels.

The stated goal of the Rs 9,631-crore National Clean Air Programme (NCAP) is to reduce average particulate matter concentrations 40 per cent by 2026 (compared to 2017) in 131 cities.

When the programme was initiated, the aim was to cut pollution 20-40 per cent by 2024 in these cities but this goalpost was later shifted to 2026.

Between 2019 and 2023, Varanasi achieved a significant reduction in PM2.5 and PM10 levels. It shows a 72 per cent reduction in PM2.5 (from 96 to 26.9 ug/m3) and a 69 per cent reduction in PM10 (from 202.5 to 62.4 ug/m3).

Likewise, Agra and Jodhpur saw significantly lower PM2.5 levels, and Talcher in Odisha saw a considerable PM10 reduction.

In 2023, Delhi recorded the highest PM2.5 levels of 102 ug/m3, a decrease of 2.5 per cent compared to 2022.

Patna exhibited the highest PM10 levels in 2023 at 212.1 ug/m3, an increase of 10.7 per cent compared to 2022.

Among the top 20 most polluted cities of 2023, air quality improvements in PM2.5 were observed in 10 out of 15 cities, including Delhi and Patna, when examining air quality data from 2019 to 2023. As far as PM10 was concerned, a total of 14 out of 19 cities saw improvements.

Silchar in Assam recorded the lowest PM2.5 level in 2023 at 9.6 ug/m3. However, it remains noteworthy that this seemingly low level is nearly double the WHO’s stipulated safe limit of 5 ug/m3. Silchar also recorded the lowest PM10 level at 29.2 ug/m3. However, this seemingly moderate value is nearly double the WHO safe limit of 15 ug/m3.

Air quality monitoring strengthened in most cities, with a significant number seeing an increase in active monitors, and almost all cities improved their uptime, says the analysis.

However, challenges persist, with certain cities experiencing increases in pollution concentrations.

The dispersion of pollutants over a city is influenced by several factors, including its geographical location, diverse sources of particulate matter emissions, and meteorological conditions. Notably, the government has installed a number of new air quality monitoring stations in many of the NCAP cities, which is a positive development indeed.

That said, an average of data from two monitors in crowded locations of a city can provide a different picture of air quality compared to an average of, say, data from five stations spread across the city.

Saying the National Clean Air Programme has made noteworthy progress in tackling air pollution, witnessing notable reductions in PM2.5 and PM10 levels in top polluted cities, Aarti Khosla, Director, Climate Trends, said, “Despite these positive strides, persistent challenges exist, with some urban areas facing an uptick in pollution concentrations.

“The programme's revised goal of a 40 per cent reduction in particulate matter by 2026 reflects a commitment to ambitious environmental targets.

“As cities add new air quality monitoring stations, strengthened monitoring will give a better picture of the problem and allow for better mitigation measures. These must feed into the next phase of the NCAP and sustained efforts must continue for achieving nationwide cleaner air, underscoring the importance of robust regulatory frameworks aligned with global standards and public health gains.”