Delhi has been named the most polluted city in India for October 2024, according to a report by the Centre for Research on Energy and Clean Air (CREA). Other cities nearby, like Ghaziabad, Noida, and Gurgaon, which are all part of the National Capital Region (NCR), also ranked among the top 10 most polluted places. 

Capital’s air quality hits alarming levels

In October, Delhi's average level of PM2.5, a harmful air pollutant, went up to 111 µg/m2. This is the highest pollution level Delhi has seen since 2021. Even though the city started using a pollution control plan called the Graded Response Action Plan (GRAP) on October 15 to reduce pollution, the air quality still got much worse.

According to data from CREA, pollution in Delhi didn't just come from local sources. A large part—about 60–70%—of the PM2.5 pollution actually came from outside Delhi, drifting in from other areas. Stubble burning (when farmers burn crop leftovers) from nearby states added less than 10% to the pollution in Delhi, though this started increasing after October 21, based on data from the Ministry of Earth Sciences.

Experts say that Delhi's increasing pollution needs a stronger, wider plan to bring it under control. Sunil Dahiya, founder of Envirocatalysts, explained that local pollution sources in Delhi and the surrounding NCR areas are still not being properly managed. He pointed out that things like car emissions, power plants, brick-making factories, and construction work are all adding to the poor air quality in and around the city.

The CREA analyst pointed out that it's important to focus on pollution sources that are active all year. Industries, transportation, and power plants add to Delhi's pollution throughout the year, causing the pollution levels to go up even more during the winter months.

NCR cities among the top polluted areas

Delhi is not the only city dealing with high pollution. Other cities in the National Capital Region (NCR), such as Muzaffarnagar, Hapur, Meerut, Charkhi Dadri, Greater Noida, and Bahadurgarh, are also among the 10 most polluted cities in India. Uttar Pradesh has six cities in this top 10 list, showing that pollution has gone up a lot in that state too.

In October, Delhi had very few days with good air quality. Only 9 days were rated as “good,” and 5 days were rated as “satisfactory.” However, for 14 days, the air quality was “very poor,” with PM2.5 levels between 121-250 µg/m3. This was more than double the average pollution level in September.

Cleanest cities in India for October 2024

Aizawl, the capital of Mizoram, was the cleanest city in October, with a very low PM2.5 level of just 6 µg/m2. Some cities in Karnataka and Tamil Nadu also had low pollution levels, helped by seasonal rains from the southwest and northeast monsoons.