Mumbai's air quality has seen a notable decline since the pre-pandemic era, with toxic PM2.5 levels rising by a troubling 2.6% since 2019, according to a recent report by India Times. This alarming trend has made the city a pollution hotspot, with winter PM2.5 levels exceeding 45 µg/m³ in certain areas. The report, which commemorates the sixth anniversary of the National Clean Air Programme (NCAP), emphasizes that locations such as Mazgaon (57.1 µg/m³) and other industrially dense regions are contributing significantly to the air quality crisis.

Meanwhile, Delhi has been ranked as India's second most polluted city with an average PM2.5 level of 107 µg/m³ for 2024, trailing only Byrnihat, Assam (127.3 µg/m³), as per the same report from India Times. This continues a concerning trend for the national capital, which reported a minimal reduction of just 1.3% in PM2.5 levels since 2019. Areas like Anand Vihar and Jahangirpuri are consistently among the worst affected, with levels surpassing hazardous thresholds.

Both reports underscore the impact of urbanization and vehicular emissions on air quality, with Delhi's pollution levels nearly three times higher than those of Mumbai (36.1 µg/m³) and Bengaluru (33 µg/m³). The ongoing challenges include high vehicle density, inefficient emission regulations, and seasonal factors like stubble burning in surrounding states exacerbating the situation.

Overall, as both cities continue to grapple with air quality issues, experts stress the urgent need for comprehensive measures including enhanced public transport systems, stringent controls on emissions, and regional collaboration to combat these environmental crises effectively. "Delhi's slow progress reflects the need for deeper structural changes and sustained efforts," stated Ronak Sutaria, founder of Respirer Living Sciences, reinforcing the call for innovative solutions and local interventions to meet the NCAP's ambitious targets.