Byrnihat a small industrial town on the Assam-Meghalaya border, has recorded the highest air pollution levels in India during the first half of 2025, according to a new analysis by the Centre for Research on Energy and Clean Air (CREA). With PM2.5 concentrations averaging 133 micrograms per cubic meter, Byrnihat has overtaken Delhi, which recorded 87 µg/m³ in the same period.
The spike in pollution levels has drawn national attention, especially since Byrnihat is not traditionally known as an air quality hotspot. CREA attributes the city’s toxic air to a combination of unregulated industrial activity, vehicular emissions, and biomass burning. Unlike metropolitan areas that have stricter monitoring and regulatory mechanisms, smaller towns like Byrnihat often lack robust pollution control infrastructure.
Other heavily polluted cities on the list include Ghaziabad, Gurugram, and Patna, all grappling with similar pollution sources. While Delhi has taken steps to curtail vehicle emissions and implement seasonal restrictions, CREA notes that industrial emissions and agricultural burning remain widespread across northern India, including the Byrnihat region.
Experts stress that without a comprehensive and enforceable strategy including mandatory pollution control technologies for industries, better public transport systems, and stricter enforcement of emission standards India smaller urban centres could become new air pollution epicentres.
Byrnihat’s rise to the top of the pollution charts highlights the growing need for air quality interventions beyond metro cities, as toxic air continues to threaten public health across diverse geographies in India.