Shillong, Dec 7: Meghalaya’s air quality fails national and global standards for very fine particulate matter (PM 2.5) year-round, a report from the Centre for Research on Energy and Clean Air (CREA), an independent research organisation, has said.
PM 2.5 refers to tiny inhalable airborne particles (dust, soot, smoke) less than 2.5 micrometres in diameter, making them 30 times smaller than a hair and a major health risk as they penetrate deep into the lungs and bloodstream, causing respiratory, heart and neurological issues from sources like vehicle emissions, industry and fires.
The report applied a novel machine learning algorithm to derive estimates of population-weighted PM 2.5 concentrations for India using ground-level air quality measurements and remote sensing data.
Sixty per cent of India’s 749 districts breach the annual National Ambient Air Quality Standard (NAAQS) of 40 µg/m³, with no district meeting World Health Organisation (WHO) PM 2.5 guideline of 5 µg/m³.
Meghalaya is one of a few states and territories that maintained a 100 per cent district-level exceedance in all seasons except for the monsoon, the others being Delhi, Tripura, Punjab, Haryana, Himachal Pradesh and Chandigarh.
Khasi-Jaintia Hills, much of Assam, Tripura and parts of Mizoram actually experienced year-round exceedance, even during the monsoons. Garo Hills’ levels of PM 2.5 concentrations, on the other hand, fall below the NAAQS limit during the rainy season.
The CREA said that in many districts and states limited monitoring infrastructure makes it difficult to accurately capture real-world exposure. “Monitoring stations are often located in cleaner areas, away from industrial zones or busy corridors, which leads to underestimation of actual pollution levels. For example, an industrial hub situated on the outskirts of a compliant district may appear clean because its nearest monitor is placed in a less polluted suburban zone.”
Its report includes satellite observations to try and correct for some of this and provide a more accurate picture that covers rural India as well.
Although North India, especially Delhi, is seen as the centre of the air pollution crisis in the country, the CREA stated that the Eastern and North Eastern states showed similarly concerning levels, with PM 2.5 average concentrations in Bihar, West Bengal, Jharkhand, Odisha, Assam, Meghalaya, Nagaland, Tripura and Arunachal Pradesh all above the NAAQS.
“This persistent presence of North Eastern states in the most polluted category challenges the conventional focus on northern plains and highlights the need for region-specific air quality interventions,” the report stated.
The Meghalaya average for winter, when dense cold air, lack of rain and greater use of charcoal and wood fires for warmth increases pollution levels, is the seventh-worst in the country at 70 µg/m³ of PM 2.5, behind only Delhi (135), Chandigarh (90), West Bengal (86), Tripura (83), Assam (83) and Bihar (78).
The CREA advised expanding clean air planning beyond just a few big polluting cities. “States should develop district-level air quality action plans, guided by satellite data to identify hotspots, prioritise high-exposure populations and allocate mitigation resources efficiently,” it said
The report also called for greater use of satellite data in air quality governance; targeting regional and sectoral emission sources, such as power generation, industrial activity, biomass burning and transport; incentivising state-level accountability and performance tracking; and adopting management frameworks that go beyond individual states as pollution travels across administrative borders.
