Why Air Pollution In The Northeast Needs Urgent Attention
In 2021, the Delhi-based Centre for Science and Environment (CSE) had also analysed air pollution in India and cautioned about the rising pollution in the Northeast. “Signs of worsening air quality in this region has not drawn adequate public attention. Winter air quality in Guwahati can be almost as bad as what we see in NCR and UP cities. Smaller cities like Agartala and Kohima have begun to experience high pollution days,” CSE found. Winter air pollution in Delhi and the National Capital Region (NCR) caught the country’s attention as early as October. Just last week, the government revoked stage III of the graded action plan—targeted interventions at different levels of pollution. The Northeast faces a similar crisis, but with far less public attention. States such as Assam and Tripura now have poor air quality for a large part of the year, and within the larger NE region, some cities have air quality indices as bad as their NCR counterparts. Cities such as Guwahati and Silchar have not been able to reduce their PM 10 concentrations and the city of Byrnihat, an industrial town on the border of Assam and Meghalaya, ranks as one of the most polluted places in the world. Experts warn that air quality is a problem beyond the non-attainment cities targeted under India’s National Clean Air Programme (NCAP) and that India needs to look at airsheds instead of cities. While meteorological factors such as temperature and geographical factors such as hills and river banks help reveal the problem of polluted air, sources that contribute to this pollution year-round must be identified and addressed. IndiaSpend wrote to the Union environment ministry, Central Pollution Control Board and the chief ministers of each state in the Northeast with detailed questions on what steps are being taken to control air pollution. We will update this story when we receive a response. The hidden hotspot India’s Northeast has been bestowed with some of the most dense forests in India and the hill states generally enjoy good air quality. In fact, the region is also home to Gangtok, the Indian city with the cleanest air in 2024. But over the years, air quality in the larger Northeast region has become a cause for concern. Air quality is categorised between good and severe based on ambient concentrations of pollutants and their likely health impacts. India measures pollutants such as particulate matter PM 10, PM 2.5, NO2, SO2 and others to determine an air quality index for a given place at a given time. Particulate matter measuring less than 10 micrometre in diameter has the ability to penetrate deep into the respiratory system, as we explained in October 2023. Among these particles, those with a diameter of less than 2.5 micrometre, known as PM 2.5, pose the most significant health risk. PM 2.5 particles are capable of infiltrating the lungs and occasionally entering the bloodstream, resulting in serious health consequences. India measures its air quality as per the National Ambient Air Quality Standards or NAAQS which are more lax than the standards recommended by the World Health Organisation. Overall in India, PM 10 concentrations almost doubled from 1994-08 levels to 2009-19 levels due to various factors such as increased industrial and commercial activities, urbanisation, and changes in land use patterns. The Northeast is no exception. For instance, a satellite-based assessment of air quality by the Centre for Research on Energy and Clean Air (CREA) found that in 2024, except in the monsoon months, every district in Tripura and Meghalaya exceeded the NAAQS for PM 2.5. Even in Nagaland, 11 of 12 districts exceeded the standards. Along with Delhi and Punjab, the analysis pointed to Assam and Tripura (six of eight districts) as having high PM 2.5 levels even during the monsoon, “showing that meteorological relief alone is insufficient to overcome their substantial baseline emissions”. Among India's 50 most polluted districts, Assam contributed 11—one-third of its total districts—while Delhi saw all its 11 districts in the list. Tripura had three, and Meghalaya and Nagaland had one each.
