In the latest “World Air Quality Report 2023” released by Swiss air quality monitoring body IQAir, India landed on the “third-most polluted country” spot after Bangladesh and Pakistan. IQAir report shows the escalating pollution levels in the country comparing to that of the previous year. The country’s air quality continues to pose a significant concern with 42 of her cities featuring in the top 50 most polluted cities worldwide. Begusarai in Bihar has emerged as the most polluted metropolitan area with an average PM2.5 concentration of 118.9 micrograms per cubic metre in 2023 followed by Guwahati as the “second most polluted city” in the world. The City’s PM2.5 concentration doubled from 51 to 105.4 micrograms per cubic meter between 2022 and 2023.
The Swiss air quality monitoring body’s report on Guwahati as the “second-most polluted city”, however, has been rejected by the Assam State Pollution Control Board calling it “unscientific and absurd.” The state board claimed that air pollution in Guwahati is “absolutely under control” and was much less than that shown in the report. The Board further issued a statement contradicting the report of IQAir –“Our data contradicts the report of IQAir, whose data source is not known. As per the IQAir report, the average PM2.5 concentration in Guwahati for 2023 has been reported as 105.4 microgram per cubic meter, which is almost reported at 200% more than the actual recorded value by the government of India through Central Pollution Control Board and the state board”.
There is no denying the fact that Guwahati, over the years, has seen significant increase in pollution levels owing to rapid increase in vehicular emissions, fast industrial growth as well as infrastructure development. With rapid urbanization and infrastructure development that led to severe depletion of green cover, air pollution levels in Guwahati reached alarming proportions.
Situated on the southern bank of the Brahmaputra, Guwahati continues being an administrative capital since days of yore. The largest metropolitan area in north eastern India, Guwahati lost much of its pristine charm with continued urban sprawl. Reports reveal, over 7,000 trees have been felled within 2-3 years to accommodate the expansion of a stretch of the National Highway 37 and construction of bridges, flyovers, riverfront beautification projects, water supply projects, government quarters and halls. Air pollution levels crept up with indiscriminate felling of trees coupled by ongoing construction-related activities. The air quality in Guwahati worsens with the onset of winter. Dust increase particulate matter and worsen air quality during dry months.
In 2012, the then chairman of Assam State Pollution Control Board admitted to the presence of much higher levels of Respirable Suspended Particulate Matter (RPSM) and Suspended Particulate Matter (SPM) between the months of December to March even before the 1990s due to various local geographical reasons.
A research paper – “Strong Radiative Heating due to Wintertime Black Carbon Aerosol in the Brahmaputra Valley” published in Geophysical Research letters in May, 2012–found Guwahati, the largest city in the Brahmaputra River Valley (BRV) to having one of the highest black carbon pollution levels in the world. “The concentration of black carbon pollution during winter observed in the city was higher than levels in the other large cities in India and China, and much higher than in urban locations in Europe and the US. A week-long study using a micro-Aethalometer was conducted during January-February 2011 to measure black carbon (BC) aerosol mass concentrations in Guwahati (India), the largest city in the BRV region. Daily median values of BC mass concentration were 9-41 mu gm(-3), with maxima over 50 mu gm(-3) during evenings and early mornings. Median BC concentrations were higher than in mega cities of India and China, and significantly higher than in urban locations of Europe and USA”, revealed the study.
Black carbon, commonly known as soot, is a component of fine particulate matter (PM 2.5) air pollution, the leading environmental cause of poor health and premature deaths. Black Carbon (BC) aerosols can stay in the atmosphere for a short period (4–12 days) compared to CO2 but contribute significantly to warming of the atmosphere and has direct and indirect impacts on the climate, agriculture, and human health.
Black Carbon has also been described as the third largest warming agent contributing to climate change and considered a dual threat as it pollutes the air and warms the atmosphere. Several studies highlighted the role of BC aerosols in “impeding the development of the atmospheric boundary layer by altering surface radiation energy balances and heating the boundary layer top, thereby exacerbating severe haze pollution in urban centers”.
The prevalence of black carbon has been closely linked to anthropogenic activities including routine operations of factories, industries, vehicular emissions and open biomass burning. In Guwahati, it is basically the burning of Municipal Solid Waste (MSW) or garbage or trash, in the landfill that exacerbates pollution levels.
No more green and clean
Guwahati has been in the bottom when it comes to clean cities in India. Swachh Survekshan 2023 placed Guwahati in the 402nd position out of 446 Urban Local Bodies in the main category (population above one lakh).The city has managed to address only 46 per cent of the daily household waste with only 3 per cent of it segregated at the source. Guwahati generates around 625 tons of garbage each day. About 95 per cent of this waste had been dumped in the Boragaon dumpsite since. The Guwahati Municipal Corporation (GMC) had chosen Boragaon located near the Deepor Beel Wildlife Sanctuary, violating the Wetland (Conservation and Management) Rules, 2010 as well as the Municipal Solid Wastes (Management and Handling) Rules, 2000 polluting a protected site. Degradation of this important water body started heavily with dumping of waste in close proximity of the water body since 2006 flouting all norms of municipal solid waste rules that has been challenged in the National Green Tribunal.
Selected by the Union government to be developed as “smart cities” under Mission Transform India, Guwahati is crumbling under the weight of an expanding population. The 2012 statistics show the number of inhabitants in city metropolitan area climb to a whooping 1.5 million. That number is going to be doubled soon. It has been evaluated that Guwahati metro will house around 2.8 million occupants by 2025.
The burden to manage waste in a smart city is colossal and needs diligent municipal authorities that are also professional and proactive. Smart city guidelines mentions a waste management system that removes household and commercial garbage and disposes of it in an ecologically and economically sound manner while guidelines for water quality mentions treatment of all sewage to prevent the pollution of water bodies and aquifiers. Guwahati does not have a sewage treatment plant—this information was given to a team from the Planning Commission (present NITI Aayog) visiting the dumping site near Deepar Beel in 2008.
Guwahatians feel dismayed by the city’s recent rankings; more so when the concerned authorities remain numb rather than finding workable solutions to address these pressing environmental challenges.