Choked city: Guwahati’s breathless battle with dust & development

The city is choking beneath a blanket of dust. In March last year, the "Gateway to the Northeast" was ranked the second most polluted city in the country—an alarming distinction reported by a Swiss air quality firm. Since then, the situation appears to have only deteriorated.

The Pollution Control Board of Assam (PCBA) recorded Guwahati’s ambient air quality across key pollutants in 2021 with sulphur dioxide at 6.4 micrograms/ metre cube, nitrogen dioxide at 14.6 micrograms/ metre cube, and PM10 rising to 108.0 micrograms/ metre cube.

The average Air Quality Index (AQI) for the city during 2022–23 was recorded at 114. Although data for 2023–24 and 2024–25 is available, it was still being compiled by the PCBA at the time of filing this report.

Among those struggling the most, it is children who are bearing the brunt. As one of the most vulnerable groups, they face a heightened risk of respiratory illnesses—largely due to their shorter height, which puts them closer to the suspended dust particles that linger at lower levels.

So, what’s driving Guwahati’s worsening air quality? Is it the relentless construction activity that now dots nearly every corner of the city—or are there other culprits at play?

In this report, we set out to trace the causes behind the city’s deteriorating air and examine how it’s impacting children in particular, while also casting a spotlight on what the government is doing to address the crisis.

What’s causing pollution?

Dr Arup Kumar Misra, Chairman of the Pollution Control Board, Assam (PCBA), pointed to multiple factors contributing to Guwahati’s deteriorating air quality—chief among them, rampant infrastructure development.

“Barring the Noonmati refinery—which has its own self-contained pollution control mechanisms—Guwahati’s air pollution is not industrial in nature. In fact, there are hardly any industries within city limits. The primary cause is the scale of infrastructure work being carried out across the city,” Misra said.

Over the past few years, Guwahati has seen a surge in construction activity, including multiple flyovers and bridges—projects that have significantly impacted ambient air quality. 

A flyover under construction in Guwahati (AT Photo)

Adding to the burden is vehicular growth. According to data from the Transport Department, around 10,000 personal vehicles are registered each month in Guwahati and Kamrup (Metro) district, contributing heavily to emissions. 

Vehicles plying on the streets in Guwahati (AT Photo)

Meanwhile, ongoing civic works—including road excavation for water supply pipelines by the Jal Board, the laying of optical fibre cables, and the shift from LPG cylinders to piped gas under the Gas Grid programme—have only added to the dust load in the air.

A prolonged lack of rainfall has further worsened conditions. “Regular showers help settle dust and particulate matter. But long dry spells have allowed pollutants to remain suspended for longer durations, amplifying anthropogenic—or man-made—factors,” Misra noted. According to recent IMD data, Assam recorded a 26% rainfall deficit in March, further exacerbating the situation.

Misra emphasised that air pollution in Guwahati is primarily mechanical, with dust being the dominant element. “Unlike larger metros like Mumbai or states like Gujarat, where chemical pollutants play a major role, Assam’s pollution is largely caused by dust and sand,” he explained.

A survey conducted across 106 urban local bodies—from Barak Valley to the Brahmaputra Valley—reinforced this finding, identifying dust as the key pollutant in much of Assam, and particularly in Guwahati.

“Assam in general, and Guwahati in particular, is passing through a transitional phase. Major metropolitan cities in the country such as New Delhi, Mumbai, and Kolkata have also been through similar phases. Our challenges are not unique—there has always been a debate between environment and development, and often, a price is paid for progress,” Misra explained.

The curious case of Byrnihat

Just 14 km from Guwahati lies the Byrnihat industrial cluster, which experts say has become a major contributor to the city’s worsening air pollution.

“Byrnihat was somewhat of a compromise between Assam and Meghalaya when the latter became a state. Situated 90 km from Shillong and just 14 km from Guwahati, it was a convenient location, especially in the 1970s and ’80s, given its ample land and water availability on both sides,” explained environmental expert Misra.

However, decades later, Byrnihat now faces a serious air pollution crisis, largely due to what Misra described as the unchecked growth of industries.

A section of the cluster falls under the Critically Polluted Area (CPA) category—a designation highlighting the severity of the pollution. Roughly 2.9 km of Byrnihat lies within Meghalaya, while about 3.1 km falls in Assam.

“On the Assam side alone, there are 39 industries. Of these, 18 fall under the red category (the most polluting), 16 under the orange category, and the rest are classified as green,” Misra said. These include stone crushers, coal crushers, and grinding units for cement production.

A file image of the industrial cluster in Byrnihat (AT Photo)

To address the issue, the Pollution Control Board of Assam (PCBA) has taken steps such as restricting vehicular movement—particularly trucks transporting raw materials—to and from certain high-emission industries like cement manufacturing.

“Interestingly, the loading and unloading of fly ash bags for the cement industry is a major source of pollution. When dropped from a height, these bags release fine particles that remain suspended in the air,” Misra noted.

Other mitigation efforts include planting fast-growing native trees along stretches of NH 37 and NH 14, in collaboration with the National Highways Authority of India (NHAI) and the Forest Department.

Misra added that both the Assam and Meghalaya governments are planning to jointly tackle the issue. “A joint monitoring committee will be set up, with both state governments coordinating regular inspections through their respective district administrations,” he said.

Particulate matter menace

Paediatrician Dr Rekha Borkotoky echoed the concern, pointing out that children, with developing immune systems and higher exposure to outdoor air due to school and play, are particularly susceptible.

“Particulate matter, being extremely fine, can enter the bloodstream and trigger various diseases. Early exposure can lead to respiratory conditions like asthma, allergic rhinitis, and pneumonia. Later in life, it can manifest as chronic obstructive pulmonary disease (COPD) and even cardiac issues,” she warned.

Dr Borkotoky also highlighted a worrying trend known as airway remodelling, where repeated exposure to pollutants and long-term use of respiratory drugs result in reduced drug effectiveness.

“What’s alarming is not just the use of these drugs, but the fact that children require them in the first place. Airway remodelling makes them unresponsive to medication over time. These are often the children who go on to develop COPD or heart conditions in adulthood,” she said.

She further observed a rising incidence of neuro-cognitive issues in children—not always directly linked to pollution, but possibly aggravated by it.

“There’s increasing concern about irritability, loss of focus, and even autism in children. While more research is needed, there is speculation that maternal exposure to air pollutants could play a role,” she added.

On the subject of drug therapy for respiratory issues, Dr Borkotoky stressed that inhalers are a safer alternative to oral medication.

“Inhalers specifically target the lungs, unlike oral drugs that enter the bloodstream and impact other organs like the kidneys, brain, or liver. Moreover, inhalers use lower dosages, making them a safer option,” she said.

Reassuringly, she added, most children eventually outgrow respiratory conditions by adolescence. “Only a small number go on to become adult asthmatics,” Dr Borkotoky noted.

PCBA’s mitigation measures

The PCBA has introduced several initiatives to curb air pollution in and around Guwahati. One key step is daily stack monitoring, where industries are required to measure emissions and ensure they are within limits set by the Minimum National Standards (MINAS) for pollutants like PM 2.5, carbon, ozone, nitrogen oxide, and sulphur oxide.

“Industries are mandated to monitor emissions regularly and submit reports so we can evaluate their compliance,” Misra explained.

Other key measures:

• Restricting night-time operations of certain industries
• Enforcing the proper use of pollution control devices
• Planting fast-growing native trees along highways
• Increasing the number of electric vehicles (EVs)—with around 200 green buses now operating in the city
• Deploying 40 garbage collection vehicles to prevent open dumping
• Using water sprinkler vehicles to settle dust particles

Misra also pointed to community engagement as a key part of the solution. Programmes like the Nagar Van initiative for urban forestry and the National Clean Air Programme (NCAP) launched in January 2019 aim to involve citizens in clean air efforts.

“Buying expensive water sprinklers is not a cure-all. Real change comes when individuals stop burning household waste and maintain their private vehicles properly. Public and mass transport should be the preferred choice,” he said.

Water sprinklers at work (AT Photo)

During construction, environmental safeguards must also be observed. As per High Court directives, water sprinkling is mandated three times a day at construction sites—a measure closely monitored by the PCBA.

“Everyone understands the importance of this. In fact, there’s a growing opinion that we should increase it to five times a day,” Misra added.

The roadmap ahead

According to the Pollution Control Board of Assam (PCBA), air pollution knows no boundaries. Its control and mitigation require a cross-sectoral, multidisciplinary, and inter-departmental approach.

“Eight organisations are involved in managing air pollution in Guwahati, including the PCBA, Public Works Department, Transport Department, Department of Housing and Urban Affairs, Guwahati Municipal Corporation, GMDA, Guwahati Smart City Project, and the Forest Department,” said Misra.

Construction activities carried out in Guwahati (AT Photo)

Looking ahead, Misra emphasised the urgent need to eliminate diesel usage and stop the burning of waste and construction debris. He stressed the importance of shifting to eco-friendly vehicles powered by green hydrogen and compressed natural gas (CNG).

He also mentioned the expansion of community-based efforts such as the National Clean Air Programme (NCAP), which will soon evolve into NCAP 2.0, focusing on waste management and treatment alongside air quality initiatives.

A key concept Misra advocated for is the adoption of the air shed approach to pollution control.

“Instead of a narrow, city-centric approach, we need to think in terms of the air shed. Air doesn’t respect boundaries—it travels freely and is shared by all. Our strategy must reflect that reality,” he said.

Dr Borkotoky noted that in addition to pollutants from construction sites, domestic sources such as sprays, deodorants, and insect repellents also contribute to poor air quality. Highlighting the vulnerability of children, she stressed the importance of preventive care.

“The best way to mitigate respiratory illnesses is through prevention. Parents must be aware of their children’s triggers. If a child is prone to wheezing, wearing a mask while going to school or stepping outdoors can help. Teachers too can play a key role in educating children on self-care,” she said.

Calling for societal support for clean air initiatives, she said that planting more trees and creating green spaces and public parks can help in this regard. She echoed Misra’s advocacy for renewable and sustainable energy sources, urging a move away from fossil fuels like diesel and petrol.

“Ultimately, it is the collective behaviour of individuals and industries that will drive change. Without their cooperation, rules and regulations alone will have little impact,” Misra concluded.

Citizen-led initiatives will go a long way in mitigating air pollution in the city (AT Photo)