A THICK, dirty fog often settles over Dhaka by late morning. This vast, overcrowded metropolis, now home to over 20 million people, is grappling with a dire environmental emergency. According to the World Bank, in 2019, air pollution, contaminated water, poor sanitation and exposure to lead were responsible for more than 272,000 premature deaths in Bangladesh. These environmental hazards cost the country approximately 17.6 per cent of its total gross domestic product. Dhaka, bearing the brunt, endures noxious air and polluted water daily. Studies show Bangladesh has the worst air pollution globally in terms of tiny particulate matter, which shortens average life expectancy by nearly seven years. In Dhaka, PM2.5 levels 鈥� a particularly harmful pollutant 鈥� exceed 70 micrograms per cubic metre, far above the World Health Organisation鈥檚 safe limit. If pollution were brought down to acceptable levels, residents of Dhaka could expect to live around eight years longer. The city now stands as a real-time case study of the devastation wrought by rapid, unplanned urban expansion.
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Blanket of dirty air
DHAKA鈥橲 air is a toxic mix of gases and dust. Every day, smoke from vehicles blends with emissions from coal-burning, diesel-powered engines and cooking fires. Research indicates that emissions from factories, traffic congestion and the open burning of waste are the primary culprits. The situation worsens in winter, when cooler air traps pollutants close to the ground. The Air Quality Index frequently enters the hazardous zone. In 2020, the city鈥檚 annual average PM2.5 reading stood at 77, more than sevenfold the WHO鈥檚 safe threshold of 10. On certain days, the figures rise even higher.
Prolonged exposure to such air can be fatal. WHO estimates suggest that roughly 108,000 Bangladeshis die annually from outdoor air pollution, many of them in Dhaka. Doctors across the city report a worrying rise in asthma, cardiovascular issues and chronic respiratory illnesses. Children, in particular, show signs of compromised lung function. These health conditions are not just personal tragedies, they have broader economic implications as workers, especially in poorer neighbourhoods, fall ill and are unable to work.
Air pollution in Dhaka also has regional consequences. Polluted air travels across borders, affecting parts of India and Nepal. Dhaka and New Delhi frequently top the list of the world鈥檚 most polluted capitals. Experts argue that the problem cannot be solved by Dhaka alone. Regional cooperation is vital. Nevertheless, local action remains urgent. Targeted steps, shutting down or upgrading polluting factories, replacing old buses with cleaner models and halting open waste burning, could yield substantial improvements. One study identifies the most effective measures as stricter industrial regulations, enhanced waste management, and greener transport systems. Cleaning the air ultimately means addressing deeper dysfunctions in traffic regulation and industrial policy.
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Rivers now sewers
IF THE air is foul, the water in Dhaka is equally contaminated. The unchecked proliferation of industry has transformed once-lively rivers into industrial drains. The Buriganga, once a vital waterway, is now polluted with chemical effluent. Government data and local testimonies confirm that dyes, bleaching agents, and untreated sewage are routinely dumped into the river. Residents describe the water as black and putrid, devoid of fish and aquatic life. During the dry season, experts declare the river to be 鈥榖iologically dead.鈥� Yet children are still seen playing in this water, often falling ill with skin infections, diarrhoea and eye ailments.
This reflects a larger crisis: a significant portion of Dhaka鈥檚 population lacks access to safe, clean drinking water. The city鈥檚 main water supply network cannot meet demand, and parts of it are linked to polluted rivers. In low-income areas, residents rely on shallow wells and shared public taps, many of which are contaminated with bacteria and arsenic. The World Bank reports that most rivers in Bangladesh are heavily polluted due to industrial runoff, plastic waste and untreated sewage. Waterborne illnesses such as cholera, typhoid and hepatitis routinely break out, particularly during the monsoon, when floodwaters mix with contaminated waste. Mosquitoes breeding in stagnant, polluted pools also exacerbate the spread of dengue. Poor sanitation infrastructure, including open drains and makeshift toilets, intensifies these public health threats. Experts say the expansion of treatment plants, better toilets and improved waste systems could save thousands of lives annually.
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Dirty soil, dangerous waste
EVEN the soil beneath Dhaka鈥檚 feet is poisoned. Toxic industrial waste and household garbage accumulate along the city鈥檚 fringes. In both older industrial zones and newer peri-urban areas, people cultivate vegetables and extract groundwater from land that is chemically contaminated. A study in Savar, where many leather-processing tanneries were relocated, found soil chromium levels at 3,220 mg/kg, over 32 times the safe limit set by WHO/FAO. Vegetables grown in these soils contained dangerous levels of lead, zinc, and cadmium, putting children at high risk of cancer and developmental disorders. Within Dhaka, scrapyards and metal workshops further leak hazardous substances. Battery acid, paint flakes and heavy metals pollute the very soil where street children often play.
Pollution does not stay in one place. In the monsoon, rivers flood and deposit toxic sediment into farmlands. In the dry season, winds carry dust from waste heaps into water sources, food chains, and homes.
At the heart of these interlinked problems is the failure to manage waste. Less than half of Dhaka鈥檚 solid waste is officially collected. The remainder is incinerated in open pits or dumped indiscriminately. In informal settlements, plastic and refuse are often burned outdoors, emitting poisonous smoke and microplastics. Trucks offload domestic and industrial waste along rivers. When it rains, this toxic sludge is flushed into open drains. During hot weather, it releases noxious gases. A World Bank study of Lagos found similar trends: absent robust waste infrastructure, communities resort to burning and illegal dumping, releasing hazardous pollutants. Dhaka, too, is paying the price for systemic neglect.
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Global problem听
DHAKA is not alone. Across South Asia, cities like Delhi, Lahore and Kabul also rank among the world鈥檚 most polluted. Dhaka is often in the top ten. In Jakarta, pollution levels in August 2023 reached an alarming 116.7, 23 times the recommended safe level, fuelled by vehicular emissions, coal plants and remote wildfires. In Lagos, PM2.5 levels hover around 68. The pattern is familiar: traffic congestion, diesel generators and open waste burning.
What this illustrates is a shared global predicament. Rapidly growing tropical cities are failing to implement pollution control mechanisms at the pace required, leading to public health disasters. But there are examples of hope. In the past decade, Beijing cut its air pollution in half by shutting down high-emission factories and adopting clean transport. London鈥檚 low-emission zones significantly improved air quality. Singapore recycles almost all of its wastewater into high-grade 鈥淣EWater.鈥� Even Doha, in an arid environment, has managed to curb foul odours by covering sewage reservoirs. These successes were achieved through goal setting, strict enforcement and investment in clean technology. The C40 network of cities is pushing for adherence to WHO standards by 2030. Dhaka鈥檚 challenges, while immense, are not insurmountable, but they demand political will and visionary planning.
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Solutions
WHAT, then, can Dhaka鈥檚 leaders and citizens do? Some steps have already begun. In 2023, the government introduced stricter air quality regulations. A National Air Quality Plan for 2024鈥�2030 is now in development, targeting major polluters and proposing actionable solutions. Experts advocate a multi-pronged approach.
To combat air pollution, the city should enforce stringent environmental regulations on factories and brick kilns. Replacing ageing diesel buses and vehicles with electric or low-emission alternatives is a must. Transition to cleaner household energy sources should get more priority and long term planning. Encourage rooftop solar adoption could help to manage crisis.听
To tackle water and waste crises, authorities must expand sewer networks and construct more treatment plants. Improving waste collection and recycling systems, using low-cost techniques like chlorination to make water safer, penalise industrial polluters dumping into rivers is must. Remediating contaminated land and educate the public about food safety risks should start now.
All of this requires coordinated governance and sustained investment. But Bangladesh has made big environmental strides before. When leaded petrol was banned, blood lead levels in children dropped sharply. That success proves that meaningful change is possible. None of this will be easy, but inaction will come at a far higher cost. Achieving WHO鈥檚 air quality standards could extend lifespans in Dhaka by more than eight years. The World Bank argues that Bangladesh can pursue a greener growth model. A cleaner Dhaka would mean fewer emergency hospital visits, a more productive workforce and children playing outside without protective masks.
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Arghya Protik Chowdhury is a student of environmental science at the Bangladesh University of Professionals.