The nexus of unplanned urbanization and pollution

Dhaka, the bustling center of Bangladesh, faces severe challenges due to rapid growth. The morning sun struggles to pierce through thick smog, as unregulated development pollutes the air. The Air Quality Index (AQI) often ranks among the worst worldwide, with residents exposed to harmful dust and emissions. On January 4, 2025, reports indicated Dhaka's AQI reached 493, far beyond the hazardous level of 301, highlighting an urgent environmental crisis. Despite its rise as a megacity, pollution remains a critical issue. Rapid urbanization has led to economic growth but has also caused significant environmental harm. Once-promising streets are now overwhelmed by traffic and waste, indicating a city at a crucial juncture. This underscores failures in urban planning and governance. This op-ed examines the link between Dhaka's growth and its environmental issues, calling for a reevaluation of urban strategies to safeguard residents' health and future.

The rapid growth of Dhaka mirrors its economic aspirations. With over 22 million residents, Bangladesh's capital has experienced remarkable urbanization. As of 2023, the urbanization rate of the country has been reported as 40.47 per cent of which, majority of the population resides in Dhaka city. Research mentioned that averaging an annual growth rate, the capital city grew by 8 per cent from 1991 to 2019. During this time, the outskirts expanded by 43 per cent, with built-up areas increasing by 234 km², while the city itself grew by about 116 km². Migration drives this urban expansion, as people from rural areas flock to the city for jobs, education, and better living standards. Dhaka serves as the epicenter for economic, educational, healthcare, and urban services in Bangladesh, housing numerous tertiary institutions and a thriving garment industry among the largest globally. The promise of employment in factories, service sectors, and informal economies draws millions of rural migrants seeking improved livelihoods.

Dhaka's rapid urbanization has been alarmingly swift, yet it lacks effective urban planning, comprehensive strategies, and proper infrastructure development. The city's growth has been largely reactive, resulting in chaotic expansion with minimal public input and disregard for long-term sustainability and the diverse needs of its population. This has led to numerous informal settlements where millions lack secure tenure and basic services. The absence of clear zoning regulations has caused overlapping residential, commercial, and industrial areas.

Dhaka has undergone rapid and unplanned growth, leading to chaotic spatial expansion and significant socio-spatial divisions. This unregulated development has resulted in high-density urban living, straining housing and urban services. Low-lying areas designated for flood retention have been filled by land developers, increasing the city's vulnerability to flooding. The consequences of unplanned urbanization have culminated in a severe pollution crisis, threatening the health and well-being of residents and undermining environmental sustainability.

The construction sector is the primary contributor to Dhaka's pollution, accounting for 30 of the total. During winter, construction activities intensify, exacerbating air quality deterioration and raising the Air Quality Index (AQI) levels. Poor regulation allows construction sites to release significant dust, while outdated brick kilns emit harmful particulate matter.

The industrial sector is another major contributor to air pollution in Dhaka, responsible for 29 per cent of emissions. As the city experiences economic growth, its burgeoning industries, particularly brick kilns, produce billions of bricks annually to meet rising demand. 

The surge in population has also led to a dramatic increase in the number of vehicles, resulting in higher CO2 emissions and deteriorating air quality. From diesel-spewing buses to gas-guzzling private cars, the exhaust from these vehicles releases harmful substances like carbon monoxide (CO), nitrogen oxides (NOx), hydrocarbons, and particulate matter (PM2.5 and PM10) into the atmosphere. The vehicular sector contributes 15 per cent to the city's air pollution. In many areas being rapidly urbanized areas, underdeveloped or nonexistent public transportation systems force residents to rely on personal vehicles, further exacerbating emissions. The lack of efficient public transport options discourages walking or cycling, compounding the pollution issue.

The consequences of poor urban planning are evident in the severe traffic congestion that plagues the city. Vehicles often sit idle for extended periods, increasing emissions and prolonging travel times. This not only diminishes productivity but also intensifies the overall pollution problem, creating a cycle that jeopardizes the quality of life for Dhaka's inhabitants.

Unplanned growth has led to the over-exploitation of groundwater resources, resulting in a significant decline in piezometric levels and threatening the sustainability of water resources in the city. Additionally, unprecedented expansion frequently overwhelms existing waste management systems. Inadequate infrastructure for waste collection, treatment and disposal leads to littering and illegal dumping, contributing to land and water pollution. Decomposing waste emits harmful gases, such as methane, further impacting air quality.

 Air pollution in Dhaka is not merely an environmental issue; it is a public health catastrophe. The World Health Organization (WHO) estimates that fine particulate matter (PM2.5) alone is responsible for thousands of premature deaths annually in Bangladesh. The World Bank estimates that air pollution cost Bangladesh nearly 3.9-4.4 per cent of its GDP in the year 2019, with Dhaka bearing a significant share of this loss. Unplanned urbanization has resulted in environmental conditions that pose serious health risks, such as air pollution, poor water and sanitation, and overcrowding. These issues lead to respiratory diseases and waterborne illnesses, increasing health risks for residents and burdening healthcare systems, which diminishes overall quality of life. Additionally, factors like poverty and limited access to healthcare worsen this decline. Socioeconomic determinants, including income inequality and insufficient healthcare resources, further amplify the health risks faced by urban populations.

The nexus of unplanned urbanization and pollution in Dhaka demonstrates how short-term gains create long-term challenges. The cycle of pollution is exacerbated by traffic congestion, inadequate infrastructure, and poor waste management. To resolve these issues, comprehensive planning is essential. Dhaka requires policies that prioritize decentralization over mere growth. A cohesive national and local policy, supported by an active city government, is crucial for addressing the city's multifaceted crisis. Effective strategies should improve urban planning, infrastructure, and governance to mitigate health risks associated with pollution and urbanization. Furthermore, addressing socioeconomic disparities and ensuring equitable healthcare access are critical. Urban planning should embrace diversity and inclusivity to create cohesive, affordable neighborhoods.

In summary, a comprehensive and inclusive approach to urban planning is vital for transforming Dhaka into a resilient city that prioritizes the health and well-being of its citizens while tackling the challenges of rapid urbanization and pollution.

Dr. Md. Abdul Latif, additional director of Bangladesh Institute of Governance and Management (BIGM) and Ms. Sabila Binta Saif Sondhi is research associate at  BIGM

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