India is a country of dreams, where thousands of people living in impoverished rural areas aspire to create a better life in the cities.  Yet, arrival in a metropolis like Delhi rarely results in a more comfortable existence with having a roof over their heads remaining a distant dream for most migrant workers.

At the end of their working day, most have little choice but to bed down on pavements. An estimated 46,000 or more people live and work on Delhi’s streets; a community of pavement dwellers mirrored in other Indian cities – men, women and children facing serious illness because of their constant exposure to dangerous levels of air pollution.

Notoriously bad air is Delhi killer

Delhi’s air quality is notoriously bad. After Diwali celebrations, for example, levels of fine particles in the air (PM2.5) reach over 750μg/m3. In comparison, such levels in Birmingham do not exceed 20μg/m3, with WHO guideline average limits of 25μg/m3.  Associated human health impacts are severe, with air pollution linked to 10% of the city’s deaths. 

In March 2019, Greenpeace named Delhi as the world’s most polluted capital, with Indian cities making up 22 of the 30 worst cities on the planet for air pollution. The announcement coincided with University of Birmingham experts joining researchers and policy makers at a workshop in the city - part of the ASAAP India (A Systems Approach to Air Pollution India) project.

As part of the project, researchers from the University of Birmingham, Population Council and IIT Delhi studied several locations in Delhi. They discovered pavement dwellers were often exposed to severe or hazardous levels of particulate matter (PM) air pollution which could lead to conditions such as acute or chronic lung disease – one of the most common causes of death among this group of citizens. 


Air quality key to achieving green goals

The research findings provided a backdrop to ASAAP India’s call for air quality metrics to be placed at the heart of relevant UN Sustainable Development Goals. The study, carried out in partnership with Population Council – India, prompted the team to recommend that the Homeless Pavement Dwellers (Welfare) Bill by Shri Gopal Chinayya Shetty M.P. considers the impact of poor air quality upon pavement dwellers.

“Street dwellers are uniquely vulnerable to air pollution because they’re exposed to the highest levels of roadside pollution both at work and rest. Without the financial means to reduce their exposure to air pollution, they’re highly susceptible to related illnesses as they have reduced access to healthcare, often alongside pre-existing medical conditions and exposure to other environmental risks,” says Dr William Avis, International Development Research Fellow at the University of Birmingham.


ASAAP India is a unique research partnership that draws in participants from India, Africa, Asia, Europe and US to explore how cities such as Delhi can better understand how to tackle air pollution. It has its roots in Birmingham’s collaboration with Indian Institute of Technology (IIT) Delhi stretching back to 2012. Air pollution researchers from Birmingham joined forces with counterparts at IIT Delhi in a partnership aimed at creating a greater understanding of the impact of PM2.5 pollution in Indian cities, including Delhi.

Broadening our understanding of air pollution

Larger diameter PM 10 particles, originating from activities such as construction, were relatively well understood, but less was known about the origins and behavior of PM2.5 air pollution.

Professor Mukesh Khare, from the Department of Civil Engineering at IIT Delhi began initial work with Professor Roy Harrison at Birmingham to understand the concentrations PM2.5 in Delhi, testing at two sites – one at IIT Delhi itself, the other at a heavily-trafficked location elsewhere in the city, with a ‘control’ site in Birmingham.

The work allowed the team to begin to understand the sources of PM2.5 pollution in Delhi and as Professor William Bloss, from Birmingham, came on board the emerging partnership attracted UK Natural Environment Research Council (NERC) and Indian Ministry of Earth Sciences funding in 2018 to set up 12 months of comparative monitoring of smaller PM2.5 particles, often originating from vehicle emissions, across six Indian cities, including Delhi; the origin of ASAAP India.

Drawing experts from across the Global South

From a starting point focused on understanding the origin and spread of airborne pollution particles in Indian cities, ASAAP India has broadened its approach to draw in participants from across the Global South via the sister project ASAP East Africa.

Key contributors to air pollution in Delhi are vehicles; construction, road dust, burning of solid waste, crop burning in Northern Indian states and, during Diwali, fireworks.


The project adopts a ‘systems’ approach to dealing with urban air pollution – not just in Delhi, but African cities such as Kampala, Nairobi and Addis Ababa. This takes into account social, economic and environmental factors when designing ways to tackle air pollution.

“At the time we were simply working to improve air quality and did not take into account the impact of PM2.5 pollution on pavement dwellers, but, as our research continued, it became clear that here was a group of citizens disproportionately affected by air pollution,” comments Professor Khare.

Pavement dwellers prioritised over air pollution

“There are several challenges ahead, but biggest is sensitisation of regulations – how do we prioritise pavement dwellers? Our cities are growing fast with a predicted 40% rise in population by 2030 and increasing exposure to air pollution for those people who are forced to live on the streets. There are a number of short-term goals that must be achieved. We need to define pavement dwellers, find out who the employers are and provide shelters away from the pollution. At the same time, we must work towards reducing urban air pollution.”

The ASAAP India workshop, convened by Dr William Avis and Professor Francis Pope, from the University of Birmingham, and Professor Khare, closed with a call for air quality metrics to be incorporated into several of the 17 UN Sustainable Development Goals, most notably SDG3 – Good Health and Well-being.

Experts also proposed that air pollution be treated as a disaster, in the same way as natural events such as earthquakes and forest fires. Additionally, they called for access to clean air to be considered as a basic human right.

Millions dead and billions wasted

“Air pollution kills millions and costs the world economy billions - tackling the problem is not just a technological issue, but a social-economic and social-political challenge that requires a new approach,” comments Professor of Atmospheric Science Francis Pope.

“Causes and effects of air pollution are now largely known, but contemporary challenges are increasingly complex - new approaches and tools are needed.  As a community of researchers and policy makers, we must also be bolder in making it clear when current approaches are insufficient.

“By adopting a ‘systems’ approach, we can help to resolve health, social and economic problems associated with air pollution in Delhi and other similarly polluted regions. This type of pollution is more than just a health risk; it slows countries’ development, diminishes the quality of life and reduces people’s incomes.”


ASAAP India and ASAP East Africa illustrate the need to develop an integrated and inter-disciplinary understanding of the challenges facing cities – not just in India, but across the Global South. Collection of evidence from across disciplines allows analysis and application in the development of tools that policy makers can draw upon on to diagnose urban challenges and develop air quality interventions.

The Delhi workshop built on Birmingham’s research in Indian and East African cities to explore solutions to a problem that kills up to 7.3 million people around the world every year, as well as costing the world economy $225 billion.

Gathering expertise from Kenya to Kathmandu

It focussed on air pollution-related problems experienced by people living in cities in the Global South. These included impacts on health in India, Kathmandu and East Africa; crop waste burning in northern Indian states; impact on India’s tourist industry; and communicating effectively with the public about air pollution in Nepal and India.

“There is a real sense of urgency about the need to bring together researchers from different disciplines; social scientists, economists, environmental scientists and others coming together to develop research projects that spark discussions across disciplinary boundaries and forge links with partners across the public and private sectors,” says Professor Pope.

“For researchers at the University of Birmingham, it is tremendously exciting to work with excellent scientists across the region to tackle problems that pose an existential threat to people in India and beyond.

Harnessing the potential of partnerships

Professor Pope notes that the University is harnessing the potential of partnerships to explore and develop solutions to air pollution. Researchers are working with government partners such as Ugandan National Roads Authority and Kampala Capital City Authority, academics at IIT Delhi, the University of Nairobi and De La Salle University, as well as organisations such as Population Council, African Centre of Technology Studies and the All India Disaster Mitigation Institute.

“We’re forging links with academics – across east Africa and Asia, civil society groups and garnering a better understanding about how to raise the profile of air pollution as an issue of concern,” he comments. “We want to support people’s aspirations to a better life in the cities without having to face the danger of ever-decreasing urban air quality.”

Header image credit: Paul Kennedy / Alamy Stock Photo.


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