Cambridge researcher Meelan Thondoo – Urban Health is essential for the future of our cities


Dr. Meelan Thondoo is a research associate at the MRC Epidemiology Unit of the University of Cambridge. She has a Doctor of Medicine degree and her research interests include environmental health, urban health, and global diet and activity research. She is also a consultant for various organizations and projects related to public health and sustainable development.

One of her current projects is GDARSpaces, which aims to better understand urbanisation and climate-change-related non-communicable disease (NCD) hazards. She also works on city-level health impact assessments (HIA) and multi-sectoral interventions and integrated policies for health. Additionally, she contributed to the sixth Global Environment Outlook, a report that argues that the planet is becoming seriously polluted, with huge consequences for the health and wellbeing of people. She is also working as a consultant for the World Health Organisation (WHO), where she is providing technical assistance and support on various urban health-related projects, presentations, and briefs. She is also conducting a review of urban health-related networks within and beyond the WHO and their role in implementing location action in cities. Dr. Thondoo has played a key role in identifying strategic actions by preparing expert consultations with a pool of over 30 experts and mapping over 500 products in urban health across all regions and different technical programs of the WHO.

Do you think academia and science are currently heard enough on the topic of health impacts of urbanization, motorization, and climate-change in cities?

No, evidence shows that health remains largely inexistent on many urban agendas across the world. Within and across cities, this is particularly true for the agendas of non-health sectors such as transport, energy, trade, and industry. In the aftermath of Covid-19 pandemic, we now know that cities are a driving force to achieving the Sustainable Development Goals (SDGs) and the New Urban Agenda. For this reason, many cities are encouraged to adopt the Health in All Policies (HiAP), an approach to ensure that public policy across sectors systematically consider the health implications of decisions, seeks synergies, and avoids harmful health impacts to improve population health and health equity. But the situation is not all bleak, within the HiAP approach, there is some evidence showing that tools such as Health Impact Assessments (HIAs), that assess the impacts of urbanisation, motorisation and climate change are increasingly influencing policy makers towards healthier and more sustainable decision-making. And this is promising!

Do you see collaborative leadership and coalitions of academia, science, private sector and policy decision makers as a potential solution to faster advancement towards urban health? 

Yes, intersectoral and multisectoral collaboration between sectors and actors are key, if not vital, to advance urban health. The effects of urbanisation on health are complex, with urban populations at higher risk of falling sick due to existing chronic diseases, lack of physical activity, unhealthy food behaviours and unequal exposure to socio-economic inequity. One action on a particular health problem in a sector can affect others, and often in unpredictable ways. City responses to health threats can be fragmented, focusing on siloed interventions, particular locations or diseases, missing opportunities for synergies across sectors and scales. The responsibilities of city planners and implementers often overlap, and many non-health actors remain unaware of the health impacts of their decisions and actions on citizens and the environment. Given the multifaceted nature of urban health challenges, it is crucial to acknowledge that many determinants and drivers of health lie outside the health sector and within the power of actors at different levels: community, local, city, sub-national and national levels. Stakeholders who have the potential to advance urban health can come from different backgrounds and pertain to various groups: citizen, community-based, academia, industry, NGO, as well as private and public sector groups.

At the MRC Epidemiology Unit, under the leadership of Dr. Tolu Oni, I am leading transdisciplinary work that focuses on co-designing and engaging a wide range of health and non-health actors in a network-based research on urban and climate health impacts. We are running engagement workshops with over 300 stakeholders in 7 different cities across public, private, multilateral, commercial, citizen and policy groups to identify strategies to increase health in cities. We are examining how action at local level is best planned and deployed based on the ability for these actors to collaborate and build coalitions in the face of climate shocks and rapid urban growth. Most importantly, we are generating transdisciplinary knowledge on how they share roles and responsibilities when it comes to health-proofing their cities from different entry points.

Your work shows high ambient temperatures are associated with many health effects, including premature mortality. The combination of global warming due to climate change and the expansion of the global built environment makes urban heat islands (UHIs). What can local governments start doing today differently to prevent this ?

Yes, I am involved in assessing how different exposure pathways in cities can affect health, with a particular focus on air pollution, physical activity, heat, blue and green spaces, noise, traffic injuries, and food. Indeed, exposure to heat can cause premature mortality, cardiorespiratory diseases, and higher rates of hospital admissions. These impacts are larger in cities where urban features such as less vegetation, higher population density, and impermeable surfaces for buildings and roads (e.g., asphalt), lead to a temperature difference between the city and surrounding areas (also known as urban heat islands). Our work shows that if local governments achieve a 30% tree cover goal per neighbourhood for cooling their cities, then one third of urban heat island-related deaths could be prevented per year. There are different strategies that local governments can adopt and combine with tree planting to mitigate the health impacts of high temperatures. These include 1) introducing green roofs or facades, (2) enhancing the re­flective properties of buildings by using light colours for roof and wall surfaces, and (3) replacing impervious surfaces with permeable or vegetated areas.

Are you collaborating with some of the cities to help them understand how much impact their work have on the health of their citizens? Any good examples among cities so far? 

Yes, I collaborate with Prof. Mark Nieuwenhuijsen, at Urban Planning, Environment and Health Initiative based at IS Global Institute for Global Health. IS Global works very closely with the city of Barcelona on several programs that places health at the centre of urban planning and citizen well-being. One example is the Superblock model which is a strategic plan for the whole city to turn 1 out of 3 streets in the city into walkable green streets by 2030. Barcelona and other cities such as Bristol, Philadelphia and Seattle have already set a 30% tree cover as a target given the ongoing global warming phenomena. This guideline is in line with scientific evidence showing that urban green infrastructure promotes physical activity, is associated with better perceived health, improved physical and mental health, among other benefits including lower rates of diabetes, hypertension, and cardiovascular disease.

I do think that European cities can also learn from different bottom-up interventions and citizen-led initiatives happening in Latin America and Africa. Successful interventions such as the ciclovias and the clear air runs are largely ran by or in close collaboration with, local citizens and play an important role in prompting city actors and decision-makers to act in favour of people, health and climate.

Can you define urban health and tell us what are you currently working on related to urban health?

I have been lucky to work as a consultant with the Urban Health Unit at the World Health Organisation (WHO) under the leadership of Dr. Nathalie Roebbel. With nearly 70% of the global population projected to live in cities by 2050, urban health is a growing priority for the WHO. As part of my work, I was in charge of generating the first Repository for Urban Health to enable Member states and city actors to better access WHO resources to increase health in cities. I have also contributed to the Urban Health Research agenda along with colleagues across different units of the organisation and in collaboration with the International Society for Urban Health. In a more applied approach to urban health, I have supported in globalising the Health Economic Assessment tool (HEAT) for cycling and walking. The HEAT tool is an online tool which helps city actors to perform evidence-based decision-making by estimating the health value and averted deaths that can results from policies and interventions promoting walking and cycling in cities.

What I have learnt across these public, private, academic, and multilateral spaces is that defining urban health is a complex task that requires inclusive engagement from all parties at the table. This point was also agreed upon during one of the recent technical expert meetings on urban health led by the WHO. Indeed, a wide and complex range of health issues can be triggered when urban growth exceeds the capacity of a city to provide adequate resources, housing, employment and services, and results in the exposure of increasing numbers of urban dwellers to the hazards of poverty, unemployment, inadequate housing, poor sanitation, pollution, disease vectors, poor transport, and psychological and social stress.

One thing is certain, cities play a crucial role in either preserving or degrading human health. Unless mayors, decision-makers and city actors consider the dimension of health in urban agendas, countries face the risk of getting locked in unhealthy, costly, inequitable, and unsustainable systems. The priority is about identifying the most effective policy measures that respond to the populations and sectors that are most in need for reform and innovation.

There are top-notch research institutes, think tanks, and organisations such as IS Global, ICLEI, C40, and UCLG working on evaluating, ranking, and keeping cities accountable for the health of people and planet. Tools such as HIAs can be used by policymakers to assess local policies, and design alternative scenarios that can decrease impacts of motorisation on health and mitigate climate impacts while decrease economic strain on city budgets. The integration of health into wider policy agendas focused on urban development is no longer an option, it is a matter of necessity, social equity, and environmental justice.