Key urban challenges and their unequal impact on health

GCHU Intern Anna Todsen, an MSc Evidence-Based Social Intervention and Policy Evaluation student at the University of Oxford, discusses key urban challenges for major cities and their impact on human health.

Anna Todsen

MSc Evidence-Based Social Intervention and Policy Evaluation Student, University of Oxford

Email: [email protected]


The blog arose from a review of current research that highlighted key challenges for major cities, and how these affect human health. The initial focus of interest was London and the South-East of England, which is the most densely populated area of the UK and a major international economic hub. This results in an annual population growth which puts pressure on the built and natural environment, and that can reinforce economic disparities. This blog post draws on a range of evidence and beyond to consider three key urban challenges, and their impact on health of the population in the region, and for many cities at large: air pollution, access to green spaces, and affordable healthy housing.

Air pollution

Air pollution is a significant environmental risk to public health, with the European Economic Area (EEA) estimating that it leads to 50 thousand premature deaths annually in the UK alone. The urban population in London and the South-East is the group that is the most affected by pollution in the UK. While air pollution has been decreasing in London since 2010 with policy initiatives like the low-emission zone being implemented, a recent study has found that the current pace of decrease means it will take 193 years to reach acceptable levels.

A recent mapping review of all systematic reviews and meta-analyses carried out in the area of air pollution supports a strong correlation between air quality and respiratory diseases and cardiovascular problems, with children being particularly vulnerable to this. However, these health consequences impact people differently, as a study has found that economically disadvantaged areas have higher rates of air pollution, and people living in these areas are more likely to suffer from the health consequences of air pollution.


The second key urban challenge is the shortage of affordable and healthy homes in the region. To keep up with population growth in the South-East, it is estimated that 53,800 new homes need to be built every year. However, this need is not being met and the gap between supply and demand leads to inflated prices that compromise living standards and fuel housing instability, especially amongst people in lower-earning jobs. This can lead to increasing rates of homelessness, which is currently on the rise in London.  

Housing instability, which encompasses several challenges such as struggling to pay rent, moving frequently, and living in overcrowded housing, also impacts on the health of individuals. A systematic review found that housing instability is a major correlate of cardiovascular health problems. Additionally, experiencing housing instability affects mental health: a further study found that there are lasting negative effects on individuals’ mental health, even after the housing situation has improved.

Access to green spaces

A third key urban challenge in the South-East is the access to green and blue spaces in urban areas, such as accessible and safe rivers and parks, as these are less common in economically deprived neighbourhoods. Green and blue urban spaces have potential for improving human health as well as addressing other urban challenges. A systematic review found a correlation between exposure to urban green space and positive health outcomes such as lower heart rate, lower rates of premature mortality and more physical activity. Additionally, access to green urban areas is also associated with having a positive impact on mental health, in particular depression and stress.

Green and blue spaces can also help improve other urban challenges. For example, tree canopy helps alleviate air pollution and more trees can therefore be a way of improving air quality. Additionally, with average summer temperatures rising due to global warming and urban heat islands forming, green spaces can have a cooling effect during the night.


These three key urban challenges currently facing the region, and many urban agglomerations, are complex and interconnected issues. Outlining their impact on human health allows for an understanding of how they affect the people living in the region. In this case, it also became clear how the health impact of urban challenges falls disproportionally on people living in economically deprived areas.