Scientific Consensus Leaves No Doubt that the Ambient Air in Urban Centres is Harming Our Health: What Are We Waiting For?

[This article has been published together with the First Conference on Air Quality in Catalonia]

The First Conference on Air Quality in Catalonia, held recently in Sabadell, was exceptional. The two-day event brought together a broad range of stakeholders interested in urban air quality. Policy makers and technical personnel from local governments, metropolitan bodies, provincial bodies (Diputació) and the Autonomous Catalan Government (Generalitat) came together with academics and scientists with expertise in health, the environment, mobility, education, citizen associations and industry.

Today, the scientific consensus is that there is no doubt that the ambient air in our cities is harming our health. Every day, about eight scientific articles are published that present new evidence on the topic and most of them corroborate this consensus. These articles not only discuss the known negative effects of urban air, such as cardiovascular diseases, but also refer to newly discovered links, for example with Alzheimer’s disease and other neurological disorders. City dwellers do not have the physical, cerebral, and pulmonary development they should owing to their exposure to air pollution in the womb and during childhood, the phases in which our bodies are at their most vulnerable.

Every day, about eight scientific articles are published and most of them corroborate that the ambient air in our cities is harming our health

In general, the sources of urban air pollution are well known, although certain aspects still need more research, such as the size of the most toxic particles we breathe and the specific role of each one of the components found in particulate matter. The usual, and generally the main, source of pollution in cities is motorised transport, given the high density of vehicles powered by internal combustion engines. One important factor is the close proximity between these engines and the city’s inhabitants. Of course, each city could make its own specific diagnosis because of the presence of differentiating factors, including the role of biomass, ozone, intensive agriculture and the presence of industrial facilities with inadequate pollution controls.

Jordi Sunyer, head of the ISGlobal Childhood and Environment programme, during the First Conference on Air Quality in Catalonia. Photo: Conference on Air Quality.
 

We must act because we know that pollution affects human health and development. We must act because, as a society, we understand that we have to return to a position closer to nature; we know that we must protect nature because of ecologism, because of the climate crisis, because clean air is a good thing and because having clean air to breathe is surely a right.

What can we do? The problem we are facing is one of great complexity. On one hand, we have modern transport, which is fast and personal and offers generally appreciated benefits in terms of time, freedom, privacy and comfort. On the other hand, we have the benefits linked to clean air, including a quieter environment and social connectivity as well as the presence of vegetation and physical activity. And these two worlds are competing one with the other.

Many other fundamental factors also intervene in this scenario: ingrained habits and social inertia; economic interests (the automobile industry represents 13% of the GDP); political will, for example the neglect of the commuter train system; urban planning policies, in particular spatial planning; property values, for instance the gentrification that may be generated by superblocks; and the complexity of the political interventions required to effect change, which may be seen as risky and associated with uncertain outcomes. On the other hand, there is no doubt that community measures are more efficient than individual remedies, such as using face masks or indoor air purifiers, because of the limited impact of the latter.

There is no doubt that community measures are more efficient than individual remedies, such as using face masks or indoor air purifiers, because of the limited impact of the latter

We need to do more than just define air quality criteria, a measure that has to date proved insufficient. We need community interventions that target overall urban planning and mobility and seek to achieve cultural and behavioural changes in the population. Isolated actions are not enough; we need a comprehensive package of measures. In the case of transportation, it is clear that private vehicle use has to be reduced and that internal combustion engines must be replaced with cleaner alternatives. To achieve these goals, we must improve and reinforce the public transport system and support a mix of modes of transport (by building park and ride facilities, for example). We must encourage and facilitate active mobility (walking and cycling). At the same time logistic traffic and public transport must be electrified and, above all, the use of private cars in cities has to be reduced drastically with the creation of low emission zones, non-emission zones and congestion tolls.

Jordi Sunyer, head of the ISGlobal Childhood and Environment programme, during the First Conference on Air Quality in Catalonia. Photo: Conference on Air Quality.

The ultimate aim of the new urban planning model is to create public spaces that encourage and facilitate active mobility and provide more spaces for people. Above all, we need to create green spaces in our towns and cities—especially in areas around schools, along school routes and in hospitals. One way to do this is by creating superblocks. Finally, our habits have to change. We must use shared transport and, when possible, switch to active mobility: moving from place to place should become part of our daily physical exercise.

Beyond the principle of subsidiarity between administrations, the compartmentalisation of competences and metropolitan initiatives, it is the urban centres that must drive this change. And we need model towns and cities that will motivate others to act. We have the advantage that we are late starting so we can learn a lot from others. However, each measure has to be tailored to each particular situation, which means that lengthy transition periods are required to assess and enhance the effects. This is what London has been doing with its low emission zone, which has been improved gradually since its introduction in 2006.

The cities and towns of the 21st century will be characterised by clean air, greenery and an absence of noise. They will be places where the public space is used by people rather than occupied by vehicles. In Catalonia, we need a city or town at the forefront of this effort that will motivate others to move forward as we adapt to these new times.