World Environmental Day: Three Ways to Achieve Less Polluted Cities

[This article is written by Jordi Sunyer and Mireia Gascon (CREAL-ISGlobal) and it has been published in Spanish in El País - Planeta Futuro ]

Today, air pollution due to toxic agents is the most serious environmental health problem, locally and worldwide. In fact, with an impact almost as damaging as that of tobacco, it is a major health risk. Scientific evidence indicates that first stroke and then myocardial infarction are the leading consequences of exposure to air pollution, followed by chronic obstructive pulmonary disease (COPD) and other respiratory problems. Recent studies have shown that air pollution can also have an impact on cognitive abilities, particularly in children, and can even affect reproductive health.

Today, air pollution due to toxic agents is the most serious environmental health problem

The particulate content in air, including fine (PM2.5) and ultrafine particles, is more toxic than the gas content (NO2, O3). The main source of particles in our cities is traffic, but they are also produced by power generation and industrial activities. Globally, intensive agriculture is also a major source of particulate air pollution.

To reduce traffic-related air pollution at least three types of interventions are needed

The problem of urban air pollution has been diagnosed and clearly described: the air in our cities contains hazardous pollutants that are derived primarily from vehicle emissions, and this situation represents a major health problem because we are all exposed to the risks. But more importantly, we can prevent this pollution and reduce its impact on our health, which is or should be central to our well being. The task facing us now is to find ways to improve air quality, and reducing the volume of traffic will be a key factor. But how can we reconcile a reduction in traffic with other aspects of our lives that are also valued in our society, such as goods transport, time saving, and the comfort and privacy associated with the use of private vehicles?

To reduce traffic-related air pollution at least three types of interventions are needed and these should be implemented on both the local and regional level:

1) The recovery of public space: a significant portion of the space currently occupied by motor vehicles should be used to create segregated bike lanes and pedestrian walkways, including green corridors and school routes, and these elements should be adapted for use by people with disabilities.

2) A switch to public transport on the part of a significant percentage of users. (To ensure that this happens public transport should be affordable and more efficient than private options.)

3) The creation of low-emission zones where more polluting vehicles are prohibited. (Vehicles would be classified and labelled according to engine type and age.)

With an impact almost as damaging as that of tobacco, it is a major health risk

A congestion charge or toll is another strategy that has produced very positive results in some cities, including Stockholm. However, if such measures are to be effective, they must be permanent and encompass large areas rather than being limited to small sections of the city. They may also be complemented locally by other measures, such as a ban on burning biomass fuels in the home, which has been implemented in Paris.

Apart from reducing pollution, these measures have other beneficial effects on the environment and consequently on our health and well being: they facilitate social interaction, reduce social inequality, increase the level of physical exercise in the population, expand green areas, and reduce noise and temperature in areas of the city known as hot islands.

Stroke and then myocardial infarction are the leading consequences of exposure to air pollution, followed by chronic obstructive pulmonary disease

Undoubtedly, changes of this kind require a cultural shift in the population. Apart from demanding that the authorities take action, people must learn to value the advantages of travelling by foot or bicycle (the recommendation is that most trips under 2 km should be by foot or bicycle) and commuting in shared vehicles (carpooling), for example. But above all, it is essential that people should appreciate the advantages of having quality public space open to everyone.

We need to move forward together—politicians, scientific and communications experts and, above all, citizens—to resolve this complex issue

While the concept of a people-friendly city undoubtedly meets universal approval, if we are to achieve this goal, the perceptions and opinions of the population must be based on a sound understanding of the issues involved. For example, the referendum in Stockholm on the congestion charge was held after a six-month pilot project, which meant that the population was informed about the advantages and disadvantages of the measure.

Sacrificing the comfort of private vehicles may seem like a burden. But it should be remembered that many successful public health interventions which have had significant impact have been implemented by the community and not left up to the free will of individuals; the case of banning tobacco use in closed spaces is a good example. Thus, faced with the challenge of improving air quality, we need to move forward together—politicians, scientific and communications experts and, above all, citizens—to resolve this very complex issue in which, it seems, we are all guinea pigs taking part in an immense experiment.

Jordi Sunyer is co-director of CREAL, an allied centre of the Barcelona Institute for Global Health (ISGlobal).

Mireia Gascon is a researcher at CREAL-ISGlobal.