November 2015 archive

Air Pollution: Urban Myths and Realities

Note: I am honoured to be a contributor to the The Nature of Cities virtual magazine, and very pleased to shared excerpts from my first essay below.

As a start, let us remind ourselves of the figures published by WHO last year: air pollution is responsible for over 7 million deaths a year. Out of those, around 3.7 million are due to outdoor air pollution. So, ambient air pollution and its detrimental health impacts are a reality. And we are almost certainly underestimating the negative health impacts, as these figures are based on the impacts of only some of the known pollutants (e.g. PM2.5). Moreover, there are additional health impacts to consider beyond mortality, such as respiratory infections. While the majority of the deaths are in developing countries, air pollution is still a serious issue in the developed world. For example, in the U.K. it is estimated that early deaths from air pollution are higher than those from obesity and alcohol combined.

Let us also remind ourselves that, as a human race, we have previously won the battle against air pollution. In cities such as London and Dublin, where pollution was primarily linked to coal, banning the use of coal in cities has helped us get rid of the visible, short-term black carbon smog. Even in the case of non-coal-related (photochemical) smog in Los Angeles and the wider area of Southern California, improved emission standards and other policy interventions over the past two decades have significantly improved both the air quality and the health of residents. This collective experience has left us with a wealth of knowledge on managing air quality—it is a science that we understand well. At least, the scientists and experts do.

London buses

Today, some cities, such as Beijing and Krakow, are still struggling with air pollution impacts of coal burning. Other cities have the challenge of addressing air pollution from transport, industry, agriculture or natural dust. In the vast majority of instances, pollution results as a combination of these sources in varying proportions. Moreover, this pollution is often not generated within the city’s limit, or even within the country’s borders.

Where does this leave us?

  1. Measure: given the evidence on the serious health risks of air pollution and the technology and information available today, there is no excuse for not understanding a city’s air quality performance. Air quality experts can advise on the most suitable indicators to measure and the most appropriate analytical and modeling tools to utilize. With global-satellite modeling data becoming widely accessible through global ranking studies, there is little room for hiding our heads in the sand. Ground-based measurements are still needed to set context-specific standards and to monitor compliance with them.
  2. Address root causes: understanding the root causes will help us to develop and implement effective interventions at a national, regional and city level. In drastic situations, these may need to be equally drastic interventions, such as banning use of all or some vehicles in certain locations or at certain times. Particular focus should be placed on improving air quality where people live. Mitigation and compensation measures (e.g. planting trees, moving residents away from motorways) should be a last resort and not a primary strategy.
  3. Raise awareness: the World Resources Institute is campaigning for better access to environmental information for the general public They report that 53 percent of countries in the world do not report urban outdoor air pollution information. I strongly believe that people have a right to know when air quality conditions are unsafe in their neighbourhoods, to allow them to plan their activities accordingly and take the necessary precautions. Organizations such as Clean Air London have done a tremendous job of cutting through the myths and jargon to bring a clear and compelling argument for addressing air pollution to both the public and the politicians. One Atmosphere is a recent video they produced as part of these efforts, and it provides a good example of effective communication.

The recent trend towards healthy, liveable cities has helped bring air pollution back to the spotlight in many regions around the world. It is a global issue with many local flavours—one which we have successfully addressed before and which we cannot afford to ignore now.

Full article published on The Nature of Cities.