In March 2014, the World Health Organization (WHO) reported that urban and indoor air pollution kills more than 7 million people every year; the figure for Europe alone is 230,000 deaths, compared to around 20,000 from road traffic accidents. The same report identified air pollution as the largest single environmental health risk facing the world today. Nevertheless, it is not seen in these terms by the general public, perhaps because we are used to living with pollution or because we lack information about its effects or cannot directly perceive its invisible and odourless presence with our senses. The WHO Global Burden of Disease programme, which convened a large number of experts, concluded that indoor pollution is the fourth preventable risk factor for health, coming after high blood pressure, tobacco and alcohol. Particulate urban pollution comes ninth, followed by lack of exercise and high cholesterol.
The evidence from thousands of epidemiological and toxicological studies on the effects of pollution is so overwhelming that in 2013 the WHO classified particulate urban air pollution as a proven human carcinogen
The time will come when our current complacency about the poisonous air we breathe in our streets and our homes will be seen as a sign of the barbarism of a bygone age
The evidence from thousands of epidemiological and toxicological studies on the effects of pollution is so overwhelming that in 2013 the WHO’s International Agency for Research on Cancer (IARC) classified particulate urban air pollution as a proven human carcinogen because of its role in lung cancer. This classification is limited to a small number of pollutants, including carbonaceous particles from diesel engine exhaust that are coated in metals and hydrocarbons. These particles, which are close in size to the range of nanoparticles, can cause inflammation and damage beyond the lungs and can even reach distal areas of the body such as the heart and brain. The damage caused by such particles is not limited to the respiratory system, they also have effects on cardiovascular disease, heart attacks, childhood growth, and even reproductive health, all of which are important enough to warrant the attention of society and politicians so that we can start to deal with the problem.
The air in our cities must be cleaned, not only to comply with legislation, but above all to protect our health. In Europe, 220 cities are making a concerted effort in line with the medium- and long-term vision of their regional and state governments. Achieving a clean urban environment will require a new kind of urban development and planning and new ways of organizing our cities. In this new model, space for living must take precedence over the space set aside for traffic, increasing green space and spaces for physical exercise, measures that will reduce both air and noise pollution. Promoting active travel (walking and cycling) through urban planning reduces air pollution and has other advantages, such as the health benefits of the physical exercise. Architects, urban planners, engineers and ecologists who are experts in mobility and social interactions will all play a crucial role in the design of the cities of the future, where the air will meet much higher quality standards than the air we breathe today. Moreover, just as we now find it unacceptable to eat our meals or to sit in a classroom enveloped in tobacco smoke, the time will come when our current complacency about the poisonous air we breathe in our streets and our homes will be seen as a sign of the barbarism of a bygone age.
Jordi Sunyer is Joint Scientific Director of the Centre for Research in Environmental Epidemiology (CREAL), an ISGlobal research centre. He recently received the John Goldsmith Award for his contribution to the field of environmental health research..