In April, 2013, The American Lung Association (ALA) released their latest State of the Air report, which highlighted mixed results in reducing air pollution in the USA. While in the UK, air quality was also a key concern, with the UK Supreme Court reporting that the country is in breach of the European Union’s air quality directive for nitrogen dioxide levels from traffic pollution. This ruling is welcome as it could force the UK Government into action to avoid punitive fines by finally addressing the growing issue of increased traffic on its roads and the consequences for air quality.
So what are the key challenges when considering air pollution, and where should we start? A reduction in life expectancy from cardiovascular and respiratory diseases as a result of air pollution is well established. However, studies at the recent American Thoracic Society’s 2013 conference showed that risks can be greater than previously thought, and can have multiple effects on respiratory diseases; for example, even low levels of traffic pollution has been shown to increase asthma morbidity in pregnant women, and expectant mothers living near major roads have children at increased risk of respiratory infections before the age of 3 years. But even a small reduction in particulate matter (PM) 2·5 can improve life expectancy; a study in Epidemiology earlier this year showed an increase in mean life expectancy of 0·35 years for a 10 μg/m3 decrease in PM 2·5. Unfortunately, as in this paper, most data on pollution and its effects on health are derived from association studies, and considered weak evidence, because quantifying the risk and benefit of any single factor can be difficult, and data are affected by chance, confounding, and interlinking risks. Furthermore, it might not be in governments’ interests to monitor accurately the levels of any pollution, and government and independent measures can differ. Independent studies are therefore vital to improve the evidence base and prompt action.
The ALA report is a good basis on which to build quality evidence and action plans that could be applied globally. Data for the report were compiled by the US Environmental Protection Agency (EPA) which measured levels of two major pollutants, ozone and PM 2·5, from 2009 to 2011. Encouragingly, 18 cities had reduced annual average PM 2·5 in this latest 2013 ALA report, and a record number of four cities were on all three of the cleanest cities lists. However, 42% of the US population (more than 131 million people) still live in counties with unhealthy levels of either smog or PM 2·5. Nevertheless, much progress has been made recently in major industrial countries to tackle the enormity of the problem. Legislation in the USA and Europe, such as the Clean Air Act of 1970 and EU Directive on ambient air quality and cleaner air (2008/50/EC), have provided a framework for regulatory agencies and governments to tackle major types of air pollution, with the requirements of EU directives from 2004 and 2008 being transferred into English law in the 2010 Air Quality Standards Regulation.
But despite some progress, there is no room for complacency, and monetary support should be diverted from projects likely to increase pollution to those that encourage greener transport, transport-free areas, improved road infrastructure, and safety for cyclists. The EPA has recently announced funding of around US$9 million for projects that reduce diesel emissions, while President Obama launched a publicly accessible platform in May, 2013, that will search and synthesise metadata to help to analyse links between climate change and health. Projects such as green walls at major traffic intersections are additional admirable efforts, and many countries, often at city level, are embracing efforts to increase and protect cyclists on the road, and to try and encourage motorists out of their cars. Plane travel could be reduced through use of modern telecommunications, lessening the need for physical face-to-face meetings and additional runways. Carbon offsetting has also been at the forefront of individual and industry efforts to protect air quality and the environment. However, the ruling by the UK Supreme Court suggests that the innovation and forward thinking that is required at the government level to address pollution is still some way off fruition, at least in the UK, perhaps because air quality in the UK is a devolved responsibility.
The industrial revolution has changed forever the societies of developed countries and the irony of this progress is that individuals have become increasingly sedentary. This lack of movement has not only polluted the air we breathe, from increased traffic and reduced green spaces, but has also spread insidious tentacles of morbidity, disease, and death that act synergistically in a vicious circle. Practical incentives and action plans must be set to break down this circle at both the government and individual level. Current efforts should be acknowledged, but must be escalated if we are all to breathe easy in the future.