Footballers’ performance is affected by particles in the air, says German study
Down the years, professional footballers have blamed a lacklustre performance on many things. Famous explanations have included the ball being too bouncy (Newcastle United); the pitch being too small (Tottenham Hotspur); and the team being forced to play in the wrong colour kit (Manchester United).
Now a group of health economists has discovered another reason that should send alarm bells ringing far beyond the world of sport. Andreas Lichter, Nico Pestel and Eric Sommer, researchers at the IZA economic institute in Bonn, Germany, will present a study at this month’s Royal Economic Society’s annual conference in Brighton which shows that air pollution is significantly affecting the performance of professional footballers. Their findings are based on analysing the form of players in Germany’s Bundesliga between 1999 and 2011.
The three economists measured the total number of passes each player made in the matches in which they participated. “While the number of passes is not a measure of physical performance per se, it serves as our preferred productivity indicator since it is related to the speed of the game and, importantly, is highly relevant for a team’s success by retaining ball possession and creating scoring opportunities,” Lichter and his colleagues explained. “Moreover, passes provide a reliable measure, as passing is the essential nature of the game, which limits the role of chance.”
The number of passes was then mapped against hourly air pollution data collected outside each stadium by the German Federal Environment Agency.
The economists found that, at kick-off on any given match day, the mean concentration of pollution, the “particulate matter”, was 23.8 micrograms per cubic metre. In almost half of the matches covered (44%), the level ranged between 20 and 50 micrograms per cubic metre, the latter figure being the European Union regulation threshold for particulate pollution. This threshold was exceeded in 7% of the matches.
The economists found that player performance was impeded by pollution even at levels well below these health limits. And at high levels – above the EU threshold – there was a significantly noticeable decline equivalent in performance, by as much as 16%.
Some players were more affected by air pollution than others. The researchers write: “We find that negative effects of pollution on short-run productivity increase with the individuals’ age and are largest for players aged above 30. Moreover, midfielders’ and defenders’ productivity is particularly affected by pollution, players who are more attached to the game and exert a larger number of passes.”
They found that the shorter the gap between games, the more pronounced were the effects of air pollution on performance. Intriguingly, there is some evidence that the players adapted to higher levels of pollution. “Our analysis also suggests that players tend to marginally adjust their style of play, given that the ratio of long over short passes slightly increases with the concentration of particulate matter,” they note.
The findings are likely to be studied far beyond the world of professional football. And the academics want more work to be done to assess what impact pollution has on other professions’ “physical and cognitive productivity” and to broaden knowledge on the benefits of environmental regulation.
The European Environment Agency says the financial impact of air pollution on Europe’s population could be as high as €200bn (£154bn). About 40,000 people are estimated to die prematurely every year in the UK because of poor air quality. In April the Supreme Court ruled that an immediate plan was needed after the UK breached EU limits for nitrogen dioxide. Last week the government was threatened with legal action if it does not take steps to introduce the plan urgently.