Even though environmental pollution is one of the most concerning problems in society, scientific research on how pollution affects professional sport has just taken its first steps. There are several studies about how the environment affects workers and the general population, but athletes are not often the subjects of study even though their inhalation is greater during physical activity. The only fact documented is that exposure to emissions causes oxidative stress and inflammation in the cardiovascular system in the long term.

Does pollution affect athletic performance?

The campaign Cleaner Air, Better Game, started by UEFA in 2021 was part of a commitment to compensate for greenhouse emissions generated by its football competitions, but it also referred to a research that noticed changes in the player’s play due to bad air quality. The research mentioned was carried out in Germany in 2015. It compared the performance data of footballers over the period 1999-2011 in relation to the air quality dataset in each city.  Andreas Lichter, Nico Pestel and Eric Sommer considered the levels of ozone and PM10 (solid or liquid particles in dust, ashes, soot, metal particles, cement or pollen spread in the atmosphere) in 2956 matches played by 1771 players in 32 stadiums over a twelve-year period. The most alarming piece of information was that 7% of the matches were disputed exceeding the PM10 EU regulation threshold. 

This research found that, on average, a player passes the ball between 26 and 34 times per game, with an accuracy rate of 77%. 90% of them were short passes, less than 30 meters. However, these statistics were altered depending on the PM10 level in the air.  There were even significant changes with moderate levels of PM10. Pollution affected not only the number of passes and accuracy but also their distance. Scholars consider that long passes may reduce the overall physical burden, since the higher the pollution levels, the greater the number of long passes over short passes. Besides, the effect of pollution is greater in players older in age and those positions that require more physical effort and are more active in the game, such as midfielders and strikers.  Taking all these parameters into account, they concluded that performance could be reduced up to 16% depending on air quality.

Adaptation to pollution

With the previous results as a basis, a Chinese research has just confirmed some of these findings. The research covers all the Chinese Super League (CSL) games held from May 2015 to November 2017, for a total of 576 games in 16 cities. Once again, the research is targeted to the number of passes each player makes, and the success rate of passes as ways of balancing effort. The new target this research adds is to find out if players can adapt to unfavorable external conditions, such as pollution.  Empirical evidence suggests that animals and humans mitigate heart and respiratory rates for a period of time if they are exposed to ambient air pollution.

Results confirm that pollution affects the number and quality of players’ passes. However, these scholars specify that home team players are barely affected by air quality. This information indicates that there could exist some kind of adaptation, and besides, it exposes the advantage of playing home. 

The research reports three significant findings:

• Pollution has a higher effect on the player if there is a difference in the pollution level between a given place and the player’s home city. The decrease in performance is 2% less in the participation in the game (passes), and 3.1% in its accuracy (success of a pass).
• The football player can adapt to their usual environment because the effects of pollution could be more clearly seen in the visiting teams, up to a 7.1% and 7.8% reduction of performance.
• As it was already indicated by the German research, younger players are less sensitive to pollution.

Pollution and cognitive abilities

There is still great divergence over the conclusions of this kind of research about sport and pollution. However, the results of the research mentioned above clearly indicate that air quality has an impact, at least, on cognitive ability. This information is not new. In 2020, the University of Amsterdam suggested that pollution could alter risk attitude. Its research is based on the national chess championship. When pollution was higher, there were more probabilities of a draw.  Another Dutch research on chess also showed that in indoor spaces, PM2.5 concentration in the air, the smallest particulate matter, increased the player’s probability of making a wrong move by 26.3%. The authors analyzed 30000 moves in 596 games.

This idea could validate the hypothesis that in a football match, air pollution would contribute to the fact that players make more long passes since they are less risky. The Dutch based their idea on a research related to the finance world to contrast their finding. In 2016, a research revealed that when pollution in Manhattan increased, fewer risky operations were performed in the stock market.  Not in vain, talking again about sports, it was also proven that in American baseball the decision-making accuracy of umpires falls an 11.5% when there is a 1ppm (parts per million) increase of carbon monoxide in the ambient.

Do stadium events pollute?

It is also clear that, in general, all the impacts that could be proven are detrimental to the quality of the game and the show. This problem is especially relevant in stadium sports. The celebration of a sports event generates pollution peaks due to all the cars going to the field. In the United States, even barbecues in the nearby areas of the football field have been counted as a pollution factor. In numbers, for every 10000 spectators that attend an NFL match, there is a 0.3% increase in AQI (Air Quality Index). Talking to The Sustainability Report, Nicholas Watanabe from the University of South Carolina said that when Columbia University held the basketball NCAA tournament, AQI increased over 150 in a city where the maximum is not over 40. 

Athletes in focus of climate emergency

So far, there is no more eloquent research in this field than the ones that analyzed the records of marathon runners in China. Conclusions, after reviewing 56 race events in 2014 and 2015, were solid. On average, a runner could lose up to twelve minutes in their normal time in a race on a day with high pollution index. However, there are still a lot of factors to determine this phenomenon. In the mid-term, it is necessary to install air quality meters so training sessions and matches can take place at the times with the best air quality, taking also into account health criteria. We have to take into account that the air inhaled by an athlete, due to the breath frequency during the activity, takes the polluting substances deeper into their organisms. Besides, when breathing through the mouth, the filtering effect of the nasal hair is lost. In three hours of exercise, the volume of air that goes into athletes’ bodies is the same volume of air that a sedentary person breathes in two days.  We already have enough evidence to place athletes in the focus of climate emergency.

SOURCES

UEFA explainer: ‘Cleaner Air, Better Game’ campaign

https://www.uefa.com/insideuefa/sustainability/activities/0267-11dfaadcb305-75a1b049fdcd-1000–explainer-cleaner-air-better-game/

Productivity effects of air pollution: Evidence from professional soccer

https://www.sciencedirect.com/science/article/abs/pii/S0927537117302658?via%3Dihub

Who Can Adapt to Air Pollution? Evidence from Professional Football Players in China

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3669464

Match Performance of Soccer Teams in the Chinese Super League—Effects of Situational and Environmental Factors

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6862007/

Risk Attitude and Air Pollution: Evidence From Chess

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3609237

The effect of air pollution on investor behavior : evidence from the S&P 500

https://www.econbiz.de/Record/the-effect-of-air-pollution-on-investor-behavior-evidence-from-the-s-p-500-heyes-anthony/10011567445

Indoor Air Quality and Cognitive Performance

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3460848

Air Pollution at College Football Games: Developing a Methodology for Measuring Air Pollutant Exposure in a Sport Event Microenvironment

https://www.researchgate.net/publication/331469026_Air_Pollution_at_College_Football_Games_Developing_a_Methodology_for_Measuring_Air_Pollutant_Exposure_in_a_Sport_Event_Microenvironment

Running With a Mask? The Effect of Air Pollution on Marathon Runners’ Performance

https://journals.sagepub.com/doi/10.1177/1527002518822701

Contaminación en el aire y deporte

https://www.kunak.es/blog/contaminacion-aire-deporte/