Paris and pollution, heats in the heat: a topical discussion of the relationship between the climate and sport

Climate change from human activities increases the likelihood of heatwaves, translating to a 70% increase in heat-related mortality risk.3 In the summer of 2003, a heatwave killed more than 14 000 people across France.4 At the time, the maximum temperature recorded in Paris was 39.5°C, now sitting at 42.6°C since 2019.5 As a result, ‘scorching’ summers, just like 2003, are now 10 times more likely due to climate change6 and going nowhere fast. Notwithstanding the additional 2500 kilotons associated with transporting ~500 000 global spectators.10 An emerging body of research has linked air pollutants like ozone and sulphur dioxide to increased bronchoconstriction and airflow obstruction during exercise, compared with the same pollution exposure at rest.11 A 2022 study found that higher air pollution levels also predicted increased errors and interceptions in professional baseball and American football.12 Further research in Major League Baseball noted that a 1 part per million increase in carbon monoxide levels over 3 hours caused an 11.5% increase in umpires’ likelihood to make an incorrect call.13 All this is to say nothing of the general health burden of air pollution that may impact spectators and individuals in their daily lives.14 An ecological shift? [...]the organisers of Rio 2016 promised to restore the city’s waterways through investments in sanitation; however, many of them were littered with rubbish only a year later.16 Indeed, due to concerns around water quality in the River Seine, Paris 2024 saw the postponement of multiple triathlon events, with three athletes also falling ill after the 10 km open water swimming event.17 While the lasting effects of hosting the Olympics remain to be seen, Mike Gagliardi of NBC News (USA) highlights that Paris is noticeably different compared with 10 years ago, primarily due to its policy on reducing car dependence. Paris has closed 100+ streets to motor vehicles, tripled SUV parking fees, removed ~50 000 parking places and added 1300 km of bike lanes since Mayor Anne Hidalgo took office in 2014.18 City officials report that this has aided a 40% decline in air pollution.18 The aim of Paris 2024 was to host more responsible games, contributing to an ecological shift in the world of sports and events, which may still prove to float.19 From our perspective in sport and exercise medicine, an ecological shift may start by improving our understanding of the impact of environmental factors such as heat on athlete pe