Airparif's conclusion leaves no room for doubt: "the air quality is poor," particularly in most of the Ile-de-France area. Experts report that this issue arises from high concentrations of ozone, a harmful substance when found at ground level. This type of gas is primarily produced when pollutants emitted by traffic and industrial activities react with sunlight.

The news comes just seven days before the opening ceremony, which will take place on 26 July along the River Seine, in the heart of the French capital. The data provided by Airparif adds an additional layer of concern for the Olympic organising committee, which has already been dealing with challenges related to the quality of the Seine’s water. In fact, Paris Mayor Anne Hidalgo took a symbolic swim in the river on Wednesday to demonstrate that the water is in good condition and poses no risk to aquatic competitions.

Moreover, air quality has been a central issue during the preparation for Paris 2024. Earlier this week, the French charity Respire published a report highlighting that the pollution levels recorded at 112 sports fields around the capital exceeded the maximum levels recommended by the World Health Organisation. This document used data provided by Airparif.

Though often overlooked, the effects of pollution on athletic performance can be significant. In this regard, Airparif notes on its website that even minor levels of atmospheric alteration can be enough to influence the results of athletic events and, consequently, the scores or the composition of a podium.

The report comes after numerous athletes, including 800-metre world record holder David Rudisha, have spoken out about the necessity of clean air for athletes. "Spikes in pollution can prevent sportspeople from reaching elite performance levels and cause asthma attacks and even dizzy spells."

Regarding the weather for the opening ceremony, current forecasts are optimistic. Cyrille Duchesne, from the weather channel La Chaine Meteo, told AFP that on the night of 26 July, Paris should experience a "fairly typical summer scenario," with a mix of cloudy periods and clear skies.

Concerns about weather conditions have been constant for the organisers, as the opening ceremony will be held entirely outdoors, showcasing many of the iconic sites in central Paris. Fortunately, extreme heat is not expected, which is good news for the thousands of athletes, performers, and the 326,000 spectators expected to attend the event. We shall wait and see.