Part 2/5:
During the concert, I kept track of the CO₂ levels inside the stadium. CO₂ readings serve as a useful proxy for how much exhaled air—potentially containing virus particles—is present in the environment. I kept my sound on to give you a sense of the lively atmosphere, as many attendees were shouting and cheering. The elevated CO₂ levels indicate a high concentration of exhaled air, which is common in crowded events, but understanding these levels helps assess potential risks.