Take a deep breath. Yes, literally. And ask yourself: what's in the air I just inhaled? It's almost certain, with our modern lives and built, busy environments, that it contains a range of harmful particles. Whether it stems from city traffic or wildfires, air pollution has many sources, it affects all of us, and it has the potential to become much worse. So today, we're examining what constitutes a bad air day, the biggest producers of pollution, how we monitor the problem, and what can be done to improve matters. Like this podcast? Please help us by supporting the Naked Scientists