What's the CO2 in those trains? Japan tends to have great ventilation and has CO2 meters around the place. It isn't impossible to ventilate a train well. I've

What's the CO2 in those trains? Japan tends to have great ventilation and has CO2 meters around the place. It isn't impossible to ventilate a train well. I've been on a train with CO2 around 600 and another around 3,000. Air system design matters However, one train in Japan did have very high levels based on a transport ministry study: https://www.asahi.com/ajw/articles/14515055 https://www.asahi.com/ajw/articles/14515055