I lived in Berlin for a year and literally can't go to big cities anymore. The pollution triggers my asthma to the point I have continuous attacks despite taking all the medication I can responsibly take. Thankfully my home town is far less polluted, but even there my asthma is being triggered. I had a meltdown after having an attack _from opening my window for 30 minutes_. I can't imagine how terrible it must be for people without easy fallback options.