Unfortunately, bleed-free won't save you from the exhaust that other planes are producing. Breathing exhaust-filled airport air can be a substantial chunk of th

Unfortunately, bleed-free won't save you from the exhaust that other planes are producing. Breathing exhaust-filled airport air can be a substantial chunk of the time spent on a short trip. Also, I don't know if I've ever experienced a "1 in 1000 fume event" that the article mentions, but I know that about half the time the pilots start the engines on the ground, I can smell the half-burnt jet A in the cabin. It seems to happen on smaller/older aircraft more often. Then again, the relative harm of all that vs. the high altitude radiation is very unclear.