Cigarette smoke was everywhere indoors, but the air outside was better than today (in Oregon anyway). And the air quality on planes was actually better before they banned smoking than after because the airlines immediately turned the expensive cabin air re-circulation way down.
Air is significantly cleaner now than the 70s/80s, and airplanes still continuously replace the air because it’s not airtight. It’s pressurized but always leaking a bit. It is not expensive nor was it turned off. About half the air is recirculated after passing through a HEPA filter, the rest is fresh air (well, fresh bleed air).
Cigarette smoke was everywhere indoors, but the air outside was better than today (in Oregon anyway). And the air quality on planes was actually better before they banned smoking than after because the airlines immediately turned the expensive cabin air re-circulation way down.
Air is significantly cleaner now than the 70s/80s, and airplanes still continuously replace the air because it’s not airtight. It’s pressurized but always leaking a bit. It is not expensive nor was it turned off. About half the air is recirculated after passing through a HEPA filter, the rest is fresh air (well, fresh bleed air).