But then the 1970s hit and suddenly energy conservation was all the rage. That's why the windows in your office probably don't open, and why every crack and gap is sealed so tight you could probably set the building on the ocean floor and everybody would stay dry. The result is buildings that are great about keeping their temperature stable, but horrible at recycling air. They inhale pollutants via the air conditioning systems, but don't let them back out--to the point that the air inside that building can be up to 100 times dirtier than what you breathe outside.
If you're wondering how OSHA and other agencies let this go on, it's because all of their rules were written for shops that work with dangerous, smelly chemicals, rather than offices. There are no real standards to protect the cubicle-dwellers. As a result, for years office workers were coming down with strange symptoms no one could pin down to any actual illness. In 1984 no less than the freaking World Health Organization determined that at least 30 percent of buildings in the world were subject to "excessive complaints" about air quality. What kind of complaints?
Look up. See that ventilation duct? That most likely ends up over your parking lot. The lot that a whole bunch of cars drove into this morning. Now all that lovely, poisonous carbon monoxide they produced is slowly making its way into your lungs.