If ‘you are what you eat’ is meant to remind people about the health issues of eating unhealthy foods then “ You are what you breathe ” should be a phrase people use to remind themselves about the hazards of spending too much time around polluted air.
Indoor air can have levels of pollution more than 2-5 times higher than outdoor air; sometimes this can even reach levels 100 times higher. The average American spends 90% of their time indoors, which means that their body is acting like the filter for all of these pollutants.
If the air isn’t filtered, you’re the filter.
These pollutants can be caused by increased levels of outdoor pollutants that build up indoors, or by office equipment, cleaning chemicals, and even dust and dirt from the building occupants. In industrial buildings the pollution levels can skyrocket due to the machinery and dust created, as well as any chemicals or solvents used or produced in the manufacturing process.
In many commercial and industrial HVAC systems it isn’t as easy as just changing out a filter, the entire system has become full of pollutants and leads to unhealthy air being circulated even when the filter appears clean. The only way to completely remove these pollutants from the air you are breathing is to clean the HVAC system and then make sure any filters used are strong enough to keep future pollutants out.