Fresh clean air is essential for health while polluted air is an environmental health hazard.  For more than fifty years the harm of air pollution has been documented.  As the National Institute of Environmental Health Sciences (NIH NIEHS) points out, initially air pollution was primarily regarded as threat to respiratory health and contributed to an increase in asthma, emphysema, chronic obstructive pulmonary disease, and chronic bronchitis.¹ More recently, air pollution has been identified as a significant risk factor for cardiovascular disease, diabetes mellitus, obesity, reproductive, neurological, and immune system disorders and ADHD.^1-3

Yet many of us are unaware that often the air we breathe indoors is even more polluted than the outside air.  The indoor air is the sum of outdoor air plus the indoor air pollution produced from cooking and outgassing of the volatile organic compounds (VOCs) from the many materials.⁴ Materials and equipment in home and office also shed micro dust particles and outgas a chemical brew of volatile organic compounds (e.g., formaldehyde, benzene and trichloroethylene). These VOCs come from paper, inks, furniture, carpet, paints, wall coverings, cleaning materials, floor tiles, and the fumes produced from gas heaters and cooking stoves. In addition, copiers and laser printers often add microscopic dust particles and sometimes ozone. These gasses stay in the room where there is limited air circulation due to sealed buildings or closed windows. Reduced air circulation is also a significant risk factor for Covid-19 since, the virus keeps recirculating in unventilated rooms. See the superb graphic illustration by Bartzokas et al (Feb 26, 2021). in the New York Times  of virus concentration in schools when the windows are opened.⁵