A Massachusetts (USA) study has found that there is ten times more
pollution indoors than outdoors. Radon, volatile organic compounds (VOCs), formaldehyde, airborne mold spores, and other contaminants accumulate in tightly sealed building envelopes. This condition can be severe, causing people to become sick, especially those who are chemically sensitive.

Therefore, all buildings should allow adequate air exchanges and be built
using natural, non-toxic materials. All architects should consider themselves house doctors and be willing to assume responsibility for the health of their clients (patients).

There are a great number of environmentally friendly substitutes to toxic materials on the market. Insulation is being made of natural cotton and also of scrap from blue jean manufacturers. Cotton and wool carpets are rather common. Companies such as Auro, Livos, and AFM have made non-toxic wood sealers, paints, and similar natural products available to homeowners and builders.

Along a similar vein, some studies suggest that electromagnetism caused by motors (in refrigerators, for example), and found in electric and radio fields, might have detrimental effect on brain neurons. Sensitive design should also take this into account. A Gausmeter should be a tool readily available to every designer, architect, and builder.