This is a great question. The idea that there is something within the green building materials that is good for you is one I had not thought of before.
In biology, "good for you" can mean two different things.
- The first is the introduction of something that increases the health of an organism: food, nutrients, or other substances that an organism lacks for optimal growth or health, similar to the basis of your question.
- The second is the removal of toxic chemicals that would decrease the health of an organism. Things that would fall into this group could be toxins, poisons, radiation, heat, cold, lack of nutrients or air, etc. This latter definition is more commonly referenced as the basis for claims about the healthiness of green building.
Introduction of something that increase your health
In order for a home, or more specifically, the materials in the home, to introduce something that increases your health, they must provide something that you do not already get from:
- your diet (nutrients, energy, essential amino acids, protein, etc. -- and water);
- breathing (oxygen taken in, carbon dioxide released); sunlight exposure (vitamin D);
- physical activity (exercise); or
- other essential biological processes.
Unfortunately, these elements are not readily gained from the materials within a home, or if they are, are gained in such small amounts as to be deemed statistically insignificant.
Now, of course, this prior analysis completely disregards the psychological effects of living in a home, which can be significant, but are subjective and can be completely dependent on the occupants.These effects can result from:
- natural daylighting,
- the feeling of security and stability that comes with home ownership, and
- the well-being that comes with the knowledge of living in a "healthy" home.
Unfortunately, these feelings can also have just the opposite effect to people in different circumstances: the increased stress that one may feel from being underwater on their mortgage and about to lose their home, from being unable to pay unforeseen home repair bills, or the effects seen in "sick building syndrome" when people know there is something wrong with their home and the psychosomatic effects on their health are not typical of the actual exposure to the toxic chemicals they are exposed to.
Again, there are a multitude of aspects that can affect human health and the job of any competent professional should be to increase the potential and proven positives and reduce the potential and proven negatives.
Reducing toxic materials that would decrease your health
Now, as was stated earlier, most of green building focuses on excluding or reducing the amount of toxic materials introduced into a home. These toxic materials can be the kinds that are directly introduced into a home, such as:
- compressed wood products that use the offgassing chemical urea-formaldehyde;
- paints, stains and other finishes that release organic solvents into the air;
- granite countertops that contain decaying uranium that releases the radioactive element radon into the air; or
- carpeting, that while made of degrading and offgassing petroleum products, also contains all of the materials ever dropped on it or scraped off shoes or feet that have tracked in all sorts of materials we have stepped in while we were outside.
The second category of toxics that are ubiquitously found in our homes are those that we produce or introduce ourselves, like carbon dioxide from exhalation; carbon monoxide from gas-burning appliances like cooktops, water heaters and furnaces; moisture-laden air from showers and improperly vented bath fans, range hoods and clothes dryers; the decomposition of all sorts of petroleum-based materials like plastics, upholstery, furniture, drapes, vinyl flooring, perfumes, deodorants, cleaning supplies, paint thinners, fingernail polishes, drain cleaners, the aforementioned carpets, etc.
Doing your own research
Unfortunately, my answer seems to have dragged on long enough. The problem is that there is no quick answer that comprehensively addresses your complex question.
To expound on my last paragraph about ways to reduce the contamination of a home by this second set of compounds would take up several book chapters by itself, so to put it simply: The best way to reduce the negatives of these compounds is to not introduce them, during construction or after.
There is no magic bullet or panacea in green building; there is only making a concerted effort to look at all aspects of "healthy" building and a lot of at-home reading.
A Google seach on "green building indoor air quality" will get you started in the right direction.
For more information:
You should also read "Green Homes 101," by Doug Smeath, for basics on the benefits of a green home.