Many people spend 90% of their of their lives in buildings. Growing plants indoors is a way to keep our connection to natural world.
There is also a growing amount of:
- Chemical sensitivity
In the past homes leaked a good amount of air. This aided natural ventilation and air changes throughout a home. With energy efficiency increasing this seals the air in, preventing natural ventilation.
A study showed that compared to older homes, new homes have 50% less fresh air infiltration. (0.9 air changes per hour down to 0.5) (Mage and Gammage, 1985).
When toxic chemicals are used in furniture, flooring, paint, etc.. they stagnant in the home and are breathed in.
This calls for a two pronged approach. Increasing filtration through mechanical filtration, and the subject of the book… filtration of chemicals using plants. A technology as old as the earth.
In his book How to Grow Fresh Air, B.C. attempt to summarize 25 years of research into the beneficial relationship of plants and indoor air.
The book rates different plants by the following traits:
- Ease of cultivation
- Removal of chemicals
- Vulnerability of insect infestation
- Humidification rate
- Preferred growing conditions (mainly temperature and light levels)
In 1950 Dr. T. G. Randolph was the first to discover allergies and chronic illnesses could be traced back to indoor air pollution.
During the 1970s oil embargo the building industry started to weatherize homes to limit energy usage. Adding insulation, and caulk to limit air and heat losses.
This led to the what is known as the sick building syndrome (SBS) during the 1980s. As a range of illnesses appeared in Canada, Europe, and the U.S. where buildings where sealed and insulated without proper ventilation.
Common Sick Building symptoms:
- Sinus congestion
- Respiratory congestion
- Nervous-system disorders
- Nose, Eye, and throat irritation
Worse yet.. the term building-related illness (BRI) came about to describe diseases caused by buildings. This is mainly due to items like asbestos that cause lung cancer, or legionnaires from air-conditioning and heating water that is often stagnant.
Sources of chemical emission include:
- Gas stoves
- Ceiling tiles
- Bioeffluents – From humans these are mainly ethyl alcohol, acetone, ethyl acetate, and methyl alcohol
- Paper towels
- Cleaning products
The list goes on… but as you can see, it’s pretty hard to get away from toxic chemicals.
In summary poor indoor air quality is mainly a result of lack of ventilation in buildings, furnishings, and bioeffluents from humans.
On of the first markers for healthy air is humidity levels. B.C. states it should be in the 35-65% range.
Tip – Allow new furnishing to off-gas chemicals before you bring them into your home.
NASA Plant Study PDF
EPA Letter to Congress on Indoor Air Quality of 10 Energy-Efficient Houses – Link
Study – Allergy and Multiple Chemical Sensitivities Distinguished – Link