Is there cause for concern?
- The EPA has recently stated that indoor air pollution is widely recognized as one of the most serious potential risks to human health.
- The average American spends 90-95% of their time indoors.
- There has been a 70% increase in childhood asthma over the last 20 years.
- Prior to World War I the world was largely free of man-made chemicals. Currently, there are more than 4 million registered. 80,000 of these are in common use. Less than 1,000 have ever been tested for their effects on the human nervous system.
- There is no toxicity data on 4 out of 5 of the most commonly used chemicals.
- 250,000 new chemical substances are created each year.
- Although chemicals acting in combination can drastically potentiate the toxic affects of one another (a well known fact in the pesticide industry) there has never been any study on the effects of chemicals in common use in new construction acting synergistically in a new building.
- Prevelancy Studies conducted by three states have revealed that as many as 15% of the population currently suffers from chemical sensitivities.
Categories of Indoor Pollutants
Volatile Organic Compounds (VOC’s)
Organic compounds are chemicals, naturally occurring or synthetic, which contain carbon hydrogen bonds at a molecular level. They can be solid, liquid or gas.
Synthetic organic compounds are primarily derived from petrochemical – oil gas or coal.
Volotile organic compounds – substances that readily release vapors or “outgas” at room temperature. They are a major source of human toxic overload in the environment and can affect any organ of the body.
Primary organic compounds are directly derived from gas oil and coal and include propane, butane, benzene, xylene, paraffin, toluene, and styrene.
Intermediate organic compounds derived from primary V.O.C.’s include formaldehyde, phenols, acetone, isopropanel and acetaldehyde.
End products include solvents, waxes, lacquers, synthetic detergent, paints, and synthetic fibers.
Most common sources of V.O.C. outgassing in construction include plywood, particle board, adhesives, paints, finishes, cleaning products, carpeting, plastics, and fabrics.
Although technically some pesticides may be considered to be V.O.C.’s their use has more far reaching consequences in terms of human and environmental health. Whereas other toxins discussed haven been introduced into the environment inadvertently as an undesirable byproduct of other building activity, pesticides have been specifically created for the purposes of destroying plant and animal life.
- Most pesticides are synthetic chemicals derived from petroleum. They were first developed as offshoots from nerve gas used during WWI.
- A National Cancer Institute study indicated that the likelihood of a child contracting leukemia was more than six times greater in households where herbicides were used for lawn care.
- According to the New York State Attorney General’s office, the EPA considers 95% of the pesticides used on residential lawns to be probable human carcinogens.
- 2,4-D was a component of Agent Orange and is used in about 1,500 lawn care products.
- Pesticides have been linked to the alarming rise in the rate of breast cancer.
- Besides causing cancer, pesticides have the potential to cause infertility, birth defects, learning disorders, neurological disorders, allergies, and multiple chemical sensitivities, among other disorders of the immune system.
Common sources of pesticides in new construction
- Soil treatment under structures
- Sill plates
- Wood windows
- Construction supplies that have been warehoused in pesticided facilities and which arrive on the site contaminated
Common construction practices that lead to future pest problems for occupants
- Tree stumps that are not removed from premise construction
- Litter of material and food that create habitats for unwanted wildlife
- Use of woods with fungus mold or insect infestation
- Failure to properly screen openings and vents
- Failure to create a weather tight building
Toxic Byproducts of Combustion
Fuels burned indoors
Toxic byproducts of combustion are produced when gas, oil, coal, wood, and tobacco are burned indoors.
Harmful emissions include:
- nitrogen dioxide
- nitrous oxide
- sulfur oxides
- hydrogen cyanide
- carbon monoxide
- carbon dioxide
- particulate matter
Sources of toxic byproducts of combustion include:
- Any appliance with a pilot light
- Cooking appliances that are inadequately ventilated
- Garages that are insufficiently isolated from living space
- Backdrafting from unprotected mechanical equipment
- Byproducts from open fireplaces and wood stoves
- Flue gasses that are drawn into living space when negative pressurization occurs
- Cigarette smoking
Naturally Occuring Pollutants
High radon levels in a home can build up to values thousands of times higher than outdoor levels equivalent in affect to thousands of X-rays per person on an annual basis. It is simple and inexpensive to abate in water and air if planned for in the initial construction.
Heavy metals in trace amounts can be found in drinking water. Metals such as aluminum, copper, and lead can accumulate over time in human tissue causing liver, brain, and kidney damage. Water from each well must be tested individually since two wells separated by a few hundred feet can have very different water content. Municipal water is usually disinfected to kill biological contaminants but very few facilities are able to remove heavy metals, pesticide residues and other contaminants. Most add chlorine and fluoride which ends up in our drinking and bathing water.
Biological pollutants include pollen, house dust, mites, and mold. Strategies for reduction include air and water filtration, control of moisture, avoidance of surface materials and appliances that trap dust such as carpeting and baseboard heaters.
Electromagnetic fields are perhaps the most controversial of pollutants. A myriad of studies have appeared over the past two decades with claims and counter claims as to whether or not EMF exposure causes certain types of cancer or increases incidence of miscarriage. The official government stance is that individuals should exercise prudent avoidance.
In fact electric and magnetic fields are two separate but related phenomena.
|Electric Fields||Magnetic Fields|
Flow in straight lines in all directions from sources unless conductors attract them.
Radiate out from the source, flowing in loops.
Can be easily shielded.
Difficult and expensive to shield. (Even lead is not effective.)
Attracted by conductors such as metal or salt-water bodies, including people.
Penetrates all normal building materials.
Present when switches for machinery are off or on.
Only occur when appliances are switched on and current is flowing.
Not widely recognized as a health threat in conventional circles at the time of this writing
Safe exposure limits not regulated by the U. S. government. Sweden has set safe exposure limits.
Reportedly affects the nervous system and can cause insomnia, anxiety, depression, and aggressive behavior.
Reportedly affects cellular function and has been statistically linked in some studies with increased cancer cell growth rate, Alzheimer’s, miscarriage, and birth defects. Some sensitive individuals report physical reactions when in elevated magnetic fields.
Electrical code permits but does not mandate reduced electric field wiring.
Electrical code offers protection against exposure to magnetic fields produced by wiring in the structure.
Proper use of electric field meters requires expertise.
Easily measured with a gaussmeter.
Common sources of EMF pollution:
- Improper wiring that produces net current
- Motorized equipment
- Proximity to overhead power lines
- Subpanels where hot and neutral field cancellation does not occur
Planning & Design Considerations
Choosing the right site
- Free from air and noise pollution from traffic
- Upwind from regular pesticide applications
- At a distance from high tension wires
- Good air circulation
- Free of geopathic zones
- Uncontaminated soils
- Radiologicals in water or soil
- Does not fry or trap dust
- Is energy efficient
- It is healthiest to have temperature variation. We do not serve our health, and we inordinately increase energy consumption, by demanding constant temperatures in all four seasons
Healthy air exchange
- Fresh air exchange by natural means or by mechanical means where conditions require it
- Allow for moist air to leave building while avoiding negative pressurization
- Sufficient through-roof range venting
- Good natural cross ventilation
- Good drainage so hot water heater does not create flood damage and mold when it does break
- Does not open into living space or mechanical equipment has power venting or sealed combustion
- Motorized equipment isolated from living space
- A good roof – preferably sloped with a decent overhang
- Positive drainage away from all points along the perimeter
- Impermeability and excellent drainage management at basement and crawl spaces to prevent mold
- Design for inevitable water disasters by building in floor drains at mechanical and laundry rooms
- Hold gypsum board off the floor in wet rooms
- Filter chlorine and other contaminants out of bathing and drinking water
Electromagnetic field protection
- Proper location for motorized equipment
- Require that electrician take care of any net current in the wiring, as detected by a gaussmeter. Do not count on the electrical inspector to catch all violations.
- Have circuitry run so bedrooms can be isolated to the greatest extent that is practical and so that electricity to the bedroom can be shut off while occupants sleep
- Have wiring runs go through circulation space not living space
The Healthy Building Process
- Select an architect and builder who are knowledgeable and enthusiastic about Healthy Building.
- Create clear written instructions for special project procedures and materials selections and work with the builder as a team member.
- Select durable, easily maintained materials.
- Alert builder to these facts: there may be longer lead times; a comparable level or quality is expected as with standard products and that if the GC is experiencing difficulty with a product to call for a reevaluation; in order for substitutions to be considered, an MSDS and physical samples must be supplied to the architect or owner.
- Avoid soft absorbent materials such as carpeting.
- Select the least toxic finishes available.
- Work with your builder and architect to create an owner’s manual that explains the regular maintenance tasks and safest maintenance products.