Indoor Air Quality
Air quality in and out of the home is of vital importance. The average person takes in 33 lbs. of air daily as compared to only 5.5 lbs. of fluids and 1.5 lbs. of food. A high level of any contaminant or combination of pollutants can cause a wide range of detrimental effects. The more exposure we have to chemical toxins the more likely a sensitivity or illness will develop, including chemical hypersensitivity.
Major Sources of Indoor Air Pollution
Volatile Organic Compounds (V.O.C.'s)
These are carbon based compounds that produce toxic gasses and vapors during drying, aging and degradation of materials. Some of the compounds include binding agents, plasticizers, stabilizers, fillers and solvents such as formaldehyde. You can find these V.O.C's in presswood products, paneling, plywoods, carpeting, paints, wood finishes, vinyl sheet flooring, kitchen cabinets, countertops, wall paper, bedding, furniture, adhesives, personal care products, plastics, fabric coatings, insulation, aerosols, and household cleansers.
The potential health hazard effects include: Skin, eye, nose and throat irritation, breathing difficulties, headache, fatigue, nausea, allergic dermatitis, respiratory tract irritant, visual disorders, weakness, neurotoxic problems (central nervous system depression), cognitive impairment (memory loss, confusion), dizziness. These compounds can be inhaled or absorbed through the skin. Water soluble compounds can dissolve in the blood stream and be carried throughout the body. Fat soluble compounds can be stored in body fat and can accumulate to toxic levels.
Allergens and Biological Contaminants
The inhalation of respiratory irritants and micro-organisms proliferating in the indoor environment due to poor ventilation and high moisture levels, create a potential for illness. These irritants include dust mites, mold, mildew, bacteria, viruses, protozoans, algae, insectbody parts and excreta, pollens, fungi, plant fragments and animal dander. Foot traffic from outside and air infiltration bring in pollutants from plants, soil, animals and humans. Moist surfaces in air conditioners and humidifiers, refrigerator drip pans, damp cellars, heating ducts and carpeting are good breeding grounds for biological irritants. Other problem high humidity areas include bathrooms, laundry and kitchens.
Many health hazards exist including: Infectious viruses and bacteria (legionnaires disease, chicken pox, staph infections), allergic reactions such as runny nose, sore throat, watery eyes, sneezing, coughing, skin rashes, asthma, headaches and upper respiratory discomfort. Prolonged excessive exposure can increase the risk of developing an allergy.
Hazardous complex mixtures of gasses are developed as a result of the combustion of fossil fuels and vegetative matter including oil, kerosene, coal, natural gas, wood and plant matter. The types of gasses produced include carbon monoxide, carbon dioxide, nitrogen oxides, sulfur dioxide, polycyclic aromatic hydrocarbons, and wood smoke (contains many compounds). These gasses appear in the indoor air from poorly vented, inefficient and back drafting combustion appliances used during cooking (gas stoves) and heating (space heaters, furnaces, hot water heaters and fireplaces) and also from vehicle exhaust from attached garages.
Reaction to these gases include: Dizziness, blurred vision, rapid breathing, irritation of the respiratory tract, coughing, headache, flue-like symptoms, brain function loss and fatigue. Many of the gasses are absorbed into the blood stream from inhalation and inhibits the bloods ability to carry oxygen. High concentrations of these gasses can cause burning of the throat and chest and can lead to loss of consciousness and death.
Particulate matter is airborne material that is small enough to be inhaled into the lungs, yet large enough to remain lodged in the lungs once there. This material includes asbestos, glass fiber (insulation), lead, heavy metals, combustion by-products, tobacco smoke and house dust. You can accumulate particulate matter from asbestos containing building materials (siding, flooring, insulation), lead in paint and outdoor air infiltration, furnishings, building materials, cigarettes, combustion appliances, wood burning stoves and fireplaces, and contaminated soil brought into the house from the exterior. These materials can alter lung function from an obstructed airway.
Potential problems: The heavy metals can enter the bloodstream and cause damage to the brain, kidneys and nervous system. Suspended particulates can be an eye and mucous membrane irritant and combine with airborne toxins to be inhaled into the lungs.
Radon is a colorless, odorless, radioactive gas that can be inhaled into the lungs and/or ingested from water. Uranium bearing rocks and soil decomposes to radon gas. This gas enters the house through cracks and penetrations in the basement floors and walls. Radon gas is also dissolved in ground water and enters the house through the use of well water. Some building materials can contain uranium such as concrete with uranium bearing stone aggregate. Also, natural gas used in cooking and heating may contain radon if mined near radon bearing rock.
Possible Health Consequences: Radon causes an increased risk of lung cancer from the inhalation of the gas. Ingestion of dissolved radon in water can increase the chance of mouth, stomach and intestinal cancer.
These long lasting chemicals can be inhaled, ingested or absorbed through the skin. This class of chemicals include insecticides, fungicides, herbicides and rodenticides. They can be detected in the indoor environment by their use indoors and from being carried in with foot traffic from the exterior. These chemicals are formulated to be toxic and can accumulate in bodyfat.
Noticeable effects include: Dizziness, headaches, muscle twitching, weakness, nausea, and tingling sensations. Long term effects include liver damage, increased risk of cancer, and central nervous system impairment.
Lack of Ventilation
Without the proper exchange of outdoor fresh air (non-contaminated) and indoor stale air, a build-up of indoor air pollutants and moisture can occur. The cause of inadequate ventilation can be from a reliance on uncontrollable air infiltration in poorly constructed homes and the lack of a mechanical whole house ventilation system. Without a controllable whole house ventilation system you are relying on climatic conditions and temperature differentials to drive air through a leaky wall cavity for an exchange of air. Opening of windows and leaky wall construction can introduce contaminants into the indoor air or may not be acceptable in certain weather conditions.
The lack of adequate ventilation can cause: An increase in moisture levels and as a result an increase in biological contamination and possibly structural damage to the building from wood rot. Non-removal and/or non-dilution of indoor pollutants may result in unhealthy contaminant levels. Spot ventilation devices (exhaust fans) can depressurize a home and create a negative pressure inside the home when compared to the exterior, which can potentially pull in combustion gasses from heating systems and fireplaces, and radon and other contaminants from their sources.
Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460