Indoor Air Quality (iAQ)

Concern about indoor air pollution

Studies have shown that the air in our homes can be even more polluted than the outdoor air in mid to big cities / metropolitan areas. Because we spend so much time indoors, the quality of our indoor air can affect our health. Infants, young children, and the elderly are groups shown to be more susceptible to pollutants. Those who suffer from chronic respiratory or cardiovascular illness or immune system diseases are also more susceptible to pollutants.

Many factors determine whether pollutants in your home will affect your health. They include the presence, use, and condition of pollutant sources, the level of pollutants both indoors and out, the amount of ventilation in your home, and your overall health.

Most homes have more than one source of indoor air pollution. For example, pollutants come from tobacco smoke, building materials, decorating products, home furnishings, and activities such as cooking, heating, cooling, and cleaning. Living in areas with high outdoor levels of pollutants usually results in high indoor levels. Combustion pollutants are another category of indoor air pollutants.

Facts:

1) It is widely recognized that most people spend more than 90% of their time indoors. Because most of us spend so much time inside, indoor pollution concentrations, even if they are uniformly lower than outdoor levels, make a significant contribution to our average exposure over a day, week, month, or year.

2) Modern indoor environments contain a complex array of potential sources of air pollution, including synthetic building materials, consumer products, and dust mites. Airborne emissions also occur because of the people, pets, and plants that inhabit these spaces. Efforts to lower energy costs by reducing ventilation rates have increased the likelihood that pollutants generated indoors will accumulate.

3) Testing and studies inside buildings and vehicles have consistently found that concentrations of many air pollutants tend to be higher indoors than out. Indoor air has been shown to be a complex mixture of chemical, biological, and physical agents/matters.

4) Complaints about inadequate indoor air quality and associated discomfort and illness are a burgeoning problem in our society. Reports of illness outbreaks among building occupants, particularly office workers, with no secondary spread of illness to others outside the building with whom affected individuals come into contact have become common. Environmental Protection Agency (EPA) classifies these reports into two general categories: building related illnesses and sick-building syndrome.

5) Exposures to many indoor air pollutants are known or suspected to occur at levels sufficient to cause illness or injury. Scientific evidence suggests that respiratory disease, allergy, mucous membrane irritation, nervous system effects, cardiovascular effects, reproductive effects, and lung cancer may be linked to exposures to indoor air pollutants.

Combustion pollutants

Combustion pollutants are gases or particles that come from burning materials such as fuels in appliances. Common fuels burned in appliances are natural or LP gas, fuel oil, kerosene, wood, or coal. The types and amounts of pollutants produced depend upon the type of appliance, how well the appliance is installed, maintained, and vented, and the kind of fuel it uses. Some of the common pollutants produced from burning these fuels are carbon monoxide, nitrogen dioxide, particles, and sulfur dioxide. Particles can have hazardous chemicals attached to them. Other pollutants that can be produced by some appliances are unburned hydrocarbons and aldehydes.

Combustion always produces water vapor. Water vapor is not usually considered a pollutant, but it can act as one. It can result in high humidity and wet surfaces. These conditions encourage the growth of biological pollutants such as dust mites, molds, and bacteria.

Sources of combustion pollutants

Combustion pollutants found indoors include: outdoor air, tobacco smoke, exhaust from car and lawn mower internal combustion engines, and some hobby activities such as welding, woodburning, and soldering. Combustion pollutants can also come from vented or unvented combustion appliances. These appliances include space heaters, gas ranges and ovens, furnaces, gas water heaters, gas clothes dryers, wood or coal-burning stoves, and fireplaces.

More facts

Based on studies by the EPA, billions of dollars are spent annually for medication to help Americans breathe or cure their respiratory illnesses. 11 million Americans have asthma, and 28 million suffer from hay fever and other allergies. Physicians are now discovering that the solution to many of these problems lies in reducing airborne pollutants.

Every year at least 6,000 new chemical compounds are developed. Many are used indoors every day, at home and at work. Add to these pollutants the mold, mildew, bacteria, viruses, tobacco smoke, grease, pollen, dirt, asbestos, lead and numerous other contaminants that can affect our breathing and health. Then allow them to re-circulate throughout today’s nearly airtight indoor environments. No wonder indoor air is, on average, 2 to 10 times as polluted as the worst outdoor air.

Viruses and bacteria that thrive in the ducts, coils, and recesses of building ventilation systems have been proven to cause ailments ranging from influenza to tuberculosis. Some heating and air conditioning systems have been found to contain up to 27 species of fungi.

Based on information given at the First Annual Air Quality convention sponsored by EPA, April 1992, Tampa, Florida:

* 40% of all buildings pose a serious health hazard due to indoor air pollution, according to the World Health Organization.

* EPA estimates an 18% annual production loss to American business due to poor indoor air quality.

*20% of all employees who have a major illness related to indoor air pollution such as allergies, asthma, auto-immune diseases, etc.

* EPA says high levels of formaldehyde (HCHO) cause cancer

* Scientists now recognize that pollutants, even at acceptable concentration, have a synergistic negative effect when combined together in an indoor environment.