Since the energy crisis of the early 1970's, emphasis on energy-efficient homes has skyrocketed. A great deal of attention centers on making homes airtight to decrease the amount of energy and expense needed for heating, which may decrease natural ventilation (an exchange of outside and inside air). Because of this, we have become concerned about the health effects of indoor air pollution within the home.
We spend approximately 80 percent of our time indoors. The percentage for children and the elderly is usually higher; in fact, they may venture outside only one hour a day, especially during the colder months of the year. Therefore, it is important to look at sources within the home that may emit particulates, gases and fumes harmful to our health.
Where are the air pollutants coming from?
Many different sources within the home can emit pollutants. Some of these sources continually pollute, such as those used in building materials and home furnishings: pressed wood products and insulation with urea-formaldehyde. Other sources may emit pollutants intermittently, such as those released from wood-burning and gas stoves, along with organic compounds released from cleaning and hobby supplies.
Some of the more common pollution sources within the home release through combustion: wood-burning stoves, fireplaces, unvented kerosene and gas space heaters and gas stoves. Carbon monoxide, nitrogen dioxide, polycyclic aromatic hydrocarbons and acid aerosols are examples of some pollutants which can be emitted by combustion.
Organic chemicals are another source of concern and are commonly found in household products such as paints, varnishes, degreasing agents, disinfectants and hobby products. These organic compounds may include benzene, perchloroethylene, paradichlorobenzene and methylene chloride.
Another common source of pollution released through combustion is secondhand smoke from cigarettes or cigars. The EPA concludes that in adults, secondhand smoke is a Class A carcinogen. It is responsible for approximately 3,000 lung cancer deaths every year in U.S. non-smokers and is associated with increased risk of severe asthma exacerbation in children.
It is important to remember that once an activity has stopped, the particulates emitted can remain in the air and continue to pose a health threat for long periods of time. In the case of cigarette smoke, there is growing evidence that particles settling on surfaces continue to pose a risk to children’s health in the form of their hand smoke.