Indoor Air Quality— Old Problem, New Focus
Allergies and Asthma on the rise
Most of us spend about 90% of our day indoors - at home, at work or school. According to EPA tests, levels of pollutants are 2 to 5 times higher indoors than outside, regardless of whether the buildings are located in rural or highly industrial areas. Other recent scientific studies have also questioned the quality of air inside our homes and buildings.
Despite this attention, poor indoor air quality is not a new phenomenon. In fact, we can find evidence from more than a century ago documenting IAQ concerns. According to The Health Reformer in 1871: “In the construction of buildings, whether for public purposes or as dwellings, care should be taken to provide good ventilation and plenty of sunlight . . . schoolrooms are often faulty in this respect. Neglect of proper ventilation is responsible for much of the drowsiness and dullness that make the teacher’s work toilsome and ineffective.”
Today’s focus on indoor air quality has been the result of years of research on pollutants found in the home and their corresponding health effects, along with development of technologies that can eliminate or reduce the amounts of these potentially harmful contaminants. Individually, some pollutants may not pose a significant risk to our health. However, the combination of multiple sources over extended periods of time can be a serious risk to many people.
Primary indoor pollutants are gasses and particles released into the air. In new homes, many building materials are manufactured with synthetics, glues and chemicals. These materials can emit or “off-gas” minute particles in the form of fumes for several years - sometimes referred to as that “new home smell”. To compound the problem, many builders now construct homes tighter and tighter to reduce energy costs, effectively sealing up the building “envelope.” This minimizes the natural air movement through walls and around windows that were common in older homes, creating the potential for mold growth.
While older homes may not have off-gassing concerns associated with new materials, air quality problems can be caused by other materials including deteriorating wood, furnishings and fabrics, asbestos-coated insulation, mold from previously wet or damp duct systems or carpet, and radon.
Regardless of whether a home is new or old, other contaminants are often found indoors including pollen, smog, plant spores, tobacco smoke, cleaning supplies, solvents, gasoline fumes, odors from improperly ventilated bathrooms, combustion gasses from fossil fuel appliances, pet dander, soiled carpets, and unfiltered outdoor air entering the building. When not enough fresh outdoor air enters a home these pollutants can accumulate to levels that could pose health concerns.
Exposure to poor indoor air quality can cause health problems that are experienced immediately or over the course of many years depending on the intensity, cause, type of pollutant and the health or susceptibility of the occupants. Adverse health effects include coughing, dizziness, fatigue, asthma, hypersensitivity pneumonitis or irritation of the eyes, nose and throat. More serious cases may induce respiratory diseases, heart disease or cancer. Unfortunately, there is some debate in the medical community over what concentrations are problematic and over what period of exposure is required to produce health related problems. There are simply too many variables to precisely determine the long term effects of indoor pollutants. Therefore, the safest approach is to take reasonable steps to eliminate or minimize the risk.