Indoor Air Quality Part 2: Something is in the air. And it’s not good.
As discussed in Part 1, controlling air quality is critical to the successful restoration of the indoor environment. In this article, we’ll take a closer look at specific types of contamination the restorer is likely to encounter, and examine the challenges and risks they present.
Pollutants of concern
Air is composed of much more than nitrogen, oxygen, and carbon dioxide. Even the relatively "clean" air of a normal (non-smoking) household or office environment contains a variety of microscopic particles, allergens, and organic chemicals. Most of these compounds and materials are the result of normal human and animal activity, as well as plants, insects, cleaning products, and personal hygiene products.
The introduction of dirt and certain soil- and plant-borne mold spores into the indoor environment normally occurs through open windows, doors, and from foot traffic. These particulates comprise most of what is found in normal indoor dust, both on surfaces (such as carpets) and in the air. A normal indoor environment also includes trace quantities of volatile organic compounds (VOCs). These VOCs are the result of evaporation or off-gassing from carpeting, furniture, and certain household or other chemical products. Most of these substances are harmless, but in a few cases, they represent potential hazards to a small number of susceptible individuals.
It is helpful to distinguish these normally occurring indoor substances from actual indoor "contaminants" or "pollutants." The latter have the potential to cause adverse health effects, both short-term (acute) and long-term (chronic). The Environmental Protection Agency (EPA)1 and American Lung Association2 have both published articles listing pollutants of concern. These pollutants can be classified into two types: 1) particulate and 2) gaseous.
1) Particulate Pollutants
These very small solid or liquid particles are light enough to float around in the air. They may include organic (i.e., carbon-containing) or inorganic compounds as well as dormant and/or living organisms. Of primary concern are non-visible respirable particles, which can penetrate deep into the lungs where they may stay a long time and cause acute or chronic health effects. Larger particles —such as pollen, animal dander, or dust— are also a concern. Although they they do not tend to enter the lungs so deeply, but they may cause an allergic reaction in sensitive individuals.
2) Gaseous Pollutants
These include combustion gases and organic chemicals that are not associated with particles. With the development of increasingly sophisticated measurement equipment, hundreds of different gaseous chemical pollutants have been detected in indoor air. Sources include combustion appliances, cigarette smoking, vehicle exhaust, building materials, furnishings, paints, adhesives, dyes, solvents, cleaners, deodorizers, personal hygiene products, pesticides, and even the cooking of food or the metabolic processes of humans, animals or plants. Health effects depend on the type and concentrations of gaseous pollutants, frequency and duration of exposure, and in the case of allergenic substances, individual sensitivity. Some of these chemicals are simply transient irritants, capable of causing short-lived reactions such as watering or burning of the eyes or nose, cough, or other adverse reactions related to their unpleasant odor. For all but a few specific agents, the long-term health effects (at relatively low concentrations found in typical indoor environments) are unknown and/or not studied.
Learn more about indoor air quality at EPA’s website http://www.epa.gov/iaq/pubs/insidestory.html
Conclusion
The presence of airborne substances, whether non-visible respirable particles or the more visible larger particles, should always be assumed. Proper HEPA air filtration will help to reduce the exposure of occupants and technicians to these potentially dangerous materials, and help to ensure that the indoor environment has truly been restored to its pre-loss condition.
Read Part 1 of "Indoor Air Quality" here.