Air Filtration: Now More than Ever
May 14, 2007
The goal of every restoration job is to safely and efficiently return the indoor environment to pre-loss condition for the customer. Part of this responsibility is to address the quality of the air inside the structure.
Any job that involves cleanup of sewage, mold and/or fire damage will generate significant amounts of particulates and odiferous (smelly) gases. These contaminants are a direct result of the damage itself, as well as the necessary process of treating and cleaning damaged materials. This includes not only damage in the occupied space, but also contaminants in wall or ceiling cavities that may be disturbed and unknowingly introduced into the occupied space. These contaminants can settle on carpet, upholstery, furnishings, and be drawn into the HVAC system.
Even clean-water losses are susceptible to compromised indoor air quality. The high-velocity airflow necessary for effective drying does more than evaporate moisture into the air; it also stirs up millions of microscopic particles that have been trapped in the carpet or have settled on structural materials.
Some of these particles, such as human skin cells, animal hair, and dirt, are nearly always present but are harmless to occupant health. Chemical agents such as soot particles, hydrogen sulfide gas, and mercaptans (organic sulfur-containing chemicals generated by sewage-borne bacteria) can create unwanted visual damage and noxious odors. Potential human allergens such as cat or dog dander or dust mites may be released in large concentrations from damaged carpets and furniture. Most importantly, readily aerosolized biological agents such as sewage-borne bacteria or mold spores (and spore byproducts) are likely to be introduced into the air in large amounts during the drying restoration process-and these agents can cause adverse human health effects when inhaled.
Ultimately, if these pre-existing or newly introduced contaminants are not removed effectively they will impact the indoor air quality of the worksite and compromise the quality of the entire restoration job. Some contaminants can even create a potential indoor health hazard. An air scrubber helps prevent these undesirable – and potentially harmful – particles and gases from remaining in the indoor environment or lodging in your equipment. By greatly reducing the types and quantity of airborne particles, an air scrubber also reduces the chances that occupants or technicians will inhale contaminants or gases. Removing contaminants safely, efficiently, and cost-effectively with an air scrubber is a great benefit to your business, your employees, and your customers.
What's In the Air?Air is composed of much more than nitrogen, oxygen, and carbon dioxide. Even the relatively “clean” air of a normal household or office environment contains a variety of microscopic particles, allergens, and organic chemicals. Most of these commonly occurring agents are the result of normal human and animal activity, plants, insects, cleaning products, and personal hygiene products. The normal introduction of dirt and certain soil- and plant-borne mold spores into the indoor environment occurs through open windows, doors, and foot traffic. These particulates comprise most of what is found in normal indoor dust, both on surfaces (such as carpet) and in the air.
A normal indoor environment also includes trace quantities of volatile organic chemicals (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 either harmless or, in a few cases, represent potential allergens to a small number of susceptible individuals.
These normally occurring indoor substances can be distinguished from actual indoor “contaminants” or “pollutants.” The latter substances have the potential to cause adverse health effects, both short-term and long-term. The Environmental Protection Agency and the American Lung Association have both published articles listing pollutants of concern. These pollutants can be classified into two types: particulate and gaseous.
Particulate PollutantsThese 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 and both dormant and living organisms. Of primary concern are:
- non-visible respirable particles that can penetrate deep into the lungs where they may stay a long time and cause acute or chronic health effects; and
- larger particle, such as pollen, animal dander, or dust, that do not penetrate as deeply, but may cause an allergic reaction.
Gaseous PollutantsGaseous pollutants 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.