Today’s headlines are full of alarming articles on building-related illnesses, bio-terrorism threats and toxic mold. Buildings and schools are regularly evacuated to minimize these risks.

Managing buildings with indoor air quality problems can be an expensive proposition. Building managers and lenders are starting to evaluate building indoor air quality as part of their due diligence efforts.

Failure to consider indoor air quality problems when purchasing a building can result in future problems, including poor employee productivity/morale, increased absenteeism or even employee complaints to the Occupational Safety & Health Administration. In many instances, lawsuits have even been initiated as a result of indoor air quality issues.

To minimize potential liabilities, building managers and lenders must have a comprehensive knowledge of how indoor air quality can be compromised, and the related costs to remediate these problems.

One of the more prevalent causes of poor indoor air quality is the lack of adequate outdoor fresh air. The energy conservation movement in the past three decades has resulted in construction of buildings with minimal fresh air makeup. To reduce heating and cooling costs, HVAC systems are commonly adjusted to take in minimal amounts of fresh air. Building renovations or HVAC system modifications/balancing can also result in unacceptable air circulation inside the building.

Starving for Air

A combination of any of the above factors literally suffocates building occupants and typically results in headache and fatigue complaints. Carbon dioxide levels above 1000 parts per million are generally an indication of inadequate fresh air makeup. The American Society of Heating Refrigeration and Air Conditioning Engineers document entitled “Ventilation for Acceptable Indoor Air Quality” recommends a minimum of 20 cubic feet per minute of outdoor air per person for most building spaces. Building managers should require that these minimum guidelines be met for acceptable occupant comfort and compliance with building codes.

Contaminants can enter buildings through a variety of pathways. Most commonly, improperly located HVAC fresh air intakes introduce outside contaminants into the building. For example, HVAC intakes located at truck loading docks can introduce carbon monoxide emissions into the building.

Rooftop exhausts, such as boiler stacks and kitchen/bathroom vents located near rooftop air intakes, can also introduce contaminants into occupied areas of a facility. If air intake positioning is a problem with a perspective building, relocation of the intakes or development of policies, e.g., no truck idling at the loading dock, can help minimize potential problems.

A number of other contaminants that can be found inside of buildings include:

• Volatile Organic Compounds, e.g., formaldehyde, from furnishings and rugs;

• Asbestos from insulating materials;

• Radon from naturally occurring soil near foundations;

• Carbon monoxide from internal combustion devices, e.g., inadequate ventilation of combustion sources;

• Pesticides and herbicides from spraying;

• Fugitive process air emissions.

A good indoor air quality evaluation should address these areas of concern through environmental testing to document acceptable levels. If elevated levels are documented, expensive engineering controls may be necessary to control contaminant sources. Additionally, OSHA requires specific operations and management programs for materials such as asbestos.

Excessive growth of bacteria and fungi can cause offensive odors as well as allergic reactions and diseases to building occupants. Typical areas of microbial growth can include HVAC condensate pans with blocked drains, hidden water-damaged materials, recirculated cooling water without bactericides, etc. In certain instances, building envelopes may require extensive repair to eliminate moisture leakage.

Bacteria and fungi will proliferate if they have the right temperature, nutrient base, moisture and seed spores. Elimination of microorganisms can be effectively undertaken by minimizing several of these factors. These microorganisms can be controlled by eliminating moisture, as well as by cleaning surfaces and treating water with an appropriate anti-microbial. In some instances, such as when rugs are contaminated with microorganisms, disposal of the infested material may be more effective than cleaning. Remediation of mold-contaminated materials in accordance with Environmental Protection Agency guidelines is extremely expensive and oftentimes requires strict contaminant control procedures.

Another cause of occupant discomfort is temperature and relative humidity. Uniformity of temperature is extremely important to occupant comfort. Oftentimes, areas which are “too cold” or “too hot” can be perceived as poor working environments. Relative humidity levels below 30 percent may cause excessive dryness, while levels above 60 percent can cause growth of allergy-causing or pathogenic organisms.

ASHRAE generally recommends that the relative humidity in a building be maintained between 30 percent and 60 percent, that winter temperature range be maintained between 68 to 74 degrees, and that summer temperatures be maintained between 68 to 74 degrees. Building managers should maintain these building HVAC systems within these standard ranges in order to minimize occupant complaints.

So how can you minimize your exposure to buildings with costly indoor air quality problems? First, a Certified Industrial Hygienist that specializes in indoor air quality should perform a preliminary evaluation of the building for potential indoor air quality problems. At a minimum, this should include discussions with maintenance employees to determine if there has been a history of indoor air quality complaints. A thorough visual inspection of the building should be performed to assess the HVAC system, water intrusion and drainage problems. Insurance records should be evaluated to identify past water damage claims.

Additional inspections by professional engineers may be necessary if the Certified Industrial Hygienist identifies problems with the HVAC system, building envelope leaks or site drainage issues. Costs associated with improving indoor air quality should be factored into the building financing. These due diligence efforts will help identify and minimize indoor air quality problems, employee complaints and potential lawsuits.