Until recently, there has been little or no meaningful regulatory emphasis on managing or controlling indoor air contaminants. Instead, fms are often faced with an indoor air quality (IAQ) concern only when building occupants complain they feel ill. In the past, building occupants who complained about feeling ill were often ignored or viewed as hypochondriacs. While often the causes of the symptoms or illnesses are never confirmed, it is frequentlydiscovered that something is indeed wrong with the indoor air—a malady sometimes referred to as “Sick Building Syndrome” (SBS).
The term SBS usually describes cases where there is no easily identifiable cause. More recently, the science of evaluating IAQ has advanced to the point where the causes of an SBS situation are more readily identifiable and more easily avoided. Standard maintenance techniques and attention to the materials used to furnish, renovate, and construct buildings have helped in this matter. Several IAQ studies have been performed and many dollars expended by IAQ professionals, only to show that the owner responded to tenant complaints “for the file.” Fortunately, enough has been learned so even non-IAQ professionals can easily identify the common causes of IAQ problems or SBS and implement common sense approaches to correcting them.
Sources and Types of IAQ Problems
IAQ problems can occur at any time when contaminants or pollutants are introduced to the air inside a building from either the inside or the outside. IAQ problems are generally associated with the following categories:
Poor or inadequate ventilation that could be the result of insufficient air flow into air intakes, insufficient makeup air, poor coordination of workspace design with the plenum/ductwork network, or an excess of the appropriate capacity of a workspace based on acceptable HVAC design criteria. Common chemical indicators of poor or inadequate ventilation or makeup air include elevated carbon dioxide, carbon monoxide, and wide swings in relative humidity.
Pollutants, contaminants, or odors from combustion sources such as oil, gas, kerosene, coal, wood; tobacco products; off-gassing of building materials, furnishings, carpets, cleaning and maintenance products, central heating and cooling systems, and humidification devices; and outdoor sources such as radon, pesticides, and outdoor air pollution from industry, vehicles, or other sources. Common chemical pollutants include volatile organic compounds such as benzene (gasoline) or toluene (nail polish remover), odors, chlorinated hydrocarbons (dry cleaning solvents), and others.
Airborne mold, fungal spores, and mold byproducts (such as mycotoxins), or bacteria and their airborne byproducts (endotoxins) resulting from growth in a moist space inside a building. Sources of moisture and water leaks can include faulty gutters or downspouts, condensation inside building envelopes, bad window or door seals, overflowing HVAC condensate pans, poorly maintained or malfunctioning air handling units, leaking roofs, and a host of other possible water sources.
According to the U.S. Environmental Protection Agency (EPA), controlling IAQ typically involves three main strategies:
- Managing potential pollutant sources either by removing them from the building or by isolating them from building occupants;
- Diluting pollutants and removing them from the building through ventilation; and
- Using filtration to clean pollutants from the air. Various methods and technologies are available to assist facility executives in this regard.
The Importance of Ventilation
Lack of proper ventilation is often found to be the cause of SBS complaints including fatigue, allergies, difficulty in concentrating, and malaise. Elevated levels of carbon dioxide given off by building occupants and high levels of carbon monoxide given off by machinery and combustion sources are common indicators of poor ventilation. Office suites frequently are renovated without proper modification of the HVAC system, resulting in “dead areas” where there is insufficient makeup air flow or areas with uneven temperatures or humidity.
Ventilation problems are often obvious and may not require expensive outside diagnosis. Air intake and ventilation problems are a primary cause of IAQ complaints and it is a very easy item to inspect and check on a periodic basis.
One recent case was reported where a school board in New Jersey retained an IAQ expert to conduct a study to investigate causes of numerous health complaints in one of the district’s schools. After extensive investigations, inspections, air sampling, laboratory analysis, meetings, and reporting, it was found that the air intake louvers were not working properly and did not open sufficiently to allow the introduction of enough makeup air to serve the population of the building. The louvers were repaired and opened, and the complaints disappeared.
Ventilation design is based in part on the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) Standard 62-1989: Ventilation for Acceptable IAQ, which is a voluntary standard for “minimum ventilation rates and IAQ that will be acceptable to human occupants and are intended to avoid adverse health effects.” This standard is normally applied to all types of occupied facilities. The specified rates at which outdoor air must be supplied to each room within the facility range from 15 to 60 cubic feet per minute (cfm)/person, depending on the activities that normally occur in that room.
More recently, ASHRAE proposed to update its ventilation standard (ASHRAE Standard 62-1999, Ventilation for Acceptable IAQ) to include changes that, in part, address the handling and control of microbial contamination in HVAC systems.
Molds and IAQ
Molds (along with the broader term fungi) and bacteria are living organisms found naturally in outdoor settings. Because IAQ will at least mirror the baseline outdoor or ambient air quality, these organisms will also be found indoors in the air and on surfaces, even in healthy buildings. The issue of the growth and health effects of bacteria is complex, but many of the same causes of mold also contribute to the growth of pathogenic (disease-causing) bacteria.
Molds can grow on almost any building material containing available carbon—such as wood, carpet, insulation, and wallboard—as long as moisture and oxygen are present. These building materials serve as a food source and will gradually be consumed and destroyed by the mold. If excessive moisture in buildings goes unabated, facility executives could be faced with expensive mold problems.
Molds are inextricably linked to IAQ because they reproduce by producing tiny spores that are dispersed into the air as the mold dries. These spores land on a surface and germinate where there is moisture and a food source.
Airborne spores and mold fragments can be inhaled or come into contact with skin, resulting in potential adverse health effects in certain individuals. The severity of mold-related health effects depends on the mold species, its by-products, the amount and duration of exposure, and the susceptibility of those exposed. It is therefore extremely difficult—if possible at all—to predict the potential of a health effect or reaction from exposure to mold or mold by-products.
It is thought that the people most at risk of mold exposure are infants, the elderly, the chronically ill, and persons with severely suppressed immune systems. Although many people suffer no adverse effects from exposure, some can experience short-term effects such as allergy, runny nose, eye irritation, cough, congestion, and aggravation of asthma. A number of molds—the so-called toxic molds—can produce toxins (mycotoxins) that are believed to cause problems ranging from flu-like symptoms to cognitive impairment, respiratory dysfunction, liver damage, and cancer. The scientific community remains divided on the extent of these more serious and sometimes longer-term health effects.
The National Environmental Health Association (NEHA) and the Underwriters Laboratory (UL) have teamed up to create an IAQ Standards committee. The committee’s main objective was to establish “a process for developing an IAQ standard.” The report embodies initial efforts pursued by UL to develop an IAQ standard that can be used to evaluate and certify commodities and services that have applied for UL certification. A significant part of this effort was collaborative with NEHA and an appointed NEHA and UL to the Indoor Air Quality Committee. The membership of the committee consisted of individuals recognized for their technical, professional, or managerial knowledge and skills.
The report of the NEHA/UL IAQ Standards Committee details the efforts and deliberations associated with IAQ Standard development and the process that was used to identify and assess the issues. It also provides UL recommendations for a shared vision, specific goals and objectives, and selected tasks. Finally, there is a recommendation for the process that can be followed to develop an IAQ Standard.
Preventing Mold and Microbial Growth
Since mold thrives in moist environments, it is critically important to stop all moisture sources that can cause mold growth. Excessive moisture in buildings has a number of sources: leaking roofs or windows, leaky plumbing, condensate overflow from HVAC systems, flooding, unvented appliances, and high indoor relative humidity (generally above 60%-70%).
Visible evidence of moisture needs to be immediately investigated, traced to the source, and corrected as soon as possible, since mold growth can occur within 24-48 hours of the first sign of excess moisture. Therefore, it is essential to dry up any excess moisture immediately. Once moisture gets into porous materials such as wallboard, removal becomes difficult and the porous material typically will require removal and disposal.
Mold growth is obvious if it occurs on the exposed surface of a wall or ceiling; however, extensive mold growth will be more difficult to observe behind wallpaper or in wall cavities, insulation, or floorboards.
Facility executives can take the following basic steps to control moisture and prevent mold growth in a building:
Train staff to be constantly on guard for signs of uncorrected moisture—stained ceiling tiles, staining on or around supply diffusers, water near air handling units and HVAC systems, stained carpeting, and water stains under or near windows (suggesting bad seals). Chronic moisture sources must be corrected on a high priority basis.
Develop a water damage response plan and standard operating procedure (SOP) for the prevention and mitigation of moisture and other potential IAQ concerns in a building. Christopher Buzgo, Ph.D., of ENVIRON’s Princeton, NJ office suggests, “The SOP is a wonderful management tool—and it should include a water damage response plan with the names, addresses, and phone numbers of competent disaster response companies that have specific expertise in drying building spaces. Fms are advised to take steps to interview consultants and drying and abatement contractors as to their qualifications and experience before water damage occurs. The response plan should also include provisions for notifying the building owner, insurers, legal counsel, and technical experts as appropriate. Preventing and responding to water leaks should receive the same kind of attention as preventing and responding to environmental spills.”
All water spills should immediately and thoroughly be dried. The key word here is speed. With major leaks (such as a water line break) where facilities staff cannot adequately dry the area themselves, a qualified and competent drying contractor should immediately be retained. In the event of a leak or water spill, drying should include all possible areas that were wetted, including any spaces that are not easily observable. A water leak in a multi-floor building could result in wet spray-on insulation on steel beams and columns, fiberglass insulation (including between the insulation and the outside of the building), carpeting (don’t forget that once wet underneath furniture, carpeting will never dry), wallboard and studs (outside and inside the walls), furniture, books, papers, and any other material. Molds can grow on or in any of these materials. Drying should include all wet surfaces and spaces including wall cavities. Some of the effort will require specialized techniques.
Wet ceiling tiles, drywall, spray-on insulation, and fiberboard ductwork are usually difficult to dry and are often disposed of after a major water leak. Carpeting can sometimes be saved—but only if it is dried quickly, usually in 24-48 hours—before mold starts to grow within and underneath the carpeting. If abatement of damaged material takes place immediately—and the timing depends upon the climate and weather, building temperature and humidity, and possible presence of existing mold—the work can often be done without the controls usually needed to abate mold contamination (such as plastic containment used for asbestos abatement, negative air, and use of special HAZMAT equipment).
Care should be taken during any removal of wet material to isolate air plenums and avoid affecting other tenants. Unless visible or hidden mold is present, this approach should be acceptable.
All HVAC and air handling units should be inspected on a fixed schedule to ensure condensate pans are not overflowing and there are no releases of condensate into drop ceiling tile, insulation, or other building surfaces. Renovation should be considered to reach or move inaccessible units where reasonably feasible.
Facilities executives should assume that building occupants will be well versed in mold issues and should anticipate communicating with them regarding the possibility for mold growth. A communications procedure should be included in a facility’s response plan.
HVAC ductwork should be inspected periodically for signs of moisture, damage, or mold growth. If fiberboard or fiberglass-lined ductwork becomes wet or impacted by mold, it is extremely difficult to clean. A mold remediation specialist should be contacted in these situations.
Mold Abatement And/Or Remediation
The U.S. EPA established guidelines for mold remediation in its March 2001 publication entitled Mold Remediation in Schools and Commercial Buildings. Guidance from the New York City Health Department (available on the Internet) also provides mold remediation guidance including cleanup methods, personal protective equipment, and, if necessary, containment measures.
The first step in remediating mold contamination is to correct any chronic or periodic sources of moisture. These sources must first be eliminated, otherwise the mold will quickly reappear. It makes no sense to conduct a mold abatement project if the area is going to be wetted again.
While there are currently no regulations requiring mold abatement in a containment situation (like asbestos abatement), an industry standard has emerged that essentially addresses large mold projects in a similar manner as asbestos—using containment and other methods to prevent the mold spores from reaching other occupants or other portions of the building and the use of respirators by trained personnel.
The New York City Health Department Guidance suggests that remediation of mold affected areas less than 10 square feet in size can be performed by general maintenance staff provided they have received training on proper clean up methods, personal protection, and potential health hazards. Personal protective equipment should include a N-95 respirator, gloves, and eye protection.
The affected material should be cleaned with a damp cloth and/or vacuumed with a wet vacuum to remove excess water followed by a HEPA vacuum to remove dry mold. Any material that cannot be cleaned should be placed in a plastic bag, sealed, and removed from the building. There are currently no special requirements for the disposal of moldy building materials, but it would be appropriate at least to place the material in doubled plastic bags if carrying it through occupied areas.
Remediation of areas greater than 10 square feet in size should be performed by experienced mold remediation contractors wearing full personal protective equipment (full-face respirators, disposable protective clothing covering both head and shoes, and gloves) and be subject to oversight by a health and safety professional experienced in performing microbial investigations.
Remediation of large mold contaminated areas is typically performed within a constructed, polyethylene enclosed, air-locked contaminant area. Mold affected material is cleaned within the containment area if possible, but porous materials such as wallboard and wood paneling will most likely be removed and discarded.
Several good references are readily available for free on the Internet:
• IAQ Hotlines and Document Clearinghouse
• Building Owners and Managers Association (BOMA) International
• The American IAQ Council
• U.S. EPA – Many useful IAQ publications specific to large buildings
• U.S. EPA – Mold Remediation in Schools and Commercial Buildings
• U.S. EPA – IAQ in Schools
• IAQ Tools for Schools kit
• The National Safety Council’s Environmental Health Center, Teacher’s Guide to Indoor Air Pollutants
• The American Industrial Hygiene Association
In general, it is not always necessary to hire an industrial hygienist to sample for mold if mold is visible. If the mold can be seen, the current belief among health professionals is that it needs to be abated/removed; therefore it is generally not necessary to test it or determine its species in order to proceed with abatement. Similarly, if a water leak is abated immediately after it occurs (not in the case of a past or chronic leak which could already have caused mold growth) and there is no sign of mold, it is not always necessary to sample for mold. Facilities executives should not hesitate to seek advice from a competent technical consultant and legal counsel in the event of any uncertainties, since each building and each situation is unique. A little money spent on timely advice can save significant abatement dollars.
In accordance with the terms of a specific policy, insurance companies should be immediately notified in the event of major water damage. It is suggested that facilities personnel stay deeply involved in the cleanup process in case the insurance company or claims adjustor has not yet realized the importance of conducting an immediate response action (drying) on an expedited basis.
After abatement, clearance sampling for species-specific viable molds should be considered, involving bulk (e.g. unaffected drywall), wipe (in HVAC systems or on other surfaces), dust (in carpeting), and/or bioaerosols (in the air) to establish that the abatement was effective and to establish a baseline that verifies the IAQ is at least similar to outdoor air quality.
These plans should be designed to be representative and to incorporate an adequate number of control or background samples so there is an appropriate context within which sampling results can be compared. There are currently no regulatory standards to be used for comparison.
IAQ issues have reached the forefront, and the public is now acutely aware of the potential aesthetic and health problems that can occur due to indoor air pollution. Facilities executives should not only develop a response plan to address catastrophic events such as water damage; a standard operating procedure and maintenance plan should also be enacted to ensure that all components of the building’s mechanical and HVAC systems are in working order and do not present a risk of continuing microbial contamination. Facilities executives should also pay attention to building occupant complaints and ensure an effective communications program is in place.
A New Public Awareness
Once relegated to obscure technical journals, IAQ issues are well known to the public thanks to the Internet and recent media attention to several high profile cases. Any Internet search engine will return thousands of hits if “indoor air quality” or “mold” are typed into the search window.
Poor IAQ blamed on mold and fungal growth resulting from chronic moisture, condensate, or water leaks that go uncorrected are now the fodder for lawsuits brought about by occupants against building owners, property managers, contractors, architects, insurance companies, and anyone else who may have responsibility for construction, design, or maintenance.
While many lawsuits have been filed in the past, several recent cases have gained significant media attention due to recent court decisions that have resulted in huge monetary awards from allegations of loss and damage due to mold and fungal contamination in a wide range of residential and commercial buildings. Almost all buildings, however, are subject to contamination by mold and fungi.
In 1996, $11.5 million plus attorneys’ fees and 8.8% annual interest was awarded as a result of mold damage to a Martin County, FL courthouse in a judgment against the builder. The lawsuit focused on matters of contractual disputes instead of negligence that allegedly resulted in a poorly designed air conditioning system and other supposed construction defects. The buildings originally cost $12 million to construct; remediation for mold contamination cost almost $30 million (which was conducted by essentially destroying and rebuilding the courthouse).
The U.S. EPA’s own office in Waterside Mall in Washington, DC is a particularly ironic sick building, case that apparently originated with the 1987 installation of 27,000 square yards of new carpeting. Nineteen plaintiffs eventually filed lawsuits against the building owners and management companies, alleging their health problems (including multiple chemical sensitivity or MPS) were caused by factors inside the EPA building. Several employees eventually argued they became disabled due to the building conditions. In 1993, a jury awarded $948,000 to the plaintiffs, but in 1995, four of the five disabled plaintiff verdicts were set aside because the four could not show any physical injuries.
These examples illustrate the willingness of juries to punish defendants who do not take IAQ issues seriously. While significant expenditures are often necessary to repair or upgrade building HVAC systems, correct moisture sources, abate mold or fungal contamination, and relocate affected tenants, these expenses can pale next to litigation defense costs. It is therefore critical for facility executives to anticipate, prevent, and quickly correct causes of indoor air pollution to prevent even more expensive abatement or litigation defense costs.
Facilities executives should also be aware that cases like those above have primed the insurance companies to petition state insurance commissions to allow “mold exclusion clauses” to be placed in renewals of commercial hazard and general liability policies. Approvals to insert these exclusions have either been granted or are pending in many states. Just as the pollution clauses added to policies in the early 1970’s resulted in massive litigation with the insurers, what may follow is a repeat of history. The practical ramifications of these new mold exclusions remain to be seen.
Facilities executives are encouraged to seek additional information about the prevention and control of indoor air pollution and the protection of IAQ, which is readily available for free through the Internet via many of the links identified.
Entin is a manager with the Princeton, NJ office of ENVIRON International Corp., a health and environmental sciences consulting firm.
Disclaimer-The author is not an attorney and nothing presented or discussed in this article is intended to be, nor should be construed as, legal advice. Legal counsel should be contacted in the event additional information on legal aspects of IAQ issues is desired. Similarly, all building conditions and problems are specific cases that may require different solutions than those discussed above and a qualified and competent consultant and/or contractor should be consulted for specific cases.