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Indoor Environmental Quality

Offices, Commercial Buildings & Schools

Maintaining a healthy indoor environment and good indoor environmental quality affects the health, productivity, comfort and quality of life of the occupants. Resolving occupant complaints, associated health symptoms, and poor morale can be difficult. Open communication and active exchange of information between building managers, employee managers, and building occupants is essential for diagnosing and correcting problems and preventing an atmosphere of distrust. With good communication, many indoor air environmental quality problems can be prevented and solved in-house.

Buildings and Health

Health effects for problems in buildings can be generally classified as Building-Related Illness (BRI) and Building-Related Symptoms (BRS). BRI in non-industrial and nonresidential buildings is characterized by illnesses where several people are affected and present similar symptoms, there are objective abnormalities on clinical or laboratory evaluation, and there are one or more identifiable sources or agents known to cause infectious, immunologic or allergic diseases. There are well-established, serious health effects known as Building Related Illnesses (BRI) resulting from poorly managed indoor environments. Carbon monoxide (CO) poisoning from poorly vented or maintained combustion appliances is a classic example. Cases of BRI are relatively rare and are largely preventable by properly designing, managing, maintaining and operating buildings.

In contrast, Building-Related Symptoms (BRS) are the most common health impacts reported by people with concerns about non-industrial indoor environments. An occupant or occupants may relate one or more of a variety of nonspecific symptoms, including upper airway (nose, throat and sinus) irritation, eye irritation, skin irritation, headache, fatigue, general malaise, increased allergy symptoms, increased asthma episodes and worsening asthma episodes. Occupants may report different sets of symptoms when in the particular building. The symptoms are real, but there may be no objective clinical or laboratory abnormalities and no particular causative agents can be found.

Building owners and managers should take reports of BRS seriously. On an individual level, BRS may reduce productivity due to discomfort and increased absenteeism. Significant costs due to healthcare expenses and sick leave may also be incurred. When a group of occupants report BRS and the concerns are not appropriately addressed, the situation can also reduce morale, strain relations between employees, managers, tenants and property owners, and may create negative publicity. Determining the specific cause of BRS is difficult because of the dynamic nature of buildings, and the complex mixtures of chemical, biological and physical agents present in buildings. Further at the individual level, determining the causes of BRI becomes even more difficult because of differences in sensitivity and vulnerability among people, confounding effects from exposures away from the buildings, and other medical and psychosocial factors. These difficulties do not discount the need to carefully and compassionately address cases of BRI.

Identifying Problems

Many occupant complaints may be related to the workplace but may not necessarily be from the quality of the air. Factors such as noise, lighting, ergonomic stressors (workstation and task design), and job-related psychosocial stressors can, individually and in combination, contribute to complaints. Thermal comfort underlies many complaints about "poor air quality". Although the comfort of every occupant cannot be satisfied at all times, temperature and humidity are among many factors that affect indoor contaminant levels.

Sometimes building operations intended to reduce short-term costs can contribute to problems. Lack of use of walk-off mats at entrances may increase the amount of soils tracked into buildings by occupants. Low-bid custodial services that use ineffective equipment and harsh chemicals may result in cleaning practices that fail to collect and remove soils and contaminants, and that may actually increase the load of volatile organic chemicals in the building. Modifications to operation and maintenance of heating, ventilation and air conditioning systems (HVAC) – such as reducing the flow of outdoor ventilation air, shutting down HVAC systems during unoccupied periods, and selecting the least expensive and least efficient panel filters – can have negative effects on the air quality.

Effective design and construction of buildings to promote healthy environments is essential. A properly designed and constructed building shell (roof, walls and foundation) isolates and insulates the indoors from the outdoors. It keeps outdoor contaminants such as dusts, liquid water, humidity, air pollution and pests from entering the building. Insulation in the building shell helps to protect the interior from temperature extremes.

Well-designed heating, ventilation and air-conditioning (HVAC) systems provide clean outdoor air, modify and control indoor temperature and humidity, and dilute general pollution from people, activities, furnishings, etc. HVAC systems also maintain correct air pressure relationships between indoors and outdoors, as well as removing pollutants by using local exhaust ventilation from point sources such as fuel-burning appliances, bathrooms, kitchens and clothes dryers.

Effective, prompt and preventive maintenance can reduce the occurrence of problems with the indoor environment. HVAC systems should be inspected for obvious malfunctions or obvious contamination, and serviced to ensure proper airflow, temperature, humidity and air balance (pressure differentials). Careful management of custodial, pest control, building engineering and maintenance activities will also help to prevent problems.

Renovation and remodeling activities can effect the indoor environment. When designing renovation or remodeling projects, when possible select new building materials that emit lower levels of volatile organic compounds (VOCs) and that are environmentally friendly. Changes in floor plans, such as moving walls or changes in the number and distribution of people, may deviate from intended design and operation of HVAC systems with the result that modification to HVAC systems may be required. Short-term problems may be reduced by scheduling work such as painting during unoccupied periods, airing out carpets before installation, and isolating the rest of the building from the ventilation systems serving the work areas.

Pollutant source control is generally the most cost-effective solution to IEQ problems. Many complaints have been eliminated by prohibiting tobacco smoking in buildings. Maintenance of modifications to ventilation systems may also help to resolve complaints by diluting contaminants with clean outdoor air. Changing air pressure relationships can help to isolate sources. Good filtration may help prevent outside pollution such as pollen from entering the building.

Occupants should not be discouraged from reporting unusual odors, discomfort or other changes in the building. These may be early signs of maintenance problems that need to be addressed.

Employees should minimize the use of perfumes or colognes or engaging in other activities such as cooking odorous foods in microwave ovens that may trigger a co-worker's discomfort. Chemical formulations should be used sparingly and only where dedicated ventilation is provided. Air supply diffusers should not be blocked or taped closed, since that disrupts proper mixing and distribution of air.

Evaluating Building IEQ

Unfortunately, IEQ concerns are a fact of life for building owners, business owners, managers, and occupants. It is possible and necessary to provide a work environment that is healthy and safe. It is not possible to satisfy every occupant at all times, particularly in the case of thermal comfort. A building managed with an eye for preventing IEQ problems may not guarantee that occupants will not occasionally complain about IEQ, but it does greatly reduce the likelihood of chronic discomfort and will likely increase building occupants' productivity and quality of life.

The following documents will assist in evaluating IEQ issues. These tools provide a systematic approach that may lead to improvement of the indoor environment.

  1. Building Assessment Questionnaire - PDF / Word
  2. IEQ Room-by-Room Checklist - PDF / Word
  3. IEQ Occupant Diary - PDF / Word

The U.S. Environmental Protection Agency has developed "IAQ Tools for Schools" (TFS), as guidance program on how to develop an overall IAQ program for schools and school systems. The program includes a TFS Action Kit, training programs, and training/educational videos. For more information on the TFS program, see the EPA web site, Creating Healthy Indoor Environments in Schools. External link

Getting Outside Assistance

If problems persist after obvious sources have been identified and corrected, outside assistance may be needed. Outside assistance might be helpful when a problem requires immediate attention, the preliminary investigation reveals little, next steps are unclear, and resources are limited. In certain cases, assistance from specialists in medicine, lighting, acoustic design, or psychology may be needed.

If an outside consultant is retained to resolve indoor environmental quality issues, owners and managers should be informed clients in order to obtain quality services and to avoid unnecessary costs and delays in solving problems. Evaluate the prospective consultant's professional background in terms of education, professional credentials, and reputation. Look for demonstrated success in resolving similar situations. Ask for and check references. Hiring a consultant who performs a poorly conceived study may be costly and lead to erroneous conclusions and costly remedial efforts of no intrinsic worth. If a consultant proposes elaborate and expensive air monitoring without demonstrating that the resulting data will be meaningful, look elsewhere for assistance.

For more tips on hiring outside assistance for mold-related and other indoor environmental quality issues, see Mold: Hiring a Consultant/Contractor.

For Additional Information