chapter of Risk Management for Texas State Agencies supplies general
information regarding state agency occupational health exposures, and
techniques and methods to manage and control those exposures. It also
identifies additional resources that may be available to assist state
agencies in developing or enhancing its occupational health program.
This chapter is not intended in any way to be a substitute for the
advice and guidance of legal counsel, who should always be consulted
regarding rights, duties, and responsibilities under the law.
The quantity and severity of health problems caused by the poor quality of indoor air has increased over the last fifteen years. This is attributed to many factors. Most Americans spend up to 90% of their time indoors and many spend most of their working hours in an office environment. Studies conducted by the United States Environmental Protection Agency (EPA) and others indicate that indoor environments sometimes can have levels of pollutants that are actually higher that levels found outside. To lower energy costs, buildings are often sealed better to prevent infiltration of outside air, and the amount of fresh air added to buildings via ventilation systems can be significantly decreased. To lower material and construction costs, as well as to provide for easy care, products are sometimes used that emit toxic and irritating vapors. As a result, employees may experience headaches, nausea, sinus congestion, dizziness, and several other physical problems both at home and at work.
People may complain of one or more of the following symptoms: dry or burning mucous membranes in the nose, eyes, and throat, sneezing, stuffy or runny nose, fatigue or lethargy, headache, dizziness, nausea, irritability, and forgetfulness. Poor lighting, noise, vibration, thermal discomfort, and psychological stress may also cause, or contribute to, these symptoms. A group of indoor contaminants, commonly termed "microorganisms," include bacteria, fungi, and viruses. These microorganisms are known to cause some serious illnesses; such as Legionnaire's disease, humidifier fever, Pontiac fever, and hypersensitivity pneumonitis. Most of these diseases can be treated, although some can pose serious risks to individuals with other health conditions or toxic sensitivities.
There is no single manner in which these health problems appear. In some cases, problems begin soon after workers enter their offices and diminish soon after workers leave (typically called sick building syndrome). At other times, symptoms continue until the illness is treated (typically called building-related illnesses). Sometimes there are outbreaks of illness among many workers in a single building; in other cases, health symptoms show up in only certain employees.
There are usually some occupant complaints about health and comfort in new buildings. In fact, the ventilation guidelines for indoor air quality set forth by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) are intended to satisfy 80 percent of a building's occupants.
In the opinion of some experts, up to 30 percent of new or remodeled commercial buildings may have unusually high rates of health and comfort complaints from occupants. These complaints may potentially be related to indoor air quality.
Occasionally, significant numbers of building occupants experience symptoms that do not fit the pattern of any particular illness and are difficult to trace to any specific source. This phenomenon has been labeled sick building syndrome (SBS).
Sources of Indoor Air Problems in Offices
Three major reasons for poor indoor air quality in office buildings are the following:
- The presence of indoor air pollution sources
- Poorly designed, maintained, or operated ventilation systems
- Uses of the building that were unanticipated or poorly planned for when the building was designed or renovated.
The most important factor influencing indoor air quality is the presence of pollutant sources. Common sources of office pollutants include the following:
- Environmental tobacco smoke (ETS)
- Asbestos from insulation and fire-retardant building supplies
- Formaldehyde from pressed wood products
- Other organics from building materials, carpeting, and similar office furnishings
- Cleaning materials and related activities
- Restroom air fresheners
- Paints and adhesives
- Copying machines, photography, and print shops
- Biological contaminants from dirty ventilation systems or water damaged walls, ceilings, and carpets
- Pesticides generated by pest management practices.
NIOSH recommends that exposure to ETS in the workplace be reduced to the lowest
feasible level through the elimination of smoking or the establishment of isolated
smoking areas. A smoke-free building reduces the need for re circulation,
requires less cleaning, reduces maintenance of air handling equipment, and
lowers heating-ventilation-air-conditioning (HVAC) operating costs. The elements
of a smoke-free workplace policy are as follows:
- Management is involved and supportive.
- A smoke-free policy is issued.
- Smoking is prohibited except in designated smoking areas.
- There is separate, dedicated ventilation for the smoking area.
Mechanical ventilation systems in large buildings are designed and operated not only to heat and cool the air, but also to draw in and circulate outdoor air. Ventilation systems can contribute to indoor air problems in several ways when these systems are poorly designed, operated, or maintained.
For example, problems may arise when, in an effort to save energy, ventilation systems are not used to bring in adequate amounts of outdoor air. Inadequate ventilation also occurs if the air supply and return vents within each room are blocked or placed in such a way that outside air does not actually reach the breathing zone of building occupants. Improperly located outside air intake air vents can also bring in air contaminated with automobile and truck exhaust, boiler emissions, fumes from dumpsters, or air vented from restrooms. Finally, ventilation systems can be a source
of indoor pollution themselves by spreading biological contaminants that have multiplied in cooling towers, humidifiers, dehumidifiers, air conditioners, or the inside surfaces of ventilation ductwork.
Indoor air pollutants can be circulated from portions of the building used for specialized purposes, such as restaurants, print shops, and dry cleaning stores, into offices in the same building. Carbon monoxide and other components of automobile exhaust can be drawn from underground parking garages through stairwells and elevator shafts into office spaces.
Buildings originally designed for one purpose may end up being converted for
use as office space. While new structures are normally used according to the
designer's plan, as time passes renovations occur: building machinery is changed
or replaced; the occupants engage in different activities; and systems degrade.
If not properly modified during building renovation, room partitions and ventilation
systems may contribute to indoor air quality problems by restricting air re
circulation or by providing an inadequate supply of outside air.
Each of these stages of a building's life can present different indoor air quality problems. New buildings frequently suffer from IAQ problems due to the off-gassing of irritants from structural materials and furnishings.
Middle-aged buildings often have a significant amount of asbestos within the structure. The problems in older buildings commonly result from antiquated mechanical systems that fail to provide uniform heating and cooling and grow microorganisms that are spread through the system. To measure the quality of air in a building, a building survey inspection should be conducted.
Building surveys are a set of procedures used to evaluate the current performance of a building and to predict the quality of future performance. These procedures are useful in all stages in the life of a building, but are of most use when a problem has been identified. For indoor air quality survey and inspection information, Texas state agencies should contact the Texas Department of Health (TDH), Toxic Substances Control Division, Indoor Air Quality Branch, or retain the services of a commercial indoor air quality inspection firm. TDH only does inspections for Texas state agencies and locations where the public may be at risk, e.g., a mall or shopping center.
It is best to work with one individual agency or firm that is able to handle the project from start to finish. A qualified agency or firm will be able to provide a comprehensive report with details on how to approach remediation, including specific design recommendations and cost estimates.
Recommendations from a qualified, indoor air quality inspector will typically center around six approaches to controlling IAQ problems. These include the following:
Guidelines for Loss Prevention and Control
- Outside air supply
- Contaminant source control
- Contaminant source substitution
- Policy implementations
- Air distribution
If sufficient information and recommendations have been obtained from the building survey to identify the problem(s) or source of concern, corrective action can be taken. Depending upon the complexity of the problem, it may be necessary for management to call in expert help, such as that of an engineering/ventilation consultant or an industrial
hygienist. Early recognition of a problem, and a timely and systematic evaluation of the problem are key factors to a quick and effective resolution of indoor air quality problems or concerns.
Guideline Adopted by Reference-Texas Department of Health,Texas Administrative Code, Title 25, Part 1, Chapter 297"Indoor Air Quality Guidelines in Government Buildings"
U.S. Environmental Protection Agency
A website that contains a thorough discussion of Indoor Air Quality (IAQ) issues and many IAQ links.
U.S. Environmental Protection Agency
This website contains information about IAQ issues in large buildings.
U.S. Environmental Protection Agency
This is a very useful website that contains information about building air quality, developing a building air quality action plan, and a building air quality checklist.
Texas Department of State Health Services, Indoor Air Quality Program (IAQ)
Reports and Publications
National Academy Press
2101 Constitution Ave., N.W.
Washington, DC 20418
ASHRAE Standard 55-1992; 55a-1995
American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc.
1791 Tullie Circle, N.E.
Atlanta, GA 30329
Industrial Ventilation, (20th Edition)
American Conference of Governmental Industrial Hygienists, Inc. (ACGIH)
6500 Glenway Avenue, Building D-7
Cincinnati, Ohio 45211-4438
Texas Department of Health, Audio/Visual Library
“Indoor Air Quality: Fundamental Improvement” – 7547
“Indoor Air Quality Tools for Schools: Taking Action/Ventilation” – 7531
“Indoor Air Quality Tools for Schools: Walkthrough Video” – 7532
1. Has a person been designated as the agency indoor air quality coordinator?
2. Has a written indoor air quality program been established for the agency?
3. Has a written log of employee complaints with written “follow-up” actions been established?
4. Is the HVAC system maintained and operated to original design specifications?
5. Has a written record of building systems inspections and maintenance been established?
6. Is relative humidity maintained below 60 percent in buildings with mechanical cooling systems?
7. Are carbon dioxide levels monitored when routine HVAC maintenance is done?
8. Is microbial contamination controlled in the building by inspecting for and promptly repairing water leaks that can promote growth of biologic agents?
9. Is microbial contamination controlled in the building by promptly drying, replacing, removing, or cleaning damp or wet materials?
10. Are chemicals used and applied according to manufacturers’ recommendations?
11. Are measures implemented to restrict the entry of outdoor air contaminants (i.e. vehicle exhaust fumes) into the building?
12. Are work procedures and appropriate controls utilized to minimize degradation of indoor air quality during renovation or remodeling?