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Guide to Indoor Air Pollutants 1.4 Common Air Pollutants and SBS/BRI Symptoms Common Air Pollutant Symptoms/Effects Radon Volatile Organic Compounds (VC) Tobacco Smoke Odors; Bioeffluents Carbon Monoxide, Carbon Dioxide, Ozone Nitrogen Microbial Allergens Legionella (a bacterium) Formaldehyde & Other Aldehydes 1.5 HVAC System Lung Cancer Irritation; Cancer Eye, Nose andThroat Irritation; Lung Cancer Discomfort Fatigue, chest pain, Impaired vision and coordination, nausea, headache, dizziness, confusion, flu-like symptoms, weekness, disorientation Eye, nose and throat irritation, impaired tung function and increased respiratoryinfection Humidifier Fever; Hypersensitivity Pneumonitis; Eye, Nose, and' Throat Irritation Legionnaires Disease; Pontiac Fever Eye, nose and throat irritation, wheezing andcoughing,fatigue, skin rash, severe allegic reactions, may cause cancer The HVAC system includes all heating, cooling, and ventilaton equipment serving a building: furnaces or boilers, chillers, cooling towers, air handling units, exhaust fans, ductwork, filters, steam piping. 2. Sources of Indoor Air Pollution Indoor air pollution in offices is caused by an accumulation of contaminants that come primarily from inside the building, although some originate outdoors. They may be generated by a specific source over a wide area, either at certain times orcontinuously. Contaminants and their sources can general- ly be classified into the following categories: • Sources of Pollutants Outside Building • Building Material Sources of Pollution • Building/Office Equipment Sources of Pollution • Maintenance Material Sources of Pollution • Building Inhabitants as Sources of Pollution I0 Detail Associates, Inc.

Guido to Indoor Air FolIutants 3. Ventilation Systems 3.1 3.2 3.3 Most mechanical ventilation systems in large office buildings are designed and operated not only to heat and cool the air, but also to draw in and circulate outdoor air. These units distribute a blend of outdoor air and recirculated indoor air. HVAC may also include units that introduce 100% outdoor air or that simply transfer air within the building. Uncontrolled quantities of outdoor air enter buildings by infiltration through windows, doors, and gaps in the exterior construction. Thermal comfort and ven- tilation needs are met by supplying "conditioned" air ( a blend of outdoor and recirculated air that has been filtered, heated or cooled, and sometimes humidified or dehumidified). Properly designed, installed, operated and maintained HVAC systems promote indoor air quality. Poor design, installation, operation or maintenance of such.systems, on the other hand, can create in- door air quality problems. Inadequate Design or Installation indoor air pollution increases when, in an effort to save energy, ventilation systems are not used to bring in adequate amounts of outdoor air: (a) Intermittent air flow - designs that operate the HVAC sys- tem at reduced or interrupted flow during certain portioris of the day in response to thermal condition- ing needs, may elevate indoor contaminant levels by reducing air flow and mi;4ing, thus impairing contaminant removal efficiency.; (b) poor air distribution .- within a room, locating air supply and return registers too close to each other can result in poor distribution of fresh dilution air and poor removal of indoor air contaminants; (c) poor intake or exhaust location - building exhaust ducts and outside air in- takes that are too close to each other can result in re-entry of contaminated exhaust air into the build- Ing and a building-up of indoor pollution. Improperly located outside intake air vents can also bring in outdoor contaminants and can result in poor intake of outdoor fresh air and recirculation of indoor air; and (d) Inadequate space design of modular furniture and walls - overloading limited space without modifying ventilation system accordingly can lead to poor distribution of air. Inadequate Operation Allowing the system operation to lag behind building occupancy or to be turned down or off before non-occupancy can increase both building- and occupant-generated pollutant levels. Inadequate Maintenance If HVAC systems are not properly maintained, their filters can become a source of contamination or be- come plugged and reduce air flow. Humidification and dehumidification systems must be kept clean to prevent the growth of bacteria and fungi. Failure to properly treat cooling tower water to mitigate growth of organisms such as legionnella may introduce such biological organisms into HVAC air in- takes with potentially serious health consequences. 4. Office Equipment As A Source of Indoor Air Pollution Office Equipment is an important factor affecting indoor air quality. Possible pollutant sources from of- fice equipment include (1) emmissions from office equipment (volatile organic compounds, ozone); (2) supplies (solvents, toners, ammonia); (3) emissions from shops, labs, cleaning processes; and (4) elevator motors and other mechanical systems. Detail Associates, Inc. ii

Guide to Indoor Air Pollutants 5. Evaluating Indoor Air Quality in Offices 5.1 Identification of Problems The investigation starts with written questionnaires and telephone consultations in which building in- vestkjators assess the history of complaints by the building occupants and building operation proce- dures. In some cases, personal interviews by the investigator may be needed. 5.2 Symptoms The effects of IAQ problems are often non-specific symptoms rather than clearly defined illnesses. These symptoms commonly attributed to IAQ problems include: (1) headache; (2) fatigue; (3) short- ness of breath; (4) sinus congestion; (5) cough; (6) sneezing; (7) eye, nose, and throat irritation; (8) skin irritation; (9) dizziness and (10) nausea. All of these symptoms, however, may also be caused by other factors, and are not necessarily due to air quality deficiencies. Individuals with these symptoms should be examined by a physician to determine if the symptoms may be related to the work environment. Consultation with a Board-certified specialist in occupational medicine may be advisable. 5.3 Identifying Sources of Pollution A walk-through should be conducted by the investigator(s) to look for obvious and potential sources of contamination. 5.4 Qualitative Diagnostics The investigators characterize the problems and complaints and evaluate the building's environmental control system design and performance relative to building performance criteria. They may evaluate the causes of suspected health problems and sample air for suspected pollutants. If discomfort or SBS is suspected, the investigators may do an engineering analysis of the HVAC system and other building support systems. If BRI is thought to be the problem, they may recommend immediate medi- cal assistance along with appropriate biological or chemical sampling. 5.5 Sampling Air for Contaminants and Indicators Although air sampling might seem to be the logical response to an air quality problem, such an ap- proach may not be required to solve the problem and can even be misleading. Air sampling should not be undertaken until some or all of qualitative diagnostic activities mentioned previously have been used to collect considerable information. Before beginning to take air samples, investigators should develop a sampling strategy that is based on a comprehensive understanding of how the buidling operates, the nature of the complaints, and a plan for interpreting the results. It may be desirable to take certain routine air quality measurements during an investigation to obtain a "snapshot" of current condition. These tests should be limited to those that are indicative of very com- mon IAQ concerns such as temperature, relative humidity, air movement, or carbon dioxide (CO2). Unusual readings may or may not indicate a problem, and should always be interpreted in perspec- tive, based upon site-specific conditions. 5.6 Recommendations The report of the investigation generally includes a series of recommendations for remedial actions, maintenance procedures, and building systems operation. 12 Detail Associates, Inc.

Guide to Indoor Air Pollutants 6. Resolving Air Quality Problems in Office Buildings 6.1 Pollutant Source Removal, Modification, or Substitution Resolution of a building which manifests BRI usually requires removal of the pollutant source. This is the most effective way to resolve an indoor air quality problem when specific sources causing the problem can be identified. This approach reduces or eliminates the emission from a pollutant source, and may be used in combination with increased ventilation to dilute the indoor pollutant level. 6.2 Time of Use Adjustment of a Pollutant Source When feasible, activities that generates pollutants should be limited to times when the building oc- cupancy is at minimum, e.g., painting during weekend or non-working hours, and allowing building materials in new or remodeled areas to off-gas pollutants under high ventilation conditions before oc- cupancy. 6.3 Improving Maintenance of Ventilation System HVAC systems must be properly maintained and operated to avoid accumulation of pollutants and minimize growth of biological organisms. Inspection of the ventilation system should be conducted frequently and regularly. 6.4 Increasing Ventilation Rates In general, increasing the ventilation rate lessens indoor air quality problems in a poorly ventilated building. In buildings with mechanical ventilation systems, outdoor air quantities should be provided at rates at least as high as those specified in appropriate standards or codes. The American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) proposed ventilation standard 62- 1989 specifies a minimum of 20 cfm per person for offices. Optimally, local exhaust should be employed to remove indoor pollution near such sources as restrooms, copying rooms, and printing facilities. 6.5 Air Filtration and Purification These processes can be used in combination with source control and ventilation where specific problems are identified and practical air cleaning options exist. There is a wide range of such devices available on the market, but increased performance can involve significantly higher costs. 6.6 Communication Effective communication can encourage building occupants to improve their work environment through positive contributions. The following objectives should be kept in mind while reviewing and revising your current approach to communicating with occupants: (1) provide accurate information about factors that affect indoor air quality; (2) clarify the responsibilities of each party including build- ing management, staff, tenants, contractors, etc. .., Control Process of Indoor Air Pollution in Buildings The process of controlling indoor air pollution in buildings is divided into a number of specific steps. A model process of this process is illustrated in Figure 1. Detail Associates, Inc. 13

Guide to Indoor Air Pollutants 8. Professional Help Frequently indoor air quality problems in large commercial buildings cannot be effectively identified or remedied without a comprehensive building investigation. The process of solving indoor air quality problems that result in health and comfort complaints can be a slow one, sometimes involving several trial solutions before successful remedial actions are identified. To successfully resolve indoor air pol- lution problems in office buildings therefore often requires the expertise of an indoor air quatity • specialist and a number of specialists. Whether or not an external specialist is needed to solve an in- door air quality problem depends on the expertise of the facilities engineering and environmental health staff. A considerable amount of literature is avagable for the guidance of in-house activities. However, when such in-house expertise is not available and not sufficient to cope with the existing scale of the problem, it is strongly recommended that external professional help be used. Firms and individuals working in IAQ may come from a variety of disciplines. Typically, the skills of HVAC engineers and industrial hygienists are useful for this type of investigation, although input from other disciplines such as chemistry, chemical engineering, architectiure, microbiology, or medicine may also be important. If problems other than indoor air quality are involved, experts in lighting, acoustic design, interior design, psychology, or other fields may be helpful in resolving occupant complaints about the indoor environment. As you prepare to hire professional services in the area of indoor air quality, be aware it is a develop- ing area of knowledge. Most consultants working in the field received their primary training in other areas. A variety of investigative methods may be employed, many of which are ineffective for resolv- ing any but the most obvious situations. Inappropriately designed studies may lead to conclusions that are either false negative or false positive. A qualified IAQ investigator should have apprpriate experience, demonstrate a broad understanding of indoor air quality problems and the conditions which can lead to them, and use a phased diagnostic approach. 14 Detail Associates, Incu ;

~uidc to Indoor Conduct No Ass~ssm~t No Heeded Cdtlc:l Zones Located Evaluate Loads & System Capacities Localed Figure 1: Process for Control of Indoor Air Pollution in Buildings No Detail Associates, Inc. 15

Guide to Indoor Air Pollutants Chapter IV Evaluation Criteria for Indoor Air Quality 1. Public Healtl~ Standards Public health standards are more frequently used to address indoor air quality problems. Some of them are as follows: 1.1 Natiional Ambient Air Quality Standards Established by the US Environmental Protection Agency Enforcement is limited to outdoor ambient levels. The standards specify concentrations of pollutants in ambient air that should not be exceeded. However, these standards may not have relevance to an indoor office environment, especially from the perspective of problem-solving. 1.2 WHO Air Quality Guidelines for Europe The Regional Office for Europeof the World Health Organization (W~HO), an agency of the United Na- tions, recently published air quality guidelines for 28 organic and inorganic substances. The guidelines were created to help governments make risk management decisions controlling exposure to indoor and outdoor air pollutants. Health effects were the major consideration in establishing the guidelines. Guidelines are set to protect all people in the European region, including sensitive popula- tion subgroups such as asthmatics. Both short- and long-term exposures are addressed (WHO, 1987). 1.3 ASHRAE Standard 62-1989: Ventilation for Acceptable Indoor Air Quality American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 62- 1989 defines acceptable indoor air quality as "air in which there are no known contaminants at harmful concentrations as determined by cognizant authorities and with which a substantial majority (80% or more) of the people exposed do not express dissatisfaction. The objective of the standard is to estab- lish minimum ventilation rates and indoor air quality that will be acceptable to human occupants and are intended to avoid adverse health effects. The ASHRAE standards cover 35 substances. For con- taminants not contained in the standard, ASHRAE recommends that levels should not exceed 1/10 the occupational standard used in the industry. These standards are frequently used by IAQ specialists in office building evaluations, especially for assessing the performance of a ventilation system. ASHRAE standards are also commonly used as criteria for assessing the thermal performance of occupied space. 1.4 Canadian Exposure Guidelines for Residential Indoor Air Quality (Excluding Radon) The guidelines were published in 1987. The guidelines contain specific quantitative limits for nine pol- lutants or pollutant categories, plus recommendations to eliminate or control exposure for other pol- lutants for which specification of exposure limits was not practical. Their application is designed for residential environments, and is based on assumptions of 24-hour exposure. The guidelines may not provide complete protection to the hypersensitive portion of the population. Effects from both short- term and long-term exposures are covered. 16 Detail Associates, Inc.

Guide to Indoor Air Pollutants 2. Occupational Health Standards tn the classic industrial hygiene sense, the Occupational Safety and Health Administration's (OSHA) permissible exposure limits (PEL), the American Conference of Governmental Industrial Hygienists' (ACGIH) Threshold Limit Values (TLV), and National Institute of Occupational Safety and Health's (NIOSH) recommended exposure limits (REL) are most commonly used in occupational exposure as- sessments. Because these criteria are based on health effects as they pertain to the manufacturing en- vironment, they may not have the same relevance for workers in an office setting, whose primary concern may be for comfort or simply an absence of unusual sensory stimuli over their working period. Although these standards may not be directly relevant to the indoor office environment, they may be used as a starting point and a guideline in the evaluation of indoor air quality of offices. 3. Evaluation of Existing Standards and Guidelines 3.1 3.2 Several points emerge from the evaluation of existing standards and guidelines. These include (1) the difference between public health and occupational standards; and (2) major omissions among existing standards with regard to indoor air quality problems. Public Health Standards vs. Occupational Health Standards The most significant differences between various standards and gu!delines are related to the differen- ces between standards set to protect the general public versus those set to protect workers in an oc- cupational setting. Public health standards are generally one to two orders of magnitude lower than occupational standards. These differences occur for both short- and long-term exposure limits. Some of the reasons for these differences are (1) public health standards include protection for the sensitive population subgroups, while occupational standards typically presume a healthy adult workforce; (2) public health standards generally assume continuous exposures while occupational standards are based on 8 hours exposure period per day for no more than 40 hours per week; (3) public health standards are usually established with adverse health concerns as the sole criteria. Regulatory Gap Two areas of particular concern in indoor air quality have yet to be adequately addressed by existing standards and guidelines. These include exposure to pollutant mixtures and to biological con- taminants (e.g., molds, fungi, mites, bacteria, and viruses). The effects of exposure to more than one contaminant in indoor air is an important issue since the typi- cal indoor environment contains multiple contaminants. Effects from mixtures may be synergistic, an- tagonistic, or additive. Existing standards and guidelines do not address biological contaminants, yet biological con- taminants pose potentially significant problems for indoor air quality. Detail Associates, Inc. 17

Guide to Indoor Air Pollutants Chapter V Common Indoor Air Quality Measurements 1. Common Sampling Devices 1.1 Vacuum Pump A vacuum pump with a known airflow rate draws air through collection devices, such as a filter, a sot- bent: tube, or an impinger. Tests originated for industrial environments typically need to be adjusted to a lower detection limit for IAQ work. Labs can be asked to report when trace levels of an identifiable contaminant are present below the limit of quantification and detection. 1.2 Direct-reading Meter Direct-reading meters estimate air concentrations through one of several detection principles. These may report specific chemicals, chemical groups, or broad pollutant categories. "Detection limits and averaging time developed for industrial use may or may not be appropriate for IAQ. 1.3 1.4 Detector Tube Kit Detector tube kits generally include a hand pump that draws a known volume of air through a chemi- cally treated tube intended to react with certain contaminants. The length of color stain resulting in the tube correlates to chemical concentration. Personal monitoring devices Personal monitoring devices area carried or worn by individuals and are used to measure that individual's exposure to particular chemical(s). Devices that include a pump are called "active" monitors; devices that do not include a pump are called "passive" monitors. Such devices are current- ly used for research purposes. It is possible that sometime in the furore they may also be helpful in IAQ investigations in public and commercial buildings. ' 1.5 Thermometer and Sling Psychromter These simple devices can be used to measure indicators of thermal comfort including temperature and relative humidity. 1.6 Chemical Smoke Chemical smoke can be helpful in evaluating HVAC systems, tracking potential contaminant move- ment, and identifying pressure differentials. Chemical smoke moves from areas of higher pressure to areas of lower pressure if there is an opening between them. Because it is heatless, chemical smoke is extremely sensitive to air currents. Chemical smoke is available with various dispensing mechanisms, including smoke "bottles," "guns," "pencils," or '~ubes." 2. Measurement of Air Flow and Outdoor Air Quantities 2.1 Airflow Measurement of airflow allow investigators to estimate the amount of outdoor air that is entering the building and to evaluate HVAC system operation. Airflow quantities can be calculated by measuring the velocity and cross-sectional area of the airstream. For expample, if air is moving at 100 feet per minute in a 24" x 12" duct, the airflow is: 100 feet/minute x 2 square feet duct area = 200 cubic feet/minute. 18 Detail Associates, Inc.

Guide to Indoor .Air Pollutants Air velocity can be measured with a pitot tube or anemometer. Air velocity within an airstream is likely to vary considerably. The best estimates of air velocity can be achieved by averaging the results of a number of measurements. ASTM Standard Practice D3i54 provides guidance on making such meas- urements. 2.2 Outdoor Air Quantities Outdoor air quantities can be evaluated by measuring airflow directly. Two frequently used techniques are thermal mass balance (temperature) and Carbon Dioxide Measurements. Outdoor air" quantities is calculated as follows: Using Thermal Mass Balance Treturn air - Tmixed air Outdoor air (percent) ............................ × 100 Treturn air - ]'outdoor air Where: T ' temperature (degrees Farenheit) Using Carbon Dioxide Measurements Cs - CR Outdoor air (percent) ........... x 100 Co - CR Where: Cs = ppm CO2 in the supply air (if measure in a room), or CS = ppm of CO2 in the mixed air (if measured at an air handler) Ca = ppm of CO2 in the return air Co = ppm of CO2 in the outdoor Air Converting Percent to CFM Outdoor air (percent) Outdoor air (cfm) ......................... x total airflow (cfm) 100 Where: cfm = cubic feet per minute The number used for total airflow may be the air quantity supplied to a room or zone, the capacity of an air handler, or the total airflow of the HVAC system. 3. Air Contaminant Concentrations 3.1 Total Volatile Organic Compounds (TVOCs) Several direct-reading instruments are available that provide a low sensitivity "total" reading for dif- ferent types of organics. Such estimates are usually presented in parts per million and are calculated with the assumption that all chemicals detected are the same as the one used to calibrate the instru- ment. A laboratory analysis of a sorbent tube can provide an estimate of total solvents in the air. Detail Associates, Inc. 19