SCOPE

5. EVALUATION OF IAQ PROBLEMS

1. Urea-formaldehyde foam insulation

2. Particle board

3. Plywood

4. Some glues and adhesives commonly used during construction

5. Furniture fabric treatments such as anti-static and flame retardants

1. date and time of onset of symptom or when the environmental condition (stuffiness, odor, temperature extreme, etc.) is first perceived.

2. description of the symptom or environmental condition.

3. length of time symptom (or condition) lasted.

4. location(s) affected (where were the people who were affected located at the time of the occurrence?); what activities were going on just prior to and during the occurrence?

5. name(s) of the person reporting the incident and those affected.

6. any other pertinent comments or notes

7. PREVENTION OF IAQ PROBLEMS

3. New Material and Equipment Considerations

1. Acquire representative samples of prospective finishing materials. Compare the odors from samples after leaving them in air-tight containers.

2. Review material safety data sheets (MSDSs) for materials that vendors may use when installing finishing materials, especially adhesives or solvents.

3. Require vendors to store unpackaged finishing materials in a ventilated warehouse. This is particularly important for items such as new carpets or new partitions.

4. Require finishing materials to be installed while providing maximum outdoor air ventilation. Restrict the quantities of adhesives and solvents used during installation to that which is necessary. Avoid the use of highly toxic or carcinogenic chemicals.

3. Proactive Building Management and Monitoring

1. All field notes and air sampling data.

2. All questionnaires that are returned by those involved, including a detailed listing of signs and symptoms described by affected individuals. This information shall be treated as strictly confidential.

3. All data collected on the building system including; temperature, relative humidity, air flow and percent outdoor air.

4. Any conclusions regarding cause and a complete list of all recommendations.

5. Documentation of follow-up.

6. All medical records pertaining to the IAQ problem, including initial report, clinical and/or lab findings as well as the diagnosis by the attending physician or occupational health nurse. This information shall be treated as strictly confidential.

7. All records of employee complaints relating to potential IAQ problems. This should include the nature of the reported illness, number of employees affected, date of employee complaint, and remedial action, if any, taken to correct the source of the problem. This information shall be treated as strictly confidential.

10. REFERENCES

1. American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE); Ventilation for Acceptable Indoor Air Quality, ASHRAE 62-1999; ASHRAE, 1791 Tullie Circle, NE, Atlanta, GA 30329; (404) 636-8400.

2. American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE); Thermal Environmental Conditions for Human Occupancy, ASHRAE 55-1992; ASHRAE, 1791 Tullie Circle, NE, Atlanta, GA 30329; (404) 636-8400.

3. Lao, K.: Controlling Indoor Radon -- Measurement, Mitigation and Prevention. Van Nostrand Reinhold, 115 Fifth Avenue, New York, New York 10003; 1990.

4. Puskin, J. and Nelson, C.: EPA's Perspective on Risks from Residential Radon Exposure. JAPCA, 39(7): 915-920 (1989).

5. American Conference of Governmental Industrial Hygienists (ACGIH); Bioaerosols, Assessment and Control, 1999; ACGIH, 6500 Glenway Ave. Bldg. D-7, Cincinnati, OH 45211 -4438; (513) 661 -7881.

6. Boxer, P.: Indoor Air Quality: A Psycosocial Perspective. JOM 32(5):425-428 ( I 990)

7. Norback, D. Michael, I. And Widstrom, J.: Indoor Air Quality and Personnel Factors Related to the Sick Building Syndrome. Scand. J. Work Environ. Health 16(2):121-128 (1990)

8. Bierbaun, P., Gorman, R., and Wallingford, K.: The NIOSH Approach to Conducting Indoor Air Quality Investigations in Office Buildings. Energy Tech no. 16(9):347-361 (1989).

9. Burton, D. J.: Indoor Air Quality Workbook. IVE, Inc., 178 No. Alta Street, Salt Lake City, Utah 84103; 1990.

10. Burge, H. and Hoyer, M.: Indoor Air Quality. Appl. Occup. Environ. Hyg., 5(2):84-93 (1990).

11. Godish, T.: Indoor Air Pollution Control. Lewis Publishers, 121 South Main St., Chelsea, Michigan 48118; 1989.

12. Manual for Ventilation Assessment in Mechanically Ventilated Commercial Buildings. Indoor Air Quality Update (IAQU) Document Code 08CZ, January 1994.

13. National Institute for Occupational Safety and Health (NIOSH); Indoor Air Quality -- Selected References, May 1989; U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, Division of Standards Development and Technology Transfer, 4676 Columbia Parkway, Cincinnati, Ohio 45226; (513) 533-8328.

14. National institute for Occupational Safety and Health (NIOSH); Guidance for Indoor Air Quality Investigations, January 1987; U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, Division of Standards Development and Technology Transfer, 4676 Columbia Parkway, Cincinnati, Ohio 45226; (513) 533-8328.

15. Brooks, B. and W. Davis (1992). Understanding Indoor Air Quality, CC Press Inc., Boca Raton, FL.

16. American Conference of Governmental Industrial Hygienists (ACGIH) (1999). Documentation Of The Threshold Limit Values And Biological Exposure Indicies, Cincinnati, OH.

17. National Academy of Sciences (NAS) (1981). Indoor Pollutants, Committee on Indoor Pollutants, Board on Toxicology and Environmental Health Hazards, Assembly of Life Sciences, National Research Council, National Academy Press, Washington, D.C.

18. National Institute for Occupational Safety and Health (NIOSH) (1984). NIOSH Manual Of Analytical Methods, Third Edition, Cincinnati, OH.

19. American National Standards Institute/ Illuminating Engineering Society (ANSI/IES) (1982). Office Lighting, ANSI/IES Standard RP1-1982, New York, NY.

20. American Conference of Governmental Industrial Hygienists (ACGIH) (2000). Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices 2000, Cincinnati, OH.

21. Hewlett-Packard Company (1990). Indoor Air Quality Program, Industrial Hygiene Technology Council, Palo Alto, CA.

22. American Industrial Hygiene Association (AIHA) (1996). Field Guide for the Determination of Biological Contaminants in Environmental Samples , AIHA, Fairfax Virginia.

23. American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE); Minimizing the Risk of Legionellosis Associated with Building Water Systems, ASHRAE Guideline 12-2000; ASHRAE, 1791 Tullie Circle, NE, Atlanta, GA 30329; (404) 636-8400.

24. Environmental Protection Agency, Building Air Quality Action Plan, EPA Publication No. 402-K-98-001, June 1998.

25. Bearg, David W.: Improving Indoor Air Quality Through the Use of Continual Multipoint Monitoring of Carbon Dioxide and Dew Point, Am Ind. Hyg. J. 59:636-641 (1998).

1. Radon Considerations

2. SBS Cause and Symptom Matrix

3. Microbiological Contamination

4. Psychosocial Considerations

5. IAQ Information for Carbon Dioxide, Temperature, Relative Humidity and Air Flow

6. Ventilation Guidelines for Buildings with Intermittent or Variable Occupancies

7. IAQ Information for Carbon Monoxide, Ozone, Formaldehyde, and Particulates

8. IAQ and Volatile Organic Compounds

9. List of Equipment for IAQ Investigations

10. Indoor Air Quality Questionnaire (Sample)

11. Design and Construction Considerations

12. Preventive Maintenance Schedule - HVAC Equipment (Sample)

Radon (Rn) is not an irritant or acute toxin, and it is therefore not normally of concern in acute epidemics of SBS or building-related illness. The major risk from exposure to Rn decay products is lung cancer. Rn, and Rn's primary decay products (Po-218 and Po-214), emit alpha particles which have half-lives of less than 30 minutes. Without a replenishing source, significant concentrations of Rn cannot be maintained. Precursors of Rn, Uranium-238 and Radium-226, are constituents of nearly all soil and rock, although there is considerable geographic variation in concentration.

Soil gas is responsible for >90% of all radon in indoor air. Where soils contain high concentrations of radon, ventilation practices that place crawl spaces, basements, or underground ductwork below atmospheric pressure will tend to increase radon concentrations in buildings and should be avoided. Other major sources of radon in indoor air include well water and masonry building materials. Due to the effect of a variety of factors, Rn levels in buildings may be several times, or even several orders of magnitude, higher than ambient levels. This is particularly true in single-family dwellings.

The EPA recommends that radon levels be maintained below 4 pCi/L by the use of forced ventilation in conjunction with sealing of below-grade access points and removal of any contaminated water supply. 8 pCi/L is the National Council on Radiation Protection guideline for unacceptably high levels.

Rn is unique in that it poses lifetime lung cancer risks orders of magnitude higher than those of commercial chemicals considered by the EPA to pose significant cancer risks to the general population. Based on current exposure and risk estimates by the EPA, Rn exposure in single-family houses may be a causal factor in about 20,000 lung cancer fatalities per year. Most of these projected fatalities are attributable to exposures in houses with average or moderately elevated Rn levels (<10 pCi/L).

To appreciably reduce Rn-induced lung cancers, remediation efforts must include houses not highly elevated in Rn. From either an individual risk or a cost-benefit standpoint, reduction of a few pCi/L per home appears to be justified. The optimal strategy for dealing with the indoor Rn problem depends on the magnitude of the risk per unit exposure, the distribution of exposure in houses, and the effectiveness and costs of mitigation. The Environmental Protection Agency's views with respect to these factors and the associated uncertainties are discussed in Reference 4.

Exposure to Rn in homes presents a greater hazard than exposure in commercial buildings because more time is spent at home than at work, and because there is the added risk of exposure to children. The Environmental Protection Agency has recommended a four-step approach for indoor radon testing procedure for homes that can be adopted for commercial buildings:

Industrial Hygiene or Health Physics personnel should be contacted for any further information regarding radon. They should be consulted for any necessary field measurements or remedial action considerations.

 Source: Reference 21 and Professional Experience

Five percent of NlOSH's investigations have involved some type of microbiological contamination. Even though this is not a common cause of office problems, it can result in a potentially severe health condition known as hypersensitivity pneumonitis. This respiratory problem can be caused by bacteria, fungi, protozoa, and microbial products that may originate from ventilation system components. A similar condition known as humidifier fever, most commonly reported in Europe, is also the result of microbiological contamination in ventilation systems. Microbiological contamination has commonly resulted from water damage to carpets or furnishings, or standing water in ventilation system components.

Although a variety of disorders (hypersensitivity pneumonitis, humidifier fever, allergic rhinitis, conjunctivitis) can result from microbiological exposure, NIOSH generally has not documented the existence of these disorders on the basis of medical or epidemiological data. However, even if visible microbial growth can not be directly related to the health complaints reported, it is a problem that needs to be addressed and corrected.

Legionella pneumophilia is a cause of potentially serious IAQ problems. It is a bacteria commonly found in nature. Optimum water temperature for growth of this bacteria is 77-108°F. Legionella bacteria can cause two distinct clinical syndromes; Legionnaires disease and Pontiac fever. Legionnaires disease is a bacterial pneumonia that sometimes results in death. It has an incubation period of five or six days, and only a small percentage of exposed persons contract symptomatic disease. In addition to pneumonia, the infection may involve the gastrointestinal tract, kidneys, and the central nervous system. Legionella is also associated with Pontiac fever that is characterized by fever, chills, headache, and muscular pain. Pontiac fever has an incubation period of about 1.5 days, an attack rate of almost 100%, and is much less severe than Legionnaires disease.

Unless there has been a diagnosis of Legionnaires disease or Pontiac fever, sampling for Legionella is generally not recommended due to the lack of generally accepted guidelines for what concentrations or amounts of the bacteria are inappropriate. However, some researchers suggest <1 per ml of water is an acceptable concentration of Legionella in reservoirs, 1 - 9 per ml requires reevaluation for evidence of further amplification, 10 - 99 per ml requires a review of the premises to ascertain whether bioaerosols have direct or indirect contact with high-risk personnel, >100 per ml requires cleaning, and >1000 per ml requires "emergency" cleaning. However, testing should not be regarded as a substitute for effective maintenance practices and water treatment.

Prevention is the best control for Legionella (e.g., no standing water and water treatment). Cold water should be stored and distributed at temperatures below 68 °F. Hot water should be stored above 140 °F and circulated with a minimum return temperature of 124 °F.

Treatment against Legionella is usually effective by treatment with chemicals such as calcium hypochlorite, quaternary ammonium compounds, and dibromonitrilopropionamide. Hyperchlorination is only effective if residual quantities of free chlorine (greater than 2 mg/L) are maintained. The pH of the water should be maintained between 7.0 and 8.0. Copper-silver ionization has been reported as a relatively new approach to successfully controlling Legionella in hot water distribution systems.

Bromides or formulations of the alkyl dialkylbenzylammonim chloride salts can be used to control slime, algae, plankton, bacteria, and other micro-organisms in cooling towers. Cooling tower water should be regularly tested to ensure that the proper amounts of biocides and corrosion inhibitor are maintained.

Bromicides have been reported to be four times more effective as biocides, and they dissipate in the blowdown in half the time of chlorine compounds (since they have a shorter half-life). Sunlight and ultraviolet light break down chlorine into other compounds, and chlorine residuals are difficult to maintain due to the variation in organic level within the condenser water. Cooling towers should be cleaned out at least once a year and more often where they are located next to farming, construction, or other types of activity that increase the suspended solids in the tower water. Regular alteration of biocides in cooling water systems may also be advisable in order to avoid the selection and growth of resistant strains of microbes.

Reference 22, Field Guide for the Determination of Biological Contaminants in Environmental Samples. A more thorough and recent summary of related bioaerosols information can be found in Reference 5, Bioaerosols, Assessment and Control. A very recent guideline related to Legionellosis is also available as ASHRAE Guideline 12-2000 (Reference 23).

Limit the number of investigating personnel involved. The more personnel involved, the greater the likelihood for conflicting opinions, which magnifies risk perception and undermines employees' confidence in management to resolve the problem. One Industrial Hygienist or other health and safety professional with a general knowledge of IAQ problems can orchestrate the investigation and recommend additional specialty investigations as needed.

Beware of insensitive managers and other personnel who can unwittingly worsen matters. For example, physicians do a disservice if they automatically attribute symptoms to workplace exposures based only on employees' beliefs. Managers and other personnel have been known to make inappropriate sexist remarks when primarily female workers have been involved in outbreaks. Regardless of his or her defined area of expertise, only personnel who are sensitive to the potentially charged emotional atmosphere in a typical IAQ complaint scenario should be permitted to address a group of employees directly.

Rarely do employees affected by IAQ problems need to be seen at a hospital. The occupational health nurse on-site should maintain a log of complaints and symptoms. The accurate report that several employees were seen in a hospital emergency room is easily distorted to rumors that they were hospitalized. Also, by sending all affected employees to a single, knowledgeable physician, the chance for physician misattribution of symptoms to a workplace hazard is minimized.

In outbreaks of moderate to severe symptoms affecting multiple employees simultaneously, remove affected employees to a common area if possible. This helps to prevent the spread of symptoms to unaffected employees via "psychologic contagion".

Unless there is convincing evidence that employees are being exposed to a significant health hazard, do not recommend evacuation of a work area. Once an area has been evacuated, it is extraordinarily difficult to convince workers that they were not being exposed to toxic materials.

Maximize employees' participation in the investigation. If an employee health and safety committee exists, involve it at the earliest stage possible.

Communicate openly and in a timely manner with employees. The most common source of information in these outbreaks is rumor. While reliance on the "rumor mill" may be regrettable in daily operations, it can be disastrous during an outbreak of health problems. Inform employees of exactly what steps are being taken to investigate the problem, what has been determined, and what remains to be determined. Both regular newsletters and face-to-face meetings are valuable. Do no wait until a definitive cause of the problem has been discovered, because distorted rumors will take hold in the interim.

Communicate effectively with the media. IAQ outbreaks are often accompanied by sensationalistic news reports. The most effective approach to neutralizing such stories is through regular press releases. A single, knowledgeable spokesperson should respond to all media requests for interviews.

Despite the desire for quick solutions and a swift return to business as usual, avoid early "definitive" pronouncements of the cause of the problem. Initial, hastily conceived impressions often turn out to be wrong. When erroneous preliminary conclusions are presented, management quickly loses credibility.

Despite careful investigation, an environmental explanation may not be found for many reported IAQ problems. Employees may then be told that the problem was psychological or due to stress, if appropriate. Stress has gradually become an acceptable explanation for a variety of physical and psychological problems. Most employees can understand a presentation of how stress can lead to symptoms commonly seen in IAQ outbreaks. However, if this explanation is used, management must be prepared to define the nature of the stressors and plans for remedial actions.

Additional information on the subject is contained in Reference 6.

Carbon dioxide (CO2) is a normal constituent of exhaled breath and, if monitored, can be used as a screening technique to evaluate whether adequate quantities of outdoor air are being introduced into a building or work area. Typical outdoor carbon dioxide (CO2) concentrations in Northern California are 300 - 400 parts per million (ppm). The CO2 level is usually higher inside than outside, even in buildings with few complaints about indoor air quality. Indoor carbon dioxide concentrations greater than 800 - 1000 parts per million (ppm) generally indicate insufficient outdoor air ventilation, based on the American Society of Heating, Refrigeration and Air-Conditioning Engineers Standard - Ventilation for Acceptable Indoor Air Quality, ASHRAE 62-1999, and professional experience. IAQ problems may develop as a result of inadequate outdoor air ventilation. The CO2 concentration itself is not responsible for the complaints. However, a high concentration of CO2 may indicate that other contaminants in the building may be concentrating and could be responsible for occupant complaints. If CO2 levels are greater than 1000 ppm, widespread complaints may occur and thus 1000 ppm may be used as an upper limit. This does not mean that if this level is exceeded the building is hazardous or that it should be evacuated, but rather this level should be a guideline that helps maximize comfort for all occupants. Carbon dioxide concentrations between 600 ppm and 1000 ppm are less clearly interpreted.

There are numerous instruments commercially available to evaluate carbon dioxide in air. A Young Environmental Systems meter, Telair Systems, or TSI meter provide continuous analysis and datalogging of carbon dioxide, temperature and relative humidity. These instruments are equivalent in most ways. A Miran IB and other infrared carbon dioxide analyzers can also be used to sample for CO2. CO2 concentrations can also be estimated using direct reading detector tubes that indicate concentration as a function of length of color change on a sampling tube (e.g., Draeger Tubes). Unlike most industrial hygiene sampling, CO2 readings for IAQ evaluations should not be taken in the breathing zone of an individual. The CO2 in exhaled breath can cause false readings.

Plan your sampling locations. Include some areas where there are reported problems and some where there are not. If there is no difference between areas, pick some from each area of the building. Be sure to sample outdoors for comparison.

Start sampling first thing in the morning. You should be among the first people in the building that day. Get baseline samples at all your major sample spots including an outside sample. During the day get representative samples in all your major sampling locations, the frequency determined by the variety and duration of activities. You will probably want to get samples just before the lunch break, particularly if there is a significant decrease in building occupancy at lunch. You will want samples again at the end of the work day just before everyone starts leaving (a lot of in-out traffic would allow more air exchange than during the major part of the day). Depending on the number of sampling sites and activities involved, you may want additional samples at other locations. Record all CO2 measurements in units of ppm, by specific location and time of day, and record occupancy at each sample location.

To round out the monitoring, temperature and humidity should be checked at various times and places throughout the day, and if necessary, air flow at vents and return air grills should be evaluated as well. Although wet bulb, dry bulb thermometers can be used, that degree of accuracy is unnecessary. A desk thermometer and relative humidity meter should be adequate. Measurements for air flow are intended to assure that vents are functioning (perhaps intermittently) and to possibly see if the airflow is directed in a suitable direction. Air movement from vents is easily checked with smoke tubes. Use of a balometer is recommended to most accurately measure the air flow at each supply and return register.

Ventilating systems for spaces with intermittent or variable occupancy may have their outdoor air quantity adjusted by use of dampers or by stopping and starting the fan system to provide sufficient dilution to maintain contaminant concentrations within acceptable levels at all times. Such system adjustment may lag or should lead occupancy depending on the source of contaminants and the variation in occupancy. When contaminants are associated only with occupants or their activities, do not present a short-term health hazard, and are dissipated during unoccupied periods to provide air equivalent to acceptable outdoor air, the supply of outdoor air may lag occupancy. When contaminants are generated in the space or the conditioning system independent of occupants or their activities, the supply of outdoor air should lead occupancy so that acceptable conditions will exist at the start of occupancy.

Reference 1 contains additional information on the subject.

Carbon monoxide is an odorless, tasteless, colorless gas which acts as an asphyxiant by binding to hemoglobin (forming carboxyhemoglobin), thus decreasing the amount of oxygen transported to tissues. While odorless itself, CO exposure often involves a combination of combustion products, many of which do have distinctive odors. The most common sources for CO in non-industrial environments include automobile exhaust from indoor garages, or inappropriately placed air intakes and smoking.

Overexposure to CO can result in fatigue, shortness of breath, headache, nausea, exacerbation of symptoms of cardiovascular disease and, at high concentrations, death. The current National Ambient Air Quality Standard for CO is 9 ppm maximum for an eight hour average exposure or 35 ppm maximum for a one-hour average exposure. Detector tubes (e.g., Draeger tubes) and electrochemical CO monitors are available that are usually adequate to assess CO levels in non-industrial situations.

Trace metals, sulfur, chlorine, potassium, nitrogen, calcium, silicon, and a variety of minerals are formed during combustion of fossil fuels. Of these, the nitrogen oxides have received the most attention with respect to (primarily residential) indoor air quality. Nitrogen dioxide is rarely associated with nonresidential, building-related complaints except in cases where entrainment from outdoor air occurs and in conjunction with environmental tobacco smoke exposure.

Ozone is a colorless gas with a characteristic odor that is produced in ambient air by the photochemical oxidation of combustion products such as the nitrogen oxides. It can also result from the operation of electrical motors, photocopy machines, and electrostatic air cleaners.

Symptoms associated with overexposure to ozone include cough, upper airway irritation, tickle in the throat, chest discomfort, difficulty or pain in taking a deep breath, wheezing, headache, fatigue, nasal congestion, and eye irritation. Symptoms usually disappear within 2-4 hours of cessation of exposure. For sedentary workers, ozone concentrations in excess of 0.1 ppm may result in symptoms such as dryness of the upper respiratory tract, and nose and throat irritation; concentrations in excess of 0.5 ppm may induce decrements in pulmonary function.

Non-industrial exposures are usually in the 0.02 ppm to 0.03 ppm range. The ACGIH TLV for ozone ranges from 0.05 to 0.20 depending on an assessment of work level. The odor of ozone can be detected by some people at levels as low as 0.001 ppm and by most people at 0.02 ppm, which is well below the level at which symptoms are induced. Therefore, in the absence of this odor, building-related symptoms are unlikely to be due to ozone exposure.

Measurement of ozone can be done using chemiluminescence, ultraviolet absorption, or detector tubes (e.g., Draeger tubes). Control of ozone in non-industrial occupational environments depends on adequate ventilation to dilute internal sources and proper maintenance of electrical equipment and other potential sources.

Formaldehyde (HCHO) is ubiquitous in the modern environment due to its extensive use in a variety of manufacturing processes. Formaldehyde is used in bonding/laminating agents, adhesives, paper and textile products, and foam insulation. Especially in new buildings, formaldehyde off-gassing from building materials and textiles can be a significant problem. Renovations involving replacement of carpeting can also temporarily raise formaldehyde concentrations into the irritant range.

Formaldehyde is a suspected carcinogen. The mean indoor concentration of formaldehyde has been reported as approximately 0.03 ppm. The odor threshold for formaldehyde is approximately 0.03 to 1.6 ppm. Possible eye irritation has been reported at concentrations of approximately 0.02 – 0.03 ppm and sensitive individuals have been reported to experience mucous membrane irritation at a concentration of 0.05 ppm. The current ACGIH TLV for formaldehyde is 0.3 ppm as a ceiling limit and it is regarded as a human sensitizer.

For indoor air quality investigations, air sampling for formaldehyde can be conducted in accordance with National Institute for Occupational Safety and Health (NIOSH) Method 3500. Samples are collected by drawing air through a midget impinger containing a sodium bisulfite reagent solution at a flow rate of approximately 1 liter per minute (LPM). An extended sampling time of 24 hours allows for a detection limit of approximately 0.0001 ppm. Care must be exercised to ensure that the reagent solution level remains at the appropriate level in the impinger. Other methods, including relatively new passive monitors, are available and are much easier to use, but be sure that the detection limit is sufficiently low.

Control of formaldehyde depends on limiting indoor sources including smoking, formaldehyde-containing building materials and textiles as well as provision for adequate ventilation. "Baking-out" of new buildings has also been used to lower indoor concentrations of formaldehyde and other VOCs. However, recently published case study reports indicate that maximizing the outdoor air supply ventilation for a 48 – 72 hour period may be just as effective without the risk of damage associated with high temperature conditions. Exposing formaldehyde-containing materials to elevated temperatures before installation would be more appropriate than attempting bake-out conditions in a building.

Respirable suspended particulates are less than 10 micrometers (um) in diameter and include a broad range of substances that remain suspended in air. In non-industrial occupational environments, the principal source of fine particulates (< 2 um) may be cigarette smoke and possibly aerosols from spray air fresheners or cleaning materials. Larger particle aerosols (2-10 um) include carpet fragments, human skin scales, and dirt carried in from outdoors. Indoor exposure to particulates is often higher than outdoor exposure.

In addition to specific effects from environmental tobacco smoke and bioaerosols, respirable particulates can be respiratory irritants, especially for asthmatics. In addition, some respirable particulates are highly reactive, although the chemistry of indoor respirable particulates has received little attention except for the specific cases mentioned above.

The EPA National Ambient Air Quality Standards for particulate matter in outdoor air is 50 micrograms per cubic meter (ug/m3), respirable, as an average concentration, and 150 ug/m3, respirable, as a 24-hour ceiling concentration. For indoor air, some industries recommend a performance criteria should be set at 75 ug/m3 for total dust and 50 ug/m3 for respirable dust until more is learned about potential adverse health effects of certain indoor air particulate such as passive smoke (Reference 21).

The EPA reference method for measuring particulate matter in outdoor air is a cascade impactor procedure. It is outlined in Appendix J of 40 CFR Part 50. Respirable particles can also be measured by a cyclone-filter assembly used in conjunction with a high-flow pump. Direct reading equipment for measuring respirable particles is also available (e.g., the HAM by PPM, Inc.). Total particulates can be measured by preweighed filters used in conjunction with high-flow pumps. An attractive alternative to using high flow pumps in occupied areas (noisy!) is to use personal low flow sampling pumps in accordance with NIOSH Method 0500 by drawing air through a 37 millimeter (mm) diameter filter cassette containing a pre-weighed 5 micron pore size, polyvinyl chloride (PVC) filter at a flow rate of approximately 2 LPM. An extended sampling time of 24 hours allows for a detection limit of less than 5 micrograms per cubic meter of air (µg/m3).

Some individuals working in this building have reported health complaints. To help investigate the possible presence, or absence, of similar complaints, this questionnaire is being distributed to all or some occupants. Your assistance is requested. Please complete this questionnaire as accurately as possible. Please respond even If you have not personally experienced any of the listed problems. Return in a sealed envelope to __________________ by __________________. Thank you!

1. Complaints: (select choices that you experience regularly and may be related to your presence in this building. This is a standard list - not all complaints listed have been noted in this building.)

3. When do you experience relief from these complaints? ______________________________________________________________________

4. Do you have any of the following? (Please check positive responses)

5. Do you smoke tobacco? ____Yes ____ No

6. What floor of the building are you located? ______________________________

7. Comments or Observations: ____________________________________________________________________________________________________________________________________________

The use of a questionnaire as part of an IAQ investigation is usually of limited value and is generally not recommended due to the difficulty in collected meaningful data and the extensive time required to properly analyze questionnaire data. Occupant interviewing is a preferred approach to collect similar information.

A questionnaire may be useful when it is necessary to identify the extent and nature of a reported problem, and to identify possible patterns at the onset of the symptoms. A questionnaire may also be used to support a conclusion that the reported symptoms are not associated with the indoor building environment. A sample questionnaire is included in this Appendix. This questionnaire may be self-administered or it may be administered by a member of the investigating team during a personal interview.

NIOSH suggests that after reviewing the questionnaire data and information from interviews, the investigator will get a sense of who is and who is not experiencing symptoms and what these symptoms are. These individuals may be categorized to at least provide numbers which may help determine the extent of the problem or to determine if one truly exists. NIOSH furthers recommends plotting this information on a floor plan to provide a graphic display of the distribution of the complaints. This may help to determine if the problem is localized or widespread.

It is not unusual to have employees with health effect symptom complaints from time-to-time. Not every health complaint will necessarily be IAQ related and the questionnaire information should be interpreted with care. Table 1 lists responses to questionnaire surveys in buildings that were regarded to be without IAQ complaints.

The increase in total VOCs from inadequate ventilation, outside contamination, a larger than normal amount of office equipment, or new building materials has often been often associated with SBS symptoms. In a study of 11 buildings with SBS, for 10 out of 16 symptoms, the mean hydrocarbon exposure was significantly higher among persons with the symptom as compared with persons without the symptom (P<0.05). These 10 symptoms were eye irritation, swollen eyelids, nasal inflammation, nasal congestion, dryness in the throat, sore throat, headache, abnormal tiredness, sensation of getting a cold, and facial itch (see Reference 7).

Typically, air sampling for total VOCs should only be considered after the HVAC system has been thoroughly checked and found to be operating correctly. And only if there are indications that VOCs may be the source of the problem (e.g., a larger than normal number of VOC-emitting office equipment, or symptoms consistent with VOC exposure such as mucous membrane irritation, headaches, and neurophysiological dysfunction). Typical concentrations of volatile organic compounds in the indoor environment are below the detection capabilities of available NIOSH methods. Currently preferred methodology for VOC sampling is solid sorbent tube or SUMMA® canister collection in accordance with EPA methods IP-1A and IP-1B, respectively. Samples are analyzed using thermal desorption and GC/MS techniques. Concurrent sets of two samples each should generally be taken:

Sample sets (2) through (4) are used for internal and external comparisons. The last set of samples (4), can be omitted if reentrainment problems are not anticipated.

Advanced VOC sampling equipment is not commonly available and is fairly expensive. It is usually easiest to obtain the necessary sorption tube or Summa® canisters from the laboratory performing the sample analysis. They will charge preparation and/or rental fees, but they will also guarantee the collection media are clean.

Total VOC monitors, such as the Photovac TIP or HNU photoionization detector (PID), the Century or Photovac portable flame ionization detector (FID), and MIRAN instrumentation, can be used to measure peak concentrations and intra-day fluctuations but then may not be sensitive enough to detect typical indoor VOC concentrations. However, recent commercially available equipment is specifically designed for indoor air quality investigation purposes.

Currently there are no generally accepted standards for total VOCs in the indoor environment. In a study of 15 office buildings, average VOC concentrations indoors were found to be approximately 650 ug/m3 while outdoor concentrations averaged about 250 ug/m3. Relating exact airborne concentrations with complaints is not usually possible because of the variation of individual chemical properties and personal response. Complaints have been reported when concentrations of VOCs in air were less than 400 ug/m3. In one study, at 600 ug/m3 more than 20% of occupants complained of upper respiratory tract irritation and/or headache. In one paper, sensory perception to VOCs was reported to occur at approximately 1000 ug/m3.

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QUARTERLY

SEMI-ANNUALLY

Proper testing and balancing should be conducted to ensure that HVAC systems meet design, comfort and health requirements, as well as save on energy consumption. The building should be balanced by a professional technician to design specifications as called out in the mechanical systems as built drawings. No changes should be made without the proper test equipment to measure changes. Air and water test and balance reports should be supplied with the building manual and contain all of the final balanced readings.