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Indoor Air Quality

I. The Issue

In the past twenty years, health officials have noted that indoor air quality can have a significant impact on the health and well being of an individual. In addition, we have learned that our recent efforts to improve heating and cooling efficiencies have also influenced air quality in many buildings including schools. As we seal buildings and reduce the rate of fresh air exchange in order to maximize our heating and cooling efforts, we have created an environment that is conducive for the build up of indoor contaminants related to our own activities. Examples of some of the common contaminants include: tobacco smoke, carbon dioxide from human respiration, carbon monoxide from inefficient heating, chemical emissions from classroom activities, maintenance activities, or off gassing from building materials or furnishings, and hydrogen sulfide released via sewer lines. In addition to chemical contaminants, biological contaminants such as bacteria, fungus, and mold may also be present in elevated concentrations in indoor air. Biological contamination is likely to occur in areas that are frequently subject to flooding, high humidity, water intrusion or repeated leaks. Pollen and animal dander are additional biological agents that may also impact indoor air quality.

The presence of these contaminants does not mean that you will automatically experience an adverse health effect. However, numerous studies have determined that exposure to these contaminants can result in an increased incidence of the following types of ailments in the exposed population: asthma, allergies, chemical and biological sensitivities, sinus infections, headaches, nausea, chronic coughs, respiratory distress, and potentially cancer. The duration and intensity of exposure and sensitivity of the individual will determine if an effect will occur.

Finally, due to the increased use of synthetic material in the construction of building materials and furnishings as well as the widespread use of chemicals in school curricula and maintenance activities, it is imperative that we monitor and reduce the potential impact of these materials on the building occupants. In addition, since the energy crisis of the 1970's, many school systems have actively implemented measures to seal their buildings and reduce fresh air exchange. In many cases, this approach may have created an environment which promotes the build up of indoor air contaminants while at the same time exposing children to the hazards associated to these materials. Another factor to the equation is that children are at a high risk to sensitization and biological response because of their metabolic rate and developmental stage. In basic terms, children have a higher metabolic rate than adults and consequently have a higher rate of respiration, as a result they inhale more air and potentially greater amounts of any contaminants present in the air. Also, children are at risk because their bodies have not fully developed and matured. This means that depending upon their age, they may lack much of the detoxification capabilities that an adult has. Therefore, we have strong incentives to monitor and improve indoor air quality at local schools in order to protect our children's health as well as that of their teachers.

II. The Approach Taken:

Since the mid-1980's the Board of Health routinely received complaints from parents and staff that the air in the local high school was "bad". These complaints centered on the report of chemical odors, stale air, no air movement, and the report of increased medical symptoms such as allergies, sinus problems, and asthma. We also received a number of comfort complaints associated with the indoor temperature and humidity. Over time we could not determine a specific pattern or location for these complaints other than a general increase during the winter months. Also, the variability and vagueness of the complaints as well as our method of recording these complaints initially hindered our ability to thoroughly investigate these reports.

Early on, we recognized that in most cases thermal complaints involving room temperature did not pose a risk to indoor air quality. Thermal problems represent a personal comfort issue which may cause an individual to be more sensitive to a real or imagined air quality concern but tend to have minimal impact on overall indoor air quality. As a result, we empathized with the staff's desire for individual temperature control but in general we placed a lower level of importance on resolving these complaints. Our primary focus was to identify and resolve the source of chemical odors reported in the building. This approach was reactive in nature. We would investigate in response to complaints rather than trying to identify and prevent potential problems from occurring. These investigations determined that the arts, science, and maintenance departments were the sources of most of the odors detected in the school.

While conducting a chemical hygiene assessment of the materials used by the staff, I began to realize the potential impact that the use of these substances could have on indoor air quality at the school. This discovery prompted a more a comprehensive and proactive approach to preventing impacts on indoor air quality. These efforts included the initiation of staff reviews of chemical usage, materials substitutions, greater use of mechanical ventilation, and the rescheduling of maintenance or laboratory activities. During this phase, we identified the following activities as having a potential adverse impact on indoor air quality at the high school. The use of volatile solvents and biological specimen preserved in formaldehyde was found to be a common source of odor complaints involving the science department. Another cause of complaints was the heating of laboratory experiments without using additional mechanical ventilation. The uncontrolled release of free silica from clay powder and toxic heavy metal colorants used in the ceramics program represented the most significant indoor air quality concern in the arts department. Free silica is comparable in both chemical and biological behavior to that of asbestos. The fine heavy metal powder colorants represent a significant respiratory hazard and some are potentially carcinogenic or teratogenic. The indoor use and application of paints, pesticides and solvents were found to be the source of the majority of the odor complaints submitted with regard to maintenance activities.

In 1992, the Board of Health adopted a municipal bylaw which regulated smoking in public places. A provision of this regulation banned smoking within the local schools. In 1993, the Massachusetts Department of Public Health banned smoking on all school grounds and at all school functions. These steps virtually eliminated the generation of second hand tobacco smoke within all local schools.

In the spring of 1993, I expanded my indoor air quality review to include the identification and inspection of potential sources of emissions within the schools. This effort lead to the identification of five ceramics kilns utilized by the school department. Initially, none of the kilns was vented to the outdoors. This effort also included a general inspection and review of the chemical fume hoods utilized by the high school science staff. The majority of these units were found to provide little noticeable air movement when operated. This prompted the initial recommendation to have these units professionally inspected, repaired and re-calibrated.

Also in the spring of 1993, the Massachusetts Department of Labor and Industries (DLI) contacted the Board of Health with regard to indoor air quality complaints submitted by the high school faculty. In response, DLI and Board of Health staff inspected the school. At the time, it was reported that all heating and ventilation maintenance and repair activities were subcontracted and as a result no maintenance records were available for review. Neither agency was able to gain access to records which described the maintenance and repair of the heating and ventilation system at this time.

In September 1993, the school department hired a private consultant to inspect and repair the chemical fume hoods present in the science laboratories. This investigation determined that 8 of the 12 hoods were inoperative and in need of repair. The main problem noted was that fans had been removed from the units or that fans had burned out.

In July 1995, a representative of the Massachusetts Office of Technical Assistance noted the presence of mold and bacterial contamination during an inspection of the high school science area. This report also provided comments regarding the `stuffiness' of the air in this portion of the school.

Continuing concerns regarding the status of the chemical fume hood utilized by the high school science department caused the School Department to hire another consultant to inspect the units. This investigation determined that only 3 of the units were operational.

In December 1995, the Massachusetts Department of Labor and Industries returned to the high school in response to continuing staff complaints regarding poor air quality. Again, no maintenance records were available to describe the current condition of the heating and ventilation system.

In May 1996, staff complaints prompted the school department to hire a consultant to determine the source of chemical odors in a portion of the building. The consultant determined that art classes in adjoining classrooms were the source of the solvent odor complaints filed by the staff. Mineral spirits had been used for several days by the staff and students without the aid of mechanical ventilation.

Persistent complaints by the high school teachers' union caused the School Department to hire a consultant to conduct an indoor air quality assessment at the school in October 1996. The primary focus of this effort was to measure the carbon dioxide and carbon monoxide concentrations, temperature and humidity within the classrooms in order to gauge the function of the heating and ventilation system. This study also included limited efforts to identify potential allergens within the study area.

In the fall of 1996, a number of parents and staff members lost patience with local efforts and filed complaints with the Massachusetts Department of Public Health and the U.S. Environmental Protection Agency. In response, both agencies contacted the Board of Health to learn of local efforts to evaluate the indoor air quality at the local high school. In addition, the Massachusetts Department of Public Health offered its assistance in conducting air quality sampling at the school. As part of this effort, representatives of the Massachusetts Department of Public Health and the Burlington Board of Health conducted air quality sampling in approximately 50 classrooms in the school. The focus of this monitoring effort was to measure the carbon dioxide concentration, humidity, and temperature within the school. A general survey of potential allergens or other potential indoor air quality concerns was also conducted at this time.

Due to the expanding interest in the air quality investigation, the Board of Health decided that a public forum was the best approach to ensure a comprehensive review of the existing conditions and to answer the questions of the general public. As a result, the Board of Health convened a public hearing in February 1997 during which the general public was offered the opportunity to discuss its concerns regarding the indoor air quality with the School Committee and representatives of the Massachusetts Department of Public Health and the U.S. Environmental Protection Agency. This event solidified community support for investigating and resolving the problems while also eliminated the possibility for the School Department to continue ignoring the issue. A byproduct of the public forum was the adoption and implementation of the indoor air tools for schools assessment protocol. The indoor air tools for schools is a comprehensive indoor air quality assessment guide prepared by the U.S. Environmental Protection Agency. As part of this effort, an indoor air quality assessment team consisting of concerned parents and staff was also assembled to assist with the implementation and interpretation of the indoor air tools for schools survey results. In addition, the Town also hired a professional assessment team consisting of an architect, a heating and ventilation specialist, and certified industrial hygienist, to ensure the completion of a comprehensive assessment and the development of a response plan.

This evaluation resulted in the identification of a number serious indoor air quality concerns. The results of these reviews were used to develop a response plan. In May 1996, a request for approximately $1.2 million dollars was submitted to and approved by the Burlington Town Meeting to fund the repair of the heating and ventilation system at the school. A variety of response actions are now in progress.

In January 1998, the Board of Health began reviewing air quality complaints involving a local elementary school. These complaints were related to the lack of adequate air exchange and the possible presence of allergens within the classroom.

III. Observations Made:

The most significant observation made was failure or unwillingness by local officials to recognize and acknowledge that obvious maintenance shortfalls could adversely impact indoor air quality at the high school. Chronic and widespread roof leaks had been a major problem at the school for years. Evidence of this problem in the form of mold, mildew, musty odors, and rusted fixtures was readily available throughout the building. In addition, there were a number of areas in the building which were commonly known to be `stuffy', yet few wanted to accept that the number and broad range of complaints could be associated with these problems.

Another critical point has been the unwillingness of the staff considering how their actions can impact indoor air quality. A number of activities have been identified involving the arts, science, and maintenance staff which can adversely impact the air quality. Many of these problems have been reviewed with the individual staff members and discussed during training sessions. Furthermore, many staff members complained about their colleagues' activities during the survey portion of the indoor air tools for schools assessment. Unfortunately, most staff members have chosen to ignore or downplay these complaints when approached. This issue could become increasingly problematic as the repairs to the physical plant are completed and these odor complaints remain unresolved.

During this review, I also noted that the staff tended not to commonly use chemical fume hoods present in the high school. This practice may have been related to the perpetual state of disrepair that many of these units displayed. In addition, the continuing inability of the repair contractors hired by the School Department to properly inspect and repair the hoods supports the need to hire competent professionals skilled and experienced in the task that they are requested to complete. In our case it took four years and four different consultants to fully assess the problems associated with the hoods and to develop a comprehensive response plan so that these units could be returned to full operation. Our first three consultants examined only portions of the hood system. Most checked the status of the exhaust and intake fans. Most did not test the integrity of the hood unit or the ductwork, and only the last consultant reviewed the actual design of the units. As a result, several consultants certified the hoods based on exhaust air movement only with out regard for whether the units leaked emissions or if the exhaust could reenter the building. The final assessment noted that all hoods possessed the design flaw of having their exhaust located near their intake so that hood emissions could reenter the building via the intake. As a result, even if fully functional, none of the hoods could be safely operated.

A survey of the five ceramics kilns utilized by the School Department found that all of these units initially to vented directly into schools. This may have resulted in the release of carbon monoxide, volatile organic compounds, and metal fumes into the schools. We were able to quickly provide proper ventilation to the units located at the local elementary and middle school. Unfortunately, at the high school, it took more than two years to equip the kilns with the appropriate mechanical ventilation needed to properly vent the emissions generated by the units. These difficulties further support the need to use skilled professionals and to adhere to state, federal or industry standards when investigating and resolving these issues.

Due to the chronic and widespread problem of roof leaks, biological contamination was found in a number of locations at the high school. Mold, mildew, and bacteria were found growing in carpets, on books, ceiling tiles, and in insulation.

The final comprehensive assessment of the heating and ventilation system found the high school ventilation system to be in a serious state of disrepair. Portions of the system were found corroded or irreparably damaged. The review team also noted that the fiberglass lining of some of the ductwork was slowly degrading and could begin to release fibers if not abated. This evaluation also observed that building renovations had occurred since the original construction of the heating and ventilation system. As a result, some sections of the build had not be connected to the ventilation system during renovation. We also found that some renovated areas had been connected to the ventilation system using flexible ductwork which had collapsed and consequently eliminated our ability to provide adequate fresh air to these areas.

The professional review team also uncovered a flaw in the heating and ventilation system design. The current construction places the air intakes and returns on one wall of each room in an alternating sequence. The positioning of these units promotes short circuiting with air entering the room via the intake and with a portion of the supply air immediately exiting via the adjacent return. In addition, it was also determined that the existing ventilation system was not capable of moving fresh air completely across many of the rooms. This may have resulted in the creation of a stagnant area on the far side of the room where little fresh air exchange occurred.

A discovery noted by a community representative on our indoor air tools for schools air quality team was the presence of transite asbestos insulation lining some ventilation ductwork in the school. This observation provided the School Department with another location to be included in their asbestos monitoring program. More importantly, this discovery raised new concerns regarding how and when to clean the heating and ventilation ductwork without creating a serious health hazard.

A more recent discovery has been that of the removal of unit ventilators at a local elementary school. These units were reportedly removed in the 1980's as a means to improve energy efficiency. Unfortunately, this step has also eliminated the only means to mechanically ventilate the building, and as a result further investigation may determine that the lack of air exchange may result in poor air quality at the school. Realistically, this issue should be reviewed at all local schools which have similar heating and ventilation systems.

IV. Problems or Concerns Noted:

V. Actions Taken:

A. The evaluation of the chemical inventory has resulted in the identification and removal of potential indoor air contaminants.

While conducting a chemical hygiene review of the materials maintained at the high school, I noted that a number of materials could have an adverse impact on the indoor air quality. These materials included volatile organic solvents and formaldehyde used by the science department, powdered clay containing free silica and toxic heavy metal powders used by the ceramics program, and solvent based cleaners and pesticides used by the maintenance staff. Upon review of the complaints received by the Board of Health, we determined that the organic solvents and formaldehyde used by the science staff as well as the maintenance materials and pesticides used by the maintenance staff were responsible for the majority of the objections raised by the staff. In addition, a review of the health hazards associated with these problem materials indicated that these materials were carcinogenic, narcotic, flammable in nature, and the pesticides were found to be intended for outdoor use only. Based on this information, the bulk of these materials were deemed inappropriate for use at the school and disposed of as hazardous waste.

B. A chemical use review policy has been adopted.

In response to the potential problems noted during the chemical hygiene review, the School Committee and Board of Health have worked together to develop a chemical use review policy which now requires the staff to evaluate procedures involving chemicals for the following parameters: 1) hazards associated with the chemicals, 2) potential impact on air quality, 3) protective equipment or safety procedures required, and 4) the generation of hazardous waste. It is hoped that this practice will help to identify and promote the elimination of potential air contaminants. Resistance to change expressed by some staff members has limited our ability to achieve the full potential of this policy.

C. All ceramic kilns were equipped with mechanical ventilation.

Initially, all five ceramic kilns operated by the school were found to vent directly into the school buildings. The practice offered the potential for volatile organic materials, metallic fumes, and carbon monoxide to build up in the buildings. This problem was corrected by connecting each kiln to a mechanical exhaust system which vented directly to the outdoors.

D. Several air quality assessments were conducted at the high school with mixed results.

Since 1992, several air quality assessments have been conducted at the high school. These efforts were all initiated in response to complaints submitted by either parents or the staff. The typical approach taken is to measure the carbon dioxide content and the humidity of occupied classrooms to assess the general ability of the heating and ventilation system to provide adequate air exchange in the building. The premise behind this assessment is that the occupants generate carbon dioxide and if the ventilation system is not functioning adequately then the carbon dioxide concentration will increase. This is a reasonably easy and inexpensive qualitative assessment tool. The most effective time for conducting this type of evaluation is when the heating and ventilation system is stressed such as during the winter heating season in the Northeast. Unfortunately, many of the investigations sponsored by the School Department were conducted during the non-heating season (late May or early October). The results of these evaluations were invalidated by the fact that the ventilation was set for maximum fresh air intake at the time of both investigations. Also, a greater amount of passive ventilation was possible during these times due to the routine practice of where possible opening windows and doors to augment the building ventilation during warm weather. These two events would not be likely during the winter months when few would want to introduce cold air into the building.

In comparing the results of the air quality assessments conducted by the School Department consultants to those studies conducted by the Massachusetts Department of Public Health and the Burlington Board of Health, it is likely that the introduction of additional fresh air during the warmer months skewed the results of those investigations. The studies conducted during the warmer months rarely indicated a problem with the ventilation system, however studies conducted during the heating season found that approximately half the classrooms developed carbon dioxide concentrations which exceeded the Massachusetts Department of Public Health guidelines for schools.

E. We implemented the EPA Tools for Schools Indoor Air Quality Assessment Program.

The tools for schools air quality assessment program provides the layman with a comprehensive guide for initiating an indoor air quality assessment. This package identifies potential areas of concern while also providing structure to your investigation. I wish I had these tools in 1993 or 1994 rather than in 1997. By the time we adopted the indoor air tools for schools, we had already identified a number of problems as well as the areas that required further review. If we had used this guide earlier our investigation could have been better focused and more efficient. An additional benefit of the indoor air tools for schools approach was that it seeks to maximize the number of individuals involved with the assessment process. This tends to ensure a comprehensive and open investigation that is conducive to brainstorming and discussion. Negatives associated with the approach are that the survey forms are vague in nature and fine tuning of the questions should be conducted prior to initiating your surveys. Also, as with anything as the committee size increases, it can become difficult to remain focused on the big picture and not get lost in the minutiae.

F. We hired a multifaceted professional review team to assist with the air quality assessment.

We learned from our past short comings and hired a multifaceted review team to assist our investigation. This team consisted of an architect, a heating and ventilation maintenance and repair specialist, and an industrial hygienist. This group proved to be invaluable in promoting the full assessment of the issues present as well as in the development of response plans for the problems noted. In addition, several local residents skilled in the design or repair of ventilation systems assisted these efforts. Their expertise was essential in determining the completeness of the review, the soundness of the response proposals, and the evaluation of the validity of cost estimates.

G. A corrective action plan has been initiated at the high school.

In the summer of 1997, we began to address these problems by repairing the roof leaks at the high school. At the same time, steps were taken to decontaminate areas or remove materials impacted by biological contamination. Once this was completed, we began to repair and modify the heating and ventilation system to improve the fresh air exchange and to eliminate the stagnant areas. The following items are scheduled to be completed in 1998: repair and re-calibration of the fume hoods, removal and replacement of flexible ductwork, and construction of ventilation to new rooms constructed without ventilation. A phased approach has been proposed for encapsulating or removing the fiberglass lining present in much of the ductwork. We intend to address the areas which pose the greatest need first until all fiberglass linings have been removed or encapsulated.

Lessons Learned:

The following is a summary of significant lessons I noted during our investigation of indoor air quality within Burlington public schools.

1. Before you can initiate an effective air quality review you need to educate and inform all participants with regard to causes and effects of poor indoor air quality.

A basic level of knowledge of the causes, concerns, and effects associated with poor indoor air quality is required before an efficient and comprehensive investigation can be implemented. I found this to be especially true with regard to the variety of health effects that may be related to poor air quality. The initial response of the Board of Health to air quality complaints was hindered by our limited understanding of the potential number and type of problems that may be manifested by a given population. Initially, we looked for a consistent trend or pattern of symptoms and effects. The failure to detect an obvious pattern lulled hopeful local officials into considering that the problem may be psychological in nature and not the sign of an inherent problem at the school. The school administrator continues to believe that the health complaints reported are not responses to problems present at the school but psychological or conditioned responses submitted by a disgruntled few. A general educational and awareness initiative should be conducted at the start of every air quality investigation.

2. Proper maintenance and calibration of the heating and ventilation system is critical to indoor air quality.

This point is a given but in the age of deferred maintenance programs or subcontracting services to the lowest bidder, it is easy to find many facilities where this step is overlooked. To put it bluntly, if you do not provide a proper rate of fresh air exchange or mechanically exhaust chemical contaminants introduced by the building occupants then a potentially hazardous level of contaminants will accumulate in the building with a resulting decline in air quality.

3. The heating and ventilation system should be inspected and repaired by a qualified professional.

The use of inexperienced and unqualified contractors to attempt to inspect and repair the chemical fume hoods and ceramics kiln exhaust at the high school lead to a more than five year delay in fully assessing the extent of the problems. These delays prolonged the potential introduction of contaminants into the indoor air via the failed exhausts, leaky ductwork, and re-entrainment of materials via the intakes of the units. In addition, each time a new contractor attempted to repair the units, the School Department came away with a false sense of security because their contractor had assured them the units were functioning properly. Remember you get what you pay for.

4. Investigate all steps taken in the name of energy savings.

Many actions initiated to promote energy efficiency can have a detrimental impact on indoor air quality. A common approach has been to seal buildings to prevent passive ventilation or to remove or disconnect exhaust fans to reduce mechanical ventilation. The net result is that we have created an environment where contaminants can accumulate while also having a lesser ability to actively remove the contaminants. Two local approaches to enhancing energy efficiency that I have noted have included the removal of fans from chemical fume hoods as well as the removal or disabling of unit ventilators at a local elementary school. Both steps may have crippled our ability to provide adequate mechanical ventilation.

5. Thoroughly record complaints received.

All air quality complaints should be thoroughly recorded. We now make an effort to record the following information whenever we receive and air quality complaint: name, age, sex of the individual, any preexisting conditions or allergies that may affect the symptoms reported (e.g. asthma), building name or address, room number, a description of any recent activities in the building or school that may have prompted the complaint (e.g. chemical usage, construction), time, and date of the complaint. We are also working with the school nurses in an effort to track medical complaints reported in the schools. We are hoping to use this information to identify sections of schools or individual rooms that may display a higher concentration of allergic or asthmatic responses or headaches.

6. A policy must be established for responding to the detection of chemical odors within a building.

On several occasions chemical odors or clouds have been detected at the local high school. In each case the identity of the material was known to local officials. In each case the school administration may have placed the students and staff at risk by postponing or not evacuating the affected areas. The administration reportedly felt that they would lose control of the students if full or lengthy evacuations were implemented. The administration was also skeptical of the potential health effects the materials posed to the building occupants. My recommendation is to avoid this potential conflict during what will already be a stressful situation and pre-plan for how to respond to a chemical release within the building. Once you have adopted a policy and trained your staff, the implementation should be almost automatic.

7. Before you attempt to clean your heating and ventilation system you must determine if the ductwork of your system is lined with a potential hazardous material.

Once people buy into the idea of inspecting, cleaning and repairing a ventilation system there develops a sense of urgency to do something. In many case, that something is clean the ductwork. This is usually accomplished by running a wire brush-like implement through the ductwork and then removing the dislodged material via a vacuum. This can be useful to remove dirt and other organic matter (e.g. leaves) from unlined ductwork. Unfortunately, this approach can also create more significant health hazards if conducted in ductwork that is lined with asbestos or fiberglass as was present in Burlington. Fortunately, we did not choose to initially clean the ductwork, but if we had we could have released a large volume harmful mineral fibers into the school. Know what you are getting into before you begin.

8. When all else fails use a coordinated and public process to review and discuss the issue.

Between 1991 and January 1997, our investigation languished due to the general acceptance by local officials that the air at the high school may be poor but `hey what can we do about it.' In February 1997, in response to inquiries received from the Massachusetts Department of Public Health and the U.S. Environmental Protection Agency, the Board of Health convened a public hearing to discuss the complaints. This forum thrust the issue into the public eye. This event also prompted the School Committee to abandon its position that no air quality concerns existed at the high school and to formally state for the first time that serious problems did exist. In addition, between February and May 1997, the air quality concerns at the high school went from a general nuisance to local officials to a major concern to local residents and then to a unanimous approval by the Burlington Town Meeting to fund a $1.2 million repair initiative to correct the problems identified. Public involvement eliminated the ability to deny that a problem existed while also providing the support to ensure that a comprehensive evaluation and abatement plan were completed.

Tips and suggestions:

1. Seek assistance from local community. Tap the knowledge and expertise of the local community. They have a vested interest as parents and taxpayers. This interest may also bring more dedicated assistance. Also, this assistance is usually free. Also, local builders and contractors frequently have a detailed knowledge of past and current building and maintenance practices which may not be well documented in existing schematics or construction records. It was a local volunteer who informed us of the use of transite asbestos insulation in the construction of heating and ventilation ductwork after numerous consultants had reviewed the same material without noting this potential problem.

2. Seek the assistance and involvement of state and federal agencies. I found that the interest and participation of Massachusetts Department of Public Health and the U.S. Environmental Protection Agency provided legitimacy to the investigation. During much of the investigation many of the local officials were willing to dismiss the air quality complaints as inflated or as lacking merit because they were submitted by the dissatisfied. Once the state and federal agencies expressed an interest in the air quality complaints, a number of key local officials experienced a conversion and began to consider that the complaints may have some basis. This change of heart and additional attention provided the motivation to conduct a comprehensive and methodical assessment of the air quality at the high school.

3. Use a smoke bomb to test mechanical ventilation. This simple and inexpensive test can provide you with a quick and easy qualitative assessment of the function of a chemical fume hood or kiln exhaust. The use of brightly colored smoke will enable you to easily determine if exhaust may be escaping from the test unit, the ductwork associated with the unit, or if the exhaust is reentering other portions of your ventilation system. This is only a quick and dirty analysis designed to check for major problems. This approach does not replace the need to have a trained professional inspect, maintain and calibrate these units. This approach can influence many skeptics who do not believe that an air quality problem may exist, especially when they observe colored smoke escaping a mechanical exhaust or moving in directions it should not. Just remember to turn off your smoke alarms before you run your test.

4. Review design plans and maintenance records of the suspected heating and ventilation system as a starting point of any air quality assessment. This is a critical first step. This will provide you with clues as to how the system is supposed to operate as well as providing you with potential points of concern such as ductwork linings or critical maintenance areas. These plans should also provide designs regarding the intended design and operation of mechanical exhausts in the building. A review of this information may also suggest potential avenues for exhausted contaminants to be reintroduced into the build via air intakes. I suggest that a review team complete this task. The multiple perspectives offered by our team were extremely valuable in identifying a number of different issues that could have been overlooked if only one or two reviewers had completed the task.

5. Identify and inspect all potential indoor pollution sources for improper emissions. Any building suspected of experiencing an indoor air quality problem should be surveyed for potential indoor pollution sources. Potential pollution sources include: all mechanical exhausts such as chemical fume hoods, spray booths, ceramic kilns, and welding hoods; boilers, computer labs, shop areas, print shops, and animal holding areas. Each of these locations has a number of potential problems associate with it and should be carefully reviewed.

6. Test the area for carbon dioxide content. This is a quick and inexpensive qualitative screening method that can be used to provide a general assessment of the function of the ventilation system. This approach can be used to help determine areas that may be receiving inadequate ventilation. Remember the most accurate measure will be acquired when the heating and ventilation system is under stress (e.g. during the heating season), when little passive ventilation is available (e.g. when the windows are closed), and when the room is occupied.


During this investigation, I utilized the resources available via the U.S. Environmental Protection Agency and the Massachusetts Departments of Public Health ,and Labor and Industries. I also reviewed guidance information prepared by the U.S. Department of Labor Occupational Safety and Health Administration. Prior to initiating an investigation, I encourage you to consult with your state environmental, health, and occupational hygiene offices, and the regional EPA and OSHA offices. These agencies will be able to provide you with an outline of issues and concerns common to your area. In addition, these agencies may also offer free technical assistance which may hasten your evaluation.

1. References books: During my investigation, I found the following references useful and informative.

"Introduction to Indoor Air Quality - A Reference Manual", prepared by the U.S. Environmental Protection Agency, the U.S. Public Health Service, and the National Environmental Health Association, July 1991, document number EPA/400/3-91/003.

"Tools for Schools Indoor Air Quality Action Kit", prepared by the U.S. Environmental Protection Agency, September 1995, document number EPA 402-K-95-001.

2. Internet resources: During my review, I found the following websites to be useful and informative.

Address: Site Description:
http://www.cdc.gov Exit EPA Click for Disclaimer NIOSH Info & Toxicological Registry
http://www.access.gpo.gov Exit EPA Click for Disclaimer Federal Government Printing Office
http://www.aiha.org Exit EPA Click for Disclaimer American Industrial Hygiene Association
http://www.ABIH.org Exit EPA Click for Disclaimer American Board of Industrial Hygiene
http://www.siri.org Exit EPA Click for Disclaimer EHS Bonanza, MSDS's & Much More
http://www.epa.gov U.S. Environmental Protection Agency
http://www.osha.gov Exit EPA Click for Disclaimer OSHA

prepared by Todd H. Dresser, Environmental Engineer
(formerly of)
Burlington Board of Health, 29 Center Street, Burlington, MA 01803

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