Dalrymple Consulting, Inc. "Your Environmental Engineering Source" 7841 SW 1 i b Street, Topeka, Kansas (785) FAX (785)

Transcription

1 Dalrymple Consulting, Inc. "Your Environmental Engineering Source" 7841 SW 1 i b Street, Topeka, Kansas (785) FAX (785) January 10,2012 Mr. Steve Wiseman, Superintendent Atchison County USD th Street Effingham, Kansas Re: Mold Assessment A Building Dear Mr. Wiseman: We have completed the authorized Mold Assessment at the above referenced location. The purpose of this initial assessment was to investigate the suspected mold growth that was occurring in the building. Summary and Recommendations This Mold Assessment took place on Wednesday, January 4, 2012, as concerns over a visible mold growth were being brought to your attention. A follow-up inspection was conducted on Friday, January 6,2012. A visual inspection and indoor air monitoring were conducted on both days to evaluate the mold concern in the building. The building was not occupied during this assessment, but the HV AC systems were fully operational during the entire assessment period. Indoor air quality was monitored initially to check the performance of the HV AC system. Measurements of temperature, relative humidity, carbon monoxide, carbon dioxide, and volatile organic chemicals were taken outdoors, inside classrooms, and in the attic. These measurements met the indoor air quality criteria recommended by ASHRAEIEP A on both days. This ruled out the HV AC system causing the mold growth. Refer to the Attachments for a review of this data. Since visible mold growth was present in Room 43 on the ceiling near the furnace room, mold in air and mold surface samples were initially collected on January 4th. Also, there was concern about mold growth in the attic above the ceiling in A Building due to the black coloration of some of the roof deck boards and wood ceiling joints in the attic area. Surface and air samples were taken in the attic to assess the presence of mold. Outdoor air samples were also taken for comparison to the indoor samples.

2 Page 2 Sample analyses were received by my office via later in the afternoon on Thursday, January 5, As soon as I reviewed the lab results, I called Mr. Dan Cowder with a verbal report on the findings. These analyses indicated that mold spores were confirmed in air samples where four (4) indoor samples and one outdoor sample were taken. The analyses also indicated that mold spores were confinned in all five (5) surface samples. The locations of these surface samples is shown in the Attachments, but in general, the surface samples were taken from the ceiling in Room 43 in an area cleaned off by school personnel, an area in Room 43 with black ceiling residue not cleaned by school personnel, black areas on attic plywood ceiling board, attic particle board ceiling board, and attic roof truss. All surface samples taken showed presence of mold spores in moderate to abundant quantities. The air samples taken were in Room 43, Room 41, attic, and outside air. All interior samples were at least twice the mold concentration as the outside air sample. The attic sample was three times the outside mold concentrations. The main concern is that the concentration of the mold spores in the inside samples for Aspergillus/Pencillium Group were 30 times greater than the outside air sample. Even though the Aspergillus/Pencillium Group of mold spores are not toxic themselves, they can produce secondary byproducts, called mycotoxins, which are considered toxic. Not all molds produce mycotoxins. These mycotoxins vary in specificity and potency for their target cells. Viability of spores is not essential to toxicity, so that the spore as a dead particle can still be a source of toxin. Due to the potential toxicity of these mycotoxins, it is warranted to prevent exposures to mold when levels of Aspergillus/Pencillium Group in the indoors exceeds the outdoor levels by a significant amount as was the case on January 4th. Due to the concern of increased concentrations of the Aspergillus/Pencillium Group on the inside rooms and attic compared to the outside air, I returned on Friday, January 6 t \ to conduct some additional investigations. The results of this additional work are as follows: 1. Moisture measurements in the sheetrock ceilings of the classrooms showed 3 to 4% moisture in the ceiling area due west of the furnace room wall in Room 43. The remainder of the ceiling areas tested out to be less than 0.5% moisture. 2. These high moisture areas were in the same areas as the black mold growth that was cleaned by school personnel earlier in the week.

3 Page 3 3. Moisture measurements in the roof deck ceilings in the attic varied between 15 to 55%. The high moisture areas were isolated in the north eastern half of the roof area from an area just west of the restrooms to the east end of the building, but only on the north side of the roof peak. 4. This high moisture area did not correspond with the wet area in the classroom ceiling. The east furnace room has a return air vent located in the hallway ceiling. There is a metal duct that extends due east from the hallway to the furnace room and the metal duct lies on the ceiling floor joists in the attic. The area under this duct was also the area of high moisture in the sheetrock, and pulling up the attic insulation under the duct showed standing water on the sheetrock ceiling and insulation jacket. Condensation of moisture in the duct was causing water to stand on the sheetrock ceiling with eventual mold growth developing. 5. On Wednesday, January 4 th, the attic area had several places where water was dripping from the ceiling joists and exposed roof felt. On Friday, January 6 th, all these areas were dry and there was no visible moisture on these same surfaces. These moist areas were only in the north eastern half of the roof. 6. Mold concentrations in the air on Wednesday, January 4t\ in the attic were approximately three (3) times the outdoor concentrations and twice the classroom concentrations. The black mold growth was denser in the northeast comer of the roof. The black mold is present on the roof deck boards throughout the north side of the roof, but it is becomes less dense the further away from the northeast comer. There is partial mold growth on the south side of the roof, but it is not very dense. 7. Mold concentrations in the air were also measured on Friday, January 6 th in the attic, but the sample was too overloaded with mold spores to get an accurate mold spore count. The lab identified mold spores on this sample, but could not quantify the counts. This indicates that the mold growth had increased in the attic in just one day. The temperature in the attic was 10 to 20 degrees above the outside temperature on Wednesday and Friday with outside temperatures reaching 50 to 60 degrees Fahrenheit. These warm temperatures and the presence of moisture will allow the mold to spread to all areas of the attic, and potentially the classroom areas below the attic area.

4 Page 4 8. Mold concentrations in the air were measured on Friday, January 6 th in the classrooms and the outside. The indoor mold concentrations were less than the outdoor mold concentrations and the Aspergillus/Pencillium Group concentrations in the classroom were less than the outside air. Currently in the United States and the State of Kansas, there are no regulations limiting mold in air and no clear authority to regulate exposure to microbial agents associated with Building Related Illnesses. The criteria used for evaluating these test results included guidelines provided by AlHA (American Industrial Hygiene Association), ACGIH (American Council of Government Industrial Hygienists), EPA, and industry reviewed references. All these guidelines generally indicate that a substantial increase in one or more of the indoor spore types, which are consistent with the outside spore types, may indicate indoor mold growth. This sampling data indicates that there was indoor mold growth on Wednesday, January 4th. The sampling data on Friday, January 6 th, indicates that the mold growth in the attic area had increased substantially since Wednesday. The following actions are recommended based on the results of this Mold Assessment: l. Remove and dispose of the attic insulation that is underneath the fresh air duct that extends from the east furnace room into the hallway. Dry all water that is standing on the sheetrock ceiling board, clean with a bleach solution. Allow the sheetrock areas to air dry before replacing new attic insulation over the area. 2. As confirmed by Mr. Cowder, the air duct and hallway vent may be removed. Also, the fresh air connection from this duct to the main furnace needs to be permanently plugged. 3. Remove and replace all water saturated roof deck boards. Clean all mold areas in the remaining attic area with a bleach solution. Coat all cleaned and dried areas with lockdown material. 4. Until the wet roof areas have been replaced and remaining attic areas cleaned of mold growth, do not allow the classrooms to be used by students. The roof replacement and cleaning should be completed as soon as possible and as weather permits to prevent mold growth from entering other parts of the building. Mold spore episodes are precipitated by moisture events. Only in the presence of moisture will mold grow.

5 Page 5 Mold in Air Sample Results Samples were taken for a period of 8.5 minutes by high volume air pumps calibrated to sample air at 15 liters per minute. Air-O-Cell Bio aerosol Sampling Cassettes were used to collect airborne aerosols including mold spores, pollen, fibers, and inorganic particulates. Any airborne aerosols are deposited on a coated glass slide contained in the cassette housing. The sampling cassette is sent to the lab where the glass slides are removed and direct microscopic analysis is performed. The microscopic analysis was performed by an AIHA accredited lab for total nonculturable fungal spores, which allows for identification of a few indoor fungi species with comparisons to the outdoor species. Spores of Aspergillus and other genera as Penicillium cannot be identified to the species level. This air sampling data and test results are presented in Attachments. This sampling methodology is useful in providing fast analysis of airborne contaminants in indoor air quality testing. Each spore encountered by the lab under a light microscope is identified and tabulated (counts). Spore concentrations are expressed as spores per cubic meter of alr. The National Allergy Bureau (NABTM) is the section of the American Academy of Allergy, Asthma and Immunology's (AAAAI) Aeroallergen Network that is responsible for reporting current pollen and mold spore levels to the public. Outdoor concentration levels can be categorized in the following spore counts per cubic meter: Low = 1-6,499 Moderate = 6,500-12,999 High = 13,000-49,000 Very High = >50,000 The levels observed outdoors on the sampling dates were considered to be in the "Low" category. The main source of mold in office/classroom environments is outdoor air. As outdoor air is often filtered before it enters the ventilation system and mold settle due to lower air velocities in buildings than outdoors, common indoor mold levels are expected to be lower than levels in outdoor air. Tape Sample Results There were nine (9) categories of species that the laboratory identified in the tape samples as compared to the eight (8) varieties noted on the outside air sample. The tape sample results detail that the species identified are considered common and are ubiquitous in nature.

6 Page 6 The laboratory results determined that the levels present in six (6) of the species noted were present in an "abundant" amount. This is considered to be at the high end of the scale. Levels present in two (2) of the species identified were present in the "moderate" designation which is considered to be next to the highest end of the scale. The table below details the laboratory's reporting criteria. Quantities reported are relative to the sample. Trace: < or = 10 spores/slide Few: > 10 spores/slide and < 10 spores/40x field Moderate: > or = 10 and> 100 spores/40x field Abundant: > or = 100 spores/40x field Health Effects The presence of fungi on building materials as identified by a visual assessment or by bulk/surface sampling results does not necessitate that people will be exposed or exhibit health effects. In order for humans to be exposed indoors, fungal spores, fragments, or metabolites must be released into the air and inhaled, physically contacted, or ingested. Whether or not symptoms develop in people exposed to fungi depends on the nature of the fungal material, the amount of exposure, and the susceptibility of exposed persons. Susceptibility varies with the genetic predisposition (e.g., allergic relations do not always occur in all individuals), age, state of health, and concurrent exposures. For these reasons, and because measurements of exposure are not standardized and biological markers of exposure to fungi are largely unknown, it is not possible to determine "safe" or "unsafe" levels of exposure for people in general. Individuals with persistent health problems that appear to be related to fungi or other bio aerosol exposure should see their physicians for a referral to practitioners who are trained in occupational/environmental medicine or related specialties and are knowledgeable about these types of exposures. Clinical tests that can determine the source, place, or time of exposure to fungi or their products are not currently available. Antibodies developed by exposed persons to fungal agents can only document that exposure has occurred. Since exposure to fungi routinely occurs in both outdoor and indoor environments this information is of limited value. The conclusions and recommendations presented in this report are based in part upon the site conditions observed during the site visits, results of the air quality tests, interviews, and from other information discussed in this report. This report reflects conditions as they existed at the time of the site visits.

7 Page 7 This report has been prepared for the exclusive use of our client for the project discussed and has been prepared in accordance with generally accepted professional engineering and industrial hygiene practices. No warranty, express or implied, is intended or made. Thank you for the opportunity to be of service to USD 377. If you have any questions about this report, please don't hesitate to contact me. Attachments