5.8. SR 06-05-2006
City of Elk River Item Number
REQUEST FOR COUNCIL ACTION 5.8.
Agenda Section I Meeting Date Prepared by
.t\.dminis tra tion Tune 5, 2006 Billlvfaertz, Parks and Recreation Director
Item Description Reviewed by
Lions Park Building lJpdate-NIold .ll\.batelnent
Introduction
Liol1S Park Building: TYloId .i\batelnent
Discussion
Some staff melnbers at Lions Park Center lla\Te been experiencing llealtll symptolTIs. Staff hired tlle
Il1stitute for En\Tironmel1tal-L\ssessment to test tlle air quality at Lions Park Center. Results indicate tllat
tllere is a significant lnold probleln in at least 1:\vo of tlle offices. The report indicates tllat lnoisture
infiltration into tlle building is tile liJ~ely cause.
TIllS contamination poses a significant Ilealtll risk and \vill require tlle telllporary relocation of SOlne staff,
correcting tlle source of tlle moisture, and abatelnent of tile existing lTIold. Due to tlle nature of tlle soils
at Lions Park, there is a possibility that dle moisture may be rising up tlltougll tlle building slab. It
appears likely dlat soil corrections \vete insufficient. Staff is \vorking \vidl building officials to detertnine
tlle cause of tlle lnoisture infiltration and strategies for eliminating it.
Financial Impact
Staff is researching costs for repairs and abatelnent and llopes to llRve specific inforlllation for tlle
Council at tlle June 5 meeting. Council is ad\Tised tllat initial researcll indicates costs \vill significant.
Attachments
Indoor .L\ir Quality l\ssessment
Action Requested
None
Council Action
IvIotioll by _
Second by _
\Tote
Follow Up
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May 25, 2006
Ms. Jackie Riebel
Elk River Parks and Recreation
1104 Lions Park Drive
Elk River, 1IIN 55330
RE: Parks and Recreation Department
Indoor Air Quality Assessnlent
lEA Project No. 7805-1301
Dear Ms. Riebel:
The Institute for Environnlental ASSeSS111ent (lEA) is pleased to provide this report on the indoor air quality (IAQ)
aSSeSS111ent conducted at the Parks and Recreation Departnlent in Elk River, Mimlesota. The investigation \vas
initiated due to employee concerns and symptoms believed to be related to indoor air quality in the building.
1.0 Introduction / Background Infornlation
T\vo enlployees have experienced health synlptolllS \vhile at \vork. No odors \vere repol1ed. The enlployees
have both been in the building for one to one and a half years. The first enlployee (see belo\\') \vorks in a
cubicle \vhile the second employee \vorks in the adjacent office.
The first en1ployee (South\vest Cubicle) has experienced sneezing, congestion, s\velling around the eyes
and a rash since Novenlber 2005. The Syn1ptOil1S begin in the 1110ming and last throughout the day.
Symptolns are not experienced outside of \vork. The en1ployee reported experiencing the sanle SynlptOillS
previously \vhen \varking at a building \vhere mold \vas present.
The second enlployee (South\vest Office) has experienced congestion and itchy, biuning eyes \vhile at \vork
since Decenlber 2005. The symptoms begin about 20 nrinutes into the \vork day and last throughout the
day. The Syn1pt0l1lS have not been experienced outside of\vork.
2.0 Observations
lEA's observations during the site visit are summarized belo\v:
. The office area is constructed of block exterior \vall, sheetrock interior \valls, carpeted floor, drop
ceiling tiles, sheetrock roof deck, and tar shingle roof.
. The lo\ver half of the exterior \valls is belo\v grade.
. Chair mats \vere identified in five areas in the office. No odors \vere detected belo\v the chair
mats. The moisture level \vas slightly elevated (20-22%) belo\v the chair n1ats as conlpared to the
carpet \vithout the chair Inats (16-180/0).
. Visible fungal gro\v1h \vas identified behind the base cove on the exterior \vall in the back left
conler of the South\vest Cubicle and in the back right corner of the South\vest Office. No elevated
moisture \vas identified on the sheetrock \valls throughout the office area.
. Unit Ale #3 serves the Office area. The filters, supply fan and supply cOll1partnlent \vere clean.
There \vas no access to the duct and the coil.
. No airflo\v \vas measured at the t\VO supply diffusers at the entrance of the office area.
. No odors \vere detected in the roonl.
Elk River Parks & Recreation
Indoor Ajr Quality ..t\ssessment
IE.A. Project No. 7805-1301
Page 2
3.0 Sampling lVIethodology
The IAQ investigation \vas conducted on May 9, 2006 and included the follo\ving activities:
. Visual evaluation of the space for signs of \vater infiltration or fungal gro\vth.
. Collection of airbollle fungal samples to determine if fungal levels \vere elevated. An outdoor
sample \vas taken for conlparison.
. Collection of fungal samples frolll observed or suspect materials including tease tape, contact and
microvac dust sanlples.
. Measurement of moisture levels in building materials.
. Measurenlent of tenlperature, relative humidity, carbon dioxide and carbon monoxide levels.
Airbollle fungal samples \vere collected using a single-stage Andersen nucrobial sanlpler and DG-18 fungal
agar plates. An outdoor fungal sample \vas taken for comparison. Each three-minute sanlple \vas collected
at an airflo\v rate of approximately 28.3 liters of air per minute. Contact fungal sanlples \vere collected on
DG-18 Rodac agar plates. Bulk samples of building materials \vere collected by renloving an actual piece
of the material. The bulk samples of dust from carpet tops \vere collected by the Microvac sanlpling
method. The sanlples \vere collected \vith three-piece, 37 n1ffi 0.8 ~lm MCE filter cassettes. Sample
incubation and analysis \vere provided by Aerotech P & K.
The tease tape sanlple \vas collected by pressing a piece of clear cellophane tape on the suspect
contanlinated surface. The tape \vas then mounted on a microscope slide for fungal analysis via light
microscopy. The tease tape sample \vas analyzed by Aerotech P & K.
Moisture content of building materials \vas evaluated \vith the Protimeter Surveymaster SM. Moisrure
levels in \vater-danlaged ll1aterials are compared \vith moisture levels of the sanle material in areas that
have not been impacted by \vater danlage.
Tenlperature, relative humidity, carbon dioxide and carbon monoxide levels \vere llleasured \vith a TSI,
Inc. Q- T rak mom tor.
Further details concerning sanlpling and analytical nlethodologies are ll1aintained at lEA and can be
provided to the client upon request.
4.0 Results & Discussion
Lab analysis reports can be found in Appendix 1. "Quick reference guidelines" for interpreting lab results
are provided follo\ving the presentation of results. Conlplete guidelines are available in Appendix II.
4.1 Culturable Airborne Fungi
Sanlples for culturable airbolne fungi \vere collected the cubicle area \vhere the occupant reported
allergy SynlptOms. An outdoor sample \vas taken for conlparison. Results are listed in the table
belo\v:
Table 1: Concentrations of Culturable Airborne Fungi - ~lay 9, 2006
Sample No.! Agar Fungal Identification Colony Con c. Percentage
Location Used Co un ts (CFU/m3) (0/0 )
050906BR-02 DG-18 Cladosporiul1z 54 635 90
Outdoors Alternaria 2 24 3
Basidionzycetes 2 24 3
Aspergillus versicolor 1 12 2
Epicoccullzlligrullz 1 12 2
Total: 706
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Elk River Parks & Recreation
Indoor Air Quality .A.ssessment
lEA Project No. 7805-1301
Page 3
Table 1: Concentrations of Culturable Airborne Fungi - May 9, 2006 (continued)
Sample N 0./ Agar Fungal Identification Colony Cone. Percentage
L.ocation Used Counts (CFU/m3) (%)
050906BR-03 DG-l 8 Aspergillus versicolor 117 1,376 90
Cubicle Area CI adosporiu/ll 9 106 7
sterile fungi 3 35 2
Alternaria 1 12 <1
Total: 1,529
CFU - Colony Fornling Unit: A distinct colony that fOnTIS on a sample plate
CFU/m3 - Colony forming units per cubic meter of air
DG-lS - Dichloran Glycerol Agar
Percentage - Percent of Total Organisnls Identified
Quick Reference Guideline:
Fungal organisms isolated in the indoor air sample are evaluated in comparison to the outdoor sample in tem1S of
type and concentration. Indoor concentrations should be lo\ver than outdoor concentrations in mechanically-
ventilated buildings \vith adequate filtration. Types of organisms found indoors should be sin1ilar to those found
outdoors.
. Discussion of Results
High airborne fungal levels \vere detected indoors in the cubicle area. Aspergillus versicolor \vas
the donrinant fungal organism \vhich is indicative of fungal gro\vth and contanrination due to
1110isture intrusion problen1S. Fungal gro\vih appears to be affecting indoor air quality. These
results indicate that an interior source of fungal contamination is present. The results of source
sanlpling (see belo\v) support this conclusion.
4.2 Fungal Contact Samples
Contact fungal samples \vere collected from the carpet bottom belo\v a chair nlat and along the
exterior \vall. Results of sampling are listed in the table belo\v:
Table 2: Contact Sanlple Fungal Concentrations - lVIay 9, 2006
Sample No.1 Agar Fungal Identification Colony Percentage
Location Used Coun ts (0/0)
050906BR-04 DG-18 Aspergillus versicolor 72 100
ReAnn's Cubicle - Bottom surface of Total: 72
carpet belo\v chair n1at
050906BR-05 DG-18 Overloaded <500 N/A
rvlichelle's Office - Bottom surface of Aspergillus versicolor Total: <500
carpet along exterior \vall
00-18 - Dichloran Glycerol Agar
Percentage - Percent of Total Organisms Identified
N/A - Not Applicable
Ouick Reference Guideline:
Contact samples \vith total colony forming units over 50 signify moderate fungal contan1ination and over 100 can
be considered heavily contaminated. The presence of potentially toxigenic or pathogenic fungi, such as
Staclzybotrys, Aspergillus or Penicilliu111 also is considered in evaluating fungal results.
. Discussion of Results
Moderate fungal counts \vere detected on the carpet bottonl sample collected belo\v the chair lllat
in the South\vest Cubicle. Aspergillus versicolor \vas the organism detected in the sanlple. The
elevated moisture levels found belo\v the chair mat suggest that moisture infiltration through the
slab \vas trapped by the chair mat and resulted in fungal gro\vih on the carpet.
The sample collected from the carpet bottom by the exterior \vall in the South\vest Office \vas
overloaded \vith Aspergillus versicolor. These results indicate that fungal gro\vth has occurred on
the carpet in the areas sampled. The visible fungal grO\vth behind the base cove on the exterior
belo\v grade \vall suggests that moisture has infiltrated through the exterior \vall and possibly the
slab in this area.
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Elk Riyer Parks & Recreation
Indoor Air Quality Assessment
lEA Project No. 7805-1301
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4.3 Tease Tape Sanlpling Results
AA. tease tape sanlple \vas collected from visible fungal gro\\lth found behind the base cove in the back
left comer of the South\vest Cubicle Area. Results are listed in the table belo\v:
Table 3: Tease Tape Sample Result - lVlay 9, 2006
Sample No.! Fungal ID Fungal structures observed Category* Comments**
Location
050906BR-0 1 Aspergillus spores, hyphae, conidiophores Massive Fungal gro\vth
Cubicle Area, Back Left
Comer - Sheetrock \vall
behind base cove
*nlassive > numerous> many> a few' > a trace
**comments reflect entire sample
> = greater than
. Discussion of Results
Aspergillus \vas identified on the tease tape sanlple collected frOlll the exterior sheetrock \vall
behind the base cove. Gro\vth structures \vere present confirnling that fungal gro\vth has occurred.
4.4 lVIicrovac Sample Results
Microvac sanlples of carpet dust \vere collected belo\v the chair mat in the South\vest Cubicle and
along the exterior \vall in the South\vest Office. Sanlple results are listed belo\v:
Table 4: Microvac Sampling Results - lVlay 9, 2006
Sample No.! Agar Fungal Identification Cone. (CFU/g) Percentage
Location Used (0/0 )
050906BR-06 DG-18 Aspergillus versicolor 61,400 93
ReAnn's Cubicle - Top Eurotiunl a/llstelodanli 3,610 5
surface of carpet belo\\' Eurotiulll herbariorulll 1 ,21 0 2
chair mat Total: 66,300
MEA Aspergillus versicolor 39,800 100
Total: 39,800
050906BR-07 DG-l 8 Aspergillus versicolor 3,250,000 93
Michelle's Office - Top Penicillhull 178,000 5
surface of carpet along Eurotiunl alllstelodanli 48,500 1
exterior \vall Total: 3,470,000
MEA Aspergillus versicolor 2,170,000 94
Pell iei II hun 113,000 5
Epicaccunl lligrUlJl 16,200 <1
lv/ucar hielllalis 16,200 <I
Total: 2,310,000
CFU - Colony Forming Unit: A distinct colony that forms on a sample plate
CFU/g - Colony forming units per gram of nlaterial
DG-18 - Dichloran Glycerol Agar
IvrEA - ivlalt Extract Agar
Percentage - Percent of Total Organisms Identified
Quick Reference Guideline:
The follo\ving numerical guidelines are utilized in helping evaluate \vhether the level of culturable fungal counts is
suggestive of interior gro\vth, or of deposition from spores that have migrated indoors from the outdoor source,
especially of fungi that are commonly found outdoors such as Cladosporilllll. Other organisms that may be
suggestive of migration from the outdoors include Alternaria, Pitho!11yces, yeasts, and EpicOCCUl11 nigrU111, Fungal
organisms at elevated levels that are associated \vith fungal gro\vth on nloisture impacted building nlaterials
include Aspergillus, Penicilliul11, Chaet0l11iunl, AcrelllOlliulll and Triclzoderl11a.
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Elk River Parks & Recreation
Indoor Air Quality Assessment
IE.;\ Project No. 7805-1301
Page 5
Concentration Qualitative Assessment
(colony formin2 units/2ram) of Funeal Counts in Carpet Dust
< 1 00,000 Not a significant presence of fungal spores.
Ho\vever, there lTIay still be an indication of interior gro\vth if donlinant* or
upper-ranked taxa are associated \vith gro\vth on moisture-impacted building
materials.
100,000 to 1,000,000 Suggestive of Fungal Gro\vth if donlinant* or upper-ranked taxa are
associated \vith gro\vth on moisture-inlpacted building materials.
Or
Suggestive of Migration from the outdoors if dominant taxa are COffiITIOn
outdoor fungi. The greater the fungal count levels, the greater the likelihood
that the carpet should be considered dirty.
> 1,000,000 Indicative of interior Fungal Gro\vth if dominant* or upper-ranked taxa are
associated \vith gro\vth on nloisture-impacted building materials,
Or
Inadequate removal of outdoor fungal spores through cleaning if dominant
taxa are common outdoor fungi.
*For this table, dominant is defined as constituting greater than fifty percent of the total fungal concentration.
. Discussion of Results
Fungal concentrations in the dust collected fronl belo\v the chair nlat in the South\vest Cubicle indicate
the presence of fungal gro\vth on the carpet. Aspergillus versicolor \vas dominant in the sample.
Heavy fungal concentrations \vere present in the dust collected from along the \vall in the South\vest
Office. Aspergillus versicolor \vas dominant in the sample. These results indicate that fungal gro\\/ih
has occurred on the carpet.
4.5 General Indoor Air Quality Parameters
Carbon dioxide, carbon monoxide, ten1perature and relative huntidity levels \vere n1easured in each
complaint area and outdoors for comparison. Results are listed belo\v:
Table 5: GenerallAQ Parameters - May 9, 2006
Location Time No. of Carbon Dioxide I Carbon IVlonoxide Temperature Rela tive
Occ. (CO2) (CO) (OF) Humidity
(ppm) (ppm) (0/0 )
Cubicle Area 2:20 pm 1 605 0 74 43
IYlichelle's Office 2:22 pm 1 I 622 0 74 44
Bill's Office 2:24 pm 1 629 0 74 44
Outdoors 2:25 pm - 359 0 70 43
Ouick Reference Guideline:
At present, indoor air quality regulatory limits do not exist apart from OSHA's Permissible Exposure Linlits (PELs),
\vhich \vere developed for traditional industrial environments and are not a suitable n1easure of good indoor air quality.
The follo\ving guidelines have generally been adopted by the practitioners of indoor air quality.
. Carbon Dioxide (C02)
The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) Standard 62-
1989, Ventilation for Acceptable Indoor Air Quality, recommends as a guideline that indoor CO2 levels do
not exceed over 700 ppm above the outdoor CO2 level. Generally, the number of reported air quality
complaints tends to increase as the CO2 levels climb past 1,200 ppm. If CO2 levels significantly exceed
1,200 ppn1 in occupied areas, additional evaluation should be considered \vhich may include ventilation or
specific contaminant testing.
. Carbon I\Ionoxide (CO)
Recomn1ended indoor air quality guidelines have been proposed to maintain indoor CO levels belo\\' 10 ppm.
Headaches, nausea and dizziness can be reported \vhen CO levels approach and exceed 10 ppm, Ho\vever, in
most indoor environments \vithout a knO\Vll CO source, a CO level of 5 ppm should be considered significant
and additional investigation is \varranted.
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Elk River Parks & Recreation
Indoor Air Quality .A.ssessment
lEA. Project No. 7805-1301
Page 6
. Temperature and Relative Humidity
Temperature and relative humidity levels affect the thermal comfort of an individual. Other factors,
including air speed, activity level, metabolic rate, and clothing also affect thermal conlfort. ASHRAE
Standard 55- I 992 provides recommendations for temperature and relative hunlidity during w"inter nlonths and
sununer months. lEA's guidelines are based on this standard. lEA reconunends that the temperature should
be benveen approxinlately 680F to 750F during the \vinter and 730F to 790P during the summer. lEA
recommends that humidity levels be maintained \vithin the range of approximately 30% to 60%.
. Discussion of Results
Carbon dioxide, temperature and relative hunlidity levels \vere all \vithin the reconunended range. No
carbon monoxide \vas detected.
4.6 Ventilation Measurements
Airflo\v measurenlents and the outdoor air calculation percentages are provided belo\v:
Table 6: Ventilation lVleasurements
Location of Diffuser/Grate Airflo,,, (cfrn) Approximate % Outdoor Air
Supply Air Diffusers
Ross's Cubicle 200 1 I
Terry's Cubicle 200 34
Office to Right of Main Entry 0 N/A
Reception Area 0 N/A
Bill's Office 135 6
Michelle's Office 135 23
Return Air Grates
Office by ivlain Entry 190 N/A
Reception Area 360 N/A
ivlichelle's Office 110 N/A
Bill's Office 90 N/A
. Discussion of Results
Total supply air measured \vas 670 cubic feet per minute (cfnl) compared to 750 cfIn return air. No
airflo\v \vas detected from the nvo diffusers in the front office and reception area. The measuren1ents
suggest that the building may be under slight negative pressure resulting in air infiltration.
Outdoor air percentage in the supply air diffusers ranged from about 6 to 34 percent. The level of
carbon dioxide in the air (see Table 5) indicates that the outdoor air supply is adequate.
5.0 Conclusions & Recommendations
Fungal san1pling results indicate that fungal gro\v1h has occurred on the top and bottom surfaces of the
carpet in the South\vest Cubicle and the South\vest Office. Visible fungal gro\vth \vas observed behind the
base cove along the exterior \vall in the north\vest comer of the South\vest Office and the south\vest corner
of the South\vest Cubicle. Airborne fungal sampling results indicate that the fungal contanlination has
in1pacted air quality in these areas.
Based on TEA's observations and sampling results, the follo\ving actions are reconmlended:
. Fungal-contanlinated carpet and \vallboard should be removed under controlled conditions. Additional
sampling may be necessary to determine the extent of the contamination. If fungal contan1ination is
present in the \vall cavity in the area \vhere fungal gro\vth \vas observed behind the base cove,
insulation \vill need to be removed and the \vall surfaces cleaned and sanitized prior to rebuilding. lEA
can provide a scope of \vork for the fungal abatement, if desired.
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Elk River Parks & Recreation
Indoor A.ir Quality Assessment
lEA Project No. 7805-1301
Page 7
. Controlled conditions, such as physical isolation and negative air pressurization of the abatenlent area,
should be used to protect adjacent areas and individuals from fungal spores that are released \vhen
fungal-contaminated materials are removed. lEA can provide a specification for renloval activities, if
desired.
. The conditions that led to moisture infiltration and resultant fungal gro\vth need to be corrected. If
these conditions are not corrected, fungal contamination \villlikely recur on the replaced materials.
Based on the location and type of fungal organisnlS present, moisture intrusion appears to be occurring
through the lo\ver portion of the exterior \valls and, possibly, through the concrete floor slab.
Please contact lEA if you \vould like further assistance \vith the implenlentation of these reconmlendations.
6.0 Standard of Care
Information provided in this document is based upon current and generally recognized scientific and
technical understanding of the issues presented. Indoor air quality problenls such as sick building
syndrome (SBS) can have many causes and, SOilletimes, these causes are not readily apparent. In addition,
some causes may be illasked or hidden by conditions or activities in the building. As a result, the
conclusions and recon1ll1endations do not guarantee that all factors have been identified and that all issues
\vill be resolved if the recomnlendations are inlplemented. The conclusions and recomnlendations made in
this docunlent are our professional opinion and are based on the observations made and conditions present
at the tinle of the investigation, discussions \vith individuals involved, and the results aftests and/or
measurements perfomled. Follo\ving or implenlenting the recommendations does not provide conlplete
protection from future building occupant irritation or possible health consequences that may be caused by
indoor environnlental conditions. No \varranty is implied or intended.
Sincerely,
Revie\ved by,
{dzitjucbl
rA:S~ie Henckel, erH
Senior Project Manager
Indoor Envirolilllents Division
Tom Kapfer, CIH
Division Manager
Indoor Environnlents Division
Ene.
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Indoor Air Quality Assessment
lEA Project No. 7805-1301
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Appendix I
Laboratory Analysis Reports
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Indoor Air Quality Assessment
lEA. Project No. 7805-1301
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Appendix II
Existing Guidelines
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IE.~ Project No. 7805-1301
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Existing GuidelineslHealth Concerns for Fungi
High levels of fungi in the indoor envirolllllent are kno\vn to cause a variety of hUlllan health concenlS and lllay constitute one
aspect of envirolllilental sensitivity knO\\'11 as "sick building syndrollle." Several fungal species are knO\Vll to be allergenic,
toxigenic and/or pathogenic if present at elevated levels. Ho\vever, the illost conmlon type of response is allergic in nature and
is nlanifested by irritation to the respiratory system and eyes, sneezing, sinus congestion and rhinitis.
The presence offungi on building nlaterials as identified by a visual assessnlent or by bulk/surface sanlpling results does not
necessitate that people \vill be exposed or exhibit health effects. In order for hUlllan to be exposed indoors, fungal spores,
fragment, or ll1etabolites must be released into the air and inhaled, physically contacted (dermal exposure), or ingested.
\Vhether or not SynlptOll1S develop in people exposed to fungi depends on the nature of the fungal matter (e.g., allergenic,
toxic, or infectious), the anlount of exposure, and the susceptibility of the exposed persons. Susceptibility varies \vith the
genetic predisposition (e.g., allergic reactions do not al\vays occur in all individuals), age, state of health, and conCUITent
exposures. For these reasons, and because 11leasurements of exposure are not standardized and biological 11larkers of
exposure to fungi are largely unkIl0\Vn, it is not possible to detem1ine "safe" or "unsafe" levels of exposure in general.(l)
Ho\vever, the follo\ving industry guidelines are helpful in determining if fungal gro\vth/contamination may be a concenl in a
building:
1. Mycologists (nucrobiologists \vho specialize in the study of fungi) and IAQ practitioners generally agree that the health
risks associated \vith exposure to and inhalation of common phylloplane (leaf-associated) fungi, such as species of
Cladosporiunz or Alternaria, is less than that associated \vith exposure to potentially toxigenic or pathogenic fungi such
as the genera Stach.,llbotrys, Aspergillus or Penicilliunl.
2. In 11lechanically ventilated buildings \vith adequate filtration, the American Conference of Governmental Industrial
Hygienists (ACGIH) has indicated that indoor bioaerosollevels should be less than the outdoor levels and the
predonunant species to be sin1ilar. (2) The publication also recomnlends the interpretation ofbioaerosol data based on a
cOlllbination of the follo\ving:
. indoor/outdoor concentration ratios,
. a comparison of species composition indoors and outdoors, and
. the presence of "indicator species" (those that indicate excessive 1110isture or a specific health hazard)
isolated from the indoor environn1ent.
"l
:Y.
Rodac contact plates and s\vab samples are used to assess the level of fungi on a surface \vhere fungal gro\vth or
deposition is suspected. A contact sample plate \vith total colony forming units (CFUlPlate) over 50 signifies ll10derate
fungal levels and over 100 can be considered a heavy level. (3)
4.
For 1vlicrovac bulk dust samples from carpet tops analyzed by a dilution lllethod, the follo\ving nUlllbers are rough rules
of thUlllb used to assess the level of culturable fungal counts (spores). The follo\ving guidelines are utilized in helping
evaluate \vhether the level and composition of culturable fungal counts is suggestive of interior grovvLh, or of the
migration of spores into a building from outdoors, especially of fungi that are conunonly found outdoors such as
Cladosporiullz. Other organisll1S that may be suggestive of migration from the outdoors include Alternaria, Ph0111a,
yeasts, and EpicocCUllZ nigrullz (4). Fungal organisms at elevated levels that are associated \vith fungal gro\vth on
nloisture impacted building ll1aterials include Aspergillus, PenicilliullZ, Chaetonziullz, AcrellzoniullZ and TrichodernzCl.
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lEA Project No. 7805-1301
Page 11
Concentration Qualitative Assessment
(colony forming units/eram) of Funeal Counts in Carpet Dust
< 100,000 Not a significant presence of fungal spores.
Ho\vever, there may still be an indication of interior gro\vth if dominant* or
upper-ranked taxa are associated \vith gro\vth on moisture-impacted building
materials.
100,000 to 1,000,000 Suggestive of Fungal Gro\vth if dominant* or upper-ranked taxa are
associated \vith gro\vth on lTIoisture-impacted building materials.
Or
Suggestive of Migration from the outdoors if dominant taxa are COl1lmOn
outdoor fungi, The greater the fungal count levels, the greater the likelihood
that the carpet should be considered dirty.
> 1,000,000 Indicative of interior Fungal Gro\vth if dominant* or upper-ranked taxa are
associated \vith gro\vth on moisture-impacted building nlaterials.
Or
Inadequate removal of outdoor fungal spores through cleaning if dominant
taxa are C0111nl0n outdoor fungi.
* For this table, dominant is defined as constituting greater than fifty percent of the total fungal concentration.
1. Ne\v Yark City Department of Health, 2000. Guidelines on Assessnlent and Relllediation oj Fungi in
Indoor Enviro1l1nents.
2. ACGIH, 1999. Bioaerosols: Assessnlent and Control, S7.4.2 Fungi
3. American Public Health Association - Committee on Microbial Contanunation of Surfaces (adjustnlent of
guidelines by lEA and N. G. Carlson).
4. Hodgson, Mark and Scott, Richard. "Prevalence of Fungi in Carpet Dust Samples." Page 268-274, Bioaerosols, Fungi,
and Mycotoxins: Health Effects, Assessnlent, Prevention and Control, 1999.
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