Guide for interpreting reports from inspections ...

1 Guide for interpreting reports from inspections /investigations of indoor moldEditor: W. Elliott Horner, PhD, FAAAAI,aContributors: Charles Barnes, PhD,bRosa Codina, PhD, FAAAAI,cand Estelle Levetin, PhD, FAAAAIdAtlanta, Ga, Kansas City, Mo, Lenoir, NC, and Tulsa, OklaInspections and testing of indoor environments for moldgrowth increased dramatically in the past decade. Allergistscan now be presented copies of reports and laboratory dataand asked to provide an interpretation, although allergists areseldom trained to review environmental data. There is nosingle sampling method that is both specific for mold growthand robust enough to reliably detect mold growth. There is nostandard method for these inspections or testing and no widelyrecognized credential for investigators, and therefore reportsalso vary in quality, objectives, and thoroughness. Despitethese issues, observations from informed inspections coupledwith results from qualified analyses of samples that arecollected with a useful strategy can usually indicate whethermold growth is present in a building, but the nature of thereport should be assessed before any interpretation of theresults and data are attempted.

2 This rostrum discussesobjectives of inspections , describes qualifications forinvestigators, outlines the limitations of various samplingmethods applicable to mold and to some degree endotoxin, andprovides guidance for data interpretation. (J Allergy ClinImmunol 2008;121:592-7.)Keywords: mold , testing, indoor air, investigation , inspectionMold growth occurs in damp buildings, and ample evidenceindicates that respiratory complaints are increased among occu-pants of damp of mechanism, the long-established damp building effect on respiratory symptomsremains ,3 Recent studies actually extend thedamp building effect beyond triggering symptoms to actuallyinciting new cases of ,5If corroborated, this effect willfurther increase the demand for building inspections and inturn increase the need for allergists to interpret and understandreports of such references cited above extensively discuss the healtheffects associated with and/or alleged to result from exposure toindoor mold growth; further discussion is beyond the scope of thisrostrum.

3 A Guide for primary care physicians pertaining to indoormold and a booklet for the lay public from the American Societyfor Microbiology are referenced among theOnline Repositorymaterials (available ). The purpose of thisrostrum is to provide the practicing clinician with guidance onthe practical objectives and methods commonly used in buildinginspections for mold , as well as a discussion of the uses and con-straints of testing (sampling) and the reasonable interpretation MYCOLOGYF ungi are eukaryotic organisms that are neither plant noranimal but are members of a separate thanyeasts, fungi are composed of multicellular, thread-like hyphae;aggregated hyphae are called a mycelium. Fungi reproducethrough spores. Depending on the species, spores can be producedby ordinary hyphae or on specialized hyphae, often within fruitingbodies. In the majority of fungi, the spores are adapted for air-borne spores are abundant in outdoor airfrom early spring through fall and occur year-round in mild cli-mates.

4 Additional mold resources are listed in theOnline major taxonomic groups of fungi are the zygomycetes,ascomycetes, and forms of ascomyce-tes (and a few basidiomycetes) produce asexual spores called co-nidia; these forms comprised the obsolete group familiar allergenic fungi, such asAlternaria,Aspergillus,Cladosporium,Cu rvularia,Drechslera,Fusarium, andPenicil-liumspecies, are conidial forms of secrete various hydrolytic enzymes and can colonizediverse materials, including many wood-based building of the common airborne fungal spores are producedbyCladosporium,Alternaria, andEpicoccumspecies that colo-nize leaf surfaces (phylloplanes).Outdoor airborne spores infiltrate through doors, windows,outdoor air intakes on mechanical ventilation systems, and tinycracks between walls and windows. Spores can also enter on thesurface of people, shoes, clothing, or pets.

5 The spores, especiallyfrom phylloplane fungi that infiltrate a building and settle out indry dust without germinating, have been called tabletopmolds. 8 However, colonization can occur indoors whenFromaAir Quality Sciences, Atlanta;bChildren s Mercy Hospital, Kansas City;cGreerLaboratories, Lenoir; anddthe University of Tulsa, of potential conflict of interest: W. E. Horner owns stock in and is employedby Air Quality Sciences, Inc; has served as an expert witness in litigation; and hasserved on ASTM technical committees pertaining to mold analysis. C. Barnes hasconsulting arrangements with Clorox Corporation, owns stock in Coca-Cola Corpo-ration and Rock Acres LLC, and has received research support from CloroxCorporation, the US Environmental Protection Agency, and the US Department ofHousing and Urban Development. R. Codina is employed by Greer Levetin is employed by the Biology Department of the University of Tulsa, whichoccasionally analyzes indoor air samples for local indoor air companies, and hasserved as an expert witness in fungal for publication October 17, 2006; revised July 22, 2007; accepted for publica-tion November 27, online February 13, requests: Elliott Horner, PhD, Air Quality Sciences, 2211 Newmarket Parkway,Marietta, GA, 30067.

6 2008 American Academy of Allergy, Asthma & usedCFU: Colony-forming unitsHVAC: Heating, ventilation, and air conditioningMVOC: Microbial volatile organic compound592sufficient moisture is present. It is critical to distinguish betweentabletop molds and colonization when interpreting sampling is required for spores to germinate, develop mycelia,and colonize an indoor substrate. Almost any damp or wet material,such as carpeting, upholstered furniture, gypsum wallboard,ceiling tiles, wood products, shower walls and curtains, and pottedplants, all can be colonized. Although central heating, ventilation,and air-conditioning (HVAC) systems with in-duct filters willremove many airborne spores, fungi can grow on air filters or oninsulation lining the interior of air-handling units or air fungi can amplify indoors; among the most commonlyidentified are species ofCladosporium,Penicillium, andAspergil-lus.

7 In addition, several species are known to be associated withextensive water damage, includingAspergillus versicolor,Sta-chybotrys chartarum,Chaetomium globosum, andUlocladiumchartarum. The last 3 are especially common on pullulansand other yeast-like fungican also proliferate in, for example, humidifier reservoirs, wetHVAC ducts, saunas, and whirlpool bathtub OF THE INSPECTOR/INVESTIGATORNo current credential is widely recognized for inspectingbuildings for water damage and mold growth. Independent tradegroups issue credentials for mold inspection , and some states arebeginning to require certifications/licenses, but the rigor of theseprograms remains for mold growth in buildings should understandmoisture, building construction, sampling techniques, and how tointerpret analytic results. Most importantly, they should recognizethe boundary between the environmental assessment of a buildingand a medical diagnosis; that is, the discovery of mold growth in abuilding does not always explain occupant symptoms.

8 Physiciansshould recognize this latter point also and avoid relying solely onpatient information to determine that buildings are the cause ofsymptoms: patients observations of conditions in their workplaceare not always reliable indicators of mold useful to identify a qualified inspector should addresstraining, experience, and practices. What specialized study orprofessional certification do they have or additional training havethey sought outside their original field? Do they rely primarily onsampling or emphasize inspection ? How long have they beenconducting inspections , how often do they inspect buildings, andwhat type or types of building or buildings do they inspect? Dothey have experience sampling, and what is their rationale fordetermining when sampling is appropriate? Do they typicallyprepare a written report , and what information is included?

9 PURPOSE OF inspection /INVESTIGATIONT hree reasons for concern about fungal growth indoors are (1)health effects, (2) rot of the building s structure, and (3) depre-ciation caused by the mold sight or smell. Mechanisms involvedin adverse health effects in damp buildings remain contentious,but most agree that a smelly, moldy building suffers structuraldamage and is not a desirable place to live or work. Perspectivemust be maintained, though, to distinguish between small areas ofmold growth in a shower or on a refrigerator gasket and largeareas of colonization caused by a systemic building physical inspection of the building is the most importantpart in any investigation of suspected mold growth indoors, and itshould have a clear and specific purpose. To determine whetherthe building is safe is too vague and subjective a purpose to beuseful. The purpose might be to determine whether mold colo-nization is present, to locate areas of mold growth, to determinewhether mold growth has affected the indoor air quality, or toassess whether colonized material was successfully removedfrom an area and associated dusts adequately cleaned.

10 Samplingmight be needed or might be superfluous for any particularinspection. Information obtained from sources other than theinvestigator should be so goal of sampling should be to test hypotheses developed aspart of the ,10 The null hypothesis is typically that a particular building has normal and typical types and amounts of airborne mold sporesor that no colonized building materials or contents are observing mold colonies disproves the latter. Addressingthe former needs results from air samples collected with appro-priate strategy and analyzed , no standardized protocols are available for samplingor interpreting results, and therefore recognized and validatedsampling and analytic methods and equipment should be usedwhere common strategy is to collect air samplesfromproblem/complaintareas,nonpro blem/noncomplaintareas, and outdoors.