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Moistureinbuildingsisverycomplicated.
Microbially-relevantmoistureisevenmorecomplicated.
Roadmap
• Microbiology
• Moisturemeasurement
• Impactofbuilding(officesurfaces)
• Impactofwetting
When/why/howdoesthebuildingmatter?
Abriefhistoryofindoormicrobiologyfromabuildingscienceperspective
• >200yearsago-present:culturing– Advantages:longhistory,“easy”todo,quantitative
– Disadvantages:Presentsaskewedpicture
• ~2000-present:DNAsequencing– Advantages:Muchricherandmorecompleteview
– Disadvantages:Generallynon-quantitative,viability,moreofchallengetoidentifyspecies,hugebioinformaticschallenges
ExampleofChallenge
Hoisingtonetal.(2014)BuildingandEnvironment
MicroorganismsareEverywhere
• Everysurface,everybreath,etc.
• Ingeneral,thisisneithergoodnorbad,withsomeexceptions
“Increasedmicrobialrichnesswasassociatedwiththepresenceofpets…”Dannemilleretal.(2014,2015)IndoorAir
Peopleaddmicroorganismstotheirhomes
Benefits:• Maintainsahealthybalanceofmicrobesinyour
home• 1applicationcovers1000squarefeet• Non-toxic,GMO-free,Gluten-free• Pleasantcitrussmellfromorganicbotanicaloils
http://www.bulletproof.com/homebiotic-concentrate-4oz
“Homebioticisasprayandleaveontreatmentthatlasts6months.Bacterialculturestakeupresidenceandpreventmoldgrowth.”
EvenByScientists
AnInnovativeApproachtoHospitalSanitizationUsingProbiotics:InVitroandFieldTrials LaFaucietal.(2015)JMicrobBiochemTechnol
Onemorething
• Whydowecareaboutmold?– Itsmells
– Itlooksugly
ConnectiontoMoistureandHealth
• Moisturedamagehasanegativeimpactonhealth– e.g.,Mendelletal.(2011)Environ.HealthPersp.
– Wedon’tknowifthismicrobiologicalornot….
• Paradox:– “Increasedmicrobialrichnesswasassociatedwiththepresenceofpets,waterleaks,longerACuse,suburban(vs.urban)homes,anddustcompositionmeasures(P<0.05).”
Dannemilleretal.(2015)IndoorAir
QuestforMicrobialRelevance
• Whatmattersformicroorganisms?• Environmentalconditions
– Smallrangesoftemperature,lightonindoorsurfaces
– Insufficientdata(generally)
• Food– Plentiful(buildingmaterials,soiling,buildingcontents)
• Water
MoistureMeasurements
• Allcommunicate
• Differentmeasurements– Differentrelevance
– Differentchallenges
– Differenttemperatureinteractions
• Wateractivitycannotbemeasuredin-situ
AirRelativeHumidityHumidityRatio
MaterialMoistureContent
Wateractivity
EquilibriumRelativeHumidityAKASurfaceWaterActivityAKAEquilibriumWaterActivity
Moisturedamage=healthproblemMendelletal.(2011)EHP
MoisturetransportwithNMRAdanetal.
PracticalityofMoistureMeasurementinBuildings
Presenceofmoisturedamage
Wateractivity,aw
Equilibriumrelative
humidity,ERH
Relativehumidity,RH
Moisturecontent
PhasesofWaterRelativeHumidity
Ref:http://buildingscience.com/documents/digests/bsd-138-moisture-and-materials
PracticalMeasurementIssues
• Relativehumidity–notverymeaningful
• Wateractivity–can’tbemeasuredin-situatnon-equilibriumconditions
• Equilibriumrelativehumidity–sensorinterfereswithexchangeofmoisturebetweenmaterialandair
• Moisturecontent–doesn’tcorrelatewithwateravailabletothemicroorganism
DedeskoandSiegel(2015)Microbiome
TOWaboveaw=0.8TOWaboveaw=0.7
0.8
0.7
Time
Wateractivity,a
w
AnotherComplexity-Time
Ourgoal:Characterizeofficesfrommanyperspectives
ExperimentalMatrix
• BuildingType:Office• Cities
Flagstaff:SemiaridSanDiego:Mediterranean/AridMediterraneanToronto:HumidContinental
• SurfacesCeilingFloorWall
• MaterialsCarpettileCeilingtilePainteddrywall
• Threeofficesineachcity
MicrobialSamplingFour6-weekseasonalsamplingcampaignsSamplingperiodeveryotherday
CarpettileCeilingtilePainteddrywall
Samplingsitesforrelativedustiness
Equilibriumrelativehumiditysensorsanddatalogger
Occupancysensor
Temperature,relativehumidity,andillumination
sensor
Time-ScaleofSampling
• Allparametersmeasuredevery5minutesforayearineachoffice
• Coincidentalmicrobial(swab)sampleseveryotherdayfor4six-weekseasonalsamplingperiods– Sequencedforbacterialandfungalcommunities
EquilibriumRelativeHumidityRange
Dr=Drywall Ca=Carpet Ce=Ceiling tile
DifferenceBetweenERHandRH
Dr=Drywall Ca=Carpet Ce=Ceiling tile
HumidityTimeSeries1. ThereisalagbetweenRHchangeandERHchange2. Differentmaterialshavedifferentamountsof
differencebetweenERHandRH
VariationAmongSurfaces,Flagstaff
SeasonalityofERH,Flagstaff
SeasonalityofERH,Toronto
0200400600800
1000120014001600180020002200240026002800
Tota
l Tim
e (h
r)
F1W F2W F3W S1W S2W S3W T1W T2W T3WERH RH ERH RH ERH RH ERH RH ERH RH ERH RH ERH RH ERH RH ERH RH
70%65%60%
TimeofWetness
ERH
RH
Communitycompositionswerenotfoundtobeassociatedwithanyindoorormaterialenvironmentalcovariates.Throughoutthisstudy,indoorenvironmentaswellassurfacemicroenvironment(i.e.,sensorsspecificallycollectingdatafromoursamplingswatches)datawerecollected,includingsurfaceandairtemperatures,equilibriumrelativehumidity,relativehumidity,roomoccupancy,andvisible-lightillumination.Despitetheextentoftheseenvironmentaldataandaconsiderableefforttoidentifyassociationsbetweenmicrobialcompositionandthesedata,wefailedtoidentifysignificantassociationsbetweenbuildingscienceandmicrobiomedata.
Chase et al. mSystems 2016;1:e00022-16
BuildingsasDeserts
• JamesScott:“…fewplacesonearthgetashotasarooftoporasdryasthecornerofaheatedlivingroom.”Wired2011
• Chaseetal:“BEsurfacemicrobialcommunitiesmaybehavesimilarlytothosefoundinthesoilsoftheAtacamaDesert,waitingforliquidwatertobecomeactive.”
mSystems2016
OngoingWork
• Non-extremeconditionsmaynotofferalotofdifferentiation
• Microorganismquantitymatterstoo
• Whatmoistureparametersshouldwemeasure?
Whatin-situandpracticalmoisturemeasurementmethodscorrelatewithmicrobialcommunityandmicrobialbiomassondrywallafterwetting?
DrywallWettingProject
• Threescales(coupons,wallsection,in-situ)
• Detailedmoistureassessments
• Quantitativemicrobiology
Name
:Dw
g. No
.:Drn
. By:
Date:
Scale
:Dry
wall S
ample
rJF
-01Gio
vanni B
uzzeo
09/19
/151:1
Mater
ial: 60
61TC
Alum
inum
Quan
tity: 1
Piec
e
60
70
80
90
100Eq
uilib
rium
and
Air
Rel
ativ
e H
umid
ity (%
)
18:40 08:33 22:26 12:20Time
RH ERHERH small volume
0
20
40
60
80
100
Area
of S
urfa
ce c
over
ed b
y W
ater
(%)
60
70
80
90
100Eq
uilib
rium
and
Air
Rel
ativ
e H
umid
ity (%
)
18:40 08:33 22:26 12:20Time
RH ERHERH small volume
Approach
• UV“sterilize”sample
• Biologicalsample1
• Inoculatesamplenaturallyfor30daysinawell-characterizedoffice
• Biologicalsample2
• Wetsampleinsealedchamber
• Biologicalsamples3-7– After1,4,7,14,28days
Notes:Norepeatsampling,nosharedbiologicalandmoisturemeasurement(singlepurposesamples)
Notes:Biologicalsampling=16S/ITS+totalfungalandbacterialqPCR+speciesspecificqPCRfor~20mostabundantspecies
ExperimentalMatrix
• Threescales(coupons,wallsection,in-situ)• Inallcases,characterizednaturalinoculation
–Drywall:Unpainted,painted,moistureresistant,lightweight(highporosity)
–Water:DNA-free,tap,rain–Wateramount:Fixed,doubled,episodic–Post-wetting:Torontowinter,Torontosummer
•Assessingvariancewithtargetedrepetitions•Differentkindsofblanksandcontrols•Samplesareusedonlyonce
Outcomes
• Whatistheimpactofwettingondifferentmeasurementsofmoistureatdifferentconditions?
• Whatistheimpactofwettingonmicrobialcommunityandquantityatdifferentconditions?
PartingThoughts
• Asbuildingscientists,weneedtodomuchbetteratconductingmicrobially-relevantmeasurements.
• Abigcomponentofthisisassemblingahighly-spatiallyresolvedmeasurementoflong-termadsorbedandliquidwater.
• Peoplewill(are)tryingtoadjusttheindoormicrobiome–thisisgoingtocauseuslotsofheadachesinthefuture.
Acknowledgements
• UofTGraduatestudents:SandraDedesko,MahnazZare,BabakKhamsehi,PhilFan,AmyLi,MasihAlavy
• Undergraduatestudents:RyanWilliams• FacultyCollaborators:GregCaporaso,ScottKelly,RobKnight,JamesScott,BrentStephens,JackGilbert,DerekSonderegger
• StudentCollaborators:JohnChase,JenniferFouquier
• Funding:AlfredP.SloanFoundation
Otherthingswelearned
• “Thesequencingruncanbeanimportantconfoundingfactorinlong-termtemporalstudiesofbacterialcommunities.”
• “Acrossallnineoffices,humanskinbacterialcommunitieswerethelargestidentifiablesourceoftheofficebacterialcommunitysamples,withatleast25to30%oftheofficesurfacemicrobiomebeingderivedfromhumanskin.”
Challenges
• Unintendedconsequences
• Buildingcomplexity
• Continuousmonitoringandmaintenance
UnintendedConsequences-1
“Increasedmicrobialrichnesswasassociatedwiththepresenceofpets…”Dannemilleretal.(2014,2015)IndoorAir
“…petallergenlevelswere13timeshigherinschoolscomparedtohomeswithoutpets.” Kropetal.(2014)PLoSOne
UnintendedConsequences-2
Kembeletal.(2012)ISMEJournal
Thephylogeneticdiversityofairbornebacterialcommunitieswaslowerindoorsthanoutdoors,andmechanicallyventilatedroomscontainedlessdiversemicrobialcommunitiesthandidwindow-ventilatedrooms.
BuildingComplexity-Failures
“In80%ofthehouses,signsofcurrentorpreviousmoisturefaultwereobserved.”Nevalainenetal.(1988)IndoorAir
LemieuxandTotten(2004)ASHRAEBldg.IXConf.Proc.
Whyisthisanissueforbioinformeddesign?
• Moisturedamageinfluencesindoormicrobialcommunitiesandquantities
• Negativeimpactonhealth– e.g.,Mendelletal.(2011)Environ.HealthPersp.
• Paradox:– “Increasedmicrobialrichnesswasassociatedwiththepresenceofpets,waterleaks,longerACuse,suburban(vs.urban)homes,anddustcompositionmeasures(P<0.05).”
Dannemilleretal.(2015)IndoorAir
BuildingComplexity-Maintenance
• Weoftenmakeadecisiontonotmaintainorcontrolourbuildingsappropriately
• Addingmicroorganismsincreasescomplexityconsiderably
MaintenanceRequiresSampling
• …..quantitativesampling
Hoisingtonetal.(2014)BuildingandEnvironment
DermentshtrakhtunGotlakht
Manplansandgodlaughs
Doesthismeanweshouldn’tdoanything?
1. Hypothesisdrivenresearchwithappropriatecontrols
2. Specificandtargeted
3. Planforfailure
4. Balancewithothergoals
5. Commissionandmaintain
6. Planformonitoring
LemieuxandTotten.(2004).Theimportanceofbuildingenvelopecommissioningforsustainablestructures.ASHRAEBuildingsIXConferenceProceedings1-12.
Whatis(potentially)importanttothemicroorganisms?
• Energyflows Whatisthewallstructure?Globallyandlocally?Howmuchinsulation?Whatisthetemperatureontheotherside?Isitconnectedtootherpartsofthebuilding?Whatisthesurfacetemperature?
Source:http://buildingscience.com,http://quiktherm.com/insulatesmart/wp-content/uploads/2014/10/Thermal-Bridging.jpg
Whatis(potentially)importanttothemicroorganisms?
• Energyflows(temperaturedoesn’ttellusthat)
• Availablemoisture
Whatisthesurfacetemperature?Whatisthewallstructure?Globallyandlocally?Howmuchvapourdiffusion?Whatisthevapourpressureontheotherside?Isitconnectedtootherpartsofthebuilding?Istherecondensation?Howmuchmoistureisatthesurface/inthematerial?
Whatis(potentially)importanttothemicroorganisms?
• Energyflows(temperaturedoesn’ttellusthat)
• Availablemoisture(RHdoesn’ttellusthat)
• Materialpropertiesofdrywall(alldrywallisdifferent)
Howmanylayersofpaint?
Whatkindofpaint?
Isthereapaperlayer?
Whatkindofadhesive?
Whatkindofgypsum?
Whatotheradditives?
Whatarebulkmaterialproperties(porosity,density,etc.)?
WhatItakefromthis
• Weneedtodoquantitativemicrobiology
• Weneedtounderstandmoistureinbuildingsinamuchmoresophisticatedway
QuestforFunctionalRelationships
• Weoftendon’thavequantitativedata– Relativeabundance
• Weoftendon’thavespecies-leveldata
• Wealmostneverhavetime-resolveddata
• Weoftendon’thavethebuildingcharacterizationdoneinamicrobial-relevantmanner
