Indoor Environmental

Quality

THAD GODISH

Indoor Environmental

Quality

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Preface

Indoor Environmental Qu

author over the past dissues associated with oindustrial indoor enviroauthors previous work

ings: Definition, Diagnos

Most important,

In

search scientists and otof indoor environmentused to investigate andof study. The published around the world are thfindings and thoughts infor use in the classroom

The author has prevwhose purpose was toment concepts and issue

Control

focused on the used to control indoor c

Mitigation

was more naof intensive public heal

Indoor Environmenta

like

Air Quality

(3rd ediserve as the genesis forenvironmental health aand other parts of the w

Indoor Environmenta

viduals who are enterinbe research, governmenpurpose by defining thefacts in a highly readabby educated laypersonsmental problems and hronmental problems in ality is the third in a series of books written by theecade and focuses on environmental problems andur homes, office buildings, schools, and other non-nments. This book differs in several ways from thes, Indoor Air Pollution Control (1989) and Sick Build-

is, and Mitigation (1995).door Environmental Quality reflects the success of re-her investigators in defining the nature and causesal health and comfort problems, and the measures control them. It reflects an increasingly mature fieldresults of well-focused, careful research of colleaguese lifeblood of the author who labors to distill theirto a review article, reference book, or a text designed.iously published review articles and reference books

describe major indoor air quality/indoor environ-s and associated research results. Indoor Air Pollutionbroad area of indoor air quality and the measuresontaminants. Sick Buildings: Definition, Diagnosis, andrrowly focused on problem/sick buildings, an areath and scientific interest.l Quality is written in the style of a textbook, muchtion), also by the author. It is anticipated that it will the establishment of indoor environment courses innd industrial hygiene programs in North Americaorld.

l Quality is intended as a primary resource for indi-g, or are already in the field, whether their interest

tal service, or private consulting. It accomplishes this major issues and concepts and providing supportingle manner. Its readability makes it suitable for use who want to learn about specific indoor environ-ow to diagnose and mitigate them, or indoor envi-

general.

By its title, the bookquality and inhalation edoor environment healthair environment, in sevroute of exposure. This iappears to be primarilytransfer of lead-contamiexposures, including denated house dust. Exposand other printed papemight be due to dermaattempts to expand its f

Readers of

Indoor E

concepts and issues treanew work. That is due ciples continue to be imthem may change. seeks to go beyond the historical focus on indoor airxposures to indoor contaminants. Though most in- and comfort concerns are associated with the indoor

eral major cases air appears not to be the primarys particularly true in pediatric lead poisoning, which due to exposures associated with hand-to-mouth

nated house dust and soil particles. Similar childhoodrmal exposures, may occur with pesticide-contami-ures to office materials such as carbonless copy paperrs may cause indoor air quality-type symptoms thatl and not inhalation exposures. As such, the bookocus beyond indoor air quality issues.nvironmental Quality will notice that many of theted in previous reference works are included in thisin good measure to the fact that concepts and prin-portant over time while the facts used to elucidate

About the

Thad Godish

is Profesagement at Ball State Unfrom Pennsylvania Statfor Air Environment St

Dr. Godish is best

Quality

, a widely used reference books on ind

1989) and

Sick Building

and his research, teachiindoor air/indoor enviweb site entitled Indoorprovides expert answermental quality concerns

Dr. Godish continueincluding air quality, intrial hygiene, asbestos waste operations and eWaste Management Assas a member of the AConference of Governmof Indoor Air Quality aCentral section and IndiHe has been Visiting Scand at Harvard Univerauthor

sor of Natural Resources and Environmental Man-iversity, Muncie, Indiana. He received his doctorate

e University, where he was affiliated with the Centerudies.known for his authorship of Lewis Publishers Airtextbook now in its third edition; two well-receivedoor air quality: Indoor Air Pollution Control (Lewis,s: Definition, Diagnosis, and Mitigation (Lewis, 1995);ng, and public service activities in various areas ofronmental quality. He maintains a weekly updated Environment Notebook (www.bsu.edu/IEN), whichs and advice on a wide variety of indoor environ-.s to teach a variety of environmental science coursesdoor air quality management, occupational/indus-

and lead management in buildings, and hazardousmergency response. He is a Fellow of the Air andociation and the Indiana Academy of Science, as wellmerican Industrial Hygiene Association, Americanental Industrial Hygienists, and International Societynd Climate, and has served as chairman of the Eastana chapter of the Air Pollution Control Association.ientist at Monash University, Gippsland, Australia,

sity, School of Public Health.

Contents

Chapter 1 Indoor env

I. Indoor contamII. Characteristic

A. PopulaB. OwnersC. BuildinD. ConstruE. Age anF. Site chaG. OccupaH. Exposu

III. CharacteristicA. BuildinB. Access C. BuildinD. BuildinE. OccupaF. Exposu

IV. Other indoor A. Motor vB. CommeC. TrainsD. ShipsE. Submar

Chapter 2 Inorganic c

I. AsbestosA. MineraB. AsbestoC. AsbestoD. Health

II. RadonA. Soil souB. Groundironmentsination problems

s of residential buildingstion servedhip statusg typesction characteristics

d conditionracteristicsnts and occupant behaviorre concernss of nonresidential buildingsg functions and populations servedand ownership statusg types and construction characteristicsg operation and maintenancent densities and activitiesre concernsenvironmentsehiclesrcial airplanes

ines and space capsules

ontaminants: asbestos/radon/lead

l characteristicss-containing building materialss exposureseffects

rces/transport

water

C. BuildinD. Radon E. Health F. Risk as

III. LeadA. Lead inB. Blood lC. Health

Chapter 3 Combustio

I. Vented combuA. Flue-gaB. Wood-b

II. Unvented comA. CookinB. Gas andC. Gas stoD. Gas fire

III. MiscellaneousA. TobaccoB. CandleC. PropanD. PropanE. Ice resuF. Arena eG. EntrainH. Re-entr

IV. Health concerA. CarbonB. IrritantC. NitrogeD. CarcinoE. EnvironF. Biomas

Chapter 4 Organic co

I. AldehydesA. SensoryB. FormalC. AcetaldD. AcroleiE. Glutara

II. VOCs/SVOCsA. VOCs iB. VOCs ig materialsconcentrationseffectssessment

the indoor environmentead levelseffects

n-generated contaminantsstion appliancess spillageurning appliancesbustion systems

g stoves in developing countries kerosene heating appliances

ves and ovensplaces sources smoking

s and incensee-fueled burnisherse-fueled forkliftsrfacing machinesventsmenty of flue gasesns and health effects monoxidesn oxidesgens and cancermental tobacco smoke

s cooking

ntaminants

irritationdehydeehydenldehyde

n residential buildings

n nonresidential buildings

C. SourcesD. PolyvalE. SVOCsF. Health G. Indoor

III. PesticidesA. BiocideB. FungiciC. InsecticD. Indoor

Chapter 5 Biological bacteria; viruses; aanimal allergens

I. Illness syndroA. ChronicB. AsthmaC. Hypers

II. Bacteria and vA. BacteriaB. Viruses

III. Settled organiIV. MitesV. InsectsVI. Animal allerg

A. Cat alleB. Dog allC. Rodent

VII. Passive allerge

Chapter 6 Biological

I. Biology of moA. ReprodB. DispersC. NutritioD. EnvironE. Classifi

II. Biologically siA. MVOCB. Fungal

III. Exposure asseA. OutdooB. Indoor

IV. Health concerA. Infectio/emissionsent alcohols and their derivatives

effectsair chemistry

sdesidesexposures and levels

contaminants illness syndromes;nd exposures to insect, mite, and

mes allergic rhinitis

ensitivity pneumonitisiruses

c dust

ensrgensergens allergensn transport

contaminants moldlductionalnmental requirements

cationgnificant fungal compoundsstoxinsssmentsr prevalenceprevalencens

ns

B. AllergeC. Nonalle

V. Mold infestatiA. High reB. Cold floC. CondenD. Water iE. PlumbiF. Other s

Chapter 7 Problem bu

I. Building illnesA. BuildinB. Work-rC. Sick buD. Sick/tig

II. Field investigaA. NIOSH

III. Systematic buprevalence

IV. Work performV. SBS-type sym

A. PersonaB. PsychoC. TobaccoD. EnvironE. Office mF. BuildinG. Exposu

contam

Chapter 8 Investigati

I. Awareness anA. ResidenB. Nonres

II. Conducting inA. ResidenB. Nonres

Chapter 9 Measurem

I. Measurement A. SamplinB. SamplinC. SamplinD. Samplinnic and immunological illnessrgenic illness

on risk factorslative humidityorssation

ntrusionng leaks and floodingources of indoor mold contamination

ildingss conceptsg-related illnesselated illness and symptomsilding syndromeht/problem buildingstions investigationsilding investigations symptom

ance and productivityptom risk factorsl characteristics

social phenomena and factors smokingmental factorsaterials and equipment

g furnishingsre to specific vapor- and particulate-phaseinants

ng indoor environment problemsd responsibilitytial buildings

idential buildingsdoor environment investigationstial investigations

idential investigations

ent of indoor contaminantsconsiderationsgg objectivesg airborne contaminants

g bulk materials/surface contaminants

E. Measurenviron

F. SamplinII. Source emissio

A. LaboraB. EmissioC. Full-scaD. IAQ mo

Chapter 10 Source co

I. PreventionA. Manufa

improvB. ConsumC. DesignD. Buildin

II. Mitigation meA. Source B. Source C. Climate

III. Contaminant-A. AsbestoB. LeadC. Biologi

Chapter 11 Ventilatio

I. Natural ventilA. Stack eB. WindC. InfiltratD. Leakag

II. Measuring buIII. Mechanical ve

A. GeneraB. Local e

Chapter 12 Air cleani

I. Airborne partA. FiltratioB. ElectrosC. PerformD. Use con

II. Gas/vapor-phA. AdsorpB. Activating common contaminants in indoormentsg biological aerosolsns characterization

tory methodsn rates and rate modelingle studiesdeling

ntrol

cturing safe products and productementer avoidance

ing and constructing healthy buildingsg operation and maintenanceasuresremoval and replacementtreatment and modification control

specific source control measuress

cal contaminants

nationffect

ion and exfiltration air exchange ratese characteristicsilding air exchange ratesntilationl dilution ventilationxhaust ventilation

ngicles and dustsntatic air cleanersance measurementsiderationsase contaminantstion

ed carbons

C. ChemisD. PerformE. AbsorpF. Room tG. BotanicH. Ozonat

III. Air cleaners a

Chapter 13 Regulator

I. IntroductionII. Regulatory co

A. Air quaB. EmissioC. ApplicaD. ProhibiE. WarninF. Compu

evaluatIII. Regulatory ac

A. AsbestoB. LeadC. FormalD. SmokinE. OSHA F. Other a

IV. NonregulatoryA. Health B. VentilatC. Public hD. PerformE. GovernF. CitizenG. Public iH. Civil litorptionance studies

tionemperature catalystsal air cleaningions contaminant sources

y and nonregulatory initiatives

nceptslity standardsn standardstion standards

tive bans and use restrictionsgslsory HVAC system performanceionstions and initiativess

dehydeg in public placesactions and proposalsctions and authorities approaches

guidelinesion guidelinesealth advisoriesance guidelines and requirements

mental voluntary initiatives initiativesnformation and education programsigation

To the scientists, engiefforts make our indooDedication

neers, architects, and other professionals whose r environments healthier and more comfortable.

chapter one

Indoor env

Humans in developed from depending on rockfrom the elements to mbuildings that provideneeds of shelter convof weather and climate

Our world is one osmall to grand shells thities; institutional buildiernment buildings; autoportation as well as shetrade goods and servicethat provide venues for

Built environmentsof course, forms. In addhuman aspirations and csuch as the diversity acultural tastes, and hum

We attempt to keep provide and maintain wprovide cooler and morically ventilate our largated with human bioefother aspects of indoor climate-control technolo

The built environmperil from forces by whwater, ice, and wind lelevel what man has builironments

countries have, in the past few millennia, advanced shelters, caves, and rude huts to protect themselvesodern single- and multifamily dwellings and other

amenities and conveniences far beyond the basiceniences that ensure comfort whatever the vagaries

.f the structures that shelter our many activities: theat house a myriad of industrial processes and activ-ngs such as schools, universities, hospitals, and gov-mobiles, trains, planes, and ships that provide trans-lter; shopping malls and office complexes where wes; and cinemas, theaters, museums, and grand stadia entertainment. comprise a diversity of functions, magnitudes, and,ition to functional aspects, built environments reflectreativity. They also reflect more fundamental factors,nd availability of construction materials, climate,an foibles.

rain, snow, and wind out of our indoor environments;arm thermal conditions in seasonally cold climates;

e acceptable conditions in hot climates; and mechan-er buildings to reduce odors and discomfort associ-fluents. Our ability to control thermal comfort andenvironments requires the application of a variety ofgies and a commitment to operate them properly.

ents of man are fragile artifacts. They are in constantich the earth renders all things unto itself. Just as

vel the mountains with time, so too do they act tot. Though the forms of ancient temples and buildings

remain after millennia, activities. Wooden struchave been turned to moand the forces of wind atures. They may even afbook of Leviticus in th

house and what is to be

If the prieston the wallsdish depresssurface of thefor seven dareturn to exainfection hasinfected stonplace outsideshall be scrapoff shall be dcity. Then neplace of old sand plastered

Though we design ban often hostile outdooperfect. They are subjerandomness inherent inthe law of unintended c

As we attempt to pconveniences that makeently and in other casethat have the potential tto significant health risk

Indoor environmenhazardous substances, ahumans discovered the and huts, they subjectedden of wood smoke (nooping countries) and atlogical contaminants sucommensal organisms (human disease and sufwithin the context of infand bubonic plague, illcan be seen as relativelythey have long ceased to shelter humans and theirtures that housed humans for much of our historyuld. Indeed, the contagion of decay, fed by neglectnd water, constantly imperil even our newest struc-

fect our health and make our dwellings unclean. Thee Old Testament of the Bible describes a leprous done about it.

, on examining it, finds that the infection of the house consists of greenish or red-ions which seem to go deeper than the wall, he shall close the door of the houseys. On the seventh day, the priest shallmine the house again. If he finds that the spread on the walls, he shall order thees to be pulled out and cast in an unclean the city. The whole inside of the houseed, and the mortar that has been scrapedumped in an unclean place outside the

w stones shall be brought and put in thetones, and the new mortar shall be made on the house.

uildings and other structures to provide shelter fromr environment, the shelter they provide is less thanct not only to the forces of nature, but also to the the second law of thermodynamics or its derivative,onsequences.rovide both shelter and those many amenities and life more comfortable, we, in many cases inadvert-s deliberately, introduce a variety of contaminantso diminish the quality of our lives or pose moderates to occupants.ts are often contaminated by a variety of toxic ors well as pollutants of biological origin. When earlyutility of fire and brought it into rock shelters, caves, their sheltered environments to the enormous bur-

t much different from modern cooking fires in devel-tendant irritant and more serious health effects. Bio-ch as bacteria, mold, and the excretory products ofe.g., dust mites, cockroaches, mice, etc.) have causedfering for most of human history. However, viewedectious and contagious diseases such as tuberculosisness caused by asthma and chronic allergic rhinitis

minor.

In advanced countseveral decades aboutpotential exposure riskand contemporary concair pollution, water poof our environment anddioxin, etc.

Other factors have tamination of built envsignificant public healthealth hazards of asbestother buildings, and thand private schools for renovation/demolition;aldehyde (HCHO) expedehyde foam-insulatedvariety of formaldehyproducts were used; (3schools have elevated rcant risk of lung canceenergy-reducing measu1970s, including reduciings, using alternativestoves and furnaces antration into buildings; (of buildings in the U.S(6) progressive awareneits association with houunderstanding that biolmold, dust mites, pet dahuman asthma and chr

I. Ind

The contamination of inmon to all built environindustrial environmentucts manufactured. Theare subject to regulatorgrams in most developtional exposures are siindoor air quality and cerns in this book.

Indoor air quality institutional buildings, ries, increasing concern has developed in the past contaminants in our building environments ands to occupants. These have grown out of previousern for the health consequences of ambient (outdoor)llution, hazardous waste, and the general pollution food with toxic substances such as pesticides, PCBs,

also conspired to increase our awareness that con-ironments (particularly indoor air) poses potentiallyh risks. These have included: (1) recognition of theos and its widespread presence in schools and manye regulatory requirements for inspection of publicasbestos as well as its removal prior to any building (2) recognition of the significant exposure to form-rienced by residents of mobile homes, ureaformal-

(UFFI) houses, and conventional homes in which ade-emitting ureaformaldehyde resin-containing) recognition that residential buildings and some

adon levels (thought high enough to carry a signifi-r); (4) the apparent consequences of implementingres in response to increased energy prices in the midng ventilation air in mechanically ventilated build- space heating appliances such as wood-burningd unvented kerosene heaters, and reduced air infil-5) an eruption of air quality complaints in hundreds. following changes in building operation practices;ss of the problem of childhood lead poisoning andse dust from lead-based paint; and (7) an increasingogical contaminants of the indoor environment, e.g.,nders, cockroach excreta, etc., play a role in causing

onic allergic rhinitis.

oor contamination problemsdoor air and horizontal surfaces (by dusts) is com-ments. Such contamination is most pronounced in

s where raw materials are processed and new prod-se environments pose unique exposure concerns andy control and occupational safety and health pro-ed countries. Though industrial and other occupa-gnificant, they are not included in discussions ofindoor environmental (IAQ/IE) contamination con-

as it relates to residential, commercial, office, and

as well as in vehicles of transport, is its own unique

public health and policby lead, pesticides and concerns are, by definit

Indoor environmennonresidential structureresidential buildings, ocments, which are owneand lessees have some denvironments in whichducted within, and howtial and nonresidential IAQ/IE problems and differ in how problem inconducts such investigIAQ/IE problems treateand nonresidential buil

II. Charac

Residential buildings cathey serve, (2) ownershteristics, (5) heating andand occupant behavior,

A. Population served

Residential dwellings athey must provide shelincludes individuals rawhose health status vaand infirmities, and whindoors. In the U.S., onwith approximately 14

Those who spend till or infirm, or those no

B. Ownership status

Approximately 70% of tings, while 30% lease thagencies. This significunique among nations.

Ownership status isIt is widely accepted thresponsibility and pridresult in better buildingy issue, as is the contamination of building surfacesother toxic, hazardous substances. As such, IAQ/IEion, limited to nonindustrial indoor environments.t problems, as they are experienced in residential ands, tend to have their own unique aspects. In non-cupants have little or no control over their environ-d and managed by others. In theory, homeownersegree of freedom to modify (for better or worse) the they live. Because of the nature of activities con- buildings are constructed and maintained, residen-buildings often differ significantly in the nature ofassociated health risks. These building types alsovestigations are conducted and, in many cases, who

ations. Because of the differences described above,d here are described in the context of both residentialt environments.

teristics of residential buildingsn be characterized in the context of (1) the populationip status, (3) building types, (4) construction charac- cooling systems, (6) site characteristics, (7) occupants and (8) exposure concerns.

re different from other built environments becauseter for everyone, i.e., an enormous population. Thisnging in age from infants to the elderly, individualsries from healthy to a variety of ailments, illnesses,o spend anywhere from a few to 24 hours per day average, individuals spend 22 hours/day indoors,to 16 hours at home.he most time at home are the very young, very old,t employed outside the home.

he U.S. population resides in occupant-owned dwell-eir residence from private individuals or governmentant private ownership of individual dwellings is

an important factor as it relates to IAQ/IE concerns.at home ownership carries with it both individuale. Such responsibility and pride can be expected to maintenance, reducing the potential for problems

such as extensive watehome ownership can, ibles), increase the proba(e.g., indiscriminate pematerials; or engaging isalons, silk screening, oor building surface con

Home ownership IAQ/IE issues arise. Ifradon levels, significanexposure to young childsuch problems at their party, occupants must problem, seek alternativ

C. Building types

There are two basic typple-family dwellings. detached from other recondominiums blur thegle large structures thaSingle-family dwellingsareas and older parts oof urban areas and arewell. Because of the limings are the primary forpopulated countries.

Single-family resideon site. In the U.S., ma

Figure 1.1

Single-family r damage and mold infestation. On the other hand,n many cases (because of human attitudes and foi-bility that home contamination problems will occursticide application or storage of toxic/hazardous

n commercial activities or hobbies, e.g., hair dressingr wood refinishing, that could cause significant air

tamination).is a significant decision-determining factor when a dwelling is discovered to have excessively hight mold infestation, or a high potential for lead dust

ren, homeowners have the opportunity to mitigateown expense. If the dwelling is owned by a secondconvince an often reluctant lessor to mitigate thee housing, or live with it.

es of residential structures: single-family and multi-Typically, single-family dwellings (Figure 1.1) aresidential structures (although some row houses and line); multifamily dwellings are constructed as sin-t provide 2 to >1000 leased individual apartments. are characteristic of American rural and suburbanf cities. Multiple-family dwellings are characteristic becoming increasingly common in other areas asited availability of building sites, multifamily dwell-m of housing used by families in cities and densely

nces may be site-built or manufactured and placednufactured houses (Figure 1.2) comprise approxi-owner-occupied home.

mately 10 million housihomes, double-wides, described as mobile howheels which are part houses differs significanare designed to providemploy lower cost mastructed than site-builtweather-related damagerected on substructuresimplicity of design.

Multifamily dwellinstructures. In most instaings are always site-buineering considerations.

Figure 1.2

Mobile or man

Figure 1.3

Multiple-faming units. These are often described as trailers, mobilemodulars, and, increasingly, prebuilts. Most aremes because they are transported on a frame andof the structure. The construction of manufacturedtly from that of site-built houses because the formere lower cost, more affordable housing. They oftenterials and have, in the past, been less well-con- houses. They are more vulnerable to wind ande and are usually less well-insulated. Prebuilts ares and differ from site-built homes primarily in their

gs (Figure 1.3) vary from single-story to multistorynces, ownership is second-party. Multifamily dwell-lt, with building materials that reflect cost and engi-

ufactured home.ly dwelling.

D. Construction char

Residential buildings vincluding size, design, of insulation, quality offrom simple shanties, mansions. They vary infactured houses, to the duals, to the more comprian era and the presen

All residential buildinclude a substructure, sspace ventilation, plum(depending on climate),furnishings such as stosurfaces. These reflect cosite characteristics, desigrials. They also reflect evamenities in the markeenced by cost, the most

1. Substructures

Most residential buildinand anchors them to theture: slab-on-grade, crabinations of these.

House substructureare preferred in the noequal costs, some controthers prefer slab-on-gare unsuitable for basemajor contributor to thfamily dwellings).

Substructure type olems. Houses with baselevels (given the same soproblems with water peto mold infestation andrisks may also exist in dtures when constructed

2. Roofing

Roofs are constructed toThey are designed to inthe roof edges to the grfactors determine the nacteristics

ary enormously in their construction characteristics,building materials used, substructure, cladding, use construction, and site conditions. They vary in sizeto nice single- and multifamily homes, to palatial design from the simple rectangular boxes of manu-iversity of home designs of middle-income individ-

lex and architecturally inspiring homes of the Victo-t.ings have similar construction requirements. They

idewalls, flooring, windows, roofing, attic and crawl-bing, electrical wiring, attic and wall insulation

and roof and site drainage. They also include interiorrage cabinets, closets, and finished wall and floornstruction practices that depend on regional climate,n preferences, and availability of construction mate-olving builder and homeowner preferences and newtplace. Construction characteristics are much influ-important factor in residential building construction.

gs rest on a substructure that supports their weight ground. There are three common types of substruc-

wlspace, and basement. Some residences have com-

s reflect regional preferences (in general, basementsrtheastern U.S.); contractor preferences (assumingactors prefer to build houses on crawlspaces, whilerade); soil characteristics (poorly drained clay soilsments); and cost and construction time (this is ae increasing construction of slab-on-grade, single-

ften has significant effects on building IAQ/IE prob-ments or slab-on-grade tend to have higher radonil radon-emitting potential). Basements tend to have

netration and excess humidity, factors that contribute attendant exposure and health risks. Such health

wellings with crawlspace or slab-on-grade substruc- on poorly drained sites (as is often the case).

protect building interiors from rain, snow, and wind.tercept rain and snow and carry their waters from

ound, either directly or through guttering. Climaticature of roof construction and the use of guttering.

Roof construction also rIn new U.S. residentialoriented-strand board with asphalt felt and sparts of the world (Euroofing is preferred. In sgalvanized steel is the m

Roof construction aaway water without leamold infestation occur.enough to support the wroofs must be securely cavity between the roofto prevent the build-upmay result in condensaresult in structural dam

3. Sidewalls and

The exterior sidewalls otimbers, fiberglass insuladditional low-cost insuaround windows to probrane (e.g., Tyvek), and oincludes, or has includeweatherboard, stucco ovis an important factor inand climate. All claddingfrom wind, water, and snwith brick/stone veneertear off small to large piemust be painted repeatedering and inadequate mawas painted with lead-source of lead contamininterior dust. Old weathconcern because of their

As in the story of thseem to provide the beslems. Brick/stone veneeto large settlement crackcavities. Here both liquiand mold infestation. Inveneer facades pass wasmall holes. If constructsurface of the mineral faholes at the bottom. If eflects resource availability and cultural preferences. construction, roofs are typically constructed with

decking on wood trusses. Decking is then coveredhingles. In the southwestern U.S., as in some otherrope, Southeast Asia, Japan, Australia), terra cottaome parts of the U.S. (South) and Australia, paintedost common roofing material.

nd materials used are important. The roof must carrykage, lest significant internal structural damage and In cold, snowy climates, the roof must be strongeight of heavy snow. In regions with severe storms,

anchored lest they experience serious damage. The and ceiling timbers must be adequately ventilated of excessive moisture, which in cool/cold climatestion and even freezing. Poorly ventilated attics mayage and mold infestation.

wallsf dwellings are typically constructed using structuralation, Styrofoam or polyurethane sheeting to providelation, oriented-strand board sheeting in corners andvide extra strength, an external semipermeable mem-ne or more types of external cladding. Typical claddingd, aluminum or vinyl siding, wood or fibrocementer concrete block, and brick or stone veneer. Cladding protecting the building from the vagaries of weather types indicated above provide reasonable protectionow. From a structural standpoint, houses constructed

are less prone to damage from wind gusts which cances of vinyl and aluminum siding. Wood weatherboard

ly and, with time, can deteriorate as a result of weath-intenance. In many older houses, wood weatherboardbased paint and represents a potentially significantation of the soil surrounding the building, as well aserboard-clad houses are often a major public health

potential to cause lead poisoning in young children.e three little pigs, an all-brick or stone house would

t shelter. However, such houses are not without prob-r houses constructed on unstable soils develop smalls which provide an avenue for rain to enter building

d water and water vapor can cause structural damage the absence of settlement cracks, many brick/stoneter through porous mortar and brick, and throughed properly, rain water will drain down the interior

cade and seep out through properly functioning weepbrick/stone veneer facades are poorly constructed

(without weep holes ancarried into walls, again

Timbers on wall inserves as a vapor barripassing into building cdamage and mold infes

4. Windows

Windows in dwellings are designed to keep wa means of natural venare a major source of eneproperties. On single-pinterior surfaces cools asurfaces (and in manybreak the continuity ofwith flashing or be caulduring heavy rains. Wacommon as houses age

5. Flooring

Materials used in both etime. In older houses (>construct floors. In maning. Because of the highfloors using CDX plywosoftwood plywood shee

layment above it. This attachment of wall-to-whomes were constructedpotent source of formaldment have significantlylittle used in modern site50% of new manufactubeen displaced by orienthat has better structura

The main floor surwith wall-to-wall carpeconcreteground contacmal humidity levels foSlab-on-grade substructthe conveyance of radointo building interiors.

6. Decorative wa

A variety of materials materials have historicd the removal of excess mortar), rain water will be causing mold infestation and structural damage.teriors are covered by polyethylene plastic, whicher. It is designed to prevent warm, moist air fromavities where it may condense and cause structuraltation.

differ in style, size, placement, and materials. Theyind, rain, and snow out, allow light in, and providetilation during moderate to hot weather. Windowsrgy loss because of their thermal energy transmittingane windows (found in older houses), moisture onnd condenses, causing damage to interior window

cases significant mold infestation). Windows also building cladding. These breaks must be providedked to prevent water from penetrating wall cavitiester penetration into wall cavities around windows is and maintenance is neglected.

xterior and interior house construction change with40 years), softwood boards were commonly used to

y cases these were overlain with hardwood oak floor- cost of such flooring, it became common to constructod sheeting. Later, contractors used a combination ofting as a base, with 5/8 (1.6 cm) particle board under-was inexpensive and provided a smooth surface forall carpeting. Between 1960 and 1990, over 10 million in the U.S. using particle board underlayment, a veryehyde (HCHO). Emissions of HCHO from underlay-

declined in the last decade or so (1988 to 2000). It is-built construction and has declined to approximatelyred house construction. Particle board flooring hasted-strand board (OSB), a composite wood materiall properties and very low HCHO emissions.face of slab-on-grade houses is, of course, concrete,ting and other floor coverings overlaying it. Thist provides a cool surface, which may result in opti-r the development of high dust mite populations.ures also provide (through cracks) a mechanism forn and other soil gases (most notably water vapor)

ll and ceiling materials

are used to finish interior walls and ceilings. Baseally included plaster over wood or metal lath, or

gypsum board panels. Bsum board has dominaceiling covering for theolder homes. Gypsum concerns. However, durgaps between individucontained asbestos; thecovering contain a limiacoustical plaster contafaces to provide a deco

Gypsum board has b

tarum

infestations in res

that produces a potent mof

S. chartarum

). It growit has been subjected to

Residential buildinghave been coated with pmay have significant emsemivolatile organic comOld leaded paints (pre-lems (see Chapter 2).

Base gypsum boardlatex, or in some cases oipaints, though water-bacant emissions of VOCpaints, respectively. Thoemissions from walls anof odor, and in some casNotably, some manufacpaint formulations that eweeks after application.

In some dwellings tin part, with decorativepaper, hardwood plywoplywood paneling maycase in mobile homes, paper or wallpaper oveplywood paneling covein the U.S. prior to 1985of HCHO and a majormobile homes construc

7. Energy conser

Modern dwellings are befficiency is achieved, inecause of cost factors and ease of installation, gyp-ted the construction market for interior wall and

past four decades, with plaster found primarily inboard in itself appears to pose no direct IAQ/IE

ing installation, spackling materials are used to coveral panels. Prior to 1980, most spackling compoundsrefore, many older homes with gypsum board wallted amount of asbestos fibers. In other older homes,ining 5 to 10% asbestos was sprayed on ceiling sur-rative finish with sound-absorbing properties.ecome increasingly associated with Stachybotrys char-

idences and other buildings. S. chartarum is a fungusycotoxin (see Chapter 6 for an expanded discussion

s readily on the cellulose face of gypsum board when a significant or repeated episodes of wetting.s have a variety of exterior and interior surfaces thataints, stains, varnishes, lacquers, etc. These coatingsissions of volatile organic compounds (VOCs) andpounds (SVOCs), particularly when newly applied.

1978) may pose unique indoor contamination prob-

materials are usually finished with the application ofl-based, paints. In the early history of a dwelling, latexsed, emit a variety of VOCs and SVOCs, with signifi-s and polyvalent alcohols from oil-based and latexugh these emissions diminish with time, high initiald other painted surfaces represent a significant sourcees irritant effects, in the early days of home occupancy.turers have recently included biocides in their latexmit significant quantities of formaldehyde in the first

he base gypsum board may be covered, in whole or materials other than paint. These may include wall-od paneling, hardboard, vinyl, fabric, etc. Hardwood

be used to cover walls in single rooms or, as was themost rooms. Though gypsum board panels with arlay are now used most often, decorative hardwoodred most interior walls of mobile homes constructed. Hardwood plywood paneling was a potent source contributor to elevated HCHO levels reported inted in the U.S. in the 1970s and early 1980s.

vationeing constructed to be more energy efficient. Energy

part, by using insulating materials such as fiberglass

batting in sidewalls ancavities. In the latter casin new construction. Inbuilding sidewalls coueven structural decay. Ia combination of foamtamination of buildingfrom polyurethane foam

In addition to the ustightly; i.e., modern conof cold air in the cold sseason. Concerns have reduced air exchange antrations and attendant h

8. Furnishings

Modern dwellings are pThese include wall-to-wand ceiling materials, fimodern dwellings in th

Wall-to-wall carpetisound, diminishes the ptive, and provides a cocarpeting has negative Until recently, new carpvolatile and semivolatilthe rubbery smell of 4-Phealth complaints.

Wall-to-wall carpetiand organic particles, pregular cleaning. Thesesource for a variety ofantigens, which are theasthma. They also includantigens are significant c

In addition to beingallergenic, carpeting prand a variety of mold sdevelopment of large dhomes as a result of facarpeting and cool floocarpeting are described

Most houses are fufurniture is constructedeven solid wood furnifinish coatings.d attics and blown-in cellulose in attics and walle, wet cellulose is often used to insulate wall cavitiestuitively, the practice of applying wet cellulose to

ld cause significant mold infestation problems andn some cases, wall cavities are being insulated withed-in-place polyurethane and fiberglass batts. Con- interiors with diisocyanate and other compounds

has been reported.e of insulation, dwellings are being constructed morestruction practices are designed to reduce infiltrationeason and exfiltration of cool air during the coolingbeen raised that such construction practices result ind, as a consequence, increased contaminant concen-ealth risks.

rovided with a variety of furnishings and amenities.all carpeting, floor tile, furniture, decorative wallreplaces, etc. The use of wall-to-wall carpeting in

e U.S. is now nearly universal.ng is a highly attractive home furnishing. It absorbserception of cold floor surfaces, is aesthetically attrac-mfortable playing surface for children. Wall-to-wallattributes that are not as apparent as its attractions.eting was characterized by emission of a variety of

e compounds that have caused odor problems (e.g.,C associated with latex binders) and, in some cases,

ng is an excellent reservoir for a variety of inorganicarticles that are often difficult to remove even with include human skin scales, which serve as a food mold species and dust mites, and mite excretory most common cause of chronic allergic rhinitis and

e cat and dog dander, cockroach antigens, etc. Theseauses of inhalant allergies and many cases of asthma. a reservoir for a variety of dirt particles which are

oduces a microenvironment favorable to dust mitespecies. The high relative humidity needed to sustainust mite populations (see Chapter 5) is present in

vorable conditions produced by the combination ofr surfaces. Environmental concerns associated with in detail in Chapter 7, Section F.rnished with wood furniture. Most modern wood with HCHO-emitting pressed-wood materials, and

ture is coated with HCHO- and/or VOC-emitting

9. Storage

Residential building incapabilities. These incluand bathroom cabinetrypressed-wood productsmedium-density fiber bsoftwood plywood usewood components are wood materials that hHCHO. Formaldehyde on exterior surfaces of h

10. Attached gara

Many single-family resenclosure for motor vearea for the varied need

Because of diverse ugarages may be a sourspaces are negatively psions, gasoline and solv

11. Heating/coolin

In many parts of the wotemperature require thsystem be used to provoutdoors. In addition, awashing activities.

Energy sources andheating needs (such as In developing nations limited, building occupvented fires, which dwarmth.

In developed countfor cooking and others fgas or propane-fueled microwave devices. Gaand, as such, are a poten

Single-family dwellof appliance. These inclgas, propane, or oil, or, lappliances include woofireplaces. In the U.S., fifunction.teriors are designed to provide a variety of storagede bedroom and hallway closets as well as kitchen. Most modern cabinetry is constructed with various. These include hardwood plywood, particle board,oard (MDF) and OSB. With the exception of OSB andd for shelving and counter tops, respectively, mostconstructed from ureaformaldehyde resin-bondedave the potential to emit significant quantities ofemissions also occur from acid-cured finishes usedardwood cabinets and good quality furniture.

gesidences have attached garages. These provide anhicles and utilities such as furnaces, and a storages of the buildings occupants.ses and their physical attachment to occupied spaces,ce of a variety of contaminants. Because occupiedressurized relative to garages, motor vehicle emis-ent vapors, etc., are readily drawn into living spaces.

g systemsrld as well as the U.S., seasonal changes in outdoor

at some form of heating and cooling appliance oride more acceptable thermal conditions than occurppliances provide hot water for bathing and other

appliances used to heat residences or provide otherfor cooking and supplying hot water) vary widely.where population densities are high and resourcesants rely on biomass fuels to cook food over poorlyuring cold seasons also provide some degree of

ries, a variety of manufactured appliances are usedor space heating. Cooking appliances include naturalstoves and ovens, electric stoves and ovens, ands stoves and ovens are not vented to the outdoorstially significant source of indoor air contamination.ings in the U.S. are typically heated by some formude vented furnaces fueled in most cases by naturaless commonly, wood or coal. Other vented fuel-firedd or coal stoves and, in parts of northern Europe,replaces serve primarily an aesthetic and decorative

Home space heatinfreestanding, unvented regions of the U.S. anddevices are designed to(CO) and do not pose aindoor air contaminatiChapter 3). Such space hrooms to reduce energy

Electrical devices othe U.S. These include heat pumps. In the latterwater, with a heating cheating devices do not theory, pose any indoor

Indoor space heatinor passively distribute attain and maintain desincluding those that arethrough duct systems. radiators distributed in

In forced air systemwhere it is heated andthrough supply air regthrough a second duct

Duct systems in retamination problems. Hstructed of galvanized fiberglass materials. Thply and return air truninsulated flex duct servDuct board may releasean odorant and an irritafor organic dust, whichsequent indoor air cont

Return air ductworcally located in attic, cWet crawlspaces and baand the usually leaky dfor mold spores, moistu

In many dwellingshouse systems that are

12. Plumbing

Most houses have plum(and in many cases softeg is accomplished primarily by the use of modular,natural gas or kerosene space heaters in the warmer in countries such as Japan and Australia. These emit only limited quantities of carbon monoxiden asphyxiation hazard. They may cause significant

on with a variety of combustion by-products (seeeaters are commonly used to spot heat individual costs.r systems are often used for home space heating incable heat, with elements in the ceiling, or electric case, energy is extracted from outside air or ground-oil supplement during very cold weather. Electric

produce any combustion by-products and do not, in air contamination risks.g can be provided by central systems which forciblyheat from a combustion or electrical appliance to

ired thermal conditions. Such systems heat all spaces, unoccupied. In forced air systems, heat is distributedIn radiant heat systems, hot water is pumped to

various parts of the house.s, a fan draws air through a filter into the appliance, then delivered through ducts to building spaces

isters. Air is returned to the furnace to be reheatedsystem described as a cold air return.sidences can cause or contribute to indoor air con-istorically, ducts (both supply and return) were con-steel. Increasingly, ducts are being fabricated from

ese include duct board, which is fashioned into sup-klines on-site, with polyethylene-lined, fiberglass-

ing to deliver conditioned air to supply air registers. contaminants such as methylamine, which is bothnt. Porous surfaces of duct board are deposition sites may serve as a medium for mold growth and sub-amination.k, which is under a high negative pressure, is typi-rawlspace, or basement areas, or attached garages.sements are often heavily contaminated with mold,uctwork located in these spaces serves as a conduitre, and even radon into living spaces., cooling is provided either by window or whole-integrated into heating systems.

bing systems that carry water into them, then heat

n) it and distribute it to kitchen and bathroom sinks,

toilets, showers/tubs, luse. They also carry awdensate from air condicases, food wastes. In mwell. Good maintenance(which are relatively codevelop dry traps. Pluinstallation or maintena

13. Other utilities

Other utilities that are iwiring and, in many hofor the potential to causmental concerns. Gas uan odor problem; the ofuel gas may pose an ex

E. Age and condition

Buildings vary in age anof IAQ/IE problems asused to cover exterior ssurfaces prior to the 195with lead-containing dmany older houses are

Older houses are msion, flooding, and condthan new houses. As a infested with mold.

Older houses are mventilated, than newer hThey are also more likewall-to-wall carpeting.

F. Site characteristic

Inadequate site drainagwere historically poorlyDwellings constructed oproblems, including: baspaces; water in heatintation of slab-on-grade spiders, insects, and mments, crawlspaces, andof materials and subseqincreases the risk of conaundries, and external faucets for lawn and gardenay cooking and bathing waters, toilet wastes, con-

tioners and high-efficiency furnaces, and, in someost cases, plumbing systems perform their functions, however, is required to prevent damage from leaks

mmon) and entry of sewer gases through drains thatmbing-related problems that result from impropernce are common in many residences.

ntegral parts of housing structures include electricalmes, pipe systems for natural gas or propane. Excepte structural fires, electrical wiring poses no environ-tility systems are subject to leakage and may causedor is designed to warn homeowners that leakingplosion hazard.

d condition, so they vary in the types and magnitudesociated with them. Because lead-based paint wasurfaces prior to 1978, and both interior and exterior0s, older houses are more likely to be contaminatedusts. This problem is exacerbated by the fact thatnot well maintained; many are dilapidated.ore likely to have had problems such as water intru-ensation on windows and walls during their historyconsequence, they are at much higher risk of being

ore likely to be less insulated, and therefore betterouses. As such, they have higher air exchange rates.ly to have hardwood floors and less likely to have

s

e bedevils many homeowners. Many building sites drained and remain so after building construction.n such sites are subject to a variety of water-related

sement seepage or flooding; episodically wet crawl-g/cooling ducts in slab-on-grade houses; and infes-ducts with moisture-loving crustaceans (sow bugs),old. The periodic incursion of moisture into base- slabs poses major IE problems. It may cause wetting

uent mold infestation; high indoor humidity whichdensation on cold window surfaces and a variety of

mold infestation probleof large dust mite popuexposure risks.

Other site characteHeavily shaded sites tenas the site itself. Well-drassociated with moistuhand, high soil permeab

G. Occupants and oc

Once a dwelling is ocgenerating activities. Thas well as odors associapersonal care and clothproducts (and possiblycrafts and in-home enteand decorative items, ause of candles; pet odoserves as food for antigeproper and improper ubuilding interior renovatenance of building comof furniture and other mtaminants; and introducclothing from the buildas well as work environcare establishments, etc

H. Exposure concern

Occupants of dwellingscontaminants in ways tAs indicated previouslytially toxic indoor continclude infants/childre

Contaminant exposradon; HCHO; environcombustion appliances;antigens, mold, and anemissions from personaities; and contagious di

Exposure concernstion/ventilation potentcooling seasons. Residein most cases, mechanicms; and a favorable indoor climate for developmentlations, with their associated antigen production and

ristics also contribute to moisture and IE concerns.d to retard drying of exterior building surfaces as wellained sites with sandy or gravelly soils reduce risksre-requiring biological contaminants. On the otherility may be associated with elevated radon levels.

cupant behavior

cupied, it is subject to a number of contaminant-ese include: production of bioeffluents by occupantsted with food preparation and use; emissions froming/home cleaning products; smoking of tobacco

other weeds); emissions/by-products of hobbies,rprises; fragrant emissions from candles, potpourri

s well as combustion by-products from the frequentrs and danders; production of organic debris thatn-producing dust mites, cockroaches, mice, etc.; bothse of pesticides to control common household pests;tion activities; improper/ inadequate care and main-bustion, plumbing and other systems; introductionaterials which may be a significant source of con-

tion of particulate-phase contaminants on shoes anding site (e.g., lead-based paint dusts and pesticides)ment (e.g., industrial dusts, starch and talc from hair.).

s

are exposed to indoor air and other environmentalhat are different from other nonindustrial buildings., occupants of residences can be exposed to poten-

aminants 12 to 24 hours/day. Exposed populationsn, healthy adults, the aged, and the infirm.ure concerns that are unique in residences include:mental tobacco smoke (ETS); pesticides; unvented biocontaminants such as dust mite and cockroachimal danders; lead-based paint-contaminated dust;l and home-care products, and arts and crafts activ-sease. in residences are increased due to limited dilu-ial when windows are closed during heating andnces, unlike other nonindustrial buildings, are not,

ally ventilated.

III. Characte

Nonresidential buildingulations they serve, (2) construction characterioccupant density/activ

A. Building function

Nonresidential buildinghuman needs. These in1.4), private and publment/detention, worshpopulations they serve.universities, and many

Figure 1.4

Retail building

Figure 1.5

Office buildinristics of nonresidential buildingss can be characterized by (1) the functions and pop-access and ownership status, (3) building types andstics, (4) building operation and maintenance, (5)ities, and (6) health and other exposure concerns.

s and populations served

s are designed and constructed to serve a variety ofclude retail and other commercial activities (Figureic office space, education, health care, imprison-ip, entertainment, etc. These buildings vary in the In office buildings (Figure 1.5), prisons, colleges and commercial establishments, most of the building

.g.

population is comprise18 dominate; in healthconsists of the infirm, anel; entertainment andpopularity of the enterresidences, nonresidentsuch, IAQ/IE exposurein residential buildings

B. Access and owner

Although many nonresernment and a variety by individuals or corppublic for at least a port

Figure 1.6

School buildin

Figure 1.7

Health-care fad of adults; in schools (Figure 1.6), children age 5 to-care facilities (Figure 1.7), the building populations well as care givers and a variety of service person- sport facilities serve populations that reflect thetainment provided to various age groups. Unlikeial buildings tend to serve diverse populations. As concerns differ in many cases from those that occur.

ship status

idential buildings are owned and operated by gov-of not-for-profit entities, most are privately ownedorations. Because these buildings are open to theion of the day, they can be described as public-access

g.cility.

buildings. Occupants ofon building managemenronment. Occupants anding environment condit

C. Building types an

Building type, design,served by individual buences of architects andmate, etc. Office buildinno larger than a residento millions of square feea variety of cladding tyglass and stone.

Like residences, noand furnishing requirema skeletal frame; externinterior wall coveringssuch as floor coverings,

1. Substructure/

Because nonresidential reflect structural demanthe building whose strutures therefore are slabstructural members oftbuilding frame may be In multistory buildingstion, which reduces the 1973, such fireproofing

2. Walls

Exterior walls may inclustone, brick, etc. As in climate) with materials ings. Such buildings masuch as Florida, severeoccurred as a result of building envelope (withcooled wall surfaces. Intwith other materials us

3. Flooring/floor

Floors of nonresidentialwith vinyl tile, terrazzo public-access buildings as well as visitors dependt to provide a comfortable and low-health-risk envi- visitors usually do not have any control over build-

ions.

d construction characteristics

and construction characteristics reflect the needsildings, resources and desires of the owner, prefer-

contractors, resource and material availability, cli-gs, for example, vary in size from small structures

ce to giant towers providing hundreds of thousandst of floor space. They vary from wood-framed withpes to structures with ribs of steel and facades of

nresidential buildings have similar basic structuralents. These include a substructure or building base;

al cladding; windows; a roof; insulating materials;; flooring; finish coatings; and interior furnishings furniture, storage cabinets, room dividers, etc.

structurestructures tend to be large, they are constructed tods. The building base must support the weight ofctural components are steel and concrete. Substruc-

-on-grade or have one or two subgrade levels, withen anchored to bedrock or stabilized ground. Theconstructed of steel or reinforced concrete columns., structural steel is sprayed with fireproofing insula-risk of warping and building collapse in a fire. Beforecontained asbestos.

de extensive glass or cladding of limestone buildingresidences, they are often insulated (depending onmanufactured for the walls and roofs of large build-y or may not have vapor barriers. In warm climates, mold infestations on interior wall materials havethermal-enhanced movement of water through theout vapor barrier) and subsequent condensation onerior walls are typically covered with gypsum board,ed for decorative purposes.

covering

buildings are usually poured concrete, often covered, or carpet. Vinyl asbestos tile was widely used in

schools and other nonrebuildings, floor coverinsions from carpeting ancomplaints in a numberesidential, nonindustriorganic particles.

4. Ceilings

Ceilings of many nonresto provide an aestheticathrough which utilities are extended. These cavair is conveyed to air-haceiling tile commonly sacoustical plaster may bplaster containing upwin foyers and hallways

5. Roofs

Roofs of a large percenis considered more aestform for heating, ventiexhaust vents, etc. Flat proper drainage of rainintrusion into building that damage ceiling tileis a common problem iwell as exhaust vents aother exhaust gases is a

6. Furnishings/e

Nonresidential buildingchairs, desks, storage cemit a variety of VOCs desks and storage cabininets, counter tops, andemitting pressed-woodpotential irritant effects

Nonresidential buiincluding computers, prcan be a source of indo

7. Heating, cooli

Nonresidential, nonindclimate-controlled and sidential buildings prior to 1980. Increasingly, in newgs are glued-down industrial-grade carpeting. Emis-d associated adhesives have been the subject of IAQr of buildings. As in residences, carpeting in non-al buildings becomes a sink for a wide variety of

idential buildings serve several functions. They needlly acceptable appearance and, in many cases, a cavitysuch as wiring, plumbing, and mechanical systemsities often serve as plenums through which return

ndling units (AHUs) to be reconditioned. Suspendederves as the plenum base. In other cases, decorativee sprayed on ceiling surfaces. Prior to 1978, acousticalards of 10% chrysotile asbestos was commonly usedin schools, auditoria, and other buildings.

tage of nonresidential buildings are flat. A flat roofhetically pleasing by architects and serves as a plat-lation and air conditioning (HVAC) system AHUs,roofs require design and construction care to assure and snow melt, and maintenance to prevent waterinteriors. Flat roofs are often plagued by water leakss and other interior materials. Such water intrusionn school buildings. Because HVAC system AHUs asre often located on flat roofs, re-entry of flue andlso a common problem.

quipments are provided with a variety of furnishings, e.g.,abinets, office dividers, etc. These furnishings canand SVOCs which contaminate indoor spaces. Steelets have low emissions. Wooden desks, storage cab- office dividers may be constructed from HCHO-

products, and thus serve as a source of HCHO and.ldings also contain a variety of equipment typesinters, photocopying machines, etc. Such equipment

or contaminants (see Chapter 7).

ng, and ventilation systems

ustrial buildings vary considerably in how they areventilated. Climate control in seasonally colder cli-

mates may be limited toair furnaces, boilers plutems used reflect the buprovided by mechanicawindows (natural venti

In seasonally hot cliAgain, ventilation maywindows.

The trend in most dings with year-round cliand cannot be opened provided by mechanicaheating and cooling sy(heating, ventilating, aioperation (see Chapter

HVAC systems conambient environment, scomfort and satisfactiooperated HVAC systemair sufficient to dilute limited degree, control design and operation ofcomplaints in mechanic

8. Plumbing

Plumbing systems are d(hot water or steam) orsupply for fire suppresswaste water lines. Heavariety of insulating macontaining asbestos. Inmajor site of asbestos-cwith a variety of mategypsum, etc.

Plumbing in nonreproblems that cause miThe former are commoconcerns.

9. Other utilities

In addition to heating,buildings are provided and electrical, telephoneto minimize space andruns, pipe chases, hallw providing heat by radiant heating elements, forceds forced air heating coils, heat pumps, etc. The sys-ildings needs and often its age. Ventilation may be

l systems or, as in many older buildings, by openinglation).mates, the primary focus of climate control is cooling. be provided by mechanical means or by opening

eveloped countries is to design and construct build-mate control. In these buildings, windows are sealedto provide natural ventilation. Ventilation must bel systems. Because ventilation is integrated into thestems, they are described by the acronym, HVACr conditioning). HVAC systems vary in design and11).trol thermal conditions and air exchange with theo their operation is a major determinant of occupantn with the indoor environment. Well-designed ands are essential to provide occupants with ventilationhuman bioeffluents to acceptable levels and, to a

levels of other contaminants as well. Inadequacies in HVAC systems are the primary cause of air qualityally ventilated buildings.

esigned to provide a potable water supply, heated chilled water lines serving AHUs, sprinkler waterion, static water supply for emergency fire use, and

ted or chilled water lines are typically insulated. Aterials have been used, including molded gypsum-

many older buildings, the plumbing system is theontaining materials. Modern plumbing is insulatedrials including fiberglass, foamed rubber, molded

sidential buildings is subject to a variety of leakagenor stains (and mold infestation) to major flooding.n; the latter rare. Both are environmental quality

cooling, ventilating, and plumbing, nonresidentialwith a variety of utilities including lighting fixtures, and computer wiring. Wiring is typically arranged

resource requirements and is co-located in wiring

ay plenums, etc.

D. Building operatio

Nonresidential buildingings are typically large, HVAC) that need to be and their systems are oftsubject to a variety of pventilation, inadequateand mold infestation. Pmaintenance may be duHVAC systems), inadelack of commitment boperation/maintenancenot-so-poor) school distIn such instances maintemechanical systems, wquately cleaned surface

E. Occupant densitie

Nonresidential buildingactivities. Projected occThey determine space redensities occur in schoo

Occupant activitiessingle building. In officeusing office equipment,may also include mainhorizontal surfaces, repamong others. In schootrative work, food preprojects, and maintenan

Occupant activities affect IAQ and the cleanhealth and well-being general building popul

F. Exposure concern

Nonresidential buildingand health concerns. Twith high occupant deoffice equipment and merating areas; re-entry nants generated outdooproducts that can cause n and maintenance

s such as office, commercial, and institutional build-with relatively complex systems (plumbing, lighting,properly operated and maintained. Many buildingsen poorly operated and maintained and are thereforeroblems, including poor thermal control, inadequate cleaning, recurring roof and other structural leaks,

oor building and building systems operation ande in part to the complexities involved (particularly

quately trained or motivated facilities service staff,y building management, and inadequate building resources. School buildings, in poor (and sometimesricts, are particularly subject to resource limitations.nance is often deferred. As a result, poorly operating

ater damaged/mold infested materials, and inade-s are common.

s and activities

s are distinguished by varied occupant densities andupant densities are a major building design factor.quirements and ventilation needs. Highest occupantl buildings and sports arenas.

vary from building to building, as well as within a buildings, these may include general clerical work, preparing/serving/eating food, printing, etc. Theytenance activities such as cleaning floors and otherainting, repairing problem systems, and pest control,ls, they include teaching/learning, clerical/adminis-paration/eating, athletic activities, art and shopce activities such as floor waxing and pest control.may, in many cases, be a source of contaminants thatliness of building surfaces. They may also affect the

of occupants engaged in such activities and/or theation.

s

s are subject to a number of contamination, exposure,hese include: elevated bioeffluent levels associatednsities and inadequate ventilation; emissions fromaterials; cross-contamination from contaminant-gen-of building exhaust gases; entrainment of contami-rs; contamination of AHUs by organisms/biological

illness, e.g., hypersensitivity pneumonitis, humidifier

fever, and Legionnairesflu, colds, and tuberculoto ETS where smokingunvented combustion acontaminated dusts arelead-contaminated dust

Health concerns, asnaires disease, hypersedescribed as sick build

IV. O

Because humans spend on buildings. Neverthecontaminants occur in of motor vehicles, airpl

A. Motor vehicles

Motor vehicles represeVOCs and SVOCs maye.g., vinyl plastics. Theyment from the vehiclesconditioning systems mbe brief, varying from m

B. Commercial airpla

Travel in commercial airfor most individuals (exto nonresidential buildities (2 m

3

/person) and

Figure 1.8

Commercial a disease; transmission of contagious diseases such assis; exposure to resuspended surface dusts; exposure

is not restricted; etc. With some exceptions, radon,ppliance emissions, pesticides, and lead-based-paint- not major exposure concerns; radon, pesticides, ands are, however, concerns in school buildings. indicated above, include diseases such as Legion-nsitivity pneumonitis, and illness symptoms oftening syndrome.

ther indoor environmentsso much time indoors, most IE concerns have focusedless, exposures to airborne or resuspended surfaceother environments as well. These include interiorsanes, trains, ships, submarines, and space capsules.

nt unique IAQ/IE concerns. Contaminants such as be emitted from materials used in vehicle interiors, may also become entrained in the interior compart- own exhaust or the exhaust of other vehicles. Air-ay also be a source of contamination. Exposures mayinutes to hours per day, and possibly repeated daily.

nes

craft (Figure 1.8) is a relatively infrequent occurrencecept flight crews). Airplanes are in some ways similarngs. They are characterized by high occupant densi- mechanical systems that use both recirculated andircraft.

outside air; uniquely thof 8000 feet. Despite therevised to increase outcapacities to environmethe amount of outsiderecommended for office

Commercial aircrafof contaminant exposusions from seats and othproducts, ETS on smoklate (RSP) levels are apand elevated ozone whePassengers and crew aras well.

C. Trains

Trains are used for botmillions of individuals,train transportation daUnderground transportand underground tunnetilation that occurs pass

Contaminant exposeffluents, emissions frodriven systems, entrainm

D. Ships

A ship can be likened toareas, food-handling arboard, combustion-drivage systems.

Many modern passditioned. Like land-basedegree of thermal comf

Exposure concerns from ship materials, Ecombustion systems, anspecial concern have beinfluenza, and outbreak

E. Submarines and s

Submarines and space cand exposure concerns. ey have interior pressures comparable to an altitude fact that ventilation standards for aircraft have beenside air, aircraft designs limit outside air deliveryntal control systems. In a filled-to-capacity airplane, air provided to passengers and crew is half that buildings.t personnel and passengers are subject to a varietyres. These include human bioeffluents, VOC emis-er interior materials, entrained fuel combustion by-

ing-permitted flights [respirable suspended particu-proximately 20 times those on nonsmoking flights],n flying at high altitudes (circa 30,000 to 40,000 feet).e often subject to low relative humidity (5 to 25%)

h surface and underground transportation. Tens of in North America and other parts of the world, useily. Such use is particularly heavy in large cities.ation includes two indoor environments, the trainls and platforms. Underground systems require ven-ively or by mechanical means.ures in train compartments may include human bio-m interior materials, entrainment from combustion-

ent of contaminants from underground sources, etc.

a hotel. It contains sleeping/living quarters, diningeas, lounges, theaters, etc. It also includes an on-en propulsion system, and waste handling and stor-

enger ships are mechanically ventilated and air con-d nonresidential buildings, such systems vary in theort provided, as well as ventilation adequacy.on ships may include human bioeffluents, emissionsTS in smoking-permitted areas, entrainment fromd cross-contamination from high source areas. Ofen the transmission of contagious diseases, such ass of Legionnaires disease.

pace capsules

apsules represent truly unique indoor environments

In both cases, ventilation is not possible. Air/oxygen,

which is quite limited, hcial air cleaning system

and VOC levels.Exposures to crew

emissions from interior bers in early space flighassociated with poor IA

Readings

Godish, T.,

Sick Buildings

Publishers, Boca RatoLstiburek, J.W.,

Contractor

MA, 1991.Lstiburek, J.W. and Carmo

Residential and Small C

1994.Maroni, M., Seifert, B., and

Book

, Elsevier, AmsterNational Research Counc

National Academy PrSamet, J.M. and Spengler,

Hopkins University PSpengler, J.D., Samet, J.M

McGraw-Hill, New Y

Questions

1. What factors haveenvironment probl

2. How are IAQ/indthose experienced

3. What is the significgating indoor envi

4. Describe differenceenvironment conce

5. How do site-built 6. Describe sidewall c7. Describe problems

indoor environmen8. Describe environm

windows.9. Describe residenti

problems associate10. Describe energy co

ronment problems11. What kind of envir

gypsum board?as to be continuously recycled. In submarines, spe-s must be used to maintain acceptable CO2 (

12. Describe the naturindoor environmen

13. How are site chara14. A variety of mecha

dwellings comforthuman health?

15. How do occupants16. Describe contamin17. What are public-ac18. How do roofs on

buildings? What u19. Describe the natur20. Describe the use an

and how they diffe21. Describe the nature

residential, nonind22. Describe health a

buildings.23. How do occupant

nonindustrial build24. What human expo

vehicles?25. What human expoe of storage in residences and how it may be related tot problems.

cteristics related to the indoor environment of residences?nisms/appliances are used to heat our food and make ourable. How may these affect the indoor environment and

in residential buildings affect their indoor environment?ant exposure concerns in residential buildings.cess buildings?nonresidential buildings differ from those on residentialnique problems are associated with roofs?e of ceilings in many nonresidential buildings.

d operation of HVAC systems in public-access buildingsr from residential buildings. of building operation and maintenance concerns in non-

ustrial buildings.nd exposure concerns in nonresidential, nonindustrial

activities affect the indoor environment in nonresidential,ings?sure concerns are associated with the interiors of motor

sure concerns are associated with commercial air travel?

chapter two

Inorganic casbestos/ra

Inorganic substances sucontaminants. Though inorganic nature. Expos

Lead is of concern bspaces, and contact wicause of elevated blood

Potential airborne asbeassociated public healthattention in the late 197authorities. This attentiociated with the promulas a hazardous pollutaProtection Agency (USEcation of spray-appliedstruction; there was a sbuilding products in 19hand) asbestos-containprior to building demolin accordance with Occurequirements to protectbuilding occupants. Asin buildings, particularland public health conceontaminants: don/lead

ch as asbestos, radon, and lead are major indoorvery different, they have in common a mineral orures may pose significant health risks.ecause it is a common surface contaminant of indoorth lead-contaminated building dust is the primary levels in children under the age of six.

I. Asbestosstos fiber exposures in building environments and risks were brought to the nations (United States)

0s by both public interest groups and governmentaln was a logical extension of exposure concerns asso-

gation of a national emission standard for asbestosnt (NESHAP) by the United States EnvironmentalPA) in 1973. The asbestos NESHAP banned appli- asbestos-containing fireproofing in building con-ubsequent ban of other friable asbestos-containing78. Under NESHAP provisions, friable (crushed bying building materials (ACBM) must be removedition or renovation. Such removal must be conducted

pational Safety and Health Administration (OSHA) construction workers removing asbestos, as well as a consequence of these regulatory actions, asbestosy in schools, became a major indoor air quality (IAQ)rn.

The ban on friable struction and requiremwere intended to minimnity to contaminated amoccupants from fibers rmal activities had not bto the large quantities oin school construction a

A. Mineral character

Asbestos is a collectivephysical and chemical minerals and contributcommercial applicationlation properties; chemihigh tensile strength, wbuilding products.

Asbestos comprisescrystalline structure: serure 2.1), the most widestructure with the layefibrils. The amphiboleactinolite, and tremolitechain silicate ribbons

Individual asbesto(length:width) ratios, anare defined for exposurhave an aspect ratio

3:1

Figure 2.1

Chrysotile asbHibbs, L., McTurk, G., andasbestos-containing materials used in building con-ents for removal prior to demolition or renovationize exposure of individuals in the general commu-bient (outdoor) air. Potential exposures to building

eleased from building products in the course of nor-een addressed. In 1978, public attention was drawnf friable or potentially friable ACBM that was useds well as other buildings.

istics

term for fibrous silicate minerals that have uniqueproperties that distinguish them from other silicatee to their use in a wide variety of industrial ands. These include thermal, electrical, and acoustic insu-cal resistance in acid and alkaline environments; andhich makes them useful in reinforcing a variety of

two mineral groups which are distinguished by theirpentine and amphiboles. Serpentine chrysotile (lFig-ly used asbestos mineral, has a layered crystalline

rs rolling up on each other like a scroll or tubulars, which include amosite, crocidolite, anthophyllite,, have a crystalline structure characterized by double- of opposing silica tetrahedra linked by cations.s fibers have very small diameters, high aspectd smooth parallel longitudinal faces. Asbestos fibers

e monitoring as any of the minerals in Table 2.1 that, lengths >5 m and widths

asbestos fibers have thmicroscopy: (1) particlehigher, and (2) very th

fibers often occur in buusing transmission elechave been reported to r

0.35

m, and crocidolite

the higher the tensile st

B. Asbestos-containi

Commercial and indusAsbestos fibers have beeGeneric uses have inclufriction products such a

Materials made odescribed as asbestos-cconstruction, they are i(ACBM). Types of ACBperiod of use are given

1. ACM in nonr

For regulatory purposefied as surfacing matercellaneous materials (Mproofing (Figure 2.2) aAsbestos-containing firebuildings to keep buildi

Table 2.1

Asbe

As

MineralComme

nam

Chrysotile Chrysot

Grunerite Amosite

Rubeckite Crocido

Anthophyllite Anthoph

Actinolite Actinoli

Tremolite Tremolit

* Very commonly found in** Commonly found.*** Uncommonly found.

X

Typically not used in AC

Source:

From Health Effects

Buildings: A Literature Review

permission.e following characteristics when viewed by lights typically having aspect ratios from 20 to 100:1 orin fibers (typically

plaster was widely useetc., as a decorative surfrials are very friable anfibers into the general b

Thermal system insboilers, associated equipsionally it was used forcases, TSI was wrappedto service/maintenancedamaged or disturbed. blocks or batts and to s

Table 2.2

Some

Category

Surfacing material

Thermal system insulation (preformed)

TextilesCementitious concrete-like products

Paper products

Asbestos-containing compounds

Flooring tile/sheet goods

Paints/coatings

Note:

Information in this tablhave been phased out

Source:

From Health Effects

Buildings: A Literature Review

permission.d in foyers, hallways, school gymnasia, classrooms,ace and sound absorption medium. Surfacing mate-d have a significant potential for releasing asbestosuilding environment when disturbed.

ulation was widely used to insulate mechanical roomment, and steam/hot water lines (Figure 2.3). Occa- cold water lines to prevent condensation. In most with a protective cloth and poses an exposure risk workers only when the protective cloth (lagging) is

Asbestos-Containing Materials Used in Buildings

CharacteristicsAsbestos

(%) Dates of use

Sprayed on 195 19351970sTroweled onBatts, blocks, pipe covering

85% magnesia 15 19261949Calcium silicate 68 19491970sCurtains (theater) 6065 1945presentFlat panels 4050 1930present

Corrugated panels 2045 1930presentPipe ~20 1930presentCorrugated

High temperature 90 1935presentModerate temperature 3570 1910present

Indented 98 1935presentMillboard 8085 1925presentCaulking putties 30 1930present

Adhesive 525 1945presentJoint compound 19451975Spackling compound 35 19301975Insulating cement 20100 19001973Finishing cement 55 19201973Vinyl asbestos tile 21 1960presentAsphalt/asbestos tile 2633 1920presentResilient sheeting 30 1950presentRoof coating 47 1900presentAirtight asphalt coating 15 1940present

e was based on a 1985 study by the USEPA. Many ACM productsor discontinued. Use period present indicates 1985.InstituteAsbestos Research, Asbestos in Public and Commercial

and Synthesis of Current Knowledge, Cambridge, MA, 1991. WithThermal system insulation was applied to boilers asteam/hot water lines as preformed pieces.

Miscellaneous mateings, such as ceiling tileling compounds, asbest

Chrysotile, as seen form mineral in productile accounts for 95% ofiber in ACBM. Howevminerals in TSI and S

Figure 2.2

Asbestos firep

Figure 2.3

Partially damarials include all other asbestos applications in build-, vinyl asbestos floor tile, adhesives/mastics, spack-oscement products, etc.in Table 2.2, has been the most widely used asbesti-ts used in buildings. It has been reported that chryso-f asbestos used in the U.S. and is the predominanter, in building inspections, the pattern of asbestos

M reflects different proportions of serpentine and

roofing sprayed on building I beams.ged thermal system insulation containing asbestos.

amphibole fibers. In a asbestos fibers in the fochrysotile and amphiboportions were: chrysotionly 17%. In the lattMM. This is significant iwas found in asbestos-c

Various surveys havings with friable ACBMthat approximately 70020%), out of a populatACBM. A study conducthat 47% of 839 municipACBM. In a California s1976, and 56% of all pusimilar study estimatedcontained ACBM. Mostfound in mechanical roomoderately to severely

The percentage of when other nonfriable otos tile, asbestos cemenincluded. Asbestos fiberin a hard material that they are not hand-friabcut, drilled, sanded, or can pose an exposure hsequently, such activitieand renovation requirem

2. ACM in resid

Asbestos in residences This has been due, in presidences (except largeand commercial buildinucts, e.g., TSI around hheating ducts, cement cement board (Transitecontaining asphalt roofitaining ceiling materialasbestos tiles.

With the exceptionresidences contains asbfriable and should onlyMaterials used on buildexposure.study of U.S. municipal buildings, TSI containedllowing proportions: chrysotile only 60%, mixedle 35%, and amphibole only 7%. For SM, pro-

le only 73%, mixed fibers 10%, and amphiboleer case, ceiling tile was classified as SM rather thann that most of the amphibole-only surfacing materialontaining ceiling tiles.e been conducted to assess the prevalence of build-

(SM, TSI, and ceiling tile). In 1988, USEPA estimated,000 U.S. public and commercial buildings (aboution of 3.5 million, contained some type of friableted by the Philadelphia Department of Health foundally owned or occupied buildings contained friabletudy, 78% of its public buildings constructed beforeblic buildings, were estimated to contain ACBM. A that 67% of the 800,000 buildings in New York City of this material (84%) was TSI, 50+% of which wasms. Eighty +% of this material was assessed as beingdamaged.buildings containing ACBM increases considerablyr mechanically friable materials, such as vinyl asbes-t board, mastics, and drywall taping products, ares in floor tile, cement board, and mastics are boundprevents them from being easily released. As such,le. They are, however, mechanically friable (broken,abraded in some way). Mechanically friable ACBMazard under certain conditions and activities. Con-s are regulated under federal and state demolitionents.

ences and other structureshas received relatively limited regulatory attention.art, to the fact that ACBM was not as widely used in apartment houses) as it was in large institutionalgs. ACBM in residences includes a variety of prod-ot or cold water lines, asbestos paper wrap aroundboard around furnaces/wood-burning appliances,) siding, cement board roofing materials, asbestos-ng, wallboard patching compounds, asbestos-con-

s that were spray-applied or troweled on, and vinyl

of TSI and SM used on ceilings, most ACBM inestos in a bound matrix. It is therefore mechanically produce an exposure risk if significantly disturbed.

ing exteriors should also pose little risk of human

Asbestos-containingconstruction of farm andtowers. In the latter casused in external and in

C. Asbestos exposure

Because of the many dein ACM, it is a ubiquitnumber of studies hafibers/structures in indused a variety of opticacollected samples. Earlused in occupational exnot distinguish betweesmall diameters (

of exposure. In most ca

those

5

m.

2. Persons expos

A variety of individualinclude general buildiners, and visitors; houscontact with or disturbwork activities, and mACBM during repair oration workers and embecome exposed.

3. Ambient (outd

Samples collected frombeen a ubiquitous contaSnow samples in Japan to two orders of magnconcentrations of airborthere is more ACM andering of asbestos ceme20 ng/m

3

have been rep

rural areas. Ambient conmass measurements.

4. Asbestos conc

Asbestos concentrationstechniques. Representatdetermined by TEM w2.3. These studies indicalimit of detection to maxof magnitude greater standard of 0.1 f/cc. Avlower than the occupat

Average building 0.00243 f/cc have been rcontaining buildings. Mlic/commercial buildingwith 90 percentile conhigher asbestos fiber codue to the greater activifibers. The concentratioappears to be associateactivity. These data also

resent only a small fracses, concentrations of fibers

Data based on arithtos exposure in buildindistributed and, as a rappropriate than arithreported in studies becbelow the limit of deteczero. Arithmetic means are likely to overestima

Higher exposures cities may resuspend setand disturb ACBM on ated with custodial actialso be expected for mawork. Elevated episodby phase contrast micronance activities.

5. Factors contriexposure

When fibers or asbestosis called primary releaimpaction, fallout, air eroccurs when settled asresult of human activitperiods, fiber release tyor air erosion.

Impaction and abraairborne fiber levels. F

Table 2.3