Presentation on theme: "IAQ Overview Short overview of what IAQ is about."— Presentation transcript:
1 IAQ Overview Short overview of what IAQ is about. Indoor air quality is important because we spend about 90% of our time indoors.Indoor air quality is not a simple, easily defined concept. The principles behind dealing with IAQ problems are a science, but art is involved in dealing with people. Multidisciplinary approach involving medicine, HVAC, engineering, IH, Human Resources.IAQ is a constantly changing interaction of a complex set of factors - people and mechanical systems.
2 This course will cover: Standards and CodesRespiratory SystemHVACContaminants, Chemical and BiologicalHow To Do An IAQ InvestigationPlanning to Prevent IAQ ProblemsExercises and Case StudiesStandards and Codes as they relate to IAQ.Respiratory system and how it functions in relation to inhaling irritants and disease causing organisms in buildings.Biological and chemical contaminants likely to be found in buildings. Biological includes bioaerosols, living and fragments.The practical mechanics of conducting IAQ walk-through surveys and employee surveys.Monitoring instruments and types of sampling.
3 Typical complaints Upper respiratory irritation Dry throat Eye irritationCoughingHeadache, fatigue, inability to concentrateCongestionDizziness and nauseaUpper respiratory irritation, headache, and fatigue are usually most common symptoms.May be causes unrelated to building.Multiple chemical sensitivity is sometimes mentioned. It is controversial.
4 Cause of Symptoms Nonverifiable, dissatisfied employees Actual verifiable problemBacteria grow in HVAC system and distributed throughout buildingNonverifiable, dissatisfied employeesMass psychogenic disease - caused by suggestions that people should be feeling sickIAQ investigation may not always produce a concrete reason for the problems noted.However, many times deficiencies are seen which could contribute to the problem and seem to help resolve the situation when improvements are made.The two examples on slide are meant to show the wide range of verifiable to nonverifiable problems. Most problems are in the middle in terms of finding the actual cause.The next slide shows this range graphically.
5 Spectrum of causes Actual verifiable Nonverifiable physical agent Give examples of actual verifiable physical agent and nonverifiable physical agent.Sometimes a physical agent may be present in combination with psychological factors such as a clash of personalities or a perception that the employer does not care about the well-being of employees.Bacteria throughout bldgMass psychogenic illness
6 IAQ Has Become An Issue Since 1973 tighter building construction Energy conservationCosts more to heat/cool outside airWindows do not openLess control over environmentBetter individual adjustmentIAQ issues have been around a long time. Over 200 years ago Benjamin Franklin wrote about the smoky effects of a sealed room where a fireplace was located. Much of the cooking at that time was done inside over a fire.In the 1930’s researchers first suggested an amount of outside air be brought into buildings. Mostly because of odor control from smoking and body odor (not as many baths then).Pose question “Why has IAQ become an issue in the 80’s and 90’s?”There were oil embargos in 1971 and Energy became more expensive and tried to save energy. Energy saving techniques such as better insulation and tighter, more controlled buildings were in place by 80’s and 90’s. In 1975, ASHRAE reduced recommended outside air to 1/5 of what it had been.When windows opened, employees had better control over their temperature and felt more control over environment. When individuals lose control, over their work area, more stressful. Example is one thermostat for a large office area.
7 IAQ Has Become An Issue New building and construction materials Large amount of time spent indoorsIncreased public awarenessIncreased % of population has asthma and allergiesTighter building construction methods were advised. In house construction now you see “house wrap”.Tight buildings are not necessarily bad if managed correctly with some fresh air. However, many building managers tried to keep all outside air from getting into building and standard setting organizations recommended much less outdoor air for ventilation.State of Ohio actually made grants to school systems in the 70’s to block off fresh air from coming into schools as part of their money saving strategy.Another reason for concern about IAQ is greater expectations about working conditions.
8 Importance of IAQ Productivity Desirability of rental properties Potential liability issuesGood IAQ enhances occupant health, comfort, and morale
9 Proactive ManagementBuilding air quality should be managed like other aspects of the business.To impress on top management the need for good air quality, you need to focus on how much money is being spent on the salaries of employees compared to the amount that is spent on environmental services for those employees.In most cases only, 1 percent of total cost of staffing a building are related to the energy costs.Spending a little more on having good IAQ can produce large dividends in employee productivity.
10 Proactive ManagementIAQ is influenced by a constantly changing interaction of employees and the building mechanical system.
24 Cost recoveryLabor Costs - salary levels & occupancy load (150 square feet/person)$100 to $300 per ft2 /yearEnergy Costs$1.00 to $2.00 per ft2 /yearTotal Environmental Control Costs$ $10.00 per ft2 /year13
25 Energy costs vs personnel costs Energy costs are ususally less than one percent of personnel costs.14
26 Heating, ventilation, and air-conditioning (HVAC) & costs At 20 percent relative humidity, a room temperature of 86 degrees F is needed to match comfort of a 70 degree room at percent relative humidityIt is less expensive to add 30 percent humidity than to add 16 degrees!15
28 Environmental Protection Agency Air Pollution Effects on Materials
29 Environmental Protection Agency Air Pollution Effects on Materials, cont.
30 INDIRECT COSTS ARE 4 TO 10 TIMES THE DIRECT COST INDIRECT COST DIRECT VSINDIRECTCOST7
31 Injury and Illness Costs MedicalCompensation costs (Insured costs)
32 Ledger Costs of Property Damage Building damageTool & equipment damageProduct & material damageProduction delays and interruptionsLegal expensesExpenditure of emergency supplies & equipmentInterim equipment rentalsInvestigation time
33 Uninsured Miscellaneous Costs Wages paid for time lostCost of hiring and/or training replacementsOvertimeExtra supervisory timeClerical timeDecreased output of injured worker upon returnLoss of business and good will
34 CHOP: Main Elements of IAQ Problems ContaminantsHVAC System DeficienciesOccupant BehaviorPathways
38 OSHA & ACGIH (PELs & TLVs) Based on health effects to healthy adults of exposures for 8 hour days over a working lifetimeIssue: relevance to office setting where focus may be 1) comfort or 2) desire for absence of unusual sensory stimuli?Chronic & acute / Population differences and children.
39 OSHA Occupational Safety & Health Administration IAQ standard on holdNothing newRecord-keeping is emphasized
40 NIOSH National Institute for Occupational Safety & Health Research arm for OSHAHHE* provide unique, valuable info on building related illnessesProvides useful specific guidance -- e.g., on CO2 levels even though recommendations only*Health Hazard Evaluations
41 NIOSH National Institute for Occupational Safety & Health Technical info:Publications:e.g., “Guidance For Indoor Air Quality Investigations” (1987)
42 EPA Environmental Protection Agency National Ambient Air Quality Standards (six contaminants)Set in order to protect the public 24 hours a dayIssue: relevance for office IAQ problems?Off-site vs. on-site exposures / animal & vegetation vs. man.
45 ASHRAE American Society of Heating, Refrigerating, and Air-Conditioning Engineers Developed specifically for the indoorsThermal comfort guidelines ( )See BAQ, pVentilation standard ( ) See BAQ, p. 137
46 ASHRAE 55 - 1992 Temperature range: Relative humidity range: F in winterF in summerRelative humidity range:above % in winterbelow 60 % in summerShow how to use sling psychrometer; digital pen; Q-Trak
47 ASHRAE American Society of Heating, Refrigerating, and Air-Conditioning Engineers (Now )Applies to residential & commercialGuideline: “satisfy” 80% of occupantsCFM refers to OUTSIDE air supplied per person
48 ASHRAE American Society of Heating, Refrigerating, and Air-Conditioning Engineers Defines acceptable indoor air quality as:“air in which there are no known contaminants at harmful concentrations as determined by cognizant authorities and with which a substantial majority (80% or more) of the people exposed do not express dissatisfaction.”
49 ASHRAE American Society of Heating, Refrigerating, and Air-Conditioning Engineers Fresh Air Per OccupantStandard: Non-smoking Smokingarea: area:CFM 50 CFMCFM 20 CFM/ CFM 60 CFMOver time and energy crisis.
50 ASHRAE Outdoor Air Requirements (62-1999) Show how to use CO2 equipment
51 ASHRAE Guidelines for Carbon Dioxide Instantaneous levelOutdoor air = parts per million (ppm)People exhale 2-3% CO21% = 10,000 ppm1000 ppm guidance level based on 300 ppm outdoor level
53 62-1999 (Continuous Maintenance) June 1997 instead of revision of entire std.62-c; Std. Will no longer deal with thermal comfort issue,62-d; Compliance does not assure relief for susceptible individuals,62-e; Removes smoking reference since EPA carcinogen,62-f; Changes 1000 ppm to difference between indoor and outdoor
54 62 - 1989 R (Revised) System commissioning Satisfy accustomed occupantsMinimum filtration efficienciesContinuous HVAC operationHVAC protection during renovationBalance ventilation every 5 yearsMonthly record of filter pressure dropCO level > 3 ppm above outdoor level
55 HUD US Dept. of Housing & Urban Development Source emission standardProduct standard limiting formaldehyde exposures from pressed wood products in mobile & manufactured homes<0.2 PPM plywood<0.3 PPM particleboardGoal: indoor HCHO exposures <0.4 PPM, but TLV is now 0.3 PPM!Add lead.
56 HUD (continued) Ventilation standard Part of its mortgage insurance and low rent public housing program as well as construction requirements for manufactured housing
57 HUD (continued) Ventilation standard Area at least 8% the size of floor area must be available for natural ventilation, orMechanical system available to change room air every 30 minutes (2 ach)
58 Model Building CodesPurpose: identify design & construction specifications for buildings (housing)Updated to reflect new knowledge or incorporate standardsState & local governments can use part or all of a code.
59 Model Building Codes Primary codes in US: BOCA Building Officials & Code Administrators InternationalSBCCI Southern Building Code Congress InternationalCABO Council of American Building OfficialsAPHA American Public Health Association
60 Model Building Codes Ventilation specification areas (examples): Area of window space & amount openableAlternatives to openable windowsBathroom exhaustCrawl space ventilation openingsAttic ventilation
61 Ohio Model Building Codes Ohio Basic Building Code (OBBC)Uses BOCA’s Nat’l Mechanical Code(Article 16, “Ventilation Air”)Article 16 [Ohio Admin. Code 4101:2-47]“Ventilation Air (Mechanical)”
62 Ohio Model Building Codes Ventilation required depends on occupant load & use of the space; e.g., 35 CFM in conference roomsSpecifies minimum outdoor air of 5 CFM per person
63 Ohio Model Building Codes Smoking areas not specifically addressedRecirculation rates specified (max.: 67 to 85 %)
64 Other resources :ACGIH Industrial Ventilation Manual “Ventilation Aspects of Indoor Air Quality”OSHA Technical Manual “Indoor Air Quality Investigations”ACGIH Ind. Ventilation / OSHA Tech. Manual / Stds. BooksBWC: Division of Safety & HygieneIndoor Air QualityRevised: 1/7/99Tab 3 -64
65 IAQ Tools for Schools Action Kit IAQ Coordinator’s GuideIAQ Coordinator’s FormsIAQ BackgrounderIAQ Problem Solving WheelIAQ ChecklistsTeachersAdministrative StaffHealth OfficerBuilding MaintenanceFood ServicesRenovation and Repair
66 Additional Resources American Lung Association ACGIH ASHRAE 800 LUNGUSAACGIHASHRAEBldg.Air Quality AllianceDivision of Safety & Hygiene800 OHIOBWCEPA IAQ DivisionEPA Research & Inform. ClearinghouseTool for School Pub.#National Air Duct Cleaning AssociationNational Air Filtration AssociationNational Pesticide NetworkNIOSH800-35NIOSHOhio Dept. of Health Env. Health Div.Ohio State Un. Extension ServicesOSHA / GPO ClevCol TolRadon Information Hotline
67 Standards on the Web ansi.org -Amer. Nat. Standards Institute asce.org -Amer. Society of Civil Eng.ashrae.org -Am. Society of Heating Refrig. & Air-conditioning Eng.astm.org -Am. Soc. For Testing and Materialsbocai.org -Building Officials & Code Administrators Internationalenergycodes.org-U.S.Dept. of Energy Bldg. Stds. & Guidelines Programicbo.org -International Conference of Building Officialsnateval.org -National Evaluation Services, Inc.ncsbcs.org -Nat. Conf. Of States on Bldg. Codes and Standards, Inc.nfpa.org -The National Fire Protection Associationnibs.org -National Institute of Building Sciencesnist.gov -National Institute of Standards and Technologiesnssn.org -National Resource for Global Standards
69 Content covered Overview of respiratory system function How chemicals can interact with the respiratory systemWe will examine how the respiratory system functions, how airborne chemicals behave, and how airborne chemicals interact with the respiratory system.3
70 Chemistry versus Physics 130,000 toxic chemicals - NIOSH650,000 hazardous chemicals- OSHAPhysics - only 3 physical states:SolidLiquidGasChemistry presents us with literally thousands of potential hazards. To organize our thoughts, it is helpful to turn to physics. No matter how many chemicals are present, they can only exist in three physical forms: solid, liquid or gas. It is easier to understand three physical forms than it is to think about 130,000 individual chemicals. Thus, physics provides a framework to organize our thoughts about chemical exposures.4
71 Physical states of matter -- GAS a state of matter having very low density & viscosity compared with solids & liquids (expands to fill its container)at NTP (Normal Temperature and Pressure) is in the gaseous state5
72 Physical states of matter -- LIQUID Vapor: gaseous phase of a substance whose normal state is as a liquid (mimics a gas)Mist: tiny liquid droplets suspended in air (mimics a particle)synonyms - fog, spray6
73 Physical states of matter Solids - become airborne as dusts, fumes or fibersAerosol - general term including both airborne liquids and solids7
74 Physical states of matter -- SOLID Dust:finely divided solid particlestypically generated by mechanical processesExamples: sawing, grinding, sandingIt is sometimes helpful to think about the energy required to generate air borne solids. Assume that we begin with a solid block and break it down into smaller particles. As we break the block into smaller and smaller pieces, we expend more and more energy.8
75 Physical states of matter -- SOLID Fume :a solid which has been heated to a vapor and cooled quickly, condensing as extremely small particlesExamples: welding, solderingIt requires large amounts of concentrated energy to generate fumes.9
76 Physical states of matter -- SOLID Fiber:an airborne solid whose length is at least three times its width.Examples: asbestos, fiber glass, man-made mineral fibers, refractive ceramic fibers10
77 Deposition in the Respiratory System Gases and Vapors - solubility in water. (Fat-soluble chemicals tend to affect other organs)Aerosols ( airborne liquids and solids) - particle size11
78 Water-Soluble Chemicals Highly water-soluble:FormaldehydeAmmoniaAcidsThey tend to act rapidly mainly on the eyes, skin, mouth & throat.12
79 Water-Soluble Chemicals Less water-soluble:ChlorineSulfur dioxideThese tend to affect the upper respiratory tract.13
80 Water-Soluble Chemicals Low in water-solubility:PhosgeneOxides of nitrogenSite of injury: delayed onset of symptoms affecting lower respiratory tract (at alveoli).14
81 Fat-Soluble Chemicals More likely to end up beyond the respiratory system -- for example, in the blood and major organ systemsExamples: some pesticides, amines, & alcohols15
82 Micron One millionth of a meter About 1 thousandth the size of a hair or um16
83 Particle deposition mechanics Impaction - inertiaInterception - contact especially fibersSedimentation - gravityDiffusion - movement due to kinetic energy of the particleImpaction -”An object in motion tends to stay in motion in a straight line unless acted upon by an outside force…“ Sir Isaac Newton. Larger particles have more momentum than smaller particles. It takes a greater force to divert them from their straight line of travel. When initially inhaled, air moves rather fast. Larger, heavier particles cannot negotiate the turns as readily as smaller particles. Thus, larger particles tend to impact the upper respiratory tract.Interception - When a particle touches the moist lining of the respiratory tract, it typically deposits there.Sedimentation - Once the air reaches the deepest regions of the lungs, it has lost much of its movement. With very little air movement to keep them aloft, particles tend to settle because of gravity.Diffusion - Very small particles tend to mimic individual molecules. Like a tiny puppy with too much energy, they tend to “bounce off the walls.” However, once particles contact the moist (sticky) walls of the respiratory system, they no longer “bounce,” they adhere where they contact.17
84 The Lungs Very large surface area 70 M2 in healthy male (or, about 40 times greater than surface area of external skin)Very thin membrane required at gas exchange area (only 1/2 to 1 micron thick in healthy persons, thickness of a soap bubble)Different references quote different surface areas for the lungs. The third edition of Fundamentals of Industrial Hygiene, by the National Safety Council, (page 35) states, “The respiratory surface in the lungs ranges from about 28 meters squared (300 square feet) at rest to about 93 meters squared (1,000 square feet) at deepest inspiration.”18
85 Respiratory System Function: Gas exchange between atmosphere & blood Parts:Upper respiratory system:Mouth, nose, pharynx, larynxLower respiratory system:Trachea, bronchi, bronchioles, lungs19
86 Respiratory System - Anatomy Anatomy (parts continued)In addition to upper and lower respiratory system, we can think of the respiratory system in terms of airways and gas exchange region. Actual gas exchange takes place very deep within the lungs at the respiratory bronchioles and alveoli.20
87 Upper Respiratory System Actions:Filters/traps large particles (8-10 microns)Nose filtersMucous trapsImpaction at sharp bendsHumidifies & heats air taken inReacts with water-soluble chemicals21
88 Lower Respiratory System Actions:Traps & expels particles in mucous(muco-ciliary escalator)Provides less abrupt directional changes; particles 1 to 5 microns depositedParticles in the range of 1 to 5 microns tend to be deposited in mucous and are expelled by the muco-ciliary escalator.22
89 Lower Respiratory System Actions (continued):In lungs, gas exchange actually occurs at clusters of 300 million air sacs (alveoli) 2 cells thickParticles smaller than 1 micron can reach the alveoli23
90 Gas Exchange Oxygen in (and quite a bit out) Carbon dioxide out Thin-walled (2 cells thick normally)But: chemicals (and disease) can cause thickeningExhaled air contains about 15 % oxygen and about 5 % carbon dioxide.24
91 Gas Exchange (continued) Thickening can interfere with gas exchange; example: pneumonia, pulmonary fibrosis (scarring)Lack of elasticity in lungs also a problem; example: emphysema25
92 Respiratory System Disorders Now that we know how the respiratory system functions, we can better understand what can go wrong in terms of disease.26
93 EmphysemaOccurs when adjacent walls in alveoli break through, causing a reduction in the number of air sacsThis decreases the total gas exchange surface that is availableOver time, the lung becomes less elastic, and the outflow of air is obstructedExplain the grape cluster analogy.27
94 Chronic bronchitisInhaled irritants cause excessive production of mucous in lower respiratory passagesThey also cause inflammation & fibrosis (hardening) of the skin surface (mucosa)28
95 Chronic bronchitis (continued) The result: airway obstruction, poor ventilation of lungs, & interference with the gas exchange processBacteria thrive in the mucous & so pulmonary infections often occur29
96 ETS* -- Respiratory effects Irritates mucous membranesInterferes with system which mechanically expels contaminantsCauses a decrease in respiratory performance (e.g., emphysema)Can worsen effects of a respiratory disease as well as delay healing*Environmental Tobacco Smoke30
98 Protective Measures Nasal hairs filter larger particles Sharp directional changes in pathway cause particles to be caughtAir is heated before entering lungsMoist surfaces react with water-soluble substances before they get further into the system32
99 Protective Measures (continued) Organisms may kill or neutralize inhaled particles (& even inhaled micro-organisms)Cough and sneeze reflexes expel some foreign substancesAllergic reactions can restrict entry of air33
100 Protective Measures (continued) Many of these defense mechanisms can deteriorate with age, or be compromised as a result of illness, tobacco smoking, or exposure to chemical irritants.34
101 Allergic Reactions Muscles in bronchioles (smaller branches) contract Mucous membranes swellEffect: reduction of airflowNote: not necessarily badIf the allergic reaction traps particles and expels them before they reach deep into the lungs, that is “not necessarily bad.”35
102 Allergic ReactionsCommon toxicological concepts such as “dose” and “particle size,” etc. are overpowered by the immune system.36
103 Heating, Ventilation, & Air Conditioning Introduction to HVACHeating, Ventilation, & Air Conditioning1
104 Content covered:Terminology, principles & properties of air relevant to IAQ.Primary HVAC system functions and their impact on IAQ.Major HVAC system components & configurations used to perform these functions.2
106 Dry Air Approximate Composition (by volume): 78.0 % Nitrogen 20.9 % Oxygen1.0 % Argon0.1 % Other Gases“DRY “ because it does not contain any WATER VAPOR.In other words, if air could be completely dried such that it contained no water vapor all, its composition would be as indicated above.4
108 Wet Air Composition Approximate Composition: 78.0 % Nitrogen 20.9 % Oxygen1 - 2 % Water Vapor1 % Argon0.1 % Other GasesOf the other gases, the most prevalent is CO2 which occurs naturally at approximately 350 parts per million or %.6
109 Answer: “Billions and Billions...” Question: How many molecules of air are in this room?Guffey: 2.7x10E19 / cubic cm7
110 Answer: Really fast!Question: How fast do air molecules typically move?Estimated speed: approx mph!Answer courtesy of Bill Nye.8
111 Pressure Pressure = Force / Area The total force exerted upon a given surface at any instant divided by the area of that surfaceExpressed in “pounds per square inch” (psi)9
112 Barometric PressureThe total force of all air molecules impacting a given surface at a given instant in time divided by the areaAKA: “Atmospheric Pressure”Measured using a barometer and stated in “inches of mercury”Draw a mercury barometer showing in. Hg.At sea level and 70 degrees. F the pressure exerted on the surface of the mercury by dry air is psi. This will raise the level of mercury in the tube to a height of inches.In the case of the barometer, the surface is the surface of the mercury in the dish.Draw analogy to a scale.As such, we may think of B.P. as the weight of a column of air extending from the surface of the earth to the top of the atmosphere.10
113 Trick Question #1 Which weighs more: 1 cubic ft. of dry air or 1cubic ft. of humid air?Avoid answering why, if possible.11
114 Air Density 75 lbs. per 1000 cubic ft. Mass of air per unit volume At 70 ° F., the density of dry air is75 lbs. per 1000 cubic ft.12
115 Why Does Warm Air Rise? As the temperature increases, Causing its density to DECREASEAs air is heated it EXPANDSIts density, in turn DECREASES (Fewer molecules per unit volume)Therefore, at higher temperatures, air weighs less per cubic ft.This is why warm air rises.13
116 Vapor A gas which may condense to a liquid at normal temperatures Water Vapor is actually H2O gas occurring in a mixture with dry air.14
117 Relative Humidity (RH) Ratio of the amount of moisture present in the air to the maximum amount which it can hold at saturation at a given temperatureRH varies considerably with temperature.15
118 Human Thermal ComfortDefined in terms of both temperature AND relative humidityASHRAE Standard contains a chart for determining human thermal comfort16
119 Trick Question #2 Which can hold more water vapor: WARM air or COOL air?M.W. of water: 18M.W. of nitrogen: 28M.W. of oxygen: 32Water is therefore lighter than the other primary constituents of air (namely nitrogen and oxygen)In a humid air stream a small fraction of the nitrogen and oxygen molecules will be displaced by the lighter water molecules resulting in a mixture of less overall mass than an equal volume of dry air.18
120 Sensible HeatThe amount of heat which when added to air causes a change in temperature with NO CHANGE in the amount of water vapor present19
121 Latent HeatThe heat content of the water vapor present in the air20
122 Total HeatTotal Heat = Sensible Heat + Latent Heat21
123 Part IIHVAC System FunctionsImpact on Indoor Air Quality22
129 IAQ is relevant because -- 90 percent of your time is spent indoors!Home (tight construction and high efficiency furnaces, humidity, mold) to: Automobile (exhaust vapors, mold in vent and evaporator coil) to: Office
130 IAQ is relevant because -- Change in complexity of chemicals usedIncrease in number/types of chemicalsNew methods to disperse chemicalsNew processes/equipmentRTEC’s 1000s chemicals many variants of isocyanates and glycol ethersAerosolization of surface coating during application (e.g. stucco, shellac)
131 Is the problem new?“No common air from without is so unwholesome as the air within a closed room that has been often breathed and not changed.”Ben Franklin
132 Historical examplesPhysicians in the 1700s linked the deaths of English sailors to their unventilated cabins.In World War I, high levels of carbon monoxide accumulated in Renault tanks from long-term weapons firing.
133 The Office Setting Today Pollutant sources:Building material emissionsFurnishingsOffice equipmentHuman metabolismOutside contaminants brought insideReview exposures from bldg. Materials, furnishings, office equipment, human, outdoor, etc.
134 Building-related illness Where 1 or more workers develop a well-defined illness,A specific cause (airborne agent & pathway) is found, andThe cause is clearly related to the building.Page 11 of BAQNot addressing spread of communicable illness (person to person contact, personal hygiene; does not amplify in building)
137 Sick-building syndrome* Significant number of workers develop non-specific complaints or illnessFew physical signs; absence of clinical abnormalitiesSpecific causative agent rarely found, and assumed to be multi-factorialHighest risk: new or recently remodeled structures with tight envelopes*AKA SBS, tight building syndrome, TBS
138 Common SBS symptoms: Irritation of eyes, nose, and throat Dry mucous membranes and skinErythema (reddened skin)Headache, dizziness, or mental fatigueRespiratory infections or coughHoarseness or wheezingNauseaHypersensitivity reactions (note: if unproved)Also symptoms associated with cold, flu, allergies and stress
139 Tight-building syndrome Alternative definitions:Applied where engineering or architectural flaws result in either a building-related illness or a sick-building syndrome, orApplied where symptoms occur due to a tightly sealed building -- that is, where conditions permit the build-up of contaminants.
140 Sensitization Sensitivity to individual chemical* May occur after brief or long-term exposuresAssumed to be permanentPrevention:Proactive: limit exposuresReactive: remove from workplaceExamples: isocyanates, formaldehyde*Antigen produces immune responseADA accommodations
141 Mass Psychogenic Illness “Symptoms that develop in a group that is under stress (physical or emotional)”Suggested by 1) symptoms that have no organic basis or are inconsistent with exposure & 2) illness occurring only after learning of others being ill
142 Mass Psychogenic Illness (continued) At risk: those in low-paying, stressful jobs that are boring or unrealistically paced, or within physically stressful or rigid authoritarian organizations
143 Multiple Chemical Sensitivity Particular sensitivity to a broad range of low chemical levelsDoes it exist?TheoriesSensitization spreads from chemical to chemicalStressor overloadPsychiatric in originControversal: No medical diagnosis: Orhganic; physiological;Public anxiety with scientific basis (I.e., EMF, dental amalgum)Always a man made chemical, nevery from natural exposures.
144 Indoor ContaminantsShow Drager tubes and reference pages 5-9 and 5-10; and BAQ pages 74-78; and Appendix A and mfgr’s equipment list
145 “All substances are poisons. There is none which is not a poison “All substances are poisons! There is none which is not a poison. The right dose differentiates a poison and a remedy.”ParacelsusReview acceptable risk and how we ingest many natural toxins such as aflztoxin in peanut butter.
146 Major IAQ Contaminants Carbon monoxideFormaldehydeVOCs (volatile organic compounds)ParticulatesAdd list from OSHA’s FOM including: acetic acid, Nox, O3, Radon, H2S, Ammonia, Asbestos, Man-made fibers, ETS
148 A R E C Carbon Monoxide (CO) Anticipation (sources) Cracked heat exchangersCombustion enginesPoorly located air intakesGas burners, gas ovens, wood stoves, or kerosene heatersEven from weapons firing!Mention non-vented space heaters, Lift trucks, Small engine repairACGIH Industrial Ventilation Manual on Lift truck ventilationA R E C
149 A R E C Carbon Monoxide Recognition Possibly complaints of headache Extreme: collapseThe problem: prevents blood from carrying normal oxygen level -- and puts those with heart problems at special risk.A R E C
150 Carbon MonoxideEvaluation Note: can't be smelled, tasted, or seen.Use direct-reading instrumentsPassive, electronic and draw samplersTLV(ACGIH): 25 PPMPEL (OSHA): 50 PPMA R E C
151 A R E C Carbon Monoxide Control Preventive maintenance e.g., forklift tune-upsProper ventilation design/layoutStructure & locationA R E C
152 Carbon Monoxide Control (continued) Appropriate policies/rules Where and when motor vehicles can idleEquipment choiceAirtight wood stoves, reduced fuel consumption kero heaters
153 A R E C Formaldehyde Anticipation (sources) Insulation (UFFI) Composition boardsMedium density fiberboard, hardwood plywood, pressed wood, particle boardCarpet & carpet adhesivesReview but do not do ARECA R E C
154 A R E C Formaldehyde Anticipation (sources continued) Fabrics Gas burners, gas ovensEmbalming fluidsMany other sourcesA R E C
155 A R E C Formaldehyde Recognition Burning eyes (0.1 to 0.3 PPM) Respiratory tract irritation (2 or 3 PPM)Dermal sensitizationA R E C
156 A R E C Formaldehyde Evaluation Odor threshold below 1 PPM Direct reading instruments, and long-term samplingTLV: 0.3 PPM PEL: 0.75 PPMA R E C
157 A R E C Formaldehyde Control Product choice or application method Scheduling of work (exposure)Proper isolation designLocal exhaust ventilationDilution ventilationBuilding commissioning proceduresPPEA R E C
160 VolatilityThe tendency of a material to pass into the vapor state at a given temperature; that is, the tendency to evaporate into the surrounding spaceDitto High and low volative examples. NAAQS
161 A R E C VOCs Anticipation Maintenance products Building materials Combustion processes (including tobacco smoking)Industrial / laboratory chemicalsMany potential sourcesA R E C
162 A R E C VOCs Recognition Examples: Mucous membrane irritation Ocular (eye) irritationSkin irritationA R E C
163 A R E C VOCs Evaluation Direct reading, and Long-term sampling Examples:N-hexane: TLV: 50 PPM; PEL 500 PPMMethyl alcohol: TLV & PEL: 200 PPMA R E C
164 A R E C VOCs Control Product choice or application method Scheduling of work (exposure)Proper isolation designLocal exhaust ventilationDilution ventilationPPEA R E C
165 A R E C Particulates Anticipation Grinding Welding Cutting Sawing, etc.Ditto Office ceiling vents and black marks. NAAQSDuct cleaning and guidelines of national Air Duct Cleaners AssociationA R E C
166 A R E C Particulates Recognition Visible contamination Irritation of mucous membranesLung illnessA R E C
167 A R E C Particulates Evaluation Long-term methods primarily Direct reading (increased use)Direct observation of gross contaminationA R E C
168 A R E C Particulates Control Local exhaust ventilation Dilution ventilationMaterial or process selectionWork area isolationPPEA R E C
169 Additional information Asbestos:See BAQ, Appendix D, ppRadon:See BAQ, Appendix E, ppGlossary / Acronyms:See BAQ, ppTool for SchoolsASHRAE, ACGIH, EPA IAQ Division, NIOSH, Local OSHA & GPOAir currents (Polution pathways) measurements with smoke tube, velometer
170 INDOOR AIR QUALITY CONCERNS BIOAEROSOLSINDOOR AIR QUALITY CONCERNS
171 Bioaerosols Biologically derived airborne contaminants include: MicroorganismsFragmentsToxinsParticulate waste from all varieties of living organisms5 Kingdoms (except viruses) = bacteria; fungi; animal; protozoa; plantslive microorganisms - fragments, toxins, particulate waste
172 Microorganisms Bacteria Pathogenic or Natural Flora Unicellular prokaryotic (no nucleus)Multiplies by cell divisionTypically contained within a cell wallBacteria = can also amplify indoors but lack a specific mechanism to become airborne thus needs some form of agitation (aerosolization)
175 Tuberculosis Anticipation Hospitals Nursing Homes Public Health RecognitionOccupants are sources, not building structure
176 Tuberculosis Evaluation Physician diagnosis of patient Control OSHA / CDC has guidelines for prevention of spread of TB bacillus in affected industries
177 Microorganisms Virus Group of minute infectious agents Can’t be seen by a light microscopeCharacterized by a lack of independent metabolismAbility to replicate only within living host cellsDo not grow or amplify in building resevoir (can’t reproduce)Spread the result of crowded conditions (cold, flue, rabies, measles, mumps, chicken pox, croup)
179 Fungus Mushrooms Yeast Rusts Molds Includes molds (largest biomass on earth) Can successfully colonize and amplify and disseminate large quantities of allergic particles indoors without agitation.
180 Mold Anticipation Temperature range above 40 and below 100 degree F. Mold spores presentNutrient base (most surfaces)MoistureAdd my experience with monitoring for Stachy, Atra & Pulmonary hermosiderosis in Cleveland area/Fiorilli
181 Mold Recognition Exterior corners Poor circulationWind washingLow insulation levelsGreater surface area heat lossSet Back Thermostats - heating seasonMold growth during unoccupied periods
182 Mold Recognition (continued) Air conditioned spaces Thermal bridges Conditioned air blows against the interior surface of an exterior wall.Thermal bridgesCauses localized cooling of surfacesDust accumulationWindowsConcealed condensation
183 Mold Evaluation Visible mold growth Air sampling Anderson impactor Wipe samplesBulk samples
185 Free Water in/on bldg. Materials [Aw = Water Activity] Aw Low=Primary colonizers (first to grow in dust/dirt on wall/ceiling cavities, carpet, furniture) Aspergillus and Penicillium fungiAw Moderate=Secondary colonizers (common outdoors and infiltrate through air inlets & cloths) Cladosporium fungiAw High=Tertiary colonizers (hydrophilic; grow on wet or recently wet bldg. materials; in cooling towers, humidifiers, cooling coils, and condensate pans) Fusarium/Stachybotrys fungi; Pseudomonas/ Bacillus/Streptomyces/Actinomyces G- bacteria
186 Interpretation of Results (Air) Pathogenic fungi such as aspergillus, cryptococcus, histoplasmaToxogenic fungi such as stachybotrys atra, toxic aspergillus, fuscariumPresence of 1or more species (e.g.-2X) greater than outdoor> 50 cfu/m3 of 1 or more species except cladosporium, alternariaDifferent profile of species indoor than outdoorMixture up to 150 cfu/m3 OK if similar to outdoorHigher levels OK in summer if primarily tree fungi like cladosporiumEven low levels of stachybotrys and aspergillus a concern
187 MoldControlMaintain relative humidity near surfaces below dew point. Reduce moisture content of the air by...Control of the sourceDilution of moisture laden air with outdoor air when humidity levels are lowDehumidification
188 Mold Control (continued) Increase air movement at surface Increase air temperature(general space or building)Near room surfaces by raising the thermostat settingImprove air circulationDecrease heat loss: Add insulation; Close cracks in exterior walls
189 Biocontamination Prevention Upgrade filter efficiencyRegular cleaning and maintenance of cooling coil & drain pansMaintain ductwork insulation to minimize applificationClean HVAC if there are obvious signs of contaminationDesign HVAC without porous materials inside ductworkMaintain and inspect humidifiers and cooling towers regularlyPlacement of outdoor air intakes away from street level, loading docks, and cooling towers. Inspect and keep clean.
190 ASHRAE 52.2 MERV MERV %Eff. Final Resist Controls Type < in. w.g. Pollen/mites/fiber Disp./Wash./ESin. w.g. Dust/mist/spores ES/Pleatedin. w.g. Fume/Legionella Box/Bagin. w.g. Tob.Sm./Bacteria Box/Ind. ESMinimum Efficiency Reporting Value (MERV)Highly controlled laboratory testing, instead of dust spotMinimum efficiency instead of averageFilter ability to remove particles of specific size
191 Histoplasma capsulatum HistoplasmosisAnticipationAnimal access to buildingsRecognitionBird droppingsCDC document Sept. 1997Bird droppings cource of nutrition for growth in soilBats can be infected and spread without soil.
196 Aspergillus Fumigatus RecognitionThermophilic - thrives in high temperaturesComposting sites in vicinity of HVAC fresh air intakeFarmers and construction workers - higher risk
197 Aspergillus Fumigatus EvaluationSame as histoplasmosisSoil/site evaluationAir samplingProper diagnosis
198 Aspergillus Fumigatus ControlControl animal access to attics and building structuresReduce dust disturbance
199 AllergensA substance that causes allergic reaction in sensitized populationsChemical or biological in natureAntigens Tree (April/May )- Grass (June/July) Ragweed (Sept/Oct) generally higher outside than inside. Dust Mite; Cochroach feces; VOC generation; Asthma increased 66% since 1982 even though outdoor irritants and respiral particulate levels have decreased
200 Allergens Nonviable (not living) House dust mite fecal pellets Cockroach fecesInsect and spider remainsNonviable remains of molds and their spores
228 Investigation and Evaluation of IAQ Problems We have heard a lot of information about IAQ, what causes problems, and how we look at the HVAC system.Now we will look at the practical considerations in actually conducting an investigation.
229 Recognition and Evaluation SourceHVAC systemOccupantPathwayTraditionally, industrial hygienists have used the AREC model .AnticipationRecognitionEvaluationControlDuring the investigation phase, we are interested in the recognition and evaluation of IAQ problems.4 components must be looked at in most situations to get a clear understanding of the situation. Called the SHOP or CHOP model.Source or ContaminantHVAC systemOccupantPathwayThese are usually involved and interrelated.2
230 Source Outside building Mechanical Equipment and office machines in buildingHuman activitiesBuilding components and furnishingsPage 5 of the EPA Building Air Quality manual under the “Basics” tab has a very good description of sources in a building.Ask questions of class for each of the sources in this slide.Source could be outside bldg:pollen, fungal spores, vehicle exhaust, loading dock exhaust, odor from dumpster, reentrained from building exhaust, radon, previous use of site, rooftop after rainfall with drains blocked, crawlspaceSource could be equipment in the building:dust and dirt in ducts, biological growth in drip pans, coils, cleaning of HVAC system - too much cleaner, office equipment - ozone from copiers, printing press, small labHuman sourcessmoking, cooking, body odors, perfumes, cleaning activities, dust circulated by vacuum cleaner, maintenance activities such as painting, adhesives, pesticidesBuilding components and Furnishingspressed wood, carpeting, textiles, asbestos, water damaged furnishings, dry sewer trap, VOC’s in new materials3
231 HVAC system Unable to control air contaminants Unable to control thermal climateAsk class for examples of each of these on slide.HVAC system unable to distribute adequate amounts of outdoor air.Thermal comfort on page 57 of EPA BAQ gives temperatures and relative humidities when most people are comfortable.Comfort depends on :activity levelagephysiology of individualclothingsingle thermostat for personal choicelarge window are (may be cold or hot if sunny)4
232 Occupants Sensitive TLV’s and PEL’s for average white male OvercrowdingOccupants may be allergic or sensitive individuals or have respiratory diseases.Some people may be immune suppressed, old, infantJob stress can cause similar symptoms. Improper lighting can cause similar symptoms.Multiple chemical sensitivites may be diagnosed by some physicians.5
233 Pathways Airflow patterns HVAC system predominant path Windows, doors Can use smoke tubes to check air flow.Shows air flow patterns in visible way so building maintenance or engineering people can better understand what you are trying to tell them.Look for high pressure to low pressure movvement through any openings.Look at elevators and the large amount of air they push through the building.Don’t forget about the effects of wind.6
234 Pathways HVAC system X source occupant pathway Wind Source inside building.Predominant pathway is probably through HVAC if problem is widespread.Should note direction of air flow at doors, are windows and doors open or closed, are there obstructions to air flow by walls.Wind
235 Pathways HVAC system X air intake pathway Wind Source outside Look for possible sources of contaminant and how it could get into building.If the problem is occasional, see if the problem coincides with a certain wind direction and activity outside. Could be exhaust ventilation going back into building through intake vent.pathwayWind
236 Diagnosing IAQ Complaints Meet with building owner/managerInitial walkthroughInterviews or questionnairesReview informationMore detailed investigation for specific contaminants (air sampling)Report, recommendationsApply control measures, reassessGo through step by step.8
237 Tools for initial walk-through CO2 meter or tubesCO meter or tubesTemperature, Relative humidityFlashlight, step ladder, tool kitTape measure, cameraAsk class to come up with tools they feel would be helpful.9
238 Approach to IAQ Problems Problem surfacesControlsHypothesisWalk-throughScientific hypothesis way to view solving IAQ problems. Each time around the circle would be a more in-depth investigation.Good approach to IAQ problems is in EPA BAQ page 45 called “Resolving IAQ Problems”.1) Problem surfaces2) Evaluate situation through walk through and talking to manager, occupants, HVAC person3) Tentative conclusions4) Gather additional information, more in depth info, focus on particular source or area5) Develop hypothesis and test. Change conditions and see if it helps6) Repeat and attempt a long term control strategy.Gather additional infoor In-depth samplingTentative conclusions
239 Contact building management Area where complaints originateType and frequencyGet building layoutRecent renovations?Any suspected causes?Find out where complaints came from, types and frequency.Get a building layout. Ask if anyone knows or suspects what the problem is.Very important for HVAC person responsible for that system to be present so you know the history of the HVAC system.Many buildings do not have a person dedicated to handling HVAC problems. A contractor is generally called. Make arrangements for the usual person from that contractor to be present.Ask class to think of other questions.One possible other question: Is there a preventive maint. Program?11
240 Initial walk-through Look for sources Water damage Presence of hazardous substancesObvious signs of occupant discomfortLook above dropped ceilingBAQ p. 23Talk to building manager, HVAC person, employees. Sometimes employees or managers may suspect what the problem might be but haven’t told anyone.Take along a building layout so you can make notes at each area.Look at absentee records, ask about odors.Look for signs of occupant discomfort such as redirected diffusers or blocked off diffusers.Look for obvious signs of water damage, visible growth, stains, standing water on the roof.Ask about past water problems that may have been cosmetically covered over.
241 Initial walk-through (continued) Air intakes of HVAC systemBlocked pathways of HVAC systemWere rooms constructed after the HVAC system was installed. Some rooms may not have air supply or return.Cubicle walls or too much furniture may block air circulationCheck for maintenance records for checking linkages, change filters, calibrate thermostats.Look for signs of occupant discomfort such as blocked diffusers, fans in work areas, stuffiness complaint, propped open doors, individual heaters, personal air cleaners, or humidifiers.Look above dropped ceilings for: dirt, connected ducts, grilles through walls to allow airflow in ceiling plenum, debris (nutrients), water damage(moisture).13
242 Detailed Investigation Sampling for specific contaminant if identifiedBioaerosol monitoringLimited guidelinesExpensiveSampling for carbon dioxide, carbon monoxide, temperature and relative humidity are very useful. Other sampling not as useful unless you have a reason to suspect the presence of a particular contaminant.Biological sampling can be useful to identify specific agents which are known to be problems. Here again, sampling is not indicated unless you suspect its presence because of symptoms or visible water damage.Biological sampling when there is no visible water damage or when symptoms do not indicateit, is not suggested. There are no airborne biological standards.21
244 Data collection Questionnaires / survey forms: Interviews In person Over phoneMailedSee BAQ, ppInterviews produce more info but time consumingBe careful not to ask leading questions.15
245 Data collection Activity logs: “Diary” type of data Tracking activitiesprocessessymptom occurrencesSee BAQ, pp. 183, 187, 189Case study.A hospital lab was having problems with odors at various unpredictable times. They kept a log of the occurrence of odors which was matched to the times a helicopter landed on a roof-top landing pad.Although they suspected this was the case, the diary was strong evidence to show a connection between the helicopter and the odors. They needed this evidence because the potential fix was expensive.16
246 Data collection “Proactive” Complaint form See BAQ, p. 181 Reactive Surveys, activity logs, etc.Use BAQ, page 181 sample of IAQ complaint form.If complaint forms are distributed and people know how to fill it out, it should be easier to respond quickly to a problem before more people are affected.Surveys and activity logs may be useful, but at that point many people are usually involved.For a complaint form to work, it must be taken seriously and acted on quickly.17
247 Data collection (continued) Ensure confidentialityDon’t bias processBe consistentBe accurateBe completeGet expert advice on question design (if writing own survey instrument)18
248 Data collection (continued) Compare:“Have you been sick during the past three weeks?” (yes/no)With --“Describe any unusual symptoms you’ve had recently.” (open-ended)Ask questions that are open-ended so more information is volunteered.19
249 Data collection (continued) Compare:“I haven’t felt well for three weeks.”With --“I’ve had itchy eyes and a dry throat for three weeks.”20
250 EPA Building Air Quality Action Plan Companion to the EPA BAQ. BAQ manual is meant to help investigate current problems and develop a good IAQ program. The action plan booklet is a proactive method for taking stock of where the building is now and identifying how to develop a good IAQ program.Plan for comprehensive IAQ program1998
251 Designate an IAQ Manager Employee of building owner or managerCoordinates all IAQ in buildingFamiliar with building structure and functionHas authority to make changes242
252 Develop IAQ Profile Comprehensive look at present situation Document existing practicesLook at structure, function, occupancyLook at design of HVAC system and any changesMake changes to layout of building253
253 Address Existing Problems IAQ Profile highlights potential problemsIdentify resources for emergency situationsUse flowchart in EPA BAQ book (page 45)Same steps as investigating problemsIAQ Profile helps to identify conditions or practices that could cause bad IAQ.Identify emergency resources refers to identifying experts or in-house people and what their roles should be in an IAQ emergency.Page 45 lays out how to diagnose an existing IAQ problem.After the problem is identified, identify the source, improve ventilation, and/or improve air filtration.426
254 Educate Building Personnel Give them perspective of thinking in terms of IAQIAQ Profile helps determine who is trainedBldg. Personnel may know about things that are wrong with the building but fail to understand how that may impact employees working in the building. Education may help to reinforce Bldg. Personnel’s role in keeping employees comfortable.527
255 Implement Plan for Facility Operations HVAC preventive maintenance and standard operating proceduresHousekeepingPreventive maintenanceUnscheduled maintenance286
256 Manage Potential Sources Remodel and renovationPainting, low VOCPest controlShipping/receiving, loading dockEnvironmental Tobacco SmokeTry to minimize sources, change to times when the building is sparsely populated, appropriate supervision of procedures such as pest control.729
257 Communicate with Occupants To prevent IAQ problemsTo get cooperation once a problem occursCommunication goes a long way towards alleviating fears. If employees do not know what is being done about a problem they will assume nothing or a cover-up is occurring.830
258 Establish IAQ Complaint Procedure Always take complaints seriouslyChecklist to verify implementationFollow-up on complaintsAssign each complaint to a person for follow-up and check to see what was discovered during the investigation.931