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Indoor Air Quality (IAQ) and Its Impact upon Building Occupants Andrew Burgie, MS Center for Occupational & Environmental Health at Hunter College Slide 2 OverviewOverview n Which Factors Affect Indoor Air Quality? n How Does One Approach IAQ Problems? u Recognize u Evaluate u Control Slide 3 Definition of IAQ Investigator n Scientist, Detective, Public Relations, etc. = Health & Safety Professional Slide 4 Sick Building Syndrome (SBS) n Acute health and comfort effects linked to the time spent in workplace, but no specific illness or cause can be identified n (Upper respiratory complaints, irritation, fatigue) Slide 5 Building-related Illness (BRI) n Symptoms of diagnosable illness are identified and attributed to environmental agents in workplace n (Legionnaires disease; hypersensitivity pneumonitis) Slide 6 Factors that Affect Building IAQ n Sources of Contamination n The Heating Ventilation, Air Conditioning (HVAC) System n Pollutant Pathways n Building Occupants Slide 7 Sources of Contamination n Sources Outside Building (nearby factory) n Equipment (photocopier) n Human Activities (micro-waving popcorn) n Building Components and Furnishings (carpets) n Other Sources Slide 8 EquipmentEquipment n HVAC System (heating, ventilation, air conditioning system) n Office Equipment & Supplies (photocopier) n Other Sources Slide 9 Human Activities n Personal Activities (smoking) n Housekeeping Activities (mopping with strong cleaners) n Maintenance Activities (painting) Slide 10 Building Components and Furnishings n Locations that Produce or Collect Dust, Fibers, or Odors (bathrooms) n Unsanitary Conditions/Water Damage (faucet drip) n Chemicals Released from Building Components or Furnishings (roof tarring) Slide 11 Other Sources n Accidental Events (substance spills) n Special Use Areas/Mixed Use Buildings (pantry) n Redecorating, Remodeling, Repair Activities (plumbing) Slide 12 The HVAC System (air circulation) Slide 13 The HVAC System n Thermal Comfort (heating and cooling air) n Ventilation (circulating fresh air) n Odor and Contaminant Control (filtering air devices) Slide 14 Pollutant Pathways n Stack Effect - Pressure by Convection u Air rises when heated and falls when cooled n Wind Effect - High to Low Pressure u Air moves from high to low concentrations Slide 15 Building Occupants n Hypersensitive or Susceptible Individuals (people who get sick easily) Slide 16 IAQ Investigations & Measurements n Only when you know what you are looking for do the measurements become significant Slide 17 Recognizing Building IAQ Problems n Key Questions for IAQ Investigation n Looking for IAQ Problem Identifiers Slide 18 Key Questions for IAQ Investigation n How Was this Building Originally Supposed to Function? n Is the Building Functioning as Designed? n What Changes in Building Layout and Use Have Occurred Since Original Design and Construction? n What Changes May Be Needed to Prevent Future IAQ Problems? Slide 19 Look for IAQ Problem Identifiers n Odors u moldy, chemical, exhaust fume n Signs of Moisture Damage or Accumulation u damp or wet surfaces, puddling of water n Staining or Discoloration u brownish or yellowish ceiling or carpet tiles n Presence of Hazardous Substances u chemical containers, spray bottles, etc. n Dirty or Unsanitary Conditions u unclean bathroom, dusty storage room, etc. Slide 20 Look for IAQ Problem Identifiers n Visible Fungal/Bacterial Growth u mold or slime growth n Unusual Noises from Lights or Machinery u may be caused by loose or broken parts n Inadequate Maintenance u cracked/peeling walls; equipment poorly taped n Signs of Occupant Discomfort u cough, watery and/or red eyes, headache) n Overcrowding u too many desks, chairs, etc. in room Slide 21 Look for IAQ Problem Identifiers n Blocked Airflow/Poorly Located Vents, etc. u cardboard covering vent; books stacked on vent n Ceiling Plenums u (space between the ceiling tiles and ceiling) n Heat Sources u space heaters, desk fans n Special Use Areas u food pantries, kitchens, copy rooms, bathrooms Slide 22 Look for IAQ Problem Identifiers n Carbon Dioxide (CO 2 ) concentration (ppm*) u exhaled air removed from room (stuffiness) n Temperature ( 0 F or 0 C) u warmth of room (hot or cold) n Relative Humidity (%) u moisture level in room - dry (5%) or damp (95%) n Carbon Monoxide (CO) concentration (ppm*) u generated by faulty burning (stove/heater/car/etc.) n Air Circulation u Is air sucked in (negative pressure) or pushed out (positive pressure) of room when door opened? *ppm = parts per million; measurement of volume Slide 23 Look for IAQ Problem Identifiers Indoor Air Quality direct-reading instrument: Gives air quality measurements instantaneously in the field without having air samples sent to a laboratory for analysis Sampling wand Computer display screen Function control board Slide 24 Whats Wrong with this Room? Slide 25 Evaluating Building IAQ Problems n Key Questions for Walkthrough n Conducting Initial Walkthrough n Collecting Additional Information, Including Sampling (If Necessary) Slide 26 Key Questions for Walkthrough n Are There Obvious Pollutant Sources? If so, Are They Adequately Controlled? n Are There Any Deficiencies in the HVAC System that Serves the Complaint Area? n Are there Pathways and Pressure Differences Moving Contaminants into Complaint Area(s) from Outdoors or from Other Parts of Building? Slide 27 Initial Walkthrough n Collect Info on History of Building and Complaints n Identify Known HVAC Zones and Complaint Areas n Notify Building Occupants of Upcoming Investigation n Identify Key People Needed for Access & Information Slide 28 Collecting Additional Information n Occupant Complaints Data (previous surveys, complaint letters) n HVAC System Data (maintenance schedule, standard operation) n Pollutant Pathways Data (how does the air circulate) n Pollutant Sources Data (where is the problem coming from) n Air Sampling for Contaminants & Identifiers n Building and Room Occupancy (potential crowding issues) n Identify Complaints Not Caused by Poor Air Quality (ergonomic issues poor office furniture or lighting) Slide 29 Controlling Building IAQ Problems n Source Control n Ventilation n Air Cleaning n Exposure Control Slide 30 Controlling Building IAQ Problems n Source Control u remove contaminant & contaminant generator n Ventilation u improve and/or increase air flow n Air Cleaning u filter out impurities with specialized air filters n Exposure Control u pressurize room to control air flow in and out Slide 31 Controlling Building IAQ Problems Air scrubbing device Air duct cleaning Chemical fumes in tent are pumped through large air filtering device and clean air comes out of stacks Tent Air filter Stacks Slide 32 CONCLUSION n QUESTIONS & DISCUSSION _____________________________________ ANDREW BURGIE, M.S. Center for Occupational & Environmental Health at Hunter College (212) 481-7652