Transcript General
Indoor Air Quality (IAQ) and Its Impact upon Building Occupants Andrew Burgie, MS Center for Occupational & Environmental Health at Hunter College Overview Which Factors Affect Indoor Air Quality? How Does One Approach IAQ Problems? Recognize Evaluate Control Definition of IAQ Investigator Scientist, Detective, Public Relations, etc. = “Health & Safety” Professional Sick Building Syndrome (SBS) Acute health and comfort effects linked to the time spent in workplace, but no specific illness or cause can be identified (Upper respiratory complaints, irritation, fatigue) Building-related Illness (BRI) Symptoms of diagnosable illness are identified and attributed to environmental agents in workplace (Legionnaire’s disease; hypersensitivity pneumonitis) Factors that Affect Building IAQ Sources of Contamination The Heating Ventilation, Air Conditioning (HVAC) System Pollutant Pathways Building Occupants Sources of Contamination Sources Outside Building (nearby factory) Equipment (photocopier) Human Activities (micro-waving popcorn) Building Components and Furnishings (carpets) Other Sources Equipment HVAC System (heating, ventilation, air conditioning system) Office Equipment & Supplies (photocopier) Other Sources Human Activities Personal Activities (smoking) Housekeeping Activities (mopping with strong cleaners) Maintenance Activities (painting) Building Components and Furnishings Locations that Produce or Collect Dust, Fibers, or Odors (bathrooms) Unsanitary Conditions/Water Damage (faucet drip) Chemicals Released from Building Components or Furnishings (roof tarring) Other Sources Accidental Events (substance spills) Special Use Areas/Mixed Use Buildings (pantry) Redecorating, Remodeling, Repair Activities (plumbing) The HVAC System (air circulation) The HVAC System Thermal Comfort (heating and cooling air) Ventilation (circulating fresh air) Odor and Contaminant Control (filtering air devices) Pollutant Pathways Stack Effect - Pressure by Convection Air rises when heated and falls when cooled Wind Effect - High to Low Pressure Air moves from high to low concentrations Building Occupants Hypersensitive or Susceptible Individuals (people who get sick easily) IAQ Investigations & Measurements Only when you know what you are looking for do the measurements become significant Recognizing Building IAQ Problems Key Questions for IAQ Investigation Looking for IAQ Problem Identifiers Key Questions for IAQ Investigation How Was this Building Originally Supposed to Function? Is the Building Functioning as Designed? What Changes in Building Layout and Use Have Occurred Since Original Design and Construction? What Changes May Be Needed to Prevent Future IAQ Problems? Look for IAQ Problem Identifiers Odors moldy, Signs of Moisture Damage or Accumulation damp chemical, exhaust fume or wet surfaces, puddling of water Staining or Discoloration “brownish” Presence of Hazardous Substances chemical or “yellowish” ceiling or carpet tiles containers, spray bottles, etc. Dirty or Unsanitary Conditions unclean bathroom, dusty storage room, etc. Look for IAQ Problem Identifiers Visible Fungal/Bacterial Growth mold Unusual Noises from Lights or Machinery may or slime growth be caused by loose or broken parts Inadequate Maintenance cracked/peeling Signs of Occupant Discomfort cough, walls; equipment poorly taped watery and/or “red” eyes, headache) Overcrowding too many desks, chairs, etc. in room Look for IAQ Problem Identifiers Blocked Airflow/Poorly Located Vents, etc. cardboard Ceiling Plenums (space between the ceiling tiles and ceiling) Heat Sources space covering vent; books stacked on vent heaters, desk fans Special Use Areas food pantries, kitchens, copy rooms, bathrooms Look for IAQ Problem Identifiers Carbon Dioxide (CO2) concentration (ppm*) exhaled Temperature (0F or 0C) warmth air removed from room (stuffiness) of room (hot or cold) Relative Humidity (%) moisture level in room - dry (5%) or damp (95%) Carbon Monoxide (CO) concentration (ppm*) generated by “faulty” burning (stove/heater/car/etc.) Air Circulation Is air “sucked in” (negative pressure) or “pushed out” (positive pressure) of room when door opened? *ppm = parts per million; measurement of volume 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 What’s Wrong with this Room? Evaluating Building IAQ Problems Key Questions for Walkthrough Conducting Initial Walkthrough Collecting Additional Information, Including Sampling (If Necessary) Key Questions for Walkthrough Are There Obvious Pollutant Sources? If so, Are They Adequately Controlled? Are There Any Deficiencies in the HVAC System that Serves the Complaint Area? Are there Pathways and Pressure Differences Moving Contaminants into Complaint Area(s) from Outdoors or from Other Parts of Building? Initial Walkthrough Collect Info on History of Building and Complaints Identify Known HVAC Zones and Complaint Areas Notify Building Occupants of Upcoming Investigation Identify Key People Needed for Access & Information Collecting Additional Information Occupant Complaints Data (previous surveys, complaint letters) HVAC System Data (maintenance schedule, standard operation) Pollutant Pathways Data (how does the air circulate) Pollutant Sources Data (where is the problem coming from) Air Sampling for Contaminants & Identifiers Building and Room Occupancy (potential crowding issues) Identify Complaints Not Caused by Poor Air Quality (ergonomic issues – poor office furniture or lighting) Controlling Building IAQ Problems Source Control Ventilation Air Cleaning Exposure Control Controlling Building IAQ Problems Source Control remove contaminant & contaminant generator Ventilation improve Air Cleaning filter and/or increase air flow out impurities with specialized air filters Exposure Control pressurize room to control air flow in and out Controlling Building IAQ Problems Chemical fumes in tent are pumped through large air filtering device and clean air comes out of stacks Air duct cleaning Tent Air filter Stacks “Air scrubbing device” CONCLUSION QUESTIONS & DISCUSSION _____________________________________ ANDREW BURGIE, M.S. Center for Occupational & Environmental Health at Hunter College (212) 481-7652