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INDOOR
AIR QUALITY
Indoor Air Quality ConsultantTedd@IAQconsultant.com(613) 558 - 4545
TEDD NATHANSON, P. Eng.
Union of Taxation Employees
November, 2010
Agenda
General IAQ Introduction New Initiatives ; Codes, Standards,
Guidelines What we want / have / can do VOCs , Microbials, etc. Future trends, Conclusions
AIR
78.1%20.9%
0.9%0.1%
100%
NITROGENOXYGENARGON0.035 (CO2)0.065 Mixture
IAQ FACTORS
Indoor Air Quality:
Building Envelope, Materials, Furnishings, Occupant Density and Activities, Processes
HVAC System: Design, Operation and Maintenance
Outdoor Air Quality:
Gases, Particulates, Seasons, Locations
IAQ Pollutants / Stressors
Pollutants - carbon monoxide, formaldehyde, VOCs, particulates, microbials
Stressors - temperature, RH, odours, air motion/circulation, noise, lighting, vibration, privacy, housekeeping, social
Solutions - source control, ventilation, air flow (P), isolation, time of use, sealing, substitution
INDOOR AIR QUALITY (IAQ)
Physical, chemical and biological characteristics of indoor air that can effect the comfort and
health of the occupant.
ASHRAETLVppm
ACGIHVOCppb
SBSTVOCHVAC
CANADA LABOUR CODE: PART II
Every employer shall insure that the safety and health at work of every person employed by the employer is protected [124];
Ensure that all permanent and temporary buildings and structures meet the prescribed standards [125 (a)];
Ensure that the levels of ventilation, lighting, temperature, humidity, sound and vibration are in accordance with prescribed standards [125 (1) (n)]; and
Ensure that concentrations of hazardous substances in the workplace are controlled in accordance with prescribed standards [125.1(a)].
LABOUR CANADA, PART II OSH REGULATIONS
Built or when modified, to meet ASHRAE 62 - 1989 “as
amended”
Design information to be available
All systems to have operating, inspection, testing, cleaning,
maintenance and calibration instructions
Reports to be prepared by a "qualified person" and posted
IAQ investigation to be done when warranted (Technical
Guide)
Revised in 2000, Division 3 : HVAC Systems
STANDARDS
ACGIH, Threshold Limit Values, Chemical Substances and Physical Agents
ASHRAE 62, Ventilation for Acceptable Indoor Air Quality (under continuous revision)
ASHRAE 55, Thermal Environmental Conditions for Human Occupancy
Guidelines, Good Practices, Policies
Health Canada, IAQ in Office Buildings: A Technical Guide, 1995
CSA Z2044-94, Guidelines for Managing IAQ in Office Buildings
Canadian Construction Association, Mould Remediation Guidelines, 2004
Health Canada, Fungal Contamination in Public Buildings, 1995, 2004
Duty to Accommodate
BUILDING RELATED HEALTH EFFECTS
Building Related Illness
Sick Building SyndromeMass Psychologic Illness
Multiple Chemical Sensitivity,Environmental Sensitivity
SICK BUILDING SYNDROME
Eye, nose throat irritation Headache Fatigue Reduced concentration Irritability Dry skin Nose bleeds
SBS
SBS is a multifactorial problem involving chemical,
microbiolgical, physical, and psychological mechanisms.
The syndrome may represent overlapping sets of symptoms
involving multiple causes and physiologic pathways.
Until we identify specific causes, appropriate mitigation and
prevention of building-related symptoms may need to be at
the level of prudent design, operation, and maintenance
practices, focused on factors which reduce the likelihood of
problem indoor exposures and conditions.
Mendel, 1994
52% DUE TO CONTAMINATION
Microbials VOC's, Formaldehyde Carbon Monoxide Particulates
48% DUE TO VENTILATION
Improve Operation Lack of Maintenance Poor Circulation Exhaust Re-entrainment High Temperature Low Relative Humidity High Carbon Dioxide
GOAL - to provide a healthy comfortable and productive
workplace
IAQ AND PRODUCTIVITY
Construction Cost: Land, Design & Construction: $16.00Furnishings and Office Equipment: $15.90
Operating: Utilities $2.00 Janitorial $1.00 Taxes and Insurance $2.00 Management, Services, Vacancies $3.50 $8.50Employee Costs: Salaries & Benefits: $265.00
$/sq.ft./y
Indoor Air Quality Update, August 1989, Amortized at 9% for 30 years
Employee productivity loss
attributable to IAQ is
estimated to be 3% (14
min/day) and 0.6 added sick
days annually.
Understanding Indoor Quality, Brooks and Davis Ref.: J. Woods, 1989, Occup. Med. State Art Rev.
IAQ STANDARDS AND REGULATIONS
"You don't have to know everything before you do
anything"
-- James Scheurer (D-NY)
ASSESSMENT STRATEGY
IAQ Factors and Issues
Stage 1: Walkthrough, inspection, discussion, solution?
Stage 2: Measurement
STAGE 2
HVAC AND IAQ ASSESSMENT System Design, Capacity, Performance IAQ Measurements:
Temperature, relative humidityCarbon Dioxide (ventilation rate)Carbon Monoxide (pollution intrainment)ParticulatesVolatile Organic Compounds (VOCs)Microbials (moisture content)
VOLATILE ORGANIC COMPOUNDS (VOC’S)
Off-gassing of chemicals from new materials - construction and renovation
Sources: structural; particle board, glues, paints furnishings; carpets, computers, furniture consumer products; perfume, shampoo,
cleaning agents pesticides, disinfectants, etc.
TVOC
>3 mg/m³ perceived odour intensity, mucous membrane irritation, concentration ability reduced
>8 mg/m³ degraded air quality, ventilation, dryness
>25 mg/m³ significant irritation of eyes, nose and throat, confusion, fatigue
PWGSC 1 mg/m³ target5 mg/m³ action level
Biological Agents& Sources
Bacteria : humans / water / food Fungi or mould: plants / soil / food Viruses : humans / animals Allergens/Antigens : animals (pets),
cockroach / mites, by-products of bacteria (endotoxins) and moulds (MVOCs, mycotoxins and fragments).
MICROBIAL SOURCES
Wet carpet, ceiling tiles, insulation, walls (condensation, leaks, floods)
Spray humidifiers, reservoirs Condensate pansWater towers
dirt + WATER = Microbial Growth
Pro - Active Measures to Avoid Microbial Contamination
Moisture Control in buildings and systems ~ design, construction, operation, maintenance and use.
Dust/dirt control through good HVAC O&M, and housekeeping
Water Damage Restoration
FLOOD REMEDIATION
Microbial contamination does not need to follow water damage.
A rapid response to contain and limit water damage, the removal of soiled substrates, cleaning and drying, will provide limited opportunity for microbial growth.
No need to sample if mould is visible.
No Regulated Exposure TLVs for Mould
Wide variation in individual susceptibility: genetics, age, health, past exposure at home /work, etc.
The effects of other agents and secondary by-products are unknown and few biological markers exist.
Few epidemiological studies regarding dose-response relationship. Anecdotal cases.
No Regulated Exposure TLVs for Mould (con’t)
Different sampling methods: equipment, time and period, spore type and size, (viable/non-viable) collection media (agar/slides), incubation time and temperature.
Collection methods do not reflect actual human exposure
Exposure and Risk
Must be airborne (inhaled, contacted, or ingested)
Depends on the species type, viability (allergenic, toxigenic, pathogenic)
Depends on amount ( time) Depends on susceptibility
Therefore no “threshold” - however, it is prudent to minimize exposure.
Legal Precedent : 1989, Hospital, St. Foy, Quebec. “Mould should not grow in buildings.” [adapted by PWGSC, U.S.EPA, Canadian Construction Association, etc.]
CMHC (1993) : “People should not live in moldy houses.”
Mould Exposure Guidelines
Visible or hidden microbial growth within a structure is not acceptable.
Indoor quantities should be lower than outdoors, and reflect the same rank order (biodiversity).
The confirmed presence* of toxigenic species requires risk management according to established guidelines.
* defined by AIHA
OTHER “Problems”
Histoplasma capulatum : a soil fungi that grows with bird and bat excrement. Causes histoplasmosis, a lung disease.
Hantavirus : airborne viral infection found in urine, saliva or droppings of infected deer mice, can be fatal. (BC)
Anthrax : bacteria, Bacillus anthracis, affecting grazing animals, toxic.
Escherichia coli : bacteria found in feces. Total Coliforms (water quality). TB, SARS, etc. from third-world countries Lead in drinking water and in paint
SENSITIZATION
After an initial exposure to a particular allergen, an individual who develops an allergy becomes "sensitized" to that allergen.
Subsequent lower exposures may elicit a reaction
Environmental Sensitivity
ES may be classified as a disability ? Employer has a ‘duty to accommodate’
and employees have a ‘right to work’. Employer must do so until the point of
“undue hardship”. This requires ‘one good try’ to
accommodate. Need support & cooperation of all.
LEGIONELLA: Pneumonia
American Legion Conventions,Philadelphia 1976Bellevue Stratford Hotel;(182 affected, 29 died}
Contaminated humidifiers, wet surfaces, hot water systems, hot tubs, vaporizers, cooling towers, condensers
OZONE (O3)
TOXIC Health Effects:
lung and immune system irritation, dryness of eyes, nose and throat
FDA max. acceptable level 50 ppbhealth effects 60 - 80 ppbACGIH ceiling, TLV 100 ppbsmell threshold 5 - 2000 ppb (olfactory fatigue)
PCB's: Polychlorinated Biphenyls (Chlorodiphenyls)
electric transformers, capacitors, ballastshydraulic fluids, oils
ACGIH TLV 1 - 0.5 mg/m³NIOSH TWA 1 - mg/m³, carcinogen
ASBESTOS
Insulation: pipe, walls, ceilings, ducts, boilers Ceiling and floor tiles Plaster and paints Pro-active management program for disturbance,
retrofit
"Intact and undisturbed asbestos materials do not pose a health risk" EPA, NIOSH, OSHA
RADON
Decay of Radium Þ particles, colourless,odourless
HC: 800 Becquerels/m³ action level, has been reduced to 200 in 2007.
New or Retrofitted Buildings
Select low-emitting, low solvent content, less toxic, less odourous
products. Review manufacturers' specifications and the material
safety data sheets (MSDS). Properly commission the building or space. ASHRAE Guideline
1-1989, Guideline for Commissioning of HVAC Systems, is a good
reference document. Phase in products, finishing and furnishings over different time
periods so as not to create a "sink" (e.g., VOCs from carpets
absorbing onto partitions). Ideally, products should off-gas at the
manufacturer or in off-site storage and should not be plastic
wrapped after assembly.
New or Retrofitted Buildings (cont'd)`
Increase the ventilation rate as much as possible over several weeks after installation. Run the ventilation system 24 hours a day until odours are gone. It is a good idea to open a window to exhaust pollutants during renovation, while blocking-off the returns. Schedule retrofit activity in the spring or fall, when more outside air can be supplied. If work is done over the weekend, do not shut off the ventilation system.
Monitor the total VOC (TVOC) levels and occupy space only when levels are below a certain limit (perhaps 5 mg/m³).
Establish a communication plan with the occupants, detailing the work to be done, the timetable and the method of addressing IAQ issues. Provide a contact person's name, phone number and E-mail address if applicable.
IAQ and the Future
Compliance and due diligence – building environmental audits.
Legal, liability, and insurance issues -- worker’s compensation, risk assessment, duty of building owner, employer, professionals, and trades. Certification.
Materials selection -- emissions, offgassing, “green products”. LEED (Leadership in Energy and Environmental Design) certified buildings.
Information and awareness -- WWW, court cases, news media, more “consultants and experts”.
Conclusions
Many IAQ problems can be prevented by educating facility management, staff and occupants about IAQ issues and factors.
The expense and effort required to prevent most IAQ problems is much less than that required to resolve problems after they develop.
When IAQ problems do arise, they can often be resolved using skills that are available in-house.
If outside assistance is needed to solve an IAQ problem, the best results will be achieved if building owners, managers and occupants are informed consumers.
Open and full communication is part of the successful resolution of an IAQ problem.
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