Pollution depletion mechanism (deposition and chemica

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Indoor Air Quality (IAQ)

• People spend more time indoors, thus have
  longer-time exposure to pollutants in the indoor
  environments

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Factors affecting Indoor Air Quality

• Outdoor air quality
• Indoor generation of pollutants
• Pollution depletion mechanism (deposition and
  chemical decay)
• Meteorological factors (affects air exchange)
• Permeability of structure (affects air exchange)
• Ventilation measures (affects air exchange)

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Indoor/outdoor relationship

• SO2 0.3-0.7
• NO2 lt1 gt 1 (with stove in use)
• CO 1
• HCs gt1
• HCHO gt1
• PM lt1 (no burning source)

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Pollution sources at home
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Pollution sources at office
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Office Equipment Emissions
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Sick Building Syndrome (SBS)

• A spectrum of non-specific symptoms with no
  identifiable cause
• - irritation of eyes, nose, throat, and sinuses
• - headache, fatigue, lassitude
• - dryness, rashes
• - cough, short of breath

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Procedures for investigating IAQ complaints
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Prevention and control

• Source Management
• Use of low emission products
• Carpet with low VOC and odor
• Furniture with low formaldehyde
• Electric cooker
• Source Treatment
• scavenging coatings to treat HCHO

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Contaminant control

• Ventilation
• Natural
• Open window
• Mechanical used in offices and commercial
  buildings
• General dilution is used to dilution human
  bioeffluents and other contaminants
• Used to mitigate SBS-type symptoms
• Guidelines on ventilation rate (CUM/person) for
  building designers

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Contaminant control

• Air cleaning
• Filtration to move particulate matter
• Dust-stop filters
• Pleated-panel filters
• Sorbents to remove gas contaminants
• E.g., Activated carbon (charcoal) for VOC

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A local study of indoor air pollution in offices
and public places in Hong Kong

• Study Period October 95 - March 97 (18 months)
• Consultants EHS Consultants Limited
• Contract Sum HK 11 million
• Steering Group Members SPEL, EPD, ASD, LD, EMSD,
  D of H

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Objectives

• Characterizing and understanding the indoor
  pollution in offices and public places in Hong
  Kong.
• Assessing various causes of indoor air pollution
  and factors affecting IAQ.
• Identifying cost-effective mitigation measures
  and recommending control strategy.

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Methodology

• Telephone questionnaire survey of 2000 office
  workers
• 40 representative office buildings selected for
• on-site questionnaire survey (1183 respondents)
• detailed field measurements
• Public places - field measurements
• Country study
• questionnaire design based on the one by the US
  NIOSH
• field measurement protocol based on the USEPA
  Building Assessment Survey Evaluation (BASE)
  Study

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Field measurements
Number of premises studied
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On-site survey

• Observations
• Sampling and Analysis 5 sites per building,
  total 200

• Quality assurance
• Independent audit
• Outdoor parallel sample

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Major Findings (1)

• Air quality of about 1/3 of the 1,500 office
  buildings in Hong Kong was perceived to be
  unsatisfactory or has violated relevant overseas
  standards.

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Major Findings (2)

• Offices
• 32 of the respondents dissatisfied with the IAQ
  of their workplace
• 90 had fresh air supply below minimum
  requirement of 7.51/s per occupant
• 37.5 had CO2, exceeded 1000ppm
• 32.5 had formaldehyde exceeded 100 µg/m3
• 20 had bacteria counts exceeded 1000CFU/m3
• 10 had the presence of toxigenic fungal species
• 10 had VOCs violated the relevant IAQ objectives
• Public Places
• Occasional non-compliance including CO2, NO2, RSP
  and nicotine

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• Indoor Air Quality Management Programme in Hong
  Kong (suggested by the Study)
• An inter-departmental IAQ Management Group has
  been formed to oversee the implementation
  activities, including
• Launching public education campaign
• Setting up an IAQ Information Center
• Adopting IAQ objectives
• Publishing Guide of Notes for the management of
  IAQ
• Promulgating a IAQ certification scheme
• Conducting review of legislative frame work for
  IAQ
• Publishing professional practice notes for
  public transport facilities

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Recommended indoor air quality objectives

• Level 1 represents very good indoor air quality
  that a high-class and comfortable building should
  have.
• Level 2 represents indoor air quality that
  provides protection to the public at large
  including the very young and the aged.
• Level 3 represents indoor air quality that is
  required to protect workers and employees as
  enforced under the current occupational safety
  and health laws.

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Indoor Air Quality Certification Schemefor
Offices and Public Places
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What is the "IAQ Certification Scheme"?

• The IAQ Certification Scheme aims to
• recognize good IAQ management practices
• provide incentives for owners of premises /
  buildings or property management companies to
  pursue the best level of IAQ

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Why Participate?

• provide a good and healthy indoor environment
• improve the productivity and minimize medical
  expenses
• increase the competitiveness of the building
• enhance the corporate image

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Key Features of the Certification Scheme

• Voluntary and self-regulatory approach
• Two-levels of IAQ objectives
• An IAQ certificate for display in the premises
• Certify entire building or selected location(s)
• The certificate is valid for 12 months
• Measure a full set of parameters every 5 years
• Need to maintain post-certification IAQ

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Applicability

• Buildings or totally enclosed areas for use as
  offices or public places which are served by MVAC
  systems
• office buildings
• shopping malls
• hotels restaurants
• theatres cinemas
• karaokes etc

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Key Steps for IAQ Certification

• Step 1 Engage a Competent Examiner
• Step 2 Conduct Walkthrough Inspection
• Step 3 Conduct IAQ Measurement
• Step 4 Sign Off IAQ Certificate
• Step 5 Apply for Registration
• Step 6 Complete Registration
• Step 7 Manage Post-certification IAQ
• Step 8 Initiate Certificate Renewal

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Excellent and Good Class IAQ Certificates