Indoor Air Quality
MOHD TALIB LATIF
School of Environmental and natural Resource Sciences
Faculty of Science and Technology
University Kebangsaan Malaysia
Indoor Air Quality
 Indoor air quality (IAQ) is a term referring to
the air quality within and around buildings and
structures, especially as it relates to the health
and comfort of building occupants
Indoor Air Pollution
 The National Health and Medical Research Council
(NHMRC- Australia) defines indoor air as air within a
building occupied for at least one hour by people of
varying states of health. This can include the office,
classroom, transport facility, shopping centre, hospital
and home.
 Indoor air quality can be defined as the totality of
attributes of indoor air that affect a person's health
and well being.
Sick building syndrome
Condition associated with
complaints of discomfort including
headache; nausea; dizziness;
dermatitis; eye, nose, throat, and
respiratory irritation; coughing;
difficulty concentrating; sensitivity
to odors; muscle pain; and fatigue.
Sick building syndrome
 The specific causes of the symptoms are often not
known but sometimes are attributed to the effects of a
combination of substances or individual susceptibility
to low concentrations of contaminants.
 The symptoms are associated with periods of
occupancy and often disappear after the worker leaves
the worksite.
Cause of SBS
 Inadequate ventilation 52%
 Contamination from inside building 16%
 Contamination from outside building 10%
 Microbial contamination 5%
 Contamination from building fabric 4%
 Unknown sources 13%1
Thermal Comfort
 Personal factors (health, psychology, sociology &
situational factors)
 Air temperature
 Mean radiant temperature
 Air movement / velocity (see wind chill factor)
 Relative humidity (see also perspiration)
 Insulative clothing
 Activity levels.
THE IMPORTANT OF INDOOR
AIR QUALITY
Indoor Air Quality Council-USA
The IAQ Council offers certifications in five disciplines related to
indoor air quality:
Indoor Environmental Consulting and Investigation
 Council-certified Indoor Environmental Consultant (CIEC)
 Council-certified Indoor Environmentalist (CIE)
Microbial Consulting and Investigation
Council-certified Microbial Consultant (CMC)
 Council-certified Microbial Investigator (CMI)
Microbial Remediation
 Council-certified Microbial Remediation Supervisor
(CMRS)
 Council-certified Microbial Remediator (CMR)
Indoor Air Quality Administration
 Council-certified Indoor Air Quality Manager
(CIAQM)
 Council-certified Microbial Claims Adjuster (CMCA)
Residential Mold Inspection
 Council-certified Residential Mold Inspector (CRMI)
Sources of Indoor Pollutants
Base on Specific Building
Combustion activity
Furniture
Chemical
Building materials
Food
Water
Smoking activity
Outdoor air pollution
Walkaround Inspection
 Potential Problem Areas
 Sample Collection
Contaminant
Range
Screening Method
Validation Method
Bioaerosols
0-1,000 cfu/m3
Viable biological
sampler
Carbon dioxide
0-2,000 ppm
DT, IR
Sampling bag, GC/TCD OSHA
ID172
Carbon
monoxide
2-50 ppm
DT, meter
Sampling bag, meter
Formaldehyde
0.04-1 ppm
DT
Coated XAD-2, GC/NPD OSHA-52
Nitric oxide
0-25 ppm
DT
TEA tube with oxidizer, DPP OSHA
ID190
Nitrogen
dioxide
0-5 ppm
DT
TEA-Molecular Sieve Tube, IC
OSHA ID 182
Particulates
0-40,000
particles/cc
Light scattering meter
Pesticides
(See OSHA Chemical Information Manual)
Ozone
0-0.1 ppm
DT, Chemiluminescent
meter
Radon
4-200 pCi/L
Radon Cartridge,
Electrect
VOC's
(See OSHA Chemical Information Manual)
GREEN BUILDING INDEX
http://www.greenbuildingindex.org/
Green Building Index (GBI)
 The Green Building Index (GBI) is Malaysia’s industry
recognised green rating tool for buildings to promote
sustainability in the built environment and raise
awareness among Developers, Architects, Engineers,
Planners, Designers, Contractors and the Public about
environmental issues and our responsibility to the
future generations
What is Dust
 Dust consists of tiny solid particles carried by
air currents. These articles are formed by a
disintegration or fracture process, such as
grinding, crushing, or impact.
 The Mine Safety and Health Administration
(MSHA) defines dust as finely divided solids
that may become airborne from the original
state without any chemical or physical change
other than fracture.
Occupational health point of view
 Total Dust
 Inhalable Dust
 Respirable Dust
Total Dust
 Total dust includes all airborne particles,
regardless of their size or composition.
Inhalable Dust
 The EPA describes inhalable dust as that size
fraction of dust which enters the body, but is
trapped in the nose, throat, and upper
respiratory tract. The median aerodynamic
diameter of this dust is about 10 µm.
Respirable Dust
 Respirable dust refers to those dust particles that are
small enough to penetrate the nose and upper
respiratory system and deep into the lungs.
 Particles that penetrate deep into the respiratory
system are generally beyond the body's natural
clearance mechanisms of cilia and mucous and are
more likely to be retained.
OSHA Definition
General Understanding
Fine mode
Aerosols
Other
19%
SO4237%
EC
5%
OC
24%
NH4+
11%
NO34%
Other OSHA Definition
 Inhalable Particulate Mass
 Dust particles having a 50% cut-point of 100 µm. These dust particles are
hazardous when deposited anywhere in the respiratory tract.
 Thoracic Particulate Mass
 Dust particles having a 50% cut-point of 10 µm. These dust particles are
hazardous when deposited anywhere in the lung airways and gas-exchange
regions.
 Respirable Particulate Mass
 Dust particles having a 50% cut-point of 4 µm. These dust particles are
hazardous when deposited anywhere in the gas-exchange regions.
MSHA Definition
Aerodynamic
diameter
Percent
µm
passing
(unit density spheres)
selector
2.0
90
2.5
75
3.5
50
5.0
25
10.0
0
*MSHA – Mine Safety and Health Administration
Inhalable Dust (Malaysian DOSH)
Respirable Dust (Malaysian DOSH)
INDOOR AIR SAMPLING
(DOSH METHOD)
Respirable and Total Dust
Respirable Dust Sampling Head
Respirable Dust
Total Dust Sampling Head
Total Dust
Gas Analysis
Lead in Indoor Air
Asbestos
Guideline
 Base on Code of Practice on Indoor Air Quality
(DOSH 2005)
Indoor Air
Contaminant
Eight-hour time weighted average airborne
concentration
Unit
ppm
Carbon dioxide
1000
Carbon monoxide
10
Formaldehyde
0.1
Respirable particulate
Total Volatile organic
compounds
mg/m3
0.15
3
OSHA (USA) Limit for Air
Contaminants
 http://www.osha.gov/pls/oshaweb/owadisp.show_doc
ument?p_table=STANDARDS&p_id=9992
 Total dust...........| | ........ | 15 mg/m3|
 Respirable Fraction..| | ........ | 5 mg/m3 |
Further explanation by Young, J. M. (2008).
Journal of Air Quality Atmosphere and Health.
Other Guideline
Agency
ASHARE
American Society of Heating, Air
conditioning & Refrigeration Engineers,
US
NIOSH
National Institute for Occupational
Health and Safety, US
SIAQG
Singapore Indoor Air Quality Guidelines
WHO
World Health Organization
Parameter
Air Quality Standard
Organization
35 ppm / 40,000 µgm-3/ as 1 hour average
EPA NPAAQS
9 ppm / 10,000 µgm-3/ as 8 hour average
SIAQG
Carbon Dioxide
Ventilation rate/air exchange rate to achieve carbon dioxide
level below 1,000 ppm / 1800mg m-3/
ASHRAE
SIAQG
Total Volatile Organic
Compounds
4 ppm / 5mgm-3/ for total VOCs
AIHA
3 ppm
SIAQG
0.12 ppm / 5µgm-3/ as 1 hour average
EPA
NPAAQS
0.05 ppm / 100 µgm-3/ as 8 hour average
WHO
ASHRAE
SIAQG
150 µgm-3 as 24 hour average
50 µgm-3 as annual mean
EPA
NPAAQS
0.15 mgm-3 as 24 hour average
SIAQG
Carbon Monoxide
Ozone
Respirable Suspended
Particulates
Parameter
Formaldehyde
Air Quality Standard
Organization
1 ppm
OSHA
0.4 ppm for indoor exposure
ASHRAE
0.1 ppm / 120µgm-3
SIAQG
22°C - 24°C
ASHRAE
22.5°C - 25.5°C
SIAQG
40% - 60%
ASHRAE
70%
SIAQG
Bacteria
500 CFU/ as a maximum value
WHO
AIHA
SIAQG
Air Movement
0.25m/s
WHO
SIAQG
Temperature
Relative Humidity
Singapore
http://app2.nea.gov.sg/data/cmsresource/20090618385702933220.pdf
Hong Kong
Lee, S. C., 2002
Table 1: IAQ Objectives for Office Buildings and Public Places
a
Parameter
Room
Temperature
Relative Humidity
Unit
C
8-hour average
Excellent Class
Good Class
20 to < 25.5
40 to < 70
c
b
b
< 25.5
< 70
%
Air movement
Carbon Dioxide
(CO2)
Carbon Monoxide
(CO)
Respirable
Suspended
Particulates
(PM10)
Nitrogen Dioxide
(NO2)
Ozone (O3)
Formaldehyde
(HCHO)
Total Volatile
Organic
Compounds
(TVOC)
Radon (Rn)
m/s
< 0.2
< 800
ppmv
μg/m3
ppmv
μg/m3
μg/m3
ppbv
μg/m3
ppbv
μg/m3
ppbv
< 0.3
d
< 2,000 f
< 1.7
f
< 20
g
e
< 1,000
< 10,000 g
< 8.7
h
< 180
8 hrs!
h
< 40
< 21
f
< 50
< 25
f
< 30
< 24
f
< 200
< 150
< 80
g
< 120
< 61
f, g
< 100
< 81
f
< 600
< 87
< 261
μg/m3
ppbv
Bq/m3
Airborne Bacteria
< 150
< 500
i
j, k
< 200
< 1,000
f
j, k
cfu/m3
http://www.iaq.gov.hk
http://www.iaq.gov.hk/tables.html
EEFECT OF INDOOOR AIR
QUALITY
Effect of Indoor Air Pollution
 Silicosis - Silicosis is a form of pneumoconiosis
caused by the dust of quartz and other silicates. The
condition of the lungs is marked by nodular fibrosis
(scarring of the lung tissue), resulting in shortness of
breath. Silicosis is an irreversible disease; advanced
stages are progressive even if the individual is removed
from the exposure.
 Black Lung - Black lung is a form of pneumoconiosis
in which respirable coal dust particles accumulate in
the lungs and darken the tissue. This disease is
progressive. Although this disease is commonly known
as black lung, its official name is coal worker's
pneumoconiosis (CWP).
 Asbestosis - Asbestosis is a form of pneumoconiosis
caused by asbestos fibers. This disease is also
irreversible.