Sick Building Syndrome Dr. Emilia Zainal Abidin Faculty of Medicine and Health Sciences, UPM.
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Transcript of Sick Building Syndrome Dr. Emilia Zainal Abidin Faculty of Medicine and Health Sciences, UPM.
Sick Building Syndrome
Dr. Emilia Zainal AbidinFaculty of Medicine and Health
Sciences, UPM
Contents of lecture• Indoor air quality• Ambient air composition• Sources of indoor air pollution• Definition of sick building syndrome (SBS)• Types of building associated illness• Investigation SBS (individuals and building) • Factors associated with SBS• Code of practice on indoor air quality
Indoor air qualityIndoor air level-2.5 x more pollutants than outdoor
People spend more time indoor compared to outdoor
Air is recycled again and again and pollutants easily trapped indoor
Definition of Indoor air quality (IAQ) - The nature of air that affect the health and well being of occupant inside the building or quality of air in an indoor environment
Involve 3 basic needs of humanThermal acceptability
Maintenance of normal concentration of respiratory gas
Dilution & removal of contaminants to levels below health or odor discomfort thresholds
Quality of environment indoors (noise, lighting, ergonomic stressors etc.)
Factors that influence IAQ
Sources of pollutants or odours
Maintenance & operation of building ventilation system
Moisture & humidity
Occupant perception and susceptibility
Normal Ambient Air Composition
major gas elements
dry gas wet gas
% volume % weight % volume % weight
Nitrogen, N2
Oxygen, O2
Water, H2O
Argon, Ar
Total
78.09
20.94
-
0.93
99.96
75.54
23.13
-
1.28
99.95
75.65
20.29
3.12
0.9
99.96
74.08
22.64
1.94
1.27
99.95
(Source: Bretshneider & Kursurst, 1982. Air Pollution Control Technology)
Minor gases element Dry air Wet air
Carbon dioxide(CO2)
Neon (Ne)
Helium (He)
Methane (CH4)
Crypton (Kr)
Nitrogen dioxide(N2O)
Water (H2O)
Carbon monoxide (CO)
Xenon (Xe)
Ozone (O3)
Ammonia (NH3)
Nitrogen dioxide (NO2)
Sulphur dioxide (SO2)
Hydrogen sulfide (H2S)
Hydrocarbon (CxHy)
Organic vapour
ppmv g.m-3 ppm / weight ppmv g.m-3 Ppm / weight
315
18
5.2
1.0
1.0
0.5
0.5
0.1
0.08
0.02
0.01
0.001
0.0002
-
-
0.02
567
14.9
0.85
0.656
3.43
0.90
0.0413
-
0.429
-
-
-
-
-
-
-
478
12.6
0.717
0.554
2.895
0.760
0.0348
0.200
0.362
-
0.010
0.003
0.0009
-
-
0.02
305
17.4
5.0
0.97
0.97
0.49
0.49
-
0.08
0.060
-
-
-
-
-
-
549
14.4
0.825
0.635
3.32
0.873
0.04
-
0.417
-
-
-
-
-
-
-
469
12.3
0.705
0.543
2.837
0.746
0.034
-
0.356
-
-
-
-
-
-
-
Total 341.4312 - 496.1967 330.42 - 486.521
Normal Ambient Air Composition
Indoor furnishing
outdoor
Building material
Human activitiesSources of IAP
Sources of IAP
Sources of Indoor Air PollutionOutdoor
Penetrate indoor through any opening.
e.g. O3, SO2, radon
Building material Concretes, stone, plywood, particle board, insulator, fire retardant and paints.
VOCs more in new building
asbestos
Indoor furnishing From cushions and curtains
e.g. organic dust and fibrous particles
Human activities Cooking, cleaning, smoking
Source for CO2, CO, SO2, NO2, VOCs
Inorganic contaminants Asbestos - Used for construction of building &
industrial application – asbestosis, mesothelioma Radon Lead – used as pigments in paints, lead batteries
and hair dye products, etc. Acute exposure (blood lead level >60 μg/dL) cause
Shock, severe anemia, kidney damage, encephalopathy, nervous system damage
Ozone Used in water to killed microbes Generated by photocopy machine & laser printer Outdoor source
Radon
Colorless, odorless, radioactive gas which produced naturally from the breakdown of uranium
Derived primarily from the soil
Its decay product adverse health effect
e.g. lung CA,COPD
Enter building via
water from drilled well
Basement
Cracks in the foundation
Entrance utility service lines
Combustion-generated contaminants Carbon monoxide (CO)
From incomplete burning of carbon-based fuels
Acute exposure to high concentration of CO death
CO bind with Hb in blood Carboxyhaemoglobin
Compete with Oxygen for Hb binding site - higher affinity to Hb (> 200 times higher than oxygen)
Brain, CNS affected and can be fatal Sulphur dioxide (SO2)
Colorless, nonflammable gas
Fuel combustion, manufacture of sulphuric acid, coal burning
Effect - Irritation of eyes and respiratory tract, Asthmatic symptoms
ETS or environmental tobacco smoke - Contain tar, nicotine, CO, nitrogen oxides, formaldehydes, nitrosamines etc
Organics contaminants
halogenated aliphatic oxygenated aromatic
fluorine chlorine aldehyde ketones
esters ethers
acids
Organic contaminants Formaldehyde - The smallest & simplest aldehyde
Colorless, pungent smelling, flammable gas
Sources
Particle board, hardwood, plywood paneling
medium density fiberboard
Disinfectant
Effects
low exposure tears, skin irritation
moderate exposure burning eyes, nose & trachea
severe cough
high exposure lung inflammation
edema
death
Volatile Organic CompoundsOrganic compounds-boiling point 50-100 C 240-260 C
no color, taste, smell
source : DIY work, paint
effect (chronic exposure)
benzene leukemia
PAH cancer
1,3-butiene ↑ risk of cancer
contribute to SBS (sick building syndrome)
Biological contaminants Sources
Outdoor air
Human
Animals/pets
Indoor surfaces
Water reservoir
Component of heating, ventilating, air conditioning (HVAC system)
Growth encourage by indoor that is humid
Biological contaminants cont.Health effect
Infection bacteria- Legionnaire disease- Legionella pneumophila
TB – Mycobacterium tuberculosis
Pneumonia- Mycoplasma pneumonia
Anthrax-Bacillus anthracis
virus- influenza, respiratory infection, measles,
rubella, chicken pox
fungi- mold
Hypersensitivity diseases allergen from dust mites, insects & pets
Odour
Sick building syndrome “Sick office syndrome”, “Tight building
syndrome” or “Sick building syndrome” (WHO) or “Building associated illnesses”
SBS occurs when a building in which its occupants complain of ill-health more commonly than might reasonably be expected e.g. when persons (20% or more) working or living in the building suffer from variety of non-specific symptoms, and where it is not possible to make a specific diagnosis
Sick building syndromeBuilding occupant experience acute health and discomfort effect
Appeared to be linked with time spent in building
No specific illness
Cannot identify causes
Symptom Headache, dry/itchy skin
Eye, nose, throat irritation, dry cough Dizziness & nausea, rhinitis & fatigues Sensitivity to odor
Relief when leaving the building
Different concept with Building-Related Illness and Work-Related Illness
BRIBuilding occupants complain of symptoms such as
coughchest tightness fever chills muscle aches
The symptoms can be clinically defined & have clearly identifiable causes
Complainants may require prolonged recovery times after leaving the building
WRI
Illness assoc. with specific work activities
medical & dental sector illness related to exposure to formalin
latex allergy to latex glove
office-illness related to exposure to laser printer & photocopier
Sick Building Syndrome Developed countries – 50% of the workforce
work in an office environment 30% of new and remodeled office blocks in
developed countries – signs of SBS, 10-30% of occupants affected
Concentrations of pollutants indoors may exceed standards for concentrations of pollutants outdoors
People also spend more time indoor
Acute short latency illnesses
Sick building syndrome
Mass psychogenic illness
Building associated hypersensitivity pneumonitis
Infections - Legionnaires Disease
Pontiac fever, Q Fever
Potential chronic long latency illnesses
COPD and cancer
TYPES OF BUILDING ASSOCIATED ILLNESS (ML Fischman in La Dou)
Symptoms: relatively acute onsetrelated to presence in buildingrelieved by removal from exposure
Syndrome is a group diagnosis
Physician and building manager involved in diagnosis
Investigation of individuals with SBS
Persons with symptoms must be examined by medical doctor
Symptoms: Irritation to the eyes, skin and upper respiratory tract, fatigue, headache and nausea (WHO)
Other symptoms : dizziness, difficulty in concentration, chest tightness
No specific diagnostic criteria – medical history and association of symptoms with building occupancy
SBS questionnaire In the past 12 months have you had >2 episodes of: Itchy or watery eyes; Blocked or stuffy nose; Runny nose; Dry throat; Lethargy and/or tiredness; Headache; Dry, itchy or irritated skin.
• If ‘yes’, was it better on days away from office?
(Raw, 1995)
The ‘Whitehall II’ SBS study Ongoing health survey of office based civil
servants - longitudinal study of 10,308 m+f aged 35-55 at baseline. Self-report questionnaire 10 symptoms:
Headache; cough; dry eyes; blocked/runny nose; tired for no reason; rashes/itches; cold/flu; dry throat; sore throat; wheeziness.
4052 participants (42-62 yrs, m+f) in 44 buildings.
(Marmot et al, 2006)
Questionnaire survey
Among all/representative sample
Validated questionnaires available
Building Inspection
Ventilation and air conditioning
Need for physical, chemical or biological measurement assessed
Environmental measurements – Air exchange rate, dust levels, temperature, mould, bacteria,
Investigation of SBS in building
FACTORS ASSOCIATED WITH SBS
Air conditioning and ventilation problems (low humidity)
Poor lighting.
Increased use of synthetic building materials
Use of electronic equipment
No specific disease explaining symptoms, no predisposing factors e.g. atopy present, building investigation revealed factor related with SBS – SBS probable – proceed to find source
Patient does not have disease explaining symptoms, no factors related to building – cannot draw any firm conclusion
Some disease may explain symptoms, no building related factors – probably not SBS
Decision making on diagnosis of SBS
preventionmaintaining good IAQ
Maintaining Indoor Air Quality
Control source of pollutant
Clean the air
Mechanical filter
Electronic filter: remove air borne particles
Provide adequate ventilation
regulatory limits & guidelines
authority & society initiatives
Code of Practice on IAQ in Malaysia
Under Occupational Safety & Health Act 1994 (Act 154): Industrial Code of practice on indoor air quality(2010).
set max. exposure limits
- 5 common IA contaminant
Table : List of Indoor Air Contaminants and The Maximum Limits
Where: C is the ceiling limit mg/m3 is milligrams per cubic meter of air at 250 C and one atmosphere pressure ppm is parts of vapour or gas per million parts of contaminated air by volume
(Source: Dept. of Occupational Safety & Health, 2010. Industrial Code of Practice on IAQ)
Indoor Air Contaminants
Eight-hour time-weighted average
airborne concentration
ppm mg/m3
Carbon dioxide
Carbon monoxide
Formaldehyde
Respirable particulates
Volatile organic compounds
C1000
10
0.1
3
0.15
Code of Practice on IAQ in Malaysia
Healthy indoor environment FOUR (4) parameters set up by the Department of
Occupational Safety and Health (DOSH) Malaysia to indicate whether an indoor environment is comfortable and healthy Chemical contaminants, such as carbon dioxide, carbon
monoxide, formaldehyde and environmental tobacco smoke Physical conditions, such air temperature, air velocity and
humidity Biological agents, such as mites, virus, and spores Radiation such as radon
Thank you for your attention