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