Sick Building Syndrome Sick Building Syndrome in Mauritius: Is there in Mauritius: Is there need for concern?need for concern?

Professor A H SubrattyProfessor A H Subratty Dr R.BholahDr R.Bholah

Assoc Prof V JowaheerAssoc Prof V Jowaheer Dr M. F. Lan Cheong WahDr M. F. Lan Cheong Wah

Sick Building Syndrome

• SBS refers to non-specific symptoms such as eye, nose,throat irritation, mental fatigue, headaches, nausea and skin irritation (WHO, 1983).

• Other terms– Tight Building Syndrome– Sick office Syndrome– Office Eye Syndrome but SBS is now the

accepted terminology

Indoor Air Pollution

•People spend an average of 90 percent of their time indoors while some at-risk subgroups such as the elderly, very young, and chronically ill may spend nearly all their time indoors.

Indoor Air Pollution

• When a number of occupants of a building display acute symptoms without a particular pattern and the varied symptoms cannot be associated with a particular source, the phenomenon is often referred as Sick Building Syndrome (SBS).

Sick Building Syndrome

• SBS refers to non-specific symptoms such as eye, nose,throat irritation, mental fatigue, headaches, nausea and skin irritation (WHO, 1983).

• Other terms– Tight Building Syndrome– Sick office Syndrome– Office Eye Syndrome but SBS is now the

accepted terminology

Indoor Air Pollutants

• Asbestos• Radon• Formaldehyde• Volatile Organic

Compounds• Pesticides• Carbon Monoxide

• Environmental Tobacco Smoke

• Combustion Products• Biological Agents

– mould / mildew / fungi

– pollen

– dander

– dustmites

Acute Health Effects of Sick Building Syndrome

• Sensory Irritation– mucous membrane irritants– allergic reactions (watery eyes, runny nose)

• General Symptoms– shortness of breath / respiratory tract irritation– dizziness– nausea– headache

Bronchial

Asthma

Chronic Health Effects of Sick Building Syndrome

• Cancer

• Birth Defects

• Immunologic Disorders

• Neurologic Disease

• Reproductive Disease

Causes of Indoor Air Quality Problems

• Inadequate Ventilation (52%)

• Inside Air Contaminants (17%)

• Outside Air Contaminants (11%)

• Biological Agents (10%)

• Building Materials (3%)

• Unknown (12%)

AIR, NOISE, AND RADIATION - Moore 85

SBS sources

Clinical manifestation of SBS

Nasal Manifestations Ocular ManifestationsOro-pharyngeal Manifestations Cutaneous Manifestations General Manifestations

Non-specific symptoms linked with indoor climate problem (WHO, 1983)

Acute Health Effects of Sick Building Syndrome

• Sensory Irritation– mucous membrane irritants– allergic reactions (watery eyes, runny nose)

• General Symptoms– shortness of breath / respiratory tract irritation– dizziness– nausea– headache

Sick Building Syndrome

Contributing factors:

Physical

Chemical

Biological

Mauritius :Is a small islandHas a subtropical climateIs a densely built environment Needs energy conservation requirements

All the above pose special constraints to the building industry.

Objectives of the study

Establish the prevalence of building related symptoms among office workers

Obtain baseline information on IAQ of office premises

Identify possible relationships of these symptoms (if any) to personal, demographic, occupational, psychosocial and indoor environmental factors (variables)?

Identification of sites 21 office buildings, occupied by public and private companies were investigated.

Buildings surveyed were selected according to type of organisation, type of ventilation, and office layout. All buildings selected were situated at different sites around the island (Fig.1- Map of Mauritius).

METHODOLOGY

Identification of sites

Questionnaire survey

Personal characteristics Work environment Demographic variables Perceived environment conditions Sick building syndrome symptoms, general health Psychosocial and physical conditions

Walk-through investigations

History of building Interviews with managers, engineers and maintenace officers

Work equipment, office furniture Ventilation systems Room characteristics Work environment (physical, chemical and biological) Occupational factors ( job stress, job uncertainty)  Musculoskeletal symptoms, postural discomfort, injury

Measurements of Physico-chemical and biological parameters

Statistical modeling

Questionnaire survey

Questions on personal characteristics, work environment and demographic factors formed part of the questionnaire. Other factors of relevance included indoor climate at work, perception of symptoms, psychosocial and physical conditions.

Walk-through inspection in officesA detailed walk-through inspection was also conducted to obtain information on the history of the building use and factors, which could influence indoor air quality. During this exercise, observations were made on the building and room characteristics

Indoor air quality measurementsIndoor environmental measurements were monitored for relative humidity (Griffin sling psychrometer, B.S 2842), air temperature (digital temperature meter SEI 26 Solex, temperature accuracy 0.8 C, range 0-60 C), air velocity (Lutron anenometer, AM/4201, speed range 0.4- 30 m/s), noise (Griffin sound level Meter, detection limit, 0.1 dB(A) and range 40-110 dB(A) ), light (Philips Harris luxmeter Log range 0 to 1000 lux). Carbon dioxide, carbon monoxide and nitrogen dioxide (Detectawl Toxic Gaztell Portable gas detectors, DGT model and range 0- 1000 ppm) were also measured.

•RESULTS

Prevalence, (%)

Symptoms Men Women Both men and women

Headache across forehead 61.3 73.1 66.4

Excessive mental fatigue 49.3 59.9 53.9

Nervousness 52.5 67.7 59.1

Unusual tiredness, lethargy 53.0 58.1 55.2

Lack of concentration / forgetfulness

46.5 53.3 49.5

Nausea 14.3 21.6 17.6

Dry eyes 26.7 23.4 25.3

Watery eyes 31.3 31.1 31.2

Irritated sore eyes 35.0 42.5 38.3

Tired, strained eyes 52.5 66.5 58.6

Runny nose 24.0 29.3 26.3

Stuffy, congested nose 33.2 29.9 31.8

Sneezing 35.5 44.3 39.3

Sore, irritated throat 31.3 35.9 33.3

Hoarseness 18.0 11.4 15.1

Chest tightness 13.4 13.2 13.3

Wheezing 15.7 13.2 14.6

Coughing 34.6 31.1 73.1

Skin irritation 21.2 22.8 21.9

Dry skin 29.5 34.7 31.8

Indoor climate

BUILDINGS

Natural Ventilation Mechanical Ventilation

Measures Mean value Range Mean value Range

Carbon dioxide (ppm) 106.3 15 - 312 98.20 15 - 343

Carbon monoxide (ppm) 0.20 0 - 2 0.29 0 - 3

Nitrogen dioxide (ppm) 0.12 0.00 - 0.46 0.07 0.00 - 0.40

Air temperature (/ºC) 26.60 25.4 - 28.5 26.60 19.00 - 29.10

Relative humidity (%) 72.30 49.5 - 81.2 65.80 37 - 89

Air movement (m/s) 0.08 0.00 - 1.20 0.07 0.00 - 0.40

Noise (dB A) 59.50 46 - 81 59.90 49 - 82

Lighting (lux) 226.20 57 - 491 184.80 24 - 105

Total bacteria (CFU) 428.90 124 - 824 460.70 184 - 966

Total G+ bacteria (CFU) 331.40 84 - 573 374.00 103 - 817

G+ cocci 304.70 64 - 570 350.40 100 - 755

G+ rod 26.70 0 - 94 23.60 0 - 147

Total G- bacteria (CFU) 98.00 0 - 324 87.40 6 - 251

G- cocci 0.41 0 - 20 0.04 0 - 3

G- rod 97.60 0 - 324 87.40 6 - 251

Total Fungi (CFU) 99.10 37 - 205 112.50 23 - 208

BUILDINGS

Natural Ventilation Mechanical Ventilation

Measures Mean value Range Mean value Range

Carbon dioxide (ppm) 106.3 15 - 312 98.20 15 - 343

Carbon monoxide (ppm) 0.20 0 - 2 0.29 0 - 3

Nitrogen dioxide (ppm) 0.12 0.00 - 0.46 0.07 0.00 - 0.40

Air temperature (/ºC) 26.60 25.4 - 28.5 26.60 19.00 - 29.10

Relative humidity (%) 72.30 49.5 - 81.2 65.80 37 - 89

Air movement (m/s) 0.08 0.00 - 1.20 0.07 0.00 - 0.40

Noise (dB A) 59.50 46 - 81 59.90 49 - 82

Lighting (lux) 226.20 57 - 491 184.80 24 - 105

Total bacteria (CFU) 428.90 124 - 824 460.70 184 - 966

Total G+ bacteria (CFU) 331.40 84 - 573 374.00 103 - 817

G+ cocci 304.70 64 - 570 350.40 100 - 755

G+ rod 26.70 0 - 94 23.60 0 - 147

Total G- bacteria (CFU) 98.00 0 - 324 87.40 6 - 251

G- cocci 0.41 0 - 20 0.04 0 - 3

G- rod 97.60 0 - 324 87.40 6 - 251

Total Fungi (CFU) 99.10 37 - 205 112.50 23 - 208

Fungal sepcies Natural Ventilation Mechanical ventilation

Mean

CFU/m3 Mean

CFU/m3

Asp. Niger 14.82 13.7

Asp.flavus 2.91 2.51

Aspergillus spp. 27.7 30.3

Penicillium spp. 21.1 27.0

Clad. lutarum 1.33 0.70

Cladosporium spp. 7.20 10.6

Moniliala spp. 3.88 8.02

Yeast spp. 0.82 1.15

Actinomycetes spp. 9.89 11.54

Alternaria spp. 0.24 0.15

Rhizopus spp. 2.08 1.54

Candida spp. 1.23 1.49

Hyalodendron spp. 1.06 0.19

Fusarium spp. 1.88 1.97

Talaromyces spp. 0.30 0

Paecilomyces 0.86 1.41

Mycelia sterilia 1.45 2.09

Total five unidentified spp.

.

7.74 6.57

Bacterial sepcies Natural Ventilation Mechanical ventilation

Mean

CFU/m3 Mean

CFU/m3

G+ cocci

M.luteus 122.39 144.75

Micrococcus spp. 127.27 148.05

Staph.aureus. 27.97 20.33

Staph epidermidis 3.33 4.93

Staph. spp 3.09 1.69

Streptococcus spp. 2.44 3.57

G- species

1 unidentified spp. 0.41 0.04

G+ rods

Derskovia spp 5.50 4.54

Brevibacterium spp 1.77 2.07

Cornebacterium spp . 1.50 2.99

Other unidentified spp. 15.50 23.54

G- rods

E.coli 5.05 5.17

Agrobacterium spp. 7.00 5.84

Agro.radiobacter 15.29 7.54

Sphnono spp. 1.42 2.48

Ps. vesicularis 10.41 10.96

Pseudomonas spp 19.15 14.83

Flavobacterium spp 11.82 12.79

Aeromonas spp 1.52 4.90

Other unidentified spp.

25.94 22.88

Monitoring Indoor Air Quality

• Carbon monoxide• Carbon dioxide• Ozone• Total hydrocarbons• Biological agents

• Temperature• Humidity• Formaldehyde• Nitrogen oxides• Particulates

With rapid urbanization the prevention of ill health in office and domestic interiors present a growing challenge to medical practitioners and building managers in Mauritius.