Transcript Indoor Air Quality - University of Mauritius

Sick Building Syndrome
in Mauritius: Is there
need for concern?
Professor A H Subratty
Dr R.Bholah
Assoc Prof V Jowaheer
Dr 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%)
Clinical manifestation of SBS
Non-specific symptoms linked with indoor climate
problem (WHO, 1983)
Nasal Manifestations
Ocular Manifestations
Oro-pharyngeal Manifestations
Cutaneous Manifestations
General Manifestations
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 island
Has a subtropical climate
Is 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 sym
Obtain baseline information on IAQ of office pre
Identify possible relationships of these symptom
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 offices
A 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 measurements
Indoor 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
Nausea
46.5
53.3
49.5
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
BUILDINGS
Natural
Ventilation
Mechanical
Ventilation
Mean value
Range
Mean value
Range
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
-
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
Measures
Carbon dioxide (ppm)
G cocci
Indoor climate
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
M.luteus
122.39
144.75
Micrococcus spp.
127.27
148.05
27.97
20.33
Staph epidermidis
3.33
4.93
Staph. spp
3.09
1.69
Streptococcus spp.
2.44
3.57
0.41
0.04
Derskovia spp
5.50
4.54
Brevibacterium spp
1.77
2.07
Cornebacterium spp .
1.50
2.99
15.50
23.54
E.coli
5.05
5.17
Agrobacterium spp.
7.00
5.84
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
1.52
4.90
25.94
22.88
G+ cocci
Staph.aureus.
-
G species
1 unidentified spp.
G+ rods
Other unidentified spp.
-
G rods
Agro.radiobacter
Aeromonas spp
Other unidentified spp.
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.