OSI Delhi July 2014 School Case Study
Environmental Impacts of Air Pollutants: A Case Study of Sick Building Syndrome in an Underground
Metro Station Platform Area in Tropical Region
Introduction to the Problem
Air quality is one of the major environmental concerns in urban areas. In urban indoor environments, air
can be more polluted than outdoor due to presence of various sources of air pollution, poor ventilation
and building design and outdoor infiltration. People who spend their maximum time in those indoor
spaces may get a significant exposure to various air pollutants (which may present either in gaseous or
in particle form) through inhalation exposure routes and sometimes through dermal absorption.
A number of health risks are associated with the exposure to those indoor air pollutants, which could be
temporary or permanent. The temporary health related symptoms are known as sick building symptoms
(SBS). The SBS is defined in terms of the duration of the effect of indoor air pollutants on the occupants.
It describes whether a building is sick once the symptoms disappear when the occupants are out of that
indoor environment. It is a useful diagnostic tool for investigating the health of the building. The SBS is
significant in terms of its impact on the occupant’s health and their work efficiency irrespective of types
of buildings, i.e. naturally or mechanically ventilated. It is evaluated using occupant’s perceptions
(questionnaire) and monitored pollutant and ventilation data.
Approach
The lay out of the selected building showing the indoor and outdoor monitoring locations is given in
figure 1 and monitored data for a day with 8 hours average are given in table 1a. Table 1b shows the
detailed one week data of various microorganisms monitored at selected location. SBS symptoms data
to the staff working at station are also given in table 2 after analyzing the occupant’s questionnaires. A
questionnaire designed for a multistory air conditioned building to compute the SBS is given in annexure
1.
Now, the tasks are given to you are as follows:
1. Analyze the given data/information in table 1a to explore any relationship among these
parameters.
2. Analyze the trend for each microbial population given in table 1b and give your comments.
3. What are the chances of getting lung infection due to exposure of the subjects to the given
microorganism? Enumerate data gaps, if there are any?
4. Study and modify the given questionnaire (annexure 1) for the specific building i.e. the
underground metro station.
5. Compute the SBS score separately for male and female staff of different age groups of the
selected building using data given in table 2.
6. Suggest the control measures in case the building is identified as sick.
Figure 1: Layout of an Underground Metro Station
N
TVS-2
Metro Entry/Exit-1
OML
Ancillary
Building
UMS
Parking Area
IML
SSAS
SEAS
Park
TVS-1
Metro Entry/Exit-2
IAQ monitoring location points
UMS - Underground metro station
IML - Indoor monitoring location
OML - Outdoor monitoring location point
TVS - Tunnel ventilation shaft
SSAS - Station supply air shaft
SEAS - Station exhaust air shaft
H.C.
Sen
Road
Table 1a: 8 Hours average data of PM10, Bioaerosol, CO2, Temperature and RH at
platform area
Monitoring
cycle
Cycle-1 (06:0am
to 02:0pm)
Cycle-2 (02:0pm
to 10:0pm)
Cycle-3 (10:0 pm
to 06:0am)
PM10
Bioaerosol
CO2
TEMP
RH
237.7125
318
439.2313
21.5663
39.29
352.2913
179
658.9725
22.1263
40.455
409.26
123
653.95
22.195
40.7375
Table 1b: One week data of various microbial population monitored at platform area
Concentration (cfu/m3)
Days
Average
01
02
03
04
05
06
1586
962
1103
990
810
1025
S.D.
93.599
75.139
84.602
88.682
55.643
141.860
E. coli
Bacterial types
Bacillus
Staphylococcus
32%
28%
19%
20%
30%
13%
40%
36%
35%
26%
38%
50%
15%
10%
29%
20%
15%
18%
Table 2: SBS symptoms reported from staff working at underground metro station
Symptoms
Age between
20- 39
Male Female Male Female
(12)
(10)
(23)
(15)
Irritation in the eyes (%)
19b
24a
14b
25b
Irritation in the nose (%)
31b
23a
21b
43b
Dryness in mucous (%)
16 a
18a
41b
53b
Lethargy/drowsiness/tiredness 43b
29a
49 a
58a
(%)
Dryness on the face/hands
(%)
Headache (%)
Age under 20
23a
14a
63b
37 a
Age between
40-59
Male Female
(9)
(3)
52a
55a
27b
52b
61b
75b
72a
81a
Male Female
(1)
(0)
100b
100 a
27b
100 a
42b
37b
25b
49 a
65 a
56b
78b
Note: Prevelence of symptom are reported as ‘a’- often, ‘b’- sometimes”
Age above 59
-
Outputs
Document your case study using the report template provided on the QMRA Wiki and develop a 20minute oral presentation on your results. Specific items that should be addressed in each section of the
template are provided at:
http://qmrawiki.msu.eduindex.phptitle=Case_Studies#tab=Case_Study_Criteria
References
1. Sanjeev Gupta, Mukesh Khare, Radha Goyal 2007. Sick building syndrome—A case study in a
multistory centrally air-conditioned building in the Delhi City. Building and Environment, 42, pp
2797–2809 (uploaded in drop box)
2. Gerba, C.P. Microbial Risk Assessment. Section 14.4 of Chapter 14 on Risk Assessment (uploaded
in drop box).
3. Benchmark Dose Analysis for Bacillus anthracis Inhalation Exposures in the Nonhuman Primate
and Application to Risk-Based Decision Making. EPA 600/R-10/138 | December 2010 (uploaded
in drop box).
4. Walter E. Goldstein, 2010. “Sick Building Syndrome and Related Illness: Prevention and
Remediation of Mold Contamination”. http://www.crcpress.com/product/isbn/9781439801444
5. Sabah A. Abdul-Wahab, 2011. “Sick Building Syndrome: in Public Buildings and Workplaces”.
http://www.amazon.com/Sick-Building-Syndrome-BuildingsWorkplaces/dp/3642179185#reader_3642179185
Annexure I: Indoor air quality and work environment symptoms questionnaire
I. GENERAL INFORMATION
1.
Room no. —————— Floor——————
2.
My gender is: M ——— F ——
3.
My age is: – under 20
–20–29
–30–39
Date-----
–40–49
–50–59
–over 59
II. WORKPLACE INFORMATION
How long have you worked in this building, to the nearest year? ______Years
If less than one year, how many months have you worked in this building? _____Months
On average, how many HOURS per WEEK do you work in this building? ___Hours per week
Which best describes the space in which your current workstation is located?
__ Private office (1),__ shared private office (2),__ Open space with partitions (3)
1.
2.
3.
4.
__ Open space without partitions (4),____ Other (specify) (5)
5.
How many people work in the room in which your workstation is located (including yourself)?
__ 1
__ 2–3
__ 4–7
__ 8–10
__11or more
6.
Is there carpeting on most or all of the floor at your workstation?
__ Yes(1)__ No(2)
In general, how clean is your workspace area?
____ Very clean (1)____ Reasonably clean (2)____ Somewhat dusty or dirty (3)
7.
__ Very dusty or dirty (4)
Please rate the lighting at your workstation.
__ Much too dim (1)
__ A little too dim (2)
8.
__ A little too bright (4)
__ Just right 3)
__ Much too bright (5)
How comfortable is the current set-up of your desk or worktable? (i.e., height and general
arrangement of the table, chair, and equipment you work with)
__ Very comfortable (1)__ Reasonably comfortable (2)__ Somewhat uncomfortable (3)
9.
__ Very uncomfortable (4)__ Don’t have one specific desk or work table (5)
About how many HOURS per DAY do you work with a computer or word processor, to the
nearest hour? __ Hours per day __ Don’t use one
10a. If you use a computer or word processor, do you usually wear glasses when you use these
machines?
10.
__Yes __No
III. DESCRIPTION OF WORKPLACE CONDITIONS
During the PAST THREE MONTHS, have the following changes taken place within 15 feet of
your current workstation?
YES (1)
NO (2)
New carpeting
__
__
Walls painted
__
__
New furniture
__
__
New partitions
__
__
New wall covering
__
__
Water damage
__
__
2.
What is your tobacco smoking status?
__ Never smoked (1)
__ Former smoker (2)
__ Current smoker (3)
1.
Do you consider yourself especially sensitive to the presence of tobacco smoke? __ Yes(1)
__ No (2)
4.
Do you consider yourself especially sensitive to the presence of chemicals in the air of your
workspace? __ Yes(1) __ No(2)
5.
TODAY, while working at your usual workstation, did you experience this environmental
condition?
CONDITIONS
YES
NO
(1)
(2)
too much air movement
__
__
too little air movement
__
__
temperature too hot
__
__
temperature too cold
__
__
air too humid
__
__
air too dry
__
__
tobacco smoke odors
__
__
unpleasant chemical odors
_
__
other unpleasant odors (e.g., body odor, food
3.
odor, perfume)
__
__
IV.HEALTH
1.
Have you ever been told by a doctor that you have or had any of the following?
YES
(1)
Sinus infection
Asthma
Migraine
__
__
__
NO
(2)
__
__
__
Eczema
__
Hay fever
__
Allergy to dust
__
Do you feel the following symptoms while working in the room?
2.
Irritation in the Eyes
——Often
__
__
__
—— Sometimes
——Never
3.
4.
——Often
——Often
—— Sometimes
——Sometimes
——Never
——Never
5.
Irritation in the Nose
Dryness in mucous
Membrane (throat etc)
Lethargy/drowsy/tired?
——Often
——Sometimes
——Never
6.
Dryness on the face/hands
——Often
——Sometimes
——Never
7.
Do you get headache?
——Often
——Sometimes
——Never
V. CHARACTERISTICS OF YOUR JOB
1. What is your job category?
__ Managerial (1) __ Professional (2) __ Technical (3) __ Secretarial or Clerical (4)__ Other
(specify)_________________(5)
2. All in all, how satisfied are you with your job?
__ Very satisfied (1)
__ somewhat satisfied (2)
satisfied (4)
__ not too satisfied (3) __ Not at all
3. What is your rating for the stress in work?
—— Very High (1)—— High (2)——— Average (3) ——— Low (4)—— Very Low (5)
VI. OVERALL SUBJECTIVE RATING FOR THE WORKING AREA
1.
Do you like the internal environment? ———Yes ——No
2.
What is your feeling towards the working area?
— Very Comfortable (1)
— Uncomfortable (4)
— Acceptable (2)
— Comfortable (3)
— Very Uncomfortable (5)
3.
Do you find that some/all of the symptoms you experienced as stated in IV also occurred in the
past during office hours?
——— Very often
———Seldom
———Sometimes
————Never
4.
Do you find that these symptoms are more obvious at the beginning of a week e.g. on Mondays
and Tuesdays? ————Yes
————No
Do you have any other comments on the internal environment
5.