1. Objective:
To assess the Indoor Air Quality (IAQ) of the office of the Department
of Public Health & Preventive Medicine at St. George’s University
using a 3M EVM-7 indoor air quality meter.
Background:
•More than one third of energy consumed by buildings in North
America is used for heating, cooling, lighting and ventilation (HVAC).
•In the Caribbean while little to no energy is needed for heating, a
significant amount of energy is used for cooling, lighting and
ventilation of buildings.
•Conditioning and transportation of ventilated air accounts for 50–
60% of total building energy requirements.
•In spite of this, a recent survey in the United States has shown that
65% of all office buildings operate under sick building syndrome
(SBS) conditions, resulting in an estimated loss of annual productivity
equivalent to several billion dollars.
•Office air contaminants such as malodorous gases and vapors,
allergens, irritants such as formaldehyde, and acutely toxic agents
such as carbon monoxide are ubiquitous in office environments.
•Asbestos and radon might also be present, but these are unlikely
causes of complaints of acute health effects.
•Problems associated with these indoor air contaminants occur when
concentrations are elevated, often as a result of problems with the
heating, ventilating and air conditioning (HVAC) system.
•In an IAQ investigation, basic deficiencies in HVAC system design
and operation are considered, such as inadequate supply of outdoor
air, improperly positioned fresh air intakes, improper control system
strategy, ineffective air distribution and inadequate air filtration,
humidity control or maintenance.
Methods Discussion
Assessment of the indoor air quality of a major SGU office building
Curllan Bhola, Andew Cutz, Martin S. Forde
Department of Public Health & Preventive Medicine, School of Medicine, St. George’s University, Grenada, W.I.
Conclusions
Study Site
•An IAQ assessment was carried out inside the offices of the
Department of Public Health & Preventive Medicine (DPHPM) located
in the Caribbean House, St. George’s University.
•The floor consists of 8 offices, 15 cubicles, a conference room, a
kitchen, 3 bathrooms and an open lobby/ reception area. There were
7 occupants at the time of assessment.
•The floor area is approximately 3,000 square feet, consists of
individual offices and an open office area. The office area has a
typical office layout and contains basic building components: tiled
floors with carpeting in some areas, tiled ceiling, fluorescent lighting
and un-openable windows. The space appeared to be clean, typical
office equipment such as computers, printers, fax machines and
photocopiers were noted throughout the office areas.
•Measurements of temperature, relative humidity, carbon dioxide
(CO2), carbon monoxide (CO) and total volatile organic compounds
(TVOCs) were taken using a 3M EVM-7. This instrument has four
separate sensors (one for each parameter) that are described below.
• Temperature was measured with a junction diode
sensor that has an operating range of -10.0 to 60 °C
(14 to 140 °F) and an accuracy of ± 1.1 C° (2 F°).
• Humidity was determined using capacitive sensor
which has an operating range of 0.1 to 100 % RH and
an accuracy of ± 5 % RH.
• Carbon dioxide (CO2) concentrations were determined
by a non-dispersive infrared (NDIR) sensor that has an
operating range of 1 to 20,000 ppm and an accuracy of
± 50 ppm.
• Carbon monoxide (CO) concentrations were
determined using an electro-chemical sensor that has
an operating range of 1 to 1000 ppm and an accuracy
of ± 5 %.
• Volatile organic compounds (VOCs) concentrations
were determined using a 10.6 electron volts (eV)
Photoionization Detector (PID) that has an operating
range of 0.01 - 2,000 and an accuracy of ± 5% (relative
to Isobutylene reference gas) at calibration level.
•Airborne particulate matter measurements were taken using the 3M
EVM-7. This device instantaneously measures average, minimum
and maximum particle concentrations for particles between 0.1 and
10 m in diameter, with a measuring range of 0.001 g/m3 to 199.9
mg/m3 and an accuracy of ±15 %. Air sampling is conducted at a
flow rate of 1.7 Liter per minute (Lpm) using a 10 µm inlet nozzle.
Although the quantity of air supplied to an occupied office space
is essential for diluting odors and other contaminants, indoor air
quality complaints may be related to thermal comfort rather
than contaminant levels. Temperature and relative humidity
can play a role in how people perceive their indoor
environment. Thermal comfort, as defined earlier, is a function
of temperature, relative humidity, and air motion.
Given the findings of this assessment, DPHPM occupants maybe
experience discomfort because:
• Humidity levels were higher than 60%
• According to level.org.nz, “high RH (very moist air) will
make people feel [more] chilled.” This might accounts
for the report by DPHPM occupants reporting thermal
discomfort though the thermostat was set within
ASHRAE’s thermal comfort region (22 - 26 C).⁰
• High TVOC levels
• This may be attributed to microbial VOCs (musty smell).
Temperature: 23.0 to 24.9 ˚C (Graph 1) Overall, little variations were
noted among different locations tested throughout the office areas.
Relative humidity (%RH): 59.4 and 75.9 % (Graph 2) Overall,
relative humidity levels remained relatively constant throughout the
day and all sampling locations tested for the selected office areas.
Carbon dioxide (CO2): 540 and 660 ppm (Graph 3). No significant
temporal variations were noted throughout the office. Outdoor CO2
concentrations were at 390 ppm.
Particulate matter: 0.001 to 2 µg/m3
(0.002 mg/m3
). All readings
remained fairly constant through the office areas (Graph 4)
Total volatile organic compounds (TVOCs): 403 to 3859 ppb
(Graph 5)
• Temperature levels were relatively constant in all sample
locations throughout the study period. All temperature readings
were within the thermal comfort range of 22 to 26 ºC derived from
ASHRAE guideline levels for a summer season.
• Relative humidity (%RH) levels throughout the sampling period
were relatively constant in all locations tested, though most
readings were above of the guideline range of 20 to 60% as
recommended by ASHRAE.
• Carbon dioxide (CO2) levels in an occupied space are a good
indicator of adequate outdoor air ventilation rates. All CO2
readings during the assessment period remained below
recommended CO2 concentration of 990 ppm based on the
ASHRAE guideline (600 ppm above outside levels). These results
indicate that an adequate amount of fresh outdoor air was
provided to the office areas assessed based on the number of
occupants within the office areas with adequate return and mixing
of outdoor air.
• The concentration of carbon monoxide (CO) remained low, well
below the guideline level in the office locations.
• All particulate matter readings remained relatively low and below
the recommended maximum guideline level of 50µg/m3
.
• The TVOC levels measured (403 to 3859 ppb) fell within the
“Multifactorial Exposure Range” and thus may cause irritation or
discomfort if other exposures interact.
Introduction Results
Graph 1. Indoor air temperature
ASHRAE Guidelines: 22 – 26 ˚C (solid lines)
Graph 2. Relative humidity
ASHRAE Guidelines: 20 – 60 % (solid lines)
Graph 3. Carbon dioxide concentration
ASHRAE Guideline: 990 ppm (600 ppm above outside levels) (solid line)
Graph 4. Particulate matter concentration
ASHRAE Guideline: 50 μg/m3
guideline level (solid line)
Graph 5. Total volatile organic compounds concentration (TVOCs)
European Collaborative Action Report guide line:
Greater than 10,900 ppb (>25,000 µg/m3
) (solid red line)
1,300 to 10,900 ppb (3,000 – 25,000 µg/m3
) Discomfort Range (shaded area)
90 to 1,300 ppb (200 – 3,000 µg/m3
) Multifactorial Exposure Range (solid yellow line)

2. Objective:
To assess the Indoor Air Quality (IAQ) of the office of the Department of Public Health & Preventive Medicine at St.
George’s University using a 3M EVM-7 indoor air quality meter.
Background:
•More than one third of energy consumed by buildings in North America is used for heating, cooling, lighting and
ventilation (HVAC).
•In the Caribbean while little to no energy is needed for heating, a significant amount of energy is used for cooling,
lighting and ventilation of buildings.
•Conditioning and transportation of ventilated air accounts for 50–60% of total building energy requirements.
•In spite of this, a recent survey in the United States has shown that 65% of all office buildings operate under sick
building syndrome (SBS) conditions, resulting in an estimated loss of annual productivity equivalent to several billion
dollars.
•Office air contaminants such as malodorous gases and vapors, allergens, irritants such as formaldehyde, and acutely
toxic agents such as carbon monoxide are ubiquitous in office environments.
•Asbestos and radon might also be present, but these are unlikely causes of complaints of acute health effects.
•Problems associated with these indoor air contaminants occur when concentrations are elevated, often as a result of
problems with the heating, ventilating and air conditioning (HVAC) system.
•In an IAQ investigation, basic deficiencies in HVAC system design and operation are considered, such as inadequate
supply of outdoor air, improperly positioned fresh air intakes, improper control system strategy, ineffective air
distribution and inadequate air filtration, humidity control or maintenance.
•Since Volatile Organic Compounds (VOCs) are present as a mixture of potentially several hundred or thousand
chemical components, there are no specific exposure regulations or standards available for Total VOCs (TVOCs).
Thus researches have focused on the health effects of individuals exposed to multiple VOCs.
•Studies performed to determine the effects of TVOCs on individuals have assisted in the development of exposure
guidelines. Currently accepted TVOC exposure guidelines, based on the work of Lars Mølhave (summarized in Table
II) show a comfort range of less than 90 ppb (200µg/m3
).
Assessment of the indoor air quality of a major SGU office building
Curllan Bhola, Andew Cutz, Martin S. Forde
Department of Public Health & Preventive Medicine, School of Medicine, St. George’s University, Grenada, W.I.
Introduction

3. Assessment of the indoor air quality of a major SGU office building
Curllan Bhola, Andew Cutz, Martin S. Forde
Department of Public Health & Preventive Medicine, School of Medicine, St. George’s University, Grenada, W.I.
Table 1 summarizes IAQ guidelines, which were used in the interpretation of our sampling
data. For reference, IAQ guidelines published by the World Health Organization (WHO) are
also included. The WHO guidelines do not differentiate between outdoor and indoor air
quality, and are aimed at protecting the health of the general population including sensitive
population subgroups such as the elderly and asthmatics.

4. Assessment of the indoor air quality of a major SGU office building
Curllan Bhola, Andew Cutz, Martin S. Forde
Department of Public Health & Preventive Medicine, School of Medicine, St. George’s University, Grenada, W.I.

5. Study Site
•An IAQ assessment was carried out inside the offices of the Department of Public Health & Preventive Medicine
(DPHPM) located in the Caribbean House, St. George’s University.
•The floor consists of 8 offices, 15 cubicles, a conference room, a kitchen, 3 bathrooms and an open lobby/ reception
area. There were 7 occupants at the time of assessment.
•The floor area is approximately 3,000 square feet, consists of individual offices and an open office area. The office
area has a typical office layout and contains basic building components: tiled floors with carpeting in some areas, tiled
ceiling, fluorescent lighting and un-openable windows. The space appeared to be clean, typical office equipment such
as computers, printers, fax machines and photocopiers were noted throughout the office areas.
•Measurements of temperature, relative humidity, carbon dioxide (CO2), carbon monoxide (CO) and total volatile
organic compounds (TVOCs) were taken using a 3M EVM-7. This instrument has four separate sensors (one for
each parameter) that are described below.
• Temperature was measured with a junction diode sensor that has an operating range of -10.0 to 60 °C (14 to
140 °F) and an accuracy of ± 1.1 C° (2 F°).
• Humidity was determined using capacitive sensor which has an operating range of 0.1 to 100 % RH and an
accuracy of ± 5 % RH.
• Carbon dioxide (CO2) concentrations were determined by a non-dispersive infrared (NDIR) sensor that has
an operating range of 1 to 20,000 ppm and an accuracy of ± 50 ppm.
• Carbon monoxide (CO) concentrations were determined using an electro-chemical sensor that has an
operating range of 1 to 1000 ppm and an accuracy of ± 5 %.
• Volatile organic compounds (VOCs) concentrations were determined using a 10.6 electron volts (eV)
Photoionization Detector (PID) that has an operating range of 0.01 - 2,000 and an accuracy of ± 5% (relative
to Isobutylene reference gas) at calibration level.
•Airborne particulate matter measurements were taken using the 3M EVM-7. This device instantaneously measures
average, minimum and maximum particle concentrations for particles between 0.1 and 10 m in diameter, with a
measuring range of 0.001 g/m3 to 199.9 mg/m3 and an accuracy of ± 15 %. Air sampling is conducted at a flow
rate of 1.7 Liter per minute (Lpm) using a 10 µm inlet nozzle.
Assessment of the indoor air quality of a major SGU office building
Curllan Bhola, Andew Cutz, Martin S. Forde
Department of Public Health & Preventive Medicine, School of Medicine, St. George’s University, Grenada, W.I.
Methods

6. Temperature: 23.0 to 24.9 ˚C (Graph 1) Overall, little variations were noted among
different locations tested throughout the office areas.
Relative humidity (%RH): 59.4 and 75.9 % (Graph 2) Overall, relative humidity
levels remained relatively constant throughout the day and all sampling locations
tested for the selected office areas.
Carbon dioxide (CO2): 540 and 660 ppm (Graph 3). No significant temporal
variations were noted throughout the office. Outdoor CO2 concentrations were at 390
ppm.
Particulate matter: 0.001 to 2 µg/m3
(0.002 mg/m3
). All readings remained fairly
constant through the office areas (Graph 4)
Total volatile organic compounds (TVOCs): 403 to 3859 ppb (Graph 5)
Assessment of the indoor air quality of a major SGU office building
Curllan Bhola, Andew Cutz, Martin S. Forde
Department of Public Health & Preventive Medicine, School of Medicine, St. George’s University, Grenada, W.I.
Results

7. Assessment of the indoor air quality of a major SGU office building
Curllan Bhola, Andew Cutz, Martin S. Forde
Department of Public Health & Preventive Medicine, School of Medicine, St. George’s University, Grenada, W.I.
Results

8. Assessment of the indoor air quality of a major SGU office building
Curllan Bhola, Andew Cutz, Martin S. Forde
Department of Public Health & Preventive Medicine, School of Medicine, St. George’s University, Grenada, W.I.
Discussion
• Temperature levels were relatively constant in all sample locations throughout the
study period. All temperature readings were within the thermal comfort range of 22
to 26 ºC derived from ASHRAE guideline levels for a summer season.
• Relative humidity (%RH) levels throughout the sampling period were relatively
constant in all locations tested, though most readings were above of the guideline
range of 20 to 60% as recommended by ASHRAE.
• Carbon dioxide (CO2) levels in an occupied space are a good indicator of
adequate outdoor air ventilation rates. All CO2 readings during the assessment
period remained below recommended CO2 concentration of 990 ppm based on the
ASHRAE guideline (600 ppm above outside levels). These results indicate that an
adequate amount of fresh outdoor air was provided to the office areas assessed
based on the number of occupants within the office areas with adequate return and
mixing of outdoor air.
• The concentration of carbon monoxide (CO) remained low, well below the
guideline level in the office locations.
• All particulate matter readings remained relatively low and below the
recommended maximum guideline level of 50µg/m3
.
• The TVOC levels measured (403 to 3859 ppb) fell within the “Multifactorial
Exposure Range” and thus may cause irritation or discomfort if other exposures
interact.

9. Assessment of the indoor air quality of a major SGU office building
Curllan Bhola, Andew Cutz, Martin S. Forde
Department of Public Health & Preventive Medicine, School of Medicine, St. George’s University, Grenada, W.I.
Conclusions
Although the quantity of air supplied to an occupied office space is essential for
diluting odors and other contaminants, indoor air quality complaints may be related to
thermal comfort rather than contaminant levels. Temperature and relative humidity
can play a role in how people perceive their indoor environment. Thermal comfort,
as defined earlier, is a function of temperature, relative humidity, and air motion.
Given the findings of this assessment, DPHPM occupants maybe experience
discomfort because:
Humidity levels were higher than 60%
 According to level.org.nz, “high RH (very moist air) will make people feel [more]
chilled.” This might accounts for the report by DPHPM occupants reporting
thermal discomfort though the thermostat was set within ASHRAE’s thermal
comfort region (22 - 26 C).⁰
High TVOC levels
 This may be attributed to microbial VOCs (musty smell).

10. Assessment of the indoor air quality of a major SGU office building
Curllan Bhola, Andew Cutz, Martin S. Forde
Department of Public Health & Preventive Medicine, School of Medicine, St. George’s University, Grenada, W.I.
Conclusions
Although the quantity of air supplied to an occupied office space is essential for
diluting odors and other contaminants, indoor air quality complaints may be related to
thermal comfort rather than contaminant levels. Temperature and relative humidity
can play a role in how people perceive their indoor environment. Thermal comfort,
as defined earlier, is a function of temperature, relative humidity, and air motion.
Given the findings of this assessment, DPHPM occupants maybe experience
discomfort because:
Humidity levels were higher than 60%
 According to level.org.nz, “high RH (very moist air) will make people feel [more]
chilled.” This might accounts for the report by DPHPM occupants reporting
thermal discomfort though the thermostat was set within ASHRAE’s thermal
comfort region (22 - 26 C).⁰
High TVOC levels
 This may be attributed to microbial VOCs (musty smell).