The author has also given the university permission to store or make a digital copy for similar use and for the purpose of digital preservation of the work. While the results of the questionnaire in office B had shown an increase in the symptoms experienced than in office A.
INTRODUCTION
Motivation of the study
One of the findings for the 2019 GBD study is that there is an increase in risk exposure to particulate matter pollution in the environment (Murray et al., 2020). In the 1990s, the summary exposure value (SEV) of the world population exposed to the maximum risk of particulate matter was 44.22%.
Research Question
Aims and objectives
LITERATURE REVIEW
Indoor Air Quality (IAQ)
- What is Indoor Air Quality (IAQ)
- Impact of Poor Indoor Air Quality
- Sources of Air Pollutants
The majority of deaths due to indoor air pollutants are found in low-income countries, especially on the African continent. In the 1990s, the number of deaths from indoor air pollution exceeded 4 million deaths (Figure 9).
Particulate Matter (PM)
- What is a Particulate Matter
- Sources of Indoor Particulate Matter
- Particulate Matter in the United Arab Emirates
A secondary source occurs due to the reaction of air pollutants in the atmosphere to form another pollutant. The sources of air pollutants in the United Arab Emirates (UAE) are either natural or anthropogenic.
Office Buildings
- Indoor Air Quality of office buildings
- Dubai Building Code for office buildings
Natural pollutants such as dust and sandstorms are common in the region due to the geographical location and the dry climate of the country. Although based on Table 6-1 in the same document, the minimum ventilation rate for the work spaces in office buildings is 5 cfm/person.
Measurement Approaches of PM Concentration
- Particle Mass
- Particle Number
Particle mass can be measured using two different techniques; gravimetric or optical method. However, it is affected by wind speed and particle size (Lowther et al., 2019). Using a microscope, we determine the number of particles in the examined sample, the size, shape and structure of the particle.
26 While in the optical method, the mass of the particles is measured by emitting laser beams at the sample. The concentration of the particles is then determined by measuring the light scattered and absorbed by a photometer detector. This process would increase the size of the particles to be counted after passing through the laser beam (Lowther et al., 2019).
RESEARCH METHODOLOGY
Types of Research Approaches Used
- Literature Review
- Questionnaire
- Interviews
- Field Measurement
- Simulation
The interviewer has the freedom to formulate the questions and the order of the interview. There was variation in the perception of air quality depending on age group, duration of exposure and smoking condition of the participant. The measuring equipment was placed at a height of 1 meter above the ground and placed in the center of the room.
The authors looked at the type of gaps in the facade of the building. The authors stated that the source of the air pollution in space is the incense, with an emission rate of 5.33 µg/m3 for PM2.5. The results of the simulation illustrated that the optimal level for monitoring the PM concentration is at the breathing zone.
Selected Methodologies
- Field Measurement
- Questionnaire
40 Due to the addition of sheath flow around the sample, the size resolution of the sample is improved and the surface is kept clean, minimizing the maintenance rate. The main reason is to avoid any physical contact due to the spread of the global pandemic, Covid-19. The Survey Monkey platform had been used to create the questionnaire and it had been distributed to the participants via a link in an email.
The presentation about the research was made face to face to the respondents as well as mentioned in the email. Questions in the building section focused on the location of the workspace in the building, in terms of floor and any nearby industrial or service environments that may affect the results due to emissions from the space. The questionnaire was updated based on their comments, which were then distributed to other participants.
Justification
45 broad-scale question, looking at any outdoor activity near the office building, which could affect the measured results. A pilot study was shared with two participants to ensure the clarity of the questions.
Variables’ List
Precautions taken
The morning test is taken one hour after the start of the office timing to make sure that everyone has arrived at the office. The afternoon time is the peak of the workload, and the evening time is when the majority of employees have left the office.
Air Quality Guidelines (AQG)
Based on WHO publications, table 4 shows that the highest number of deaths in 2016 are in Western Pacific countries with a total of more than 1.2 million deaths and Southeast Asian countries exceeding 1.35 million deaths. The United Arab Emirates is an Eastern Mediterranean country, with a total death toll of less than 350,000. To reach the AQG level, the number of deaths would fall to 64,000 and a total percentage reduction of about 80%.
Regional deaths associated with PM2.5 concentrations and reductions in achievement of interim targets and AQG levels.
Weather Analysis
CASE STUDY
Case Study: Office A
With the exception of employees staying in office rooms A.6 and A.10, they all stay inside their offices from 8:00 am to 5:00 pm. 57 Interior office finishes are carpet tile flooring on raised floors, emulsion paint on drywall partitions, and painted structural tile flooring. The office has no operable windows, with fresh air supplied only by the HVAC system.
58 wheel, which is transported to the fan coil units and then supplied to the office. The office management decided to hold vacuuming activities during the weekends to minimize the negative impact on the staff, in terms of noise pollution or high concentration of PM in the space. 2020) had illustrated in their study that vacuuming activities give rise to PM concentration due to particle resuspension. They investigated that the concentration of PM10 caused by vacuum cleaning in the office was 420 µg/m3, which is 9 times higher than the AQG level, while the concentration of PM2.5 was 270 µg/m3 which is 18 times higher.
Case Study: Office B
61 Office B is designed as an open-plan office with a total of 14 staff members sitting in the same space, including their manager. The office is divided into 3 spaces; the driver's space, the work space and the storage space. The interior finish of the office is ceramic flooring, emulsion painted plaster on block walls and false ceiling tiles.
The mechanical ducts, electrical wiring and fire extinguishing pipes are hidden by the false ceiling. However, they have fixedly installed 5 wall-hung split units in the office, 4 of them work constantly while 1 is switched off all the time. There are two operated windows which are used to passively ventilate the office when required.
RESULTS, FINDING AND DISCUSSION
Office A: Data Collection, Results and Discussion
- Questionnaire Distribution, Results and Discussion
- Field Measurements
While for PM10, the particle counted in the morning time was 298 particles, which dropped to 242 particles in the afternoon time and then 89 particles in the evening time. Based on the results, the presence of the users in the office had a great impact on the PM10 particle count, as the particle count by the end of the day dropped by 63% (153 particles) from the afternoon time. This indicates that the air conditioning in the space extracts the PM2.5 particles at the same rate as it is supplied by the sources.
The number of particles increased by more than 10,000 particles from morning to noon and reached 30,735 particles with a concentration of 10.31 µg/m3. On the other hand, the number of PM10 particles in the morning was 81 particles with a concentration of 7.622 µg/m3. The highest PM2.5 concentrations were at midday for room A.4, due to the relatively smaller area of the room, in which the number of particles is dispersed over a smaller area.
Office B: Data Collection, Results and Discussion
- Questionnaire Distribution, Results and Discussion
- Field Measurements
On the other hand, the PM2.5 concentration does not exceed the AQG level which is 15 µg/m3. 40% of the participants complain of dizziness while the rest do not complain at all. Burning eyes and a runny nose are major symptoms felt by 90% of the participants, which may indicate a high PM concentration.
The two devices were placed in the middle of the workspace at a height of 1 meter from the floor. In contrast, the PM10 particle count in the morning time was 354 particles with a concentration of 133,083 µg/m3. The number of particles had dropped to 275 particles in the afternoon with a total concentration of 100.661 µg/m3.
Pollutant Sources Measurements
After 1 hour, the particle count dropped to 5983 particles per minute with a concentration of 2.703 µg/m3. The particle count further dropped to 5,464 particles per minute at 1 hour 30 minutes with a total concentration of 2,360 µg/m3. At the end of the two-hour measurement, the number of particles dropped to 4638 particles per minute with a concentration of 2.005 µg/m3.
While the PM10 particle count was 6 particles per minute in the first 30 minutes, with a concentration of 0.880 µg/m3. At the 1-hour-30-minute mark, the particle count was almost at a steady state at 3 particles per minute with a concentration of 0.480 µg/m3. At the end of the measurement, the particle count was 4 particles per minute with a concentration of 0.501 µg/m3.
CONCLUSION AND RECOMMENDATIONS
Recommendations
- Corporate scale
- Individual scale
83 maintenance of the HVAC system is essential to achieve adequate indoor air quality within the space (US EPA, 1990). However, being aware of the main sources of air pollutants in an office building is essential. In addition, the operating period of the HVAC system in an office building should be turned on before the arrival of the occupants and turned off after their departure.
If the building is not ventilated during the presence of the occupants, there will be an accumulation of air pollutants in the room. During any maintenance or renovation, it is always recommended that ventilation rates be increased during these activities to control and minimize the impact on indoor air quality (US EPA, 1990). Some small actions and decisions could save us from exposure to high concentrations of air pollutants.
Limitations and Recommendations
