Investigation of Microbiological Concentration in Indoor Air at School Classrooms

INVESTIGATION OF MICROBIOLOGICAL CONCENTRATION IN INDOOR AIR AT SCHOOL CLASSROOMS

WAN NORFAZLINDA BINTI WAN MOHD ALI

SCHOOL OF CIVIL ENGINEERING UNIVERSITI SAINS MALAYSIA 2018

INVESTIGATION OF MICROBIOLOGICAL CONCENTRATION IN INDOOR AIR AT SCHOOL CLASSROOMS

WAN NORFAZLINDA BINTI WAN MOHD ALI

This dissertation is submitted to

UNIVERSITI SAINS MALAYSIA As partial fulfilment of requirement for the degree of

BACHELOR OF ENGINEERING (HONS.) (CIVIL ENGINEERING)

School of Civil Engineering, Universiti Sains Malaysia

June 2018

SCHOOL OF CIVIL ENGINEERING ACADEMIC SESSION 2017/2018

FINAL YEAR PROJECT EAA492/6 DISSERTATION ENDORSEMENT FORM

Title: INVESTIGATION OF MICROBIOLOGICAL CONCENTRATION IN INDOOR AIR AT SCHOOL CLASSROOMS

Name of Student: WAN NORFAZLINDA BINTI WAN MOHD ALI

I hereby declare that all corrections and comments made by the supervisor(s) and examiner have been taken into consideration and rectified accordingly.

Signature: Approved by:

______

(Signature of Supervisor)

Date: Name of Supervisor: PM DR NOOR FAIZAH FITRI MD YUSOF

Date :

Approved by:

______

(Signature of Examiner)

Name of Examiner:

Date :

ACKNOWLEDGEMENT

In the name of Allah, the Most Gracious and the Most Merciful

I would first like to express my great appreciation for my supervisor, Assoc. Prof. Dr.

Noor Faizah Fitri Binti Md Yusof for her valuable and constructive suggestions during planning and development of this research work. She consistently allowed this thesis to be my own work, but steered me in the right direction whenever she thought I needed it.

Furthermore, I would also like to thank to all the lecturers and staffs from School of

Civil Engineering for their guidance for my classmate and I during this research. A special appreciation also to all the teachers and staff involved from SK Bayan Lepas,

SK Tasek Gelugor, SK Machang Bubok and SMK Mutiara Impian for their support and kindness during this research.

Moreover, I would also like to acknowledge Mrs Azrin Binti Suroto, postgraduate student from School of Civil Engineering for giving opinion whenever I ran into a trouble spot or had a question about my research or writing. Her willingness to give her time so generously has been very much appreciated. I also admire all my colleagues who helped and encouraged me for the four year I was here.

Finally, I must express my very profound gratitude to my parents; Mr. Wan Mohd Ali

Bin Wan Sulaiman and Mrs. Zainab Binti Ali and also my sibling for providing me with unfailing support and continuous encouragement throughout my years of study and through the process of researching and writing this thesis. This accomplishment would not have been possible without them. To those who indirectly contributed in this research, your kindness means a lot to me. Thank you so much.

ABSTRAK

Manusia menghabiskan sebahagian besar kehidupan mereka sama ada rumah, pejabat, sekolah, hospital dan kenderaan. Pencemaran udara dalaman adalah salah satu faktor persekitaran yang paling berbahaya bagi kesihatan manusia. Tujuan kajian ini dijalankan adalah untuk mengkaji tahap kepekatan bakteria dalam empat buah kelas, perbezaan kepekatan bakteria dengan atau tanpa kehadiran pelajar berserta aktiviti dan menentukan hubungan antara kepekatan bakteria dengan suhu dan kelembapan relatif bagi sekolah yang terpilih di Pulau Pinang, Malaysia. Kepekatan bakteria telah ditentukan menggunakan kaedah “settle plate”. Agar media yang digunakan adalah agar nutrien yang didedahkan kepada persekitaran selama 15 minit pada titik terpilih bagi setiap bilik darjah. Jumlah purata bacaan bakteria bagi setiap sekolah ialah 322.39 cfu/m3, 684.89 cfu/m3, 671 cfu/m3 dan 387.44 cfu/m3 bagi SK Bayan Lepas, SK Tasek

Gelugor, SMK Mutiara Impian dan SK Machang Bubok. Kajian ini telah menunjukkan bahawa suhu dan kelembapan relatif mempengaruhi kiraan bakteria. Kesimpulannya, aktiviti oleh murid dan guru di dalam bilik darjah mempengaruhi jumlah bakteria yang dikira untuk sekolah terpilih di Pulau Pinang.

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ABSTRACT

People spend most of their lifetime indoor whether residences, offices, schools, hospital and vehicles. Indoor air pollution is one of the most harmful environmental factors for human health. This study investigates the level of concentration of bacterial at four different school classrooms and determined the relationship of bacteria with temperature and relative humidity in Penang, Malaysia. The concentration of bacterial was determined using settle plate method. The agar media used was Nutrient Agar that were exposed to the atmosphere for 15 minutes at selected points in each school classrooms. The total of mean bacterial count for each school was 322.39 cfu/m3,

684.89 cfu/m3, 671 cfu/m3 and 387.44 cfu/m3 for SK Bayan Lepas, SK Tasek Gelugor,

SMK Mutiara Impian and SK Machang Bubok, respectively. This study has shown that the temperature and relative humidity affect the bacterial counts. To conclude, activities from occupancy influence the bacterial count in selected schools in Penang.

TABLE OF CONTENTS

ACKNOWLEDGEMENT ...... II

ABSTRAK ...... III

ABSTRACT ...... IV

TABLE OF CONTENTS ...... V

LIST OF FIGURES ...... VIII

LIST OF TABLES ...... XI

LIST OF ABBREVIATIONS ...... XIII

CHAPTER 1 ...... 1

1.1 Background of the study ...... 1 1.2 Problem Statement ...... 2 1.3 Objectives ...... 3 1.4 Scope of Study ...... 4 1.5 Dissertation Outline...... 5 CHAPTER 2 ...... 6

2.1 Introduction ...... 6 2.2 Indoor Air ...... 6 2.3 Indoor Air Quality (IAQ) ...... 7 2.4 Factor of Indoor Air Contaminant ...... 8 2.4.1 Bacterial Counts ...... 8 2.4.2 Relative Humidity and Temperature ...... 9 2.4.3 Indoor Sources ...... 10 2.5 Indoor Air Quality Parameters by Industry Code of Practice ...... 11 2.6 Effect on health due to poor indoor air quality ...... 12 2.7 Summary of Literature Review ...... 14 CHAPTER 3 ...... 15

3.1 Introduction ...... 15 3.2 Study Area ...... 15

3.2.1 SK Bayan Lepas ...... 17 3.2.2 SK Tasek Gelugor ...... 19 3.2.3 SK Machang Bubok ...... 22 3.2.4 SMK Mutiara Impian ...... 24 3.3 Sampling Schedule and Duration ...... 26 3.4 Sampling Design ...... 26 3.4.1 Microbiological Sampling ...... 26 3.4.2 Instruments of Data Collection ...... 29 3.5 Data Analysis ...... 30 3.5.1 Descriptive Statistics ...... 30 3.5.2 Pearson‟s Correlation ...... 30 CHAPTER 4 ...... 32

4.1 Introduction ...... 32 4.2 Microbiological concentration in classroom for background study ...... 32 4.2.1 Bacterial count, relative humidity and temperature of different level ..... 34 4.2.2 Mean indoor bacterial count, relative humidity and temperature of background study ...... 36 4.3 Microbiological concentration during normal condition at SK Bayan Lepas . 37 4.3.1 Bacterial count, relative humidity and temperature of different level ..... 40 4.3.2 Effect of student activity on bacterial count ...... 42 4.3.3 Mean indoor bacterial count, relative humidity and temperature of SK Bayan Lepas ...... 43 4.4 Microbiological concentration during normal condition at SK Tasek Gelugor ...... 44 4.4.1 Bacterial count, relative humidity and temperature of different level ..... 47 4.4.2 Effect of student activity on bacterial count ...... 48 4.4.3 Mean indoor bacterial count, relative humidity and temperature of SK Tasek Gelugor...... 49 4.5 Microbiological concentration during normal condition at SK Machang Bubok ...... 50 4.5.1 Bacterial count, relative humidity and temperature of different level ..... 54 4.5.2 Effect of student activity on bacterial count ...... 56

4.5.3 Mean indoor bacterial count, relative humidity and temperature of SK Machang Bubok ...... 57 4.6 Microbiological concentration during normal condition at SMK Mutiara Impian...... 58 4.6.1 Bacterial count, relative humidity and temperature of different level ..... 61 4.6.2 Effect of student activity on bacterial count ...... 62 4.6.3 Mean indoor bacterial count, relative humidity and temperature of SMK Mutiara Impian ...... 63 4.7 Microbial population density of schools ...... 64 4.8 Comparison of bacterial count (cfu/m3) for background and normal condition ...... 66 4.9 Comparison of temperature (°C) between background and normal condition 67 4.10 Comparison of relative humidity (%) for background and normal condititon 68 4.11 Pearson‟s Correlation for Bacterial Count with Temperature (°C) and Relative Humidity (%)...... 69 4.11.1 Background Study ...... 69 4.11.2 SK Bayan Lepas ...... 70 4.11.3 SK Tasek Gelugor ...... 71 4.11.4 SK Machang Bubok ...... 71 4.11.5 SMK Mutiara Impian ...... 72 CHAPTER 5 ...... 76

5.1 Conclusion ...... 76 5.2 Recommendations ...... 77 REFERENCES ...... 78

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LIST OF FIGURES

Figure 3.1‎ : Flowchart of methodology ...... 16

Figure 3.2‎ : SK Bayan Lepas from satellite image (Source: Google Map) ...... 17

Figure 3.3‎ : Classroom‟s Layout at Level 2 of SK Bayan Lepas ...... 18

Figure 3.4‎ : Floor plan at Level 2 of SK Bayan Lepas ...... 18

Figure 3.5‎ : Classroom‟s Layout at Level 3 of SK Bayan Lepas ...... 18

Figure 3.6‎ : Floor plan at Level 3 of SK Bayan Lepas ...... 19

Figure 3.7‎ : SK Tasek Gelugor ...... 20

Figure 3.8‎ : SK Tasek Gelugor from satellite image (Source: Google Map) ...... 20

Figure 3.9‎ : Classroom‟s Layout at Level 1 of SK Tasek Gelugor...... 20

Figure 3.10‎ : Floor plan at Level 1 of SK Tasek Gelugor ...... 21

Figure 3.11‎ : Classroom‟s Layout at Level 3 of SK Tasek Gelugor...... 21

Figure 3.12‎ : Floor plan at Level 3 of SK Tasek Gelugor ...... 21

Figure 3.13‎ : SK Machang Bubok from satellite image (Source: Google Map) ...... 22

Figure 3.14‎ : Classroom‟s Layout at Level 2 of SK Machang Bubok ...... 22

Figure 3.15‎ : Floor plan at Level 2 of SK Machang Bubok ...... 23

Figure 3.16‎ : Classroom‟s Layout at Level 3 of SK Machang Bubok ...... 23

Figure 3.17‎ : Floor plan at Level 3 of SK Machang Bubok ...... 23

Figure 3.18: Study location from satellite image (Sources: Google Map) ...... 24

Figure 3.19‎ : Classroom‟s Layout at Level 2 of SMK Mutiara Impian ...... 24

Figure 3.20: Floor plan at Level 2 of SMK Mutiara Impian ...... 25

Figure 3.21‎ : Classroom‟s Layout at Level 3 of SMK Mutiara Impian ...... 25

Figure 3.‎ 2: Floor plan at Level 3 of SMK Mutiara Impian ...... 25

Figure 23:‎ Correlation terms (Townend, 2002) ...... 31

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Figure 4.1‎ Location of point in both classrooms of SK Bayan Lepas for background

detail study...... 32

Figure 4.2: Microorganisms formed on an agar plate after 24-hours incubation at

SK Bayan Lepas ...... 33

Figure 4.3‎ : Comparison of bacteria concentration for 24 hours at SK Bayan Lepas. . 34

Figure 4.4:‎ Relative humidity rate against ICOP 2010 ...... 35

Figure 4.5‎ : Temperature rate against ICOP 2010 ...... 35

Figure 4.6:‎ Location of point in both classrooms of SK Bayan Lepas with the

presence of student...... 37

Figure 4.7: Microorganisms formed on an agar plate after incubation (SK

Bayan Lepas) ...... 39

Figure 4.8‎ : Comparison of bacteria concentration for 24 hours at SK Bayan Lepas. . 40

Figure 4.9‎ : Relative humidity rate against ICOP 2010 ...... 41

Figure 4.10‎ : Temperature rate against ICOP 2010 ...... 41

Figure 4.11:‎ Presence of student in the classroom ...... 42

Figure 4.1‎ : Location of point in both classrooms of SK Tasek Gelugor with

the presence of student...... 44

Figure 4.13 Microorganisms formed on an agar plate after incubation (SK

Tasek Gelugor)...... 46

Figure 4.14:‎ Comparison of bacteria concentration for 24 hours at SK Tasek

Gelugor ...... 47

Figure 4.15‎ : Relative humidity rate against ICOP 2010 ...... 48

Figure 4.16‎ : Temperature rate against ICOP 2010 ...... 48

Figure 4.17:‎ Presence of student in the classroom ...... 49

Figure ‎.18: Location of point in both classrooms of SK Machang Bubok with

the presence of student...... 51

Figure 4 19: Microorganisms formed on an agar plate after incubation

(SK Machang Bubok) ...... 53

Figure 4.‎ 0: Comparison of bacteria concentration for 24 hours at SK Machang

Bubok ...... 54

Figure 4.21‎ : Relative humidity rate against ICOP 2010 ...... 55

Figure 4.22‎ : Temperature rate against ICOP 2010 ...... 55

Figure 4.23‎ : Presence of student in the classroom ...... 56

Figure 4.24‎ Location of point in both classrooms of SMK Mutiara Impian when

presence of student...... 58

Figure 4.25: Microorganisms formed on an agar plate after incubation (SMK

Mutiara Impian) ...... 60

Figure 4.26‎ : Comparison of bacteria concentration for 24 hours at SMK

Mutiara Impian...... 61

Figure 4.27‎ : Relative humidity rate against ICOP 2010 ...... 62

Figure 4.28‎ : Temperature rate against ICOP 2010 ...... 62

Figure 4.29:‎ Presence of student in the classroom ...... 63

Figure 4.30‎ : Comparison of bacterial count between background condition and

with the presence of students ...... 67

Figure 4.31:‎ Comparison of temperature between background condition and with

the presence of students ...... 68

Figure 4.32:‎ Comparison of relative humidity between background condition and

with the presence of students ...... 69

LIST OF TABLES

Table 2.1‎ : Acceptable range for physical parameters ...... 11

Table 2.2‎ : Acceptable limits for bacterial contaminants ...... 11

Table 3.1‎ : Location of the school ...... 15

Table 3.2‎ : Schedule of Indoor Air Quality sampling ...... 26

Table 3.3‎ : Sampling and Laboratory Work Instrument ...... 29

Table 4.1‎ : Bacterial colony count at Level 2 of SK Bayan Lepas ...... 33

Table 4.2‎ : Bacterial colony count at Level 3 of SK Bayan Lepas ...... 33

Table 4.3‎ Background data of bacterial colony counts (cfu) per m3 with temperature

and relative humidity at different sampling periods of day of SK Bayan

Lepas...... 36

Table 4.4‎ : Bacterial colony count at Level 2 ...... 38

Table 4.5‎ : Bacterial colony count at Level 3 ...... 38

Table 4.6‎ : Bacterial colony counts (cfu) per m3 with temperature and relative humidity

at different sampling periods of day of SK Bayan Lepas...... 43

Table 4.7‎ : Bacterial colony count at Level 1 ...... 45

Table 4.8‎ : Bacterial colony count at Level 3 ...... 45

Table 4.9‎ : Bacterial colony counts (cfu) per m3 with temperature and relative humidity

at different sampling periods of day of SK Tasek Gelugor ...... 50

Table 4.10‎ : Bacterial colony count at Level 2 ...... 52

Table 4.11‎ : Bacterial colony count at Level 3 ...... 52

Table 4.12‎ : Bacterial colony counts (cfu) per m3 with temperature and relative humidity

at different sampling periods of day of SK Machang Bubok ...... 57

Table 4.13‎ : Bacterial colony count at Level 2 ...... 59

Table 4.14‎ : Bacterial colony count at Level 3 ...... 59

Table 4.15‎ : Bacterial colony counts (cfu) per m3 with temperature and relative humidity

at different sampling periods of day of SMK Mutiara Impian ...... 64

Table 4.16‎ : Descriptive statistics for the ranges of microbial population density at the

schools study ...... 65

Table 4.17:‎ Pearson‟s correlation for background study ...... 70

Table 4.18:‎ Pearson‟s correlation for SK Bayan Lepas ...... 70

Table 4.19:‎ Pearson‟s correlation for SK Tasek Gelugor ...... 71

Table 4.20:‎ Pearson‟s correlation for SK Machang Bubok ...... 72

Table 4.21:‎ Pearson‟s correlation for SMK Mutiara Impian ...... 73

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LIST OF ABBREVIATIONS

AHPA American Public Health Association

ICOP Industry Code Of Practice

SK Sekolah Kebangsaan

SMK Sekolah Menengah Kebangsaan

WHO World Health Organization

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CHAPTER 1

INTRODUCTION

1.1 Background of the study

Penang is one of the thirteen states in Malaysia that located near the north-western coast of Peninsular Malaysia. It is separated between the State of Kedah in the north and east, the State of Perak in the south and the Straits of Malacca and Sumatra

(Indonesia) in the west. Penang State consists of two parts which is Penang Island and mainland, Seberang Perai. The island is connected to Seberang Perai by ferry and by the two bridges that is 13.5 km long Penang Bridge and 24 km long Sultan Abdul

Halim Mu'adzam Shah bridges. The island with 285 square metres is situated on the northwest side of the Peninsular Malaysia. The residents in Penang are multiracial communities and each year the population has increase.

As the population grows, all kinds of school are also increasing. The increase of this school is shared by both the government and the private sector. However, there are important aspect that need to be focused which is the learning environment especially the classroom itself and the student‟s health level (Suroto, 2010). A classroom is one of the important places, where students would stay at classroom for 6 to 8 hours. This is because outside the home, children spend most of their time indoors while at school.

The learning environment is related to indoor air quality inside the buildings which can contribute to the development of mind, learning process and the growth of the students.

Children are more susceptible to the effects of air pollution than adults because of their immature immune and respiratory system and also their breathing pattern. Asthma and

1 allergy are two of the most prevalent disease in children (Pearce et al., 2000). Indoor air pollutants can cause or contribute to short-term and long-term health problems

(Clausen et al., 2009; Simoni et al., 2010; Annesi-Maesano et al., 2013).

From the previous study, the activities of indoor occupants, such as walking, affect the concentration of ordinary aerosol particles (Batterman, 2001; Ferro et al., 2004;

Raunemaa et al., 1989; Qian et al., 2014). Besides, some studies have found that the activities of occupants increase the concentrations of aerosol diameter (> 1 μm)

(Batterman, 2001; Raunemaa et al., 1989) in indoor environments. Children‟s activity and their presence may affect the concentration of biological particles. There have been a few previous studies on the correlation between human activities and bio-aerosols concentration in indoor air environment. It was found that human occupancy increased the bacterial concentration in indoor air environments such as in a classroom

(Hospodsky et al., 2012; Qian et al., 2012).

1.2 Problem Statement

Children require good indoor environment since indoor air quality is very important for their growth and wellbeing as they are sensitive groups more compared to adults

(Kamaruzzaman & Razak, 2011). Indoor air pollutants such as particulate matter and microbes have been linked to respiratory health effects in children, especially asthma symptoms such as night coughs and wheezing due to early exposure to indoor air contaminants (Khamal et al., 2016). School is one of the most significant environments for children, and there is a proof that the indoor air quality (IAQ) and ventilation in school buildings may affect their health (Daisey et al., 2003). Teachers and students spend most of their times at the school buildings with indoor activities such as in a

2 classroom. This indoor air quality is very important as it can affect the health of the students, especially the growth and learning process of the students. Moreover, from this research, the effect of concentrations of bacteria on human health can be measured.

Respiratory illnesses due to exposure of airborne contaminants are a common problem for humans, particularly to children. Mould allergy was found to be more frequent in children than in adults, although the causes of mould allergies are still uncertain

(Aydogdu et al., 2005). According to Bayer et al. (1999), allergic diseases including nasal allergy, asthma and other allergies accounted for 20% loss of school days in both elementary and high schools in US. Furthermore, number of students in each classroom is not similar. Therefore, the presence of occupant in a classroom significantly gave effect on concentration of bacteria. The number of occupants increases the shedding of bacteria and agitation of air increases the bacterial count in indoor environment

(Meadow et al., 2014). A study is needed to analyze the concentration of bacteria in each classroom at selected school. Previous study by Kamaruddin (2017) mentioned that the school selected based on microenvironment criteria such as industrial area. The temperature of the classrooms for SK Sungai Kechil (industrial sources) and SK Khir

Johari (mobile sources) exceed the ICOP limit (23ᵒC - 26ᵒC). Besides, the values of relative humidity also exceed the limit between 40% - 70%.

1.3 Objectives

The purposes of this study are listed as follow:

1. To determine the concentration of bacteria in school classrooms.

2. To compare the concentration of bacteria in background condition with

presence of student and activities.

3. To investigate the relationship between concentration of bacteria in classrooms

with relative humidity and temperature.

1.4 Scope of Study

This research was conducted at four selected school around Penang which are

SK Bayan Lepas, SK Tasek Gelugor, SK Machang Bubok and SMK Mutiara Impian.

Firstly, agar plate was setup at the selected point in the classroom to collect the bacterial contaminants while the formaldemeter used to measure the relative humidity and temperature in the classroom. The sampling time was conducted during the morning session at 07:15 a.m. until 07:30 a.m., 10:40 a.m. until 10:55 a.m. and 12:45 p.m. until 13:00 p.m.

Then, the selection of the school classroom is based on the location of the classrooms at different levels. However, activities of occupant in the classroom affect the bacterial counts. Therefore, the presence and activities of the occupant during sampling period was recorded in order to know the movement of occupant based on learning activities.

There are two categories of indoor air contaminants that are being investigated which are physical and biological contaminants. The physical parameters used in this study were relative humidity and air temperature while the parameters used for biological contaminants was the bacterial concentrations. In addition, the parameters obtained from this study were compared with the guideline of acceptable limits by

Industry Code of Practice (ICOP) Malaysia.

1.5 Dissertation Outline

This thesis consists of five chapters. A brief outline of the structure is given below.

Chapter 1 is an introduction to the background of concentration of bacteria and scope of study. The problem statement, objectives and scope of the study are all stated in this chapter.

Chapter 2 include the literature reviews from the previous study about the parameter of indoor air quality and the factors affecting indoor air quality.

Chapter 3 explains an overall methodology that has been applied in this study.

A general flowchart is used to simplify the research study.

Chapter 4 discussed in detail the result of the analysis. The result consists of concentration of bacteria, relative humidity and temperature. The relationship of concentration of bacteria with relative humidity and temperature will be described in this chapter.

Chapter 5 conclude the objectives and the results obtained from sampling. The future recommendation is made for future research to expand the scope of the research.

CHAPTER 2

LITERATURE REVIEW

2.1 Introduction

This chapter covers the literature reviews from the previous study about the parameter of indoor air quality, the factors affecting indoor air quality and the guideline of indoor air quality from Industry Code of Practice, 2010.

2.2 Indoor Air

People spend most of their time indoors, especially at home and in school therefore scientists has been focus on indoor air during last decade (Madueira et al., 2015).

Indoor environments in workplaces and residential environments have recently caught the attention of scientists and public institutions (Lee and Chang, 2000). People spend

80% - 90 % of their time in indoors environment by breathing on average 14 m3 of air in a day (Brochu et al., 2006). Millions of children and adults from all over the country spend their days in school buildings, and they need safe, healthy environments to thrive, learn, and succeed (Borgo and Mostafavi, 2007). According to Enitan et al.

(2017), by ignored the time of the day, indoor environment allows aerosols build up which could serve as potential risk factors for spread of inspection in the classrooms of schools.

Schools are one of the institutional for communities of learners, including students and teachers (Ramli et al., 2012). According to Torres (2000), children spent only 23% of

6 their time indoors such as in kindergartens and schools. Moreover, students in Malaysia generally spent between five to ten hours per day at school. The Muslim children spend more time at school as they attending religious school such as Sekolah Rendah Agama

(SRA) or Sekolah Menengah Agama (SMA). Obviously, children spend more time in their school environment than in their home environment. Therefore, it is not wrong to conclude that their behavioural growth is affected more by their school environment than their home environment (Ramli et al., 2012).

Furthermore, the schools were selected based on their surrounding environments such as surrounded by buildings, roadways, and mountains. Children breathe a higher volume of air at very fast rate as they more sensitive when being exposed to unsafe air

(Landrigan, 1997; Faustman et al., 2000). During school days, over 30% of a pupil‟s life was spent at schools, and about 70% of their time inside a classroom (Bako-Biro et al., 2004). In school buildings, the indoor particle concentrations effect the resuspension of particles by students‟ indoor activities in occupied classrooms (Yang et al., 2009; Mullen at el., 2011).

2.3 Indoor Air Quality (IAQ)

Indoor air quality is determined from a wide range of pollution sources by a combination of various pollutants, all of them relate to the places, the climate and the culture such as the local ambient air, the building features and the indoor activities

(Fernandes et al., 2008). Indoor air quality in the residential sector is very important as it takes time to analyse indoor air quality in government schools in indoor air micro- flora (Mohan et al., 2014). Most people spend a great part of their time in the building,

7 so indoor air quality is very essential as a determinant of healthy life and welfare

(Branco et al., 2014).

Most people spend about 87% of their time indoors and only 5% to 6% in the vehicle, hence indoor air quality is an important factor in human exposure to environmental pollutants (Klepeis et al., 2001). School pupils spend more than 70% of life in the classroom and indoor air quality affects the attendance and potential of student learning. Hence, the indoor air quality in primary school buildings is highly important

(Peng et al., 2017). Fang et al. (2004) indicated that indoor air temperature has great impact on perceived air quality in office buildings, and high air temperatures can promote the generation of other pollutants, such as volatile organic compounds (VOCs) and formaldehyde.

2.4 Factor of Indoor Air Contaminant

2.4.1 Bacterial Counts

The bacterial concentration was found more in places like classrooms, toilets and canteens and fungal concentration was observed more in libraries, classrooms.

Lack of concern in indoor air qualities in the management lead to the growth of bacteria and fungi (Mohan et al., 2014). In all of the tested places a multiple growth of bacteria and significant increase of mould spores were observed in afternoon (Filipiak, 2007).

In schools the highest level of bacterial contamination was detected in the corridor and in rooms (Filipiak, 2007). The indoor levels of bacteria and fungi concentrations in schools with occupants were significantly higher than those without occupants due to contamination by the occupants (Hussin et al., 2011).

Moreover, the environmental factors mainly include temperature, humidity, air exchange rate, air movement, building structures and location, poor design, ventilation system as well as interior or redesign which enhance microorganism's growth and multiplication in the indoor atmosphere (Wamedo et al., 2012; Meadow et al., 2014;

Graudenz et al., 2005). Mohan et al. (2014) mentioned that the sources of classroom airborne infection or contamination could be traced to a variety of factors. These include the student‟s own uniforms, bags, sandals; as well as activity of students like sneezing, coughing, talking and yawning. House-keeping activity such as sweeping or using dry dust mops can aerosolize particles that may contain microorganisms.

Materials such as cupboards, books and files have been implicated as viable sources

(Faustman et al., 2000). Food stuffs, house plants and flower pots, house dust, textiles, carpets, wood material and furniture stuffing, occasionally release various fungal spores into the air (Kalogerakis et al., 2005).

2.4.2 Relative Humidity and Temperature

The average indoor temperature and relative humidity were higher in comparison with those in cold countries due to less variation in the temperature and climate that prevail throughout the year in Malaysia (Hussin et al., 2011). The indoor air temperature in winter is mainly determined by occupants‟ activities and the adiabatic ability of a building‟s fabrics (Peng et al., 2017). Kamaruzzaman and Razak

(2011) stated that the relative humidity rate is inversely proportional to the temperature and CO₂ concentration. Indoor air quality not only for comfort, which is affected by temperature, relative humidity and odours but also by harmful biological contaminants present in the conditioned space. Temperature, relative humidity, sources of nutrients,

9 and air movement affect the growth and dissemination of biological contaminants

(Seltzer, 1994).

2.4.3 Indoor Sources

The sources of classroom airborne infection or contamination could be traced to a variety of factors. These include the pupil‟s own normal flora, uniforms, bags, sandals; as well as activity of pupils like sneezing, coughing, talking and yawning (Mohan et al.,

2014). The presence of human and their activity may affect the concentration of biological particles. Talking activities, including heavy inhalation and exhalation, decreased the concentration of bacterial bio-aerosols in the confined indoor space (Heo et al., 2017). From the concentration of ordinary aerosol particles affected by the activities of indoor occupants such as walking (Batterman, 2001; Ferro et al., 2004;

Raunemaa et al., 1989; Qian et al., 2014). Besides, some studies have found that the activities of occupants increase more than one micrometre of the concentrations of aerosol diameter (Batterman, 2001; Raunemaa et al., 1989) in indoor environments.

There have been a few previous studies on the correlation between human activities and bio-aerosols concentration in indoor air environments. An indoor air environment like classroom increased the concentration of bacteria with the human occupancy

(Hospodsky et al., 2012; Qian et al., 2012). The concentrations of aero-flora above permissive standard recorded in private primary schools in Nigeria study, underscore the importance of this microenvironment for the high exposure of children to bioaerosols. Immediate interventions are therefore needed to control both human and environmental factors which favour the growth and multiplication of microorganisms

(Enitan et al., 2017). Besides, there was a higher concentration of PM indoors, when a classroom was occupied. This was caused by students‟ activities, such as walking,

10 running, and cleaning the blackboard, which increased the re-suspension of particulate matter (Peng et al., 2017).

2.5 Indoor Air Quality Parameters by Industry Code of Practice

DOSH (2010) have identified the main indoor air parameters. A temperature is the degree or intensity of heat present in a substance or object. The effects of indoor air temperature have caused dehydration but the lower temperature would bring discomfort to students and teachers. Relative humidity is the amount of water vapour present in air expressed as a percentage of the amount needed for saturation at the same temperature.

The acceptable range for temperature and relative humidity by ICOP is shown in Table

2.1. Table 2.2 shows the acceptable limits for bacterial contaminants.

Table 2‎ .1: Acceptable range for physical parameters Parameter Acceptable Range

Air Temperature 23 – 26 C

Relative Humidity 40% - 70%

(Source: Industry Code of Practice on Indoor Air Quality, 2010)

Table 2‎ .2: Acceptable limits for bacterial contaminants Indoor Air Contaminants Acceptable limits

(cfu/m³)

Total bacterial counts 500*

*excess of bacterial counts does not necessarily imply health but serve as an indicator for further investigation. (Source: Industry Code of Practice on Indoor Air Quality, 2010)

2.6 Effect on health due to poor indoor air quality

Children‟s immature immune and respiratory system and also their breathing pattern caused them more susceptible to the effects of air pollution than adults. Asthma and allergy are two of the most prevalent disease in children (Pearce et al., 2000). Short- term and long-term health problems can arise from indoor air pollutants (Clausen et al.,

2009; Simoni et al., 2010; Annesi-Maesano et al., 2013). Moreover, respiratory illnesses are common problem for humans especially children due to the exposure of air contaminants (Hussin et al., 2011). Although the causes of mould allergies are still uncertain, mould allergy was found to be more frequent in children than in adults

(Aydogdu et al., 2005).

Exposure to these indoor air contaminants particularly among school children needs closed attention as children are more susceptible to the infection or respiratory problems and a large portion of their time is spent in school (Hussin et al., 2011).

Children are exposed to ultrafine particle mainly at home and school (Buonanno et al.,

2012; Mazaheri et al., 2013). Indoor air pollution can increase chances of the development of long and short-term health problems in students and staff in school

(Lee and Chang, 2000). High exposure to particulate matters can bring misery problems like asthma, lung cancer, cardiovascular disease, respiratory diseases, birth defects, and premature death (Peng et al., 2017). Sundell et al. (2011) concluded that the incidence of inflammation, respiratory infections, asthma symptoms, and short-term sickness is enhanced as a result of high exposure to air pollutants.

School is one of the most significant environments for children, and there is a proof that the indoor air quality (IAQ) and ventilation in school buildings may affect their

12 health (Daisey et al., 2003), but a few publications has found on associations between building dampness and measured microbial exposure in schools or about sick building syndrome in school children (Meyer et al., 2004; Saijo et al., 2010). The growth of bacteria and fungi is caused by the lack of concern in indoor air qualities in the management. Indoor microbial contaminants include bacteria, molds, yeast, and various components from these organisms. The most studied bacterial compound is endotoxin

(LPS) (Seltzer, 1994).

Furthermore, one of the troubles of indoor air quality is affected by the existence of microorganisms which include bacteria, moulds and viruses (Wamedo et al., 2012).

The existence of bacteria in the indoor air pose a serious problem from the point of view of health protection and environmental engineering (Al-Mijalli, 2016). Bacteria and fungi are most commonly microorganisms associated with indoor air quality complaint and most often implicated as indoor bio-contaminants (Wong et al., 2009).

Besides, airborne microbe is one of the most contaminant that addressing major issue in defining low indoor air quality. A wide variation of microorganism such as fungi

(moulds, yeasts), bacteria, viruses, and amoebae can be found in the indoor environment (Abidin et al., 2013). According to Khamal et al. (2016), the indoor particle concentrations and presence of microbes in indoor room might increase the risk in exposed children for respiratory, particularly asthma, later in life.

Air in the indoor environment can be polluted by a number of pollutants among which airborne microorganism such as bacteria and fungi are one of the most important. It has been estimated that one-third of indoor air quality (IAQ) complaints may be due to microbial contamination (Pope et al., 1993). Lack of cleaning and checking out of the

13 heating, ventilation and air conditioning systems (HVAC) may allow microbial growth, which causes several diseases in the users. Every few month, the filters of air conditioners should be cleaning. With the cooler months approaching it becomes even more important to make sure that air conditioner is clean (Al-Mijalli, 2016). Specific classroom, cleaning and maintenance characteristics have been identified as having a direct impact on indoor air quality (Fsadni et al., 2017).

2.7 Summary of Literature Review

Previous study indicate that the presence of occupants increase the number of bacterial count in indoor environment. Hayleeyesus and Manaye (2014), revealed that the number of occupants increase the shedding of bacteria count in indoor environment.

Besides, another study by Hussin et al. (2011), found that the indoor levels of bacteria and fungi concentrations in schools with occupants were significantly higher than those without occupants due to contamination by the occupants. Furthermore, the activities of occupants in the classroom affect the bacterial counts. Heo et al. (2017) stated that the activities of occupants increase the concentration of bacteria.

On the hand, the literature presented in this chapter evaluated indoor air parameters and the biological contaminants. DOSH (2010) had recommended acceptable guideline limit for indoor air parameters and biological contaminants.

However, past investigation was using Duo SAS Super 360 microbiological air sampler. The sampling time was 2 minutes. More than half of bacteria samples had a concentration exceeding WHO recommended level of 500 cfu/m3 (Hussin et al., 2011).

Therefore, in this research, settle plate method using 9cm petri dishes were used to allow bacteria carrying particles to settle on agar media. The sampling time was 15 minutes.

CHAPTER 3

METHODOLOGY

3.1 Introduction

This chapter covers the details explanation of methodology used to complete this research. A systematic process was organized in order to achieve the objective of this study as shown in Figure 3.1.

3.2 Study Area

The research is conducted at four selected school around Penang, Malaysia as

Penang is one of the developing countries in Malaysia. The selected school of this study are government schools which are SK Bayan Lepas, SK Tasek Gelugor, SK

Machang Bubok and SMK Mutiara Impian. The coordinate of each selected schools is stated in Table 3.1. All the selected schools were built more than 15 years ago and constructed of concrete with no air conditioning. All the schools were located near to the residential area. All the schools have only morning session for teaching and learning starts at 07:30 a.m. except SK Tasek Gelugor that has morning and evening session.

Table 3‎ .1: Location of the school Name of School Coordinate SK Bayan Lepas N 05° 17‟ 48‟‟ E 100° 15‟ 38‟‟ SK Tasek Gelugor N 05° 29‟ 02‟‟ E 100° 29‟ 29‟‟ SK Machang Bubok N 05° 19‟ 40‟‟ E 100° 30’ 10’’ SMK Mutiara Impian N 05° 16‟ 28‟‟ E 100° 28‟ 39‟‟

DATA SAMPLING

Quantitative Measurements Preparation of agar Bacteria, Temperature, Relative

Humidity

Preparing for sampling plan Occupied Study - Location for agar plate Background Study - SK Bayan Lepas - 15 minutes exposure Obj. 2 - SK Bayan - SK Tasek Gelugor & 3 Lepas - SK Machang Bubok - SMK Mutiara Impian Quantitative Measurements

Bacteria Obj. 1 Compare the background and an occupied classroom Obj. 2

Calculation of bacterial for each school Data Analysis per sampling time Obj. 3 - Pearson Correlation - Descriptive Statistics

Figure 3‎ .1: Flowchart of methodology

3.2.1 SK Bayan Lepas

SK Bayan Lepas (SKBL) is one of the primary school located at Jalan Dato

Ismail Hashim, Bayan Lepas, Penang as shown in Figure 3.2. The coordinate of the school is N 05° 17‟ 48‟‟and E 100° 15‟ 38‟‟.

The school was developed on 1st January 1926. In 1957, Sekolah Umum Bayan

Lepas was change to SK Bayan Lepas. SK Bayan Lepas is located about 16 km from

Georgetown. Besides, the school only has morning session starting at 07:30 a.m. until

01:30 p.m.

Two classes have been chosen in this school which is 4 Utarid at level 2 with 24 students in the class while 4 Bumi at level 3 with 33 students in the classroom. Figure

3.3 and Figure 3.5 show classroom layout of SK Bayan Lepas for level 2 and level 3, respectively. Figure 3.4 and Figure 3.6 show floor plan for level 2 and level 3, respectively.

Figure 3‎ .2: SK Bayan Lepas from satellite image (Source: Google Map)

Figure 3‎ .3: Classroom‟s Layout at Level 2 of SK Bayan Lepas

Figure 3‎ .4: Floor plan at Level 2 of SK Bayan Lepas

Figure 3‎ .5: Classroom‟s Layout at Level 3 of SK Bayan Lepas

Figure 3‎ .6: Floor plan at Level 3 of SK Bayan Lepas

3.2.2 SK Tasek Gelugor

SK Tasek Gelugor (SKTG) in Figure 3.7 is one of the primary school located at

Jalan Hashim Awang, Tasek Gelugor, Penang as shown in Figure 3.8. The coordinate of the school is N 05° 29‟ 02‟‟ and E 100° 29‟ 29‟‟.

The school is developed in 1926. It has 755 students with 65 teachers in 2018.

This school have two sessions which are morning session that is for pupils in Year 4,

Year 5 and Year 6 while afternoon session is for pupils in Year 1, Year 2 and Year 3.

The morning sessions starts on 7.30 a.m. until 1.00 p.m. and afternoon session starts on

1.10 p.m. until 6.30 p.m. However, this study only consider the morning sessions.

At this school, the chosen class are 5 Ibnu Abbas and 5 Ibnu Majah. 5 Ibnu

Abbas is at ground floor with 38 students in classroom while 5 Ibnu Majah is at level 3 with 29 students. Figure 3.9 and Figure 3.11 show classroom layout of SK Tasek

Gelugor for level 1 and level 3, respectively. Figure 3.10 and Figure 3.12 show floor plan for level 1 and level 3, respectively.

Figure 3‎ .7: SK Tasek Gelugor

Figure 3‎ .8: SK Tasek Gelugor from satellite image (Source: Google Map)

Figure 3‎ .9: Classroom‟s Layout at Level 1 of SK Tasek Gelugor

Figure 3‎ .10: Floor plan at Level 1 of SK Tasek Gelugor

Figure 3‎ .11: Classroom‟s Layout at Level 3 of SK Tasek Gelugor

Figure 3‎ .12: Floor plan at Level 3 of SK Tasek Gelugor

3.2.3 SK Machang Bubok

SK Machang Bubok is a primary school located at Jalan Gajah Mati, Penang as shown in Figure 3.13. The coordinate of the school is N 05° 19‟ 40‟‟ and E 100° 30‟

10‟‟. This school only has one session which is morning session. This school was founded in 1921.

The chosen classes at this school are 5 Bijak and 4 Bijak. 5 Bijak is located at level 2 with 25 students in class while 4 Bijak at level 3 with 24 students in the classroom. Figure 3.14 and Figure 3.16 show classroom layout of SK Machang Bubok for level 2 and level 3, respectively. Figure 3.15 and Figure 3.17 show floor plan for level 2 and level 3, respectively.

Figure 3‎ .13: SK Machang Bubok from satellite image (Source: Google Map)

Figure 3‎ .14: Classroom‟s Layout at Level 2 of SK Machang Bubok

Figure 3‎ .15: Floor plan at Level 2 of SK Machang Bubok

Figure 3‎ .16: Classroom‟s Layout at Level 3 of SK Machang Bubok

Figure 3‎ .17: Floor plan at Level 3 of SK Machang Bubok

3.2.4 SMK Mutiara Impian

SMK Mutiara Impian is a secondary school located at Simpang Ampat, Pulau

Pinang as shown in Figure 3.18. This is a government sports school and the only secondary school chosen for this study. The coordinate of the school is N 05° 16‟ 28‟‟ and E 100° 28‟ 39‟‟. SMK Mutiara Impian started operating on 24 July 2001 after the school building completed.

At this school, 1 Olimpik and 2 Olimpik were selected for the sampling. 1

Olimpik located at level 2 with 18 students while 2 Olimpik located at level 3 with 19 students in the classroom. Figure 3.19 and Figure 3.21 show classroom layout of SMK

Mutiara Impian for level 2 and level 3, respectively. Figure 3.20 and Figure 3.22 show floor plan for level 2 and level 3, respectively.

Figure ‎3.18: Study location from satellite image (Sources: Google Map)

Figure 3‎ .19: Classroom‟s Layout at Level 2 of SMK Mutiara Impian

Figure 3‎ .20: Floor plan at Level 2 of SMK Mutiara Impian

Figure 3‎ .21: Classroom‟s Layout at Level 3 of SMK Mutiara Impian

Figure 3‎ .22: Floor plan at Level 3 of SMK Mutiara Impian

3.3 Sampling Schedule and Duration

Sampling of Indoor Air Quality at four selected schools are shown in Table 3.2.

Table 3‎ .2: Schedule of Indoor Air Quality sampling Name of schools Date of Sampling Time

SK Bayan Lepas 27/12/2017 (Background) & 07:15 a.m. until 07:30 a.m. 20/02/2018 (With presence 10:40 a.m. until 10:55 a.m. of student) 12:45 p.m. until 13:00 p.m. SK Tasek Gelugor 06/02/2018 (With Presence 07:15 a.m. until 07:30 a.m. of student) 10:40 a.m. until 10:55 a.m. 12:45 p.m. until 13:00 p.m. SMK Mutiara Impian 28/02/2018 (With Presence 07:15 a.m. until 07:30 a.m. of student) 10:40 a.m. until 10:55 a.m. 12:45 p.m. until 13:00 p.m. SK Machang Bubok 13/03/2018 (With Presence 07:15 a.m. until 07:30 a.m. of student) 10:40 a.m. until 10:55 a.m. 12:45 p.m. until 13:00 p.m.

The time chosen based on the sampling with the presence of student at SK Bayan

Lepas. At 7:15 a.m. there was no student in the classroom so 10:40 a.m. was chosen because the student entered classroom after break but at one classroom there was no students. Therefore, 12:45 p.m. was chosen as the students at both classrooms present.

Another reason 12:45 p.m. is chosen because the school session will end at 01:30 p.m.

So to avoid the absence of students, this time was chosen. For another school were followed the time at SK Bayan Lepas so that the sampling time for every school similar.

3.4 Sampling Design

3.4.1 Microbiological Sampling

In this study, two classrooms from four schools around Penang have been selected. Four or five points in one classroom selected for the sampling. The points

26 were selected based on the space available for sampling. First of all, the preparation of nutrient agar (NA) was done. The agar was prepared based on American Health Public

Association (AHPA) (Wehr and Frank, 2004).

For the sampling, agar was exposed to the air for 15 minutes by settle plate method (Hayleyeesus and Manaye, 2014) using 9 cm petri dishes. This method allows bacteria carrying particles to settle on culture media. The samplings involve two classrooms at each school and the data collection is for three times which is at 07:15 a.m. until 07:30 a.m., 10:40 a.m. until 10:55 a.m. and 12:45 p.m. until 01:00 p.m. as shown in Table 3.2. Each time after fifteen minutes exposed, the samples were sealed with para-film in order to avoid contamination with other materials and were placed in a cool box to maintain its temperature. After sampling, the samples were incubated at

37°C for 24, 48 and 72 hours. To avoid self-contamination of agar plates during air sampling, sterile gloves, mouth masks and protective gown were worn, and the agar plates were also checked visually for any microbial growth before used. Profile of the classrooms such as table layout and movement of students were recorded. The temperature and relative humidity were measured using formaldemeter. This is because the concentration of bacteria will be related with relative humidity and temperature.

After incubation of cultural plates, bacterial colony forming units (CFU) were enumerated. The mean colony forming units per cubic meter (cfu/m3) were determined using the following formula as described by Omeliansky (E nitan et al., 2017):

N = 5a x 104 (bt)-1, (3.1) Where,

N: microbial cfu/m3 of indoor air; a: number of colonies per petri dish;

27 b: dish surface area in cm2; t: exposure time of the petri dish in minutes.

After the microbial density of the colonies on each plate has been determined, the data is recorded. Then, data was analysed using SPSS Statistics Software (Version

21.0) to find the minimum, maximum, mean, standard deviation and standard error of mean for the concentration of bacteria. The relationship of concentration of bacteria with relative humidity and temperature were also determined.

Background study (without the presence of students) was conducted at SK

Bayan Lepas on December 2017. Class observations were conducted to obtained information on furniture layout plan and existence resources that can affect the bacterial growth. The purpose conducted background study was to compare the background data with the normal conditions (with the presence of students) data.

During this sampling with presence of students, class observations were conducted to obtain information such as the number of students in the classroom, volume of classroom, activity of student in class, class schedule and furniture layout plan. The purpose of this procedure is to help guide during data analysis.

The selected points cover all the areas within the class. Maximum point selection is five for each school but depending on the layout and space in the classroom. Five points were used for sampling at SK Bayan Lepas as shown in Figure

3.4 and 3.6 while SK Machang Bubok as shown in Figure 3.15 and 3.17. Four points were used at SK Tasek Gelugor as shown in Figure 3.10 and 3.12 while SMK Mutiara

Impian as shown in Figure 3.20 and 3.22.

The samples were collected near occupants breathing zone. The location of sampling point was one metre from door, window, wall or an active heating system and as far away as possible from blackboard, when applicable (Madureira et al., 2015).

Besides, the selected sampling point was not in passageways and under direct sunlight and with minimum disturbance of work activities (ICOP, 2010).

3.4.2 Instruments of Data Collection

This research involved several instruments in order to measure the concentration of bacteria, relative humidity and temperature in the classrooms. Data measured using formaldemeter was automatically recorded and the recorded data were transferred into personal laptop. Table 3.3 shows the instruments for sampling and laboratory works.

Table 3‎ .3: Sampling and Laboratory Work Instrument Instruments Function

Formaldemeter htV-M To measure the temperature and relative Brand: PPM Technology humidity at the classrooms.

Gallenkamp Colony Counter To count bacteria or other microorganisms Brand: Gallenkamp grown on an agar plate.

AMBI-HI-LO CHAMBER 16.1 CU. FT. To incubate the agar plate at 37 C for 24, Model Number: 3550-1 Series Number: 989-005 48 and 72 hours.

3.5 Data Analysis

3.5.1 Descriptive Statistics

Descriptive statistics are method used to calculate, describe and summarize collected research data in logical and efficient way. Descriptive statistics are reported numerically in text or table or graphically in figures (Vetter, 2017) to help people understand the meaning of the data being analysed.

Measures of central tendency (mean, median and mode), provide information about the center of a distribution of values while measures of variability include the standard deviation or variance, the minimum and maximum variables, and the kurtosis and skewness. The median is not strongly affected by outliers or by extreme changes to a small portion of the observations. However, the mean is sensitive to those conditions. The mode is sensitive to outliers, but it may be affected by data collection operations, such as rounding or digit preference, that alter data precision

(Larson, 2006).

3.5.2 Pearson’s Correlation

Correlation is a statistical method used to assess a possible linear association between two continuous variables. The term „correlation‟ usually referred to Pearson‟s product moment correlation. Correlation is measured by a statistic called the correlation coefficient, which represents the strength of the putative linear association between the variables in question. It is a dimensionless quantity that takes a value in the range −1 to

+1 (Mukaka, 2012).

For correlation the values for both types of measurement should have normal distribution. In a correlation, the linear association between two variables is studied. Th two variables are interchangeable for example, the strength of correlation between X and Y is the same as the strength of correlation between Y and X (Townend, 2002).

The correlation coefficient (r) is measure how well the point fits to a straight line. Value of r close to 0 indicates that no linear relationship or correlation exists between two continuous variables. This means that changes in one variable are not correlated with changes in the second variable. A correlation coefficient close to 1 indicates a perfect linear relationship or a strong correlation. This means that changes in one variable are strongly correlated with changes in the second variable.

When value of r close to positive, this means that as one variable increases in value, the second variable also increase in value. Similarly, as one variable decreases in value, the second variable also decreases in value. When value of r close to negative, this means that as one variable increases in value, the second variable decreases in value. Sig (2-Tailed) value is a statistically significant correlation between your two variables. Figure 3.23 could be used as a guide.

r -1 -0.9 -0.6 0 0.6 0.9 1

Correlation strong weak little or none weak strong

Figure 3‎ .23: Correlation terms (Townend, 2002)

CHAPTER 4

RESULT AND DISCUSSION

4.1 Introduction

Sampling was conducted in four schools around Penang during school days which is

SK Bayan Lepas, SK Tasek Gelugor, SK Machang Bubok and SMK Mutiara Impian.

The parameters considered in this study are bacterial count, temperature and relative humidity. The relationship between bacterial count with temperature and relative humidity were also considered.

4.2 Microbiological concentration in classroom for background study

The background study was conducted at SK Bayan Lepas during school break on 27 December 2017. The weather during the sampling session is cloudy. The result is shown in Table 4.1 and 4.2 for the bacterial colony counts. Figure 4.2 show microorganism formed on agar plate after 24-hour incubation. All the microorganisms formed on agar plate according to sampling time were shown in appendix. Location of the selected points is show in Figure 4.1.

Level 2 Level 3 Figure 4‎ .1: Location of point in both classrooms of SK Bayan Lepas for background detail study.

Table 4‎ .1: Bacterial colony count at Level 2 of SK Bayan Lepas Location 1 2 3 4 5 Average Total Sampling Time Number of bacteria count (cfu/m³) 0715-0730 38 189 75 113 132 109 1040-1055 19 94 113 19 113 72 1245-1300 75 57 38 57 38 53

Table 4‎ .2: Bacterial colony count at Level 3 of SK Bayan Lepas Location 1 2 3 4 5 Average Total Sampling Time Number of bacteria count (cfu/m³) 0715-0730 113 75 38 75 94 79 1040-1055 113 57 0 75 113 72 1245-1300 113 19 94 19 170 83

unt at 07:15 07:15 at unt a.m.

for level 2 level for Bacterial co Bacterial

Bacterial count for 3 count level 07:15 for Bacterial a.m.

Figure 4.2: Microorganisms formed on an agar plate after 24-hours incubation at SK Bayan Lepas

4.2.1 Bacterial count, relative humidity and temperature of different level

From the Figure 4.3, the maximum concentration of bacteria was 190 cfu/m3 at level 2 on 07:15 a.m. until 07:30 a.m. while the minimum concentration of bacteria at level 2 with 53 cfu/m3 on 12:45 p.m. until 01:00 p.m. The concentration of bacteria is similar for both classrooms during 10:40 a.m. until 10:55 a.m. at 72 cfu/m3. The bacterial count during background study affected by existing dust at bookshelf and curtain in the classrooms.

120 109 100

80 79 83 72 60 53 Level 2 40 Level 3 20

Number (cfu/m³) bacteria of Number 0 0715-0730 1040-1055 1245-1300 Time

Figure 4‎ .3: Comparison of bacteria concentration for 24 hours at SK Bayan Lepas.

Figure 4.4 shows the relative humidity against ICOP 2010. The average relative humidity at level 2 is 53.7 % while at level 3 is 54.3 %. The minimum ICOP value is

40 % and maximum is 70 %. Therefore, from this figure, the relative humidity at both classrooms did not exceed the acceptable limit from the ICOP 2010.

70 Maximum Allowable

60 53.7 54.3 50

40 Minimum Allowable

Relative Humidity Humidity (%) Relative 20

0 Level 2 Level 3 Level

Figure 4‎ .4: Relative humidity rate against ICOP 2010

Figure 4.5 shows the temperature rate at both classrooms with the ICOP acceptable limits. The average temperature at level 2 is 28.7 °C and level 3 is 29.4 °C. The minimum temperature from ICOP is 23 °C and maximum temperature is 26 °C.

Therefore, from the figure, the temperature in both classrooms exceeds the acceptable limit by ICOP.

35 29.4 30 28.7 Maximum Allowable 25 Minimum Allowable 20 15

10 Temperature C) (ᵒ Temperature 5 0 Level 2 Level 3 Level

Figure 4‎ .5: Temperature rate against ICOP 2010 35

4.2.2 Mean indoor bacterial count, relative humidity and temperature of background study

From Table 4.3, the combined mean bacterial colony counts per sampling time is higher at 07:15 a.m. (94 cfu/m3) followed by 10:40 a.m. (72 cfu/m3) and 12:45 p.m.

(68 cfu/m3). In the morning the temperature is low and will increase on midday. The range of temperature is 28.1 °C to 30.5 °C which is higher than ICOP on Indoor Air

Quality, 2010 (23°C and 26°C). The combined mean relative humidity values of 07:15 a.m. (51%), 10:40 a.m. (62%) and 12:45 p.m. (49%) were within comfort range of

ICOP on Indoor Air Quality, 2010 (40 % and 70 %). The combined mean bacterial count per classrooms was similar during the sampling. There was no student during the background study therefore contribution to bacterial growth for both classrooms only from existence source in class such as curtains or bookshelf.

3 Table 4‎ .3: Background data of bacterial colony counts (cfu) per m with temperature and relative humidity at different sampling periods of day of SK Bayan Lepas. Different air sampling of the day 7.15 am 10.40 am 12.45 pm Bacterial Bacterial Bacterial Mean Mean Mean Mean Mean Mean Study colony colony colony CMBCC/CL T RH T RH T RH count count count (cfu/m3) Class (°C) (%) (°C) (%) (°C) (%) (cfu/m3) (cfu/m3) (cfu/m3) 24 L2 Hours 109 27.8 50.0 72 28.4 62.0 53 30.0 49.0 78 24 L3 Hours 79 28.3 52.0 72 29.0 62.0 83 31.0 49.0 78 CMBCC/SP (cfu/m3) 94 72 68 CMT/SP (°C) 28.1 28.7 30.5 CMRH/SP(%) 51.0 62.0 49.0 KEY: L2= Level 2, L3=Level 3, T = Temperature, RH = Relative humidity, CMBSS/CL = Combined mean bacterial colony count per classroom (cfu/m3), CMBCC/SP = Combined mean bacterial colony count per sampling period (cfu/m3), CMT/SP = Combined mean temperature per sampling period (°C), CMRH/SP = Combined mean relative humidity per sampling period (%)

4.3 Microbiological concentration during normal condition at SK Bayan Lepas

The study at SK Bayan Lepas for normal condition (with presence of student) was conducted on 20th February 2018. The weather during the sampling session was sunny.

The result is shown in Table 4.4 and Table 4.5 for the bacterial colony counts. Figure

4.7 shows the microorganism formed on agar plate after incubation. All the microorganisms formed on agar plate according to sampling time were shown in appendix. Location of the selected points is show in Figure 4.6.

Level 2

Level 3

Figure 4‎ .6: Location of point in both classrooms of SK Bayan Lepas with the presence of student.

Table 4‎ .4: Bacterial colony count at Level 2 Table 4‎ .5: Bacterial colony count at Level 3 For 24 hours; For 24 hours; Location 1 2 3 4 5 Average Location 1 2 3 4 5 Average Total Total Sampling Time Number of bacteria count (cfu/m³) Sampling Time Number of bacteria count (cfu/m³) 0715-0730 38 57 19 57 38 42 0715-0730 57 94 19 189 113 94 1040-1055 226 189 226 283 472 279 1040-1055 94 19 170 208 113 121 1245-1300 151 75 132 264 641 253 1245-1300 755 943 962 547 792 800

For 48 hours; For 48 hours; Location 1 2 3 4 5 Average Location 1 2 3 4 5 Average Total Sampling Time Number of bacteria count Total (cfu/m³) Sampling Time Number of bacteria count (cfu/m³) 0715-0730 57 57 38 75 57 57 0715-0730 94 94 19 208 151 113 1040-1055 321 283 358 377 698 407 1040-1055 151 57 170 283 208 174 1245-1300 189 113 226 321 1000 370 11245-1300 792 943 1113 547 830 845

For 72 hours; For 72 hours; Location 1 2 3 4 5 Average Average Total Location 1 2 3 4 5 Total Sampling Time Number of bacteria count (cfu/m³) Sampling Time Number of bacteria count (cfu/m³) 0715-0730 57 75 75 113 151 94 0715-0730 113 132 19 208 189 132 1040-1055 321 283 472 396 736 441 1245-1300 226 170 283 396 1019 419 1040-1055 208 94 170 283 226 196 1245-1300 905 1094 1302 585 943 966

hours)

count at 07:15 a.m. for level 3 (24 (24 3 07:15 at level count for a.m.

Bacterial

for level 3 level for

12:45p.m. (48 hours) (48

Bacterial count for count Bacterial

a.m. for level level for a.m.

10:40

(72 hours) (72

Bacterial count for count Bacterial

Figure 4.7: Microorganisms formed on an agar plate after incubation (SK Bayan Lepas)

4.3.1 Bacterial count, relative humidity and temperature of different level

From the Figure 4.8, the maximum concentration of bacteria was 800 cfu/m3 at level 3 on 12:45 p.m. until 01:00 p.m. while the minimum concentration of bacteria at level 2 with 42 cfu/m3 on 07:15 a.m. until 07:30 a.m. The bacterial count during this sampling affected by the presence of students and dust at other existence sources that recycle such as bookshelf and curtain.

900

800 800 700 600 500 400 Level 2 300 279 Level 3 200 235 100 94 121 Number (cfu/m³) bacteria of Number 42 0 0715-0730 1040-1055 1245-1300 Time

Figure 4‎ .8: Comparison of bacteria concentration for 24 hours at SK Bayan Lepas.

Figure 4.9 shows the relative humidity against ICOP 2010. The average relative humidity for level 2 and level 3 is 87.1 %. The minimum ICOP value is 40 % and maximum is 70 %. Therefore, from this figure, the relative humidity at both classrooms exceeded the acceptable limit from the ICOP 2010.

Figure 4.10 shows the temperature rate at both classrooms with the ICOP acceptable limits. The average temperature at level 2 and level 3 were 29.3 °C. The minimum

40 temperature from ICOP is 23 °C and maximum temperature is 26 °C. Therefore, from the figure, the temperature in both classrooms exceeds the acceptable limits by ICOP.

90 87.1 87.1

70 Maximum Allowable 60 50 40 Minimum Allowable 30

Relative Humidity Humidity (%) Relative 20 10 0 Level 2 Level 3 Level

Figure 4‎ .9: Relative humidity rate against ICOP 2010

35 29.3 29.3 30

Maximum Allowable 25 ᵒC) Minimum Allowable 20

Temperature ( Temperature 10

0 Level 2 Level 3 Level

Figure 4‎ .10: Temperature rate against ICOP 2010

4.3.2 Effect of student activity on bacterial count

Students at SK Bayan Lepas did not entered classroom after they arrived at school during this sampling activity. As shown in Figure 4.11, there were no students at

7:15 a.m. as the learning process started at 07:30 a.m. During the study period at 10:40 a.m., the students were just finished from the break. So many students passed the corridor of the study class to go to their respective classes. At level 3, students are not in the classroom because they are undergoing learning process in the library. But there were some students who entered the class at that time to pick up the book. At 12:45 p.m., all students were in the classroom. Student on the level 3 were doing their own work and discussed with each other while students on level 2 stayed at their place for

Islamic religious lessons. Therefore, the student activities such as walking and talking affect the bacteria count.

900 Without With student With student 800 student 800 700 600 500 400 Level 2

300 279 Level 3 235 200

Number (cfu/m³) bacteria of Number 100 94 121 42 0 0715-0730 1040-1055 1245-1300 Time

Figure 4‎ .11: Presence of student in the classroom

4.3.3 Mean indoor bacterial count, relative humidity and temperature of SK Bayan Lepas

From Table 4.6, the combined mean bacterial colony counts per sampling time is higher at 12:45 p.m. (609 cfu/m3) followed by 10:40 a.m. (270 cfu/m3) and 7:15 a.m.

(89 cfu/m3). In the morning the temperature is low and will increase when the day goes to midday. The range of temperature is 27.8 °C to 30.6 °C which is higher than ICOP on Indoor Air Quality, 2010 (23°C and 26°C). The relative humidity is decreased when the day goes to afternoon from 92.7 % to 83.9 %. Relative humidity is also higher than

ICOP on Indoor Air Quality, 2010 (40 % and 70 %). The combined mean bacterial colony count per classrooms was increase for 24 hours until 72 hours in both classrooms. Therefore, when bacterial media was leave for a few days, the bacterial still growth.

3 Table 4‎ .6: Bacterial colony counts (cfu) per m with temperature and relative humidity at different sampling periods of day of SK Bayan Lepas. Different air sampling of the day 7.15 am 10.40 am 12.45 pm Bacterial Bacterial Bacterial Mean Mean Mean Mean Mean Mean Study colony colony colony CMBCC/CL T RH T RH T RH Class count count count (cfu/m3) (°C) (%) (°C) (%) (°C) (%) (cfu/m3) (cfu/m3) (cfu/m3) 24 Hours 42 27.8 92.7 279 29.6 84.7 253 30.6 83.9 191 48 L2 Hours 57 27.8 92.7 407 29.6 84.7 370 30.6 83.9 278 72 Hours 94 27.8 92.7 441 29.6 84.7 419 30.6 83.9 318 24 Hours 94 27.8 92.7 121 29.6 84.7 800 30.6 83.9 338 48 L3 Hours 113 27.8 92.7 174 29.6 84.7 845 30.6 83.9 377 72 Hours 132 27.8 92.7 196 29.6 84.7 966 30.6 83.9 431 CMBCC/SP (cfu/m3) 89 270 609 CMT/SP (°C) 27.8 29.6 30.6 CMRH/SP(%) 92.7 84.7 83.9 KEY: L2=Level 2, L3=Level 3, T = Temperature, RH = Relative humidity, CMBSS/CL = Combined mean bacterial colony count per classroom (cfu/m3), CMBCC/SP = Combined mean bacterial colony count per sampling period (cfu/m3), CMT/SP = Combined mean temperature per sampling period (°C), CMRH/SP = Combined mean relative humidity per sampling period (%)

4.4 Microbiological concentration during normal condition at SK Tasek Gelugor

The study at SK Tasek Gelugor for normal condition (with presence of student) was conducted on 06th February 2018. The weather during the sampling session was sunny.

The result is shown in Table 4.7 and Table 4.8 for the bacterial colony counts. Figure

4.13 shows the microorganism formed on agar plate after incubation. All the microorganisms formed on agar plate according to sampling time were shown in appendix. Location of the selected points is show in Figure 4.12.

Level 1

Level 3 Figure 4‎ .12: Location of point in both classrooms of SK Tasek Gelugor with the presence of student.

Table 4‎ .7: Bacterial colony count at Level 1 Table 4‎ .8: Bacterial colony count at Level 3 For 24 hours; For 24 hours; Location 1 2 3 4 Average Average Total Location 1 2 3 4 Total Sampling Time Number of bacteria count (cfu/m³) (cfu/m³) Sampling Time Number of bacteria count (cfu/m³) (cfu/m³) 0715-0730 170 151 75 208 151 0715-0730 19 132 566 170 222 1040-1055 132 113 151 132 132 1040-1055 245 3716 208 3792 1990 1245-1300 151 208 94 57 127 1245-1300 113 94 94 1075 344

For 48 hours; For 48 hours; Location 1 2 3 4 Average Average Total Location 1 2 3 4 Total Sampling Time Number of bacteria count (cfu/m³) (cfu/m³) Sampling Time Number of bacteria count (cfu/m³) (cfu/m³) 0715-0730 283 302 151 245 245 0715-0730 75 132 887 245 335 1040-1055 245 170 226 151 198 1040-1055 396 4244 283 4924 2462 1245-1300 189 302 189 94 193 1245-1300 151 226 132 2132 660

For 72 hours; For 72 hours; Location 1 2 3 4 Average Average Total Location 1 2 3 4 Total Sampling Time Number of bacteria count (cfu/m³) (cfu/m³) Sampling Time Number of bacteria count (cfu/m³) (cfu/m³) 0715-0730 396 528 226 396 387 0715-0730 151 226 1151 490 505 1040-1055 321 264 358 340 321 1040-1055 528 4999 472 6037 3009 1245-1300 226 358 283 226 274 1245-1300 321 377 208 2188 773

(24 hours) (24

count at 07:15 a.m. for level 3 3 07:15 at level count for a.m.

Bacterial

1 1

for level level for

10:40a.m. (48 hours) (48

Bacterial count for count Bacterial

for level level for

12:45p.m.

(72 hours) (72

Bacterial count for count Bacterial

Figure 4.13: Microorganisms formed on an agar plate after incubation (SK Tasek Gelugor)

4.4.1 Bacterial count, relative humidity and temperature of different level

From the Figure 4.14, the maximum concentration of bacteria is 505 cfu/m3 at level 3 on 12:45 p.m. until 01:00 p.m. while the minimum concentration of bacteria at level 1 with 151 cfu/m3 on 07:15 a.m. until 07:30 a.m. The bacterial count during this sampling affected by the presence of students and dust at other existence sources such as bookshelf.

600

500 505

400 387 335 300 Level 1 222 245 200 Level 3 151 100

Number (cfu/m³) bacteria of Number 0 0715-0730 1040-1055 1245-1300 Time

Figure 4‎ .14: Comparison of bacteria concentration for 24 hours at SK Tasek Gelugor

Figure 4.15 shows the relative humidity against ICOP 2010. The average relative humidity for level 1 was 78.8% and level 3 was 80.0 %. The minimum ICOP value is

40 % and maximum is 70 %. Therefore, from this figure, the relative humidity at both classrooms exceeded the acceptable limit from the ICOP 2010.

Figure 4.16 shows the temperature rate at both classrooms with the ICOP acceptable limits. The average temperature at level 2 and level 3 were 28.1 °C. The minimum temperature from ICOP is 23 °C and maximum temperature is 26 °C. Therefore, from the figure, the temperature in both classrooms exceeded the acceptable limits by ICOP.

90 78.8 80 80 70 Maximum Allowable 60 50 40 Minimum Allowable 30

Relative Humidity Humidity (%) Relative 20 10 0 Level 1 Level 3 Level

Figure 4‎ .15: Relative humidity rate against ICOP 2010

30 28.1 28.1 Maximum Allowable 25

Minimum Allowable

10 Temperature (ᵒC) Temperature

0 Level 1 Level 3 Level

Figure 4‎ .16: Temperature rate against ICOP 2010

4.4.2 Effect of student activity on bacterial count

Figure 4.17 shows the presence of students in the classroom. Students at SK

Tasek Gelugor entered classroom after they arrived at school during this sampling

activity. There were some students in the class during the study at 7:15 a.m. and

walked in the corridor because their assembly started at 07:25 a.m. This school

student breaks at 10:30 a.m. to 11:00 a.m. but there are students wandering

around the corridor during that time. The school has two sessions which are

morning and evening, so, during this study at 12:45 p.m. no students in the class

but student for afternoon sessions went to their classes. Therefore, the student‟s

activity affects the bacteria growth.

600 With Without Without student

student student 500 505

400 387 335 300 Level 1 245 222 200 Level 3 151

Number (cfu/m³) bacteria of Number 100

0 0715-0730 1040-1055 1245-1300 Time

Figure 4‎ .17: Presence of student in the classroom

4.4.3 Mean indoor bacterial count, relative humidity and temperature of SK Tasek Gelugor

From Table 4.9, the combined mean bacterial colony counts per sampling time is higher at 12:45 p.m. (878 cfu/m3) followed by 10:40 a.m. (682 cfu/m3) and 7:15 a.m.

(494 cfu/m3). In the morning the temperature is low and will increase on midday. The range of temperature is 25.8 °C to 30.2 °C which is higher than ICOP on Indoor Air

Quality, 2010 (23°C and 26°C) at 10:40 a.m. and 12:45 p.m. The relative humidity is

49 decreased when the day goes to afternoon from 85 % to 75.5 %. Relative humidity is also higher than ICOP on Indoor Air Quality, 2010 (40 % and 70 %). The combined mean bacterial colony count per classrooms at level 1 was decreased from 24 to 72 hours while bacterial count increase for 24 hours until 48 hours and decrease from 48 to

72 hours in level 3. At level 1, the bacterial count decreased because an existing of trees in front the classroom that helped to cool the classroom.

3 Table 4‎ .9: Bacterial colony counts (cfu) per m with temperature and relative humidity at different sampling periods of day of SK Tasek Gelugor Different air sampling of the day 7.15 am 10.40 am 12.45 pm Bacterial Bacterial Bacterial Mean Mean Mean Mean Mean Mean Study colony colony colony CMBCC/CL T RH T RH T RH count count count (cfu/m3) Class (°C) (%) (°C) (%) (°C) (%) (cfu/m3) (cfu/m3) (cfu/m3) 24 Hours 151 25.7 84.9 245 28.5 77.8 387 30.1 73.7 261 48 L1 Hours 132 25.7 84.9 198 28.5 77.8 321 30.1 73.7 217 72 Hours 127 25.7 84.9 193 28.5 77.8 274 30.1 73.7 198 24 Hours 222 25.8 85.0 335 28.4 77.7 505 30.2 77.3 354 48 L3 Hours 1990 25.8 85.0 2462 28.4 77.7 3009 30.2 77.3 2487 72 Hours 344 25.8 85.0 660 28.4 77.7 773 30.2 77.3 592 CMBCC/SP (cfu/m3) 494 682 878 CMT/SP (°C) 25.8 28.5 30.2 CMRH/SP(%) 85.0 77.8 75.5 KEY: L1=Level 1, L3=Level 3, T = Temperature, RH = Relative humidity, CMBSS/CL = Combined mean bacterial colony count per classroom (cfu/m3), CMBCC/SP = Combined mean bacterial colony count per sampling period (cfu/m3), CMT/SP = Combined mean temperature per sampling period (°C), CMRH/SP = Combined mean relative humidity per sampling period (%).

4.5 Microbiological concentration during normal condition at SK Machang Bubok

The study at SK Machang Bubok for normal condition (with presence of student) was conducted on 13th March 2018. The weather during the sampling session was sunny.

The result is shown in Table 4.10 and Table 4.11 for the bacterial colony counts. Figure

4.19 shows the microorganism formed on agar plate after incubation. All the microorganisms formed on agar plate according to sampling time were shown in appendix. Location of the selected points is show in Figure 4.18.

Level 2

Level 3 Figure 4‎ .18: Location of point in both classrooms of SK Machang Bubok with the presence of student.

Table 4‎ .10: Bacterial colony count at Level 2 Table 4‎ .11: Bacterial colony count at Level 3

For 24 hours; For 24 hours; Location 1 2 3 4 5 Average Location 1 2 3 4 5 Average Total Total Sampling Time Number of bacteria count (cfu/m³) Sampling Time Number of bacteria count (cfu/m³) 0715-0730 170 490 377 302 208 309 0715-0730 868 302 755 113 358 479 1040-1055 38 321 208 151 472 238 1040-1055 57 94 264 189 113 143 1245-1300 1038 434 264 302 566 521 1245-1300 358 94 94 132 170 170

For 48 hours; For 48 hours; Location 1 2 3 4 5 Average Location 1 2 3 4 5 Average Total Total Sampling Time Number of bacteria count (cfu/m³) Sampling Time Number of bacteria count (cfu/m³) 0715-0730 1056 377 773 132 490 566 0715-0730 264 547 377 396 415 400 1040-1055 113 151 264 340 208 215 1040-1055 113 377 226 245 490 291 1245-1300 283 94 189 132 245 189 1245-1300 1132 472 264 566 811 649

For 72 hours; For 72 hours; Location 1 2 3 4 5 Average Location 1 2 3 4 5 Average Total Total Sampling Time Number of bacteria count Sampling Time Number of bacteria count (cfu/m³) (cfu/m³) 0715-0730 1132 377 962 189 679 668 0715-0730 415 585 1075 490 547 623 1040-1055 132 189 358 509 208 279 1040-1055 189 415 245 283 396 306 1245-1300 1188 472 340 641 905 709 1245-1300 377 151 189 151 226 219

for for

2:45 2:45 p.m.

count at at count

level 3 (24 hours) (24 3 level Bacterial

(48 (48

for level level for

10:40a.m.

hours) Bacterial count for count Bacterial

for level level for

07:15a.m.

2 (72 hours) (72

Bacterial count for count Bacterial Figure 4.19: Microorganisms formed on an agar plate after incubation (SK Mchang Bubok)

4.5.1 Bacterial count, relative humidity and temperature of different level

From the Figure 4.20, the maximum concentration of bacteria is 521 cfu/m3 at level 2 on 12:45 p.m. until 01:00 p.m. while the minimum concentration of bacteria at level 3 with 143 cfu/m3 on 10:40 a.m. until 10:55 a.m. The bacterial count during this sampling affected by the presence of students and dust at other existence sources such as bookshelf and curtain.

600

500 521 479 400

300 309 Level 2 238 200 Level 3 170 143

100 Number of bacteria (cfu/m³) bacteria Number of

0 0715-0730 1040-1055 1245-1300 Time

Figure 4‎ .20: Comparison of bacteria concentration for 24 hours at SK Machang Bubok

Figure 4.21 shows the relative humidity against ICOP 2010. The average relative humidity for level 2 was 74.1% and level 3 was 80.4 %. The minimum ICOP value is 40 % and maximum is 70 %. Therefore, from this figure, the relative humidity at both classrooms exceeded the acceptable limit from the ICOP 2010.

Figure 4.22 shows the temperature rate at both classrooms with the ICOP acceptable limits. The average temperature at level 2 was 29.7 °C and level 3 were 29.4 °C. The minimum temperature from ICOP is 23 °C and maximum temperature is 26 °C.

Therefore, from the figure, the temperature in both classrooms exceeds the acceptable limit by ICOP.

90 80.4

80 74.1 70 Maximum Allowable 60 50 40 Minimum Allowable 30 20 Relative Humidity Humidity (%) Relative 10 0 Level 2 Level 3 Level

Figure 4‎ .21: Relative humidity rate against ICOP 2010

35 29.7 29.4 30 Maximum Allowable

Minimum Allowable ᵒC) 20

Temperature ( Temperature 10

0 Level 2 Level 3 Level

Figure 4‎ .22: Temperature rate against ICOP 2010

4.5.2 Effect of student activity on bacterial count

Students at SK Machang Bubok did entered classroom after they arrived at school during this sampling activity. Figure 4.23 shows the presence of student in the classroom during the sampling. There was some students in the class during the study at 7:15 a.m. and walked in the corridor because their assembly started at 07:25 a.m.

This school student breaks at 10:30 a.m. to 11:00 a.m. but there are students wandering around the corridor during that time at level 2 and 3. Several students entered classroom at level 3 between 10:40 a.m. until 10:55 a.m. At 12:45 p.m., all students at level 2 were in the classroom but students at level 3 having their learning process at other place. Therefore, the student‟s presence gave affect toward bacteria growth.

600 With Student Without With Student Student 521

500 479

400

300 309 Level 2 238 Level 3 200 170 143 Number of bacteria (cfu/m³) bacteria Number of 100

0 0715-0730 1040-1055 1245-1300 Time

Figure 4‎ .23: Presence of student in the classroom

4.5.3 Mean indoor bacterial count, relative humidity and temperature of SK Machang Bubok

From Table 4.12, the combined mean bacterial colony counts per sampling time is higher at 7:15 a.m. (508 cfu/m3) followed by 12:45 p.m. (410 cfu/m3) and 10:40 a.m.

(245 cfu/m3). In the morning the temperature is low and will increase on midday. The range of temperature is 27.5 °C to 31.7 °C which is higher than ICOP on Indoor Air

Quality, 2010 (23 °C and 26°C). The relative humidity is decreased when the day goes to afternoon from 83.0 % to 71.4 %. The range of relative humidity is also higher than

3 Table 4‎ .12: Bacterial colony counts (cfu) per m with temperature and relative humidity at different sampling periods of day of SK Machang Bubok Different air sampling of the day 7.15 am 10.40 am 12.45 pm Bacterial Bacterial Bacterial Mean Mean Mean Mean Mean Mean Study colony colony colony CMBCC/CL T RH T RH T RH count count count (cfu/m3) Class (°C) (%) (°C) (%) (°C) (%) (cfu/m3) (cfu/m3) (cfu/m3) 24 Hours 309 28 75.8 238 28.5 88.5 521 32.7 58 356 48 L2 Hours 400 28 75.8 291 28.5 88.5 649 32.7 58 447 72 Hours 623 28 75.8 306 28.5 88.5 709 32.7 58 546 24 Hours 479 27 90.2 143 30.8 66.3 170 30.6 84.7 264 48 L3 Hours 566 27 90.2 215 30.8 66.3 189 30.6 84.7 323 72 Hours 668 27 90.2 279 30.8 66.3 219 30.6 84.7 389 CMBCC/SP (cfu/m3) 508 245 410 CMT/SP (°C) 27.5 29.7 31.7 CMRH/SP(%) 83.0 77.4 71.4 KEY: L2=Level 2, L3=Level 3, T = Temperature, RH = Relative humidity, CMBSS/CL = Combined mean bacterial colony count per classroom (cfu/m3), CMBCC/SP = Combined mean bacterial colony count per sampling period (cfu/m3), CMT/SP = Combined mean temperature per sampling period (°C), CMRH/SP = Combined mean relative humidity per sampling period (%).

4.6 Microbiological concentration during normal condition at SMK Mutiara Impian

The study at SMK Mutiara Impian for normal condition (with presence of student) was conducted on 28th February 2018. The weather during the sampling session was sunny.

The result is shown in Table 4.13 and 4.14 for the bacterial colony counts. Figure 4.25 shows the microorganism formed on agar plate after incubation. All the microorganisms formed on agar plate according to sampling time were shown in appendix. Location of the selected points is show in Figure 4.24.

Level 2

Level 3

Figure 4‎ .24: Location of point in both classrooms of SMK Mutiara Impian when presence of student.

Table 4‎ .13: Bacterial colony count at Level 2 Table 4‎ .14: Bacterial colony count at Level 3

For 24 hours; For 24 hours; Location 1 2 3 4 Average Location 1 2 3 4 Average Total Total Sampling Time Number of bacteria count (cfu/m³) Sampling Time Number of bacteria count (cfu/m³) 0715-0730 57 698 208 189 288 0715-0730 226 132 208 245 203 1040-1055 151 151 132 113 137 1040-1055 264 566 208 453 373 1245-1300 7357 415 189 245 2051 1245-1300 151 113 170 208 160

For 48 hours; For 48 hours; Location 1 2 3 4 Average Total Location 1 2 3 4 Average Sampling Time Number of bacteria count (cfu/m³) Total Sampling Time Number of bacteria count (cfu/m³) 0715-0730 94 792 472 377 434 0715-0730 434 226 283 358 325 1040-1055 226 208 283 132 212 1040-1055 302 679 377 566 481 1245-1300 9055 585 226 396 2566 1245-1300 283 132 283 340 259

For 72 hours; For 72 hours; Location 1 2 3 4 Average Location 1 2 3 4 Average Sampling Total Number of bacteria count Total Time (cfu/m³) Sampling Time Number of bacteria count (cfu/m³) 0715-0730 94 792 490 434 453 0715-0730 453 283 302 396 358 1040-1055 245 302 321 245 278 1040-1055 321 698 377 604 500 1245-1300 9074 717 264 717 2693 1245-1300 302 132 358 434 307

(24 hours) (24

count at 12:45 12:45 at count for p.m.

level level Bacterial

for level level for

)

10:40a.m. (48 hours (48

Bacterial count for count Bacterial

for level level for

07:15a.m.

(72 hours) (72

Bacterial count for count Bacterial Figure 4.25: Microorganisms formed on an agar plate after incubation (SMK Mutiara Impian)

4.6.1 Bacterial count, relative humidity and temperature of different level

From the Figure 4.26, the maximum concentration of bacteria is 2051 cfu/m3 at level 2 on 12:45 p.m. until 01:00 p.m. while the minimum concentration of bacteria also at level 2 with 137 cfu/m3 on10:40 a.m. until 10:55 a.m. The bacterial count during this sampling affected by the presence of students and dust at other existence sources such as bookshelf.

2500

2000 2051

1500

1000 Level 2 Level 3 500 288 373 203 137 160 0 Number of bacteria (cfu/m³) bacteria Number of 0715-0730 1040-1055 1245-1300 Time

Figure 4‎ .26: Comparison of bacteria concentration for 24 hours at SMK Mutiara Impian

Figure 4.27 shows the relative humidity against ICOP 2010. The average relative humidity for level 2 was 88.1 % and level 3 is 88 %. The minimum ICOP value is 40 % and maximum is 70 %. Therefore, from this figure, the relative humidity at both classrooms exceeded the acceptable limit from the ICOP 2010.

Figure 4.28 shows the temperature rate at both classrooms with the ICOP acceptable limits. The average temperature at level 2 and level 3 were 29.6 °C. The minimum temperature from ICOP is 23 °C and maximum temperature is 26 °C. Therefore, from the figure, the temperature in both classrooms exceeds the acceptable limit by ICOP.

100 88.1 88

80 70 Maximum Allowable 60 50 40 Minimum Allowable 30

20 Relative Humidity Humidity (%) Relative 10 0 Level 2 Level 3 Level

Figure 4‎ .27: Relative humidity rate against ICOP 2010

35 29.6 29.6 30

Maximum Allowable 25 ᵒC) Minimum Allowable 20 15

10 Temperature ( Temperature 5 0 Level 2 Level 3 Level

Figure 4‎ .28: Temperature rate against ICOP 2010

4.6.2 Effect of student activity on bacterial count

Figure 4.29 shows the presence of the students in a classroom. Students at

SMK Mutiara Impian did not entered classroom after they arrived at school during this sampling activity. So, there were no students at 7:15 a.m. as the

learning process started at 07:30 a.m. During the study at 10:40 a.m., the students

were just finished from the break. So many students passed the corridor of the

study class to go to their respective classes. At level 2, students were not in the

classroom because they are undergoing learning process in the library. At 12:45

p.m., all students at level 2 and level 3 were in the classroom for their learning

process. Therefore, student‟s activity gave affect to the bacterial growth.

2500 Without At level 2, no With student student student while at level 3 have 2051 2000 student

1500

Level 2 1000 Level 3

500 Number (cfu/m³) bacteria of Number 288 373 203 137 160 0 0715-0730 1040-1055 1245-1300 Time

Figure 4‎ .29: Presence of student in the classroom

4.6.3 Mean indoor bacterial count, relative humidity and temperature of SMK Mutiara Impian

From Table 4.15, the combined mean bacterial colony counts per sampling time is higher at 12:45 p.m. (1339 cfu/m3) followed by 7:15 a.m. (344 cfu/m3) and 10:40 a.m.

(330 cfu/m3). In the morning the temperature is low and will increase on midday. The range of temperature is 27.7°Cto 31.1°C which is higher than ICOP on Indoor Air

Quality, 2010 (23°C and 26°C). The relative humidity is decreased when the day goes

63 to afternoon from 90.0 % to 86.1 %. Relative humidity is also higher than ICOP on

Indoor Air Quality, 2010 (40 % and 70 %). The combined mean bacterial colony count per classrooms was increase for 24 hours until 72 hours in both classrooms. Therefore, when bacterial media was leave for a few days, the bacterial still growth.

3 Table 4‎ .15: Bacterial colony counts (cfu) per m with temperature and relative humidity at different sampling periods of day of SMK Mutiara Impian Different air sampling of the day 7.15 am 10.40 am 12.45 pm Bacterial Bacterial Bacterial Mean Mean Mean Mean Mean Mean Study colony colony colony CMBCC/CL T RH T RH T RH count count count (cfu/m3) Class (°C) (%) (°C) (%) (°C) (%) (cfu/m3) (cfu/m3) (cfu/m3) 24 Hours 288 27.7 90.0 137 30.0 88.3 2051 31.1 86.1 825 48 L2 Hours 434 27.7 90.0 212 30.0 88.3 2566 31.1 86.1 1071 72 Hours 453 27.7 90.0 278 30.0 88.3 2693 31.1 86.1 1141 24 Hours 203 27.7 90.0 373 30.0 88 160 31.1 86.1 245 48 L3 Hours 325 27.7 90.0 481 30.0 88 259 31.1 86.1 355 72 Hours 358 27.7 90.0 500 30.0 88 307 31.1 86.1 388 CMBCC/SP (cfu/m3) 344 330 1339 CMT/SP (°C) 27.7 30.0 31.1 CMRH/SP(%) 90.0 88.2 86.1 KEY: L2=Level 2, L3=Level 3, T = Temperature, RH = Relative humidity, CMBSS/CL = Combined mean bacterial colony count per classroom (cfu/m3), CMBCC/SP = Combined mean bacterial colony count per sampling period (cfu/m3), CMT/SP = Combined mean temperature per sampling period (°C), CMRH/SP = Combined mean relative humidity per sampling period (%).

4.7 Microbial population density of schools

The ranges of microbial population density in four schools were presented in

Table 4.16. A bacterial population density at SK Bayan Lepas, SK Tasek Gelugor,

SMK Mutiara Impian and SK Machang Bubok ranges from 42-966 cfu/m3, 127-3009 cfu/m3, 137-2693 cfu/m3, and 143-709 cfu/m3, respectively. The results indicate that the highest bacterial colony count per m3 air has been recorded at 12:45 p.m. in SK

Tasek Gelugor at 48 hours after incubation which is 3009 cfu/m3, while the lowest

64 bacterial colony count per m3 air has been recorded at 7:15 a.m. in SK Bayan Lepas after 24 hour‟s incubation which is 42 cfu/m3. However, the mean bacterial population density at SK Tasek Gelugor and SMK Mutiara Impian higher than SK Bayan Lepas and SK Machang Bubok.

Table 4‎ .16: Descriptive statistics for the ranges of microbial population density at the schools study N Minimum Maximum Median Mean Standard Standard Deviation error of mean Sekolah Kebangsaan Bayan Lepas 18 42 966 224.5 322.39 283.57 66.84 Sekolah Kebangsaan Tasek Gelugor 18 127 3009 328 684.89 865.04 203.89 Sekolah Menengah Kebangsaan Mutiara Impian 18 137 2693 341.5 671.00 827.43 195.03 Sekolah Kebangsaan Machang Bubok 18 143 709 307.5 387.44 191.74 45.19

The mean bacterial count (516.43 cfu/m3) recorded in this study was lower than the ones previously reported by other research. For instance, a study of private primary schools in Nigeria reported that a mean bacterial count is 4378.82 cfu/m3(Enitan et al.,

2017). In Jimma University, Ethiopia reported that a mean bacterial count is 1476 cfu/m3 (Hayleeyesus et al., 2014). Hussin et al. (2011) reported that an average bacterial concentration in indoor air of five primary schools from Selangor, Malaysia is

1025 cfu/m3.

4.8 Comparison of bacterial count (cfu/m3) for background and normal

condition

Bacterial count is higher at 12:45 p.m. for SMK Mutiara Impian and the lowest is SK Bayan Lepas at 07:15 a.m. The work conducted by a WHO expert group on assessment of health risks of biological agents in indoor environments has set the guidelines of bio-aerosol counts at 500 cfu/m3. If the bacterial count higher than guidelines, the environment is considered as contaminated (WHO, 1990).

From Figure 4.30, the higher bacterial count is SK Machang Bubok (508 cfu/m3) at 7:15 a.m., SK Tasek Gelugor (682 cfu/m3) at 10:40 a.m. and at 12:45 p.m.,

SK Bayan Lepas (609 cfu/m3), SK Tasek Gelugor (878 cfu/m3) and also SMK Mutiara

Impian (1339 cfu/m3). Therefore, these schools are considered as contaminated during the higher bacterial count as stated by guidelines of WHO.

When the sampling result during normal condition was compared with the background study, the sampling result is higher. The background study was conducted during school holiday. Therefore, the presence of the occupancy might increase the bacterial count for each school in normal condition. The activities by the students and teacher such as walking affect the bacterial count. The number of students and teacher present in each classroom during each sampling period were determined by head count and were recorded. At some point in the classroom, there were students that stay closed to the agar plate so the bacterial form might be from students.

1339

1220

) 3 1020

878 820 Background SK Bayan Lepas 682 620 609 SK Tasek Gelugor 508 SMK Mutiara Impian 494

420 410 SK Machang Bubok Number of bacteria (cfu/m bacteria Number of 344 330 270 220 245 94 89 72 20 53 7:15 AM 10:40 AM 12:45 PM Time

Figure 4‎ .30: Comparison of bacterial count between background condition and with the presence of students

4.9 Comparison of temperature (°C) between background and normal

condition

The indoor air temperature range suggested by the ICOP on Indoor Air Quality,

2010 must be between 23°C and 26°C. The combined mean indoor temperature values of four schools obtained in this study at different sampling time of the day were 7:15 am (27.2°C), 10:40 am (29.5°C) and 12:45 pm (30.9°C). They were not within comfort range. From Figure 4.31, it shows that temperature increased from the morning to afternoon. The weather during the sampling is sunny. When the sampling results were compared with background study, the temperature was not within comfort range.

During the background study, the weather is cloudy.

32 31.7

31 31.1 30.6 30.5 30 30 30.2 29.7

29.6 ᵒC) 29 Background 28.7 SK Bayan Lepas 28.1 28.5 28 27.8 SK Tasek Gelugor

Temperature ( Temperature 27.7 SMK Mutiara Impian 27.5 27 SK Machang Bubok

26 25.8

25 7:15 AM 10:40 AM 12:45 PM Time

Figure 4‎ .31: Comparison of temperature between background condition and with the presence of students

4.10 Comparison of relative humidity (%) for background and normal

condititon

The indoor relative humidity range suggested by the ICOP on Indoor Air

Quality, 2010 must be between 40 % and 70 %. The combined mean indoor relative humidity values of four schools obtained in this study at different sampling time of the day were 7:15 am (87.7 %), 10:40 am (82.0 %) and 12:45 pm (79.2 %). They were not within comfort range. When the sampling results were compared with background study, the relative humidity was within comfort range as shown in Figure 4.32. During the background study, the weather is cloudy. Therefore, it may give effect on the relative humidity reading.

95 92.7 90 90 88.2 86.1 85 85 84.7 83 83.9

80 77.8 77.4 75 75.5 Background 71.4 70 SK Bayan Lepas SK Tasek Gelugor 65 SMK Mutiara Impian 62 Relative Humidity Humidity (%) Relative 60 SK Machang Bubok

50 51 49 45 7:15 AM 10:40 AM 12:45 PM Time

Figure 4‎ .32: Comparison of relative humidity between background condition and with the presence of students

4.11 Pearson’s‎ Correlation for Bacterial Count with Temperature (°C) and Relative Humidity (%)

4.11.1 Background Study

Table 4.17 shows the correlation between the combined bacterial count (cfu/m3) with temperature (°C) and relative humidity (%) of the background study. Temperature correlates with bacterial count by a Pearson correlation with -0.446. The two tailed P value is 0.375, considered not significant (P>0.05). Relative humidity correlates with bacterial count by a Pearson correlation with -0.211. The two tailed P value is 0.688, considered not significant (P>0.05). From correlation terms (Townend, 2002), this was a little or no correlation for temperature and relative humidity with bacterial count.

Table 4‎ .17: Pearson‟s correlation for background study Bacterial Temperature Relative Count Humidity Bacterial Pearson Correlation 1 -0.446 -0.211 Count Sig. (2-tailed) 0.375 0.688 N 6 6 6 Temperature Pearson Correlation -0.446 1 -0.359 Sig. (2-tailed) 0.375 0.485 N 6 6 6 Relative Pearson Correlation -0.211 -0.359 1 Humidity Sig. (2-tailed) 0.688 0.485 N 6 6 6

4.11.2 SK Bayan Lepas

Table 4.18 shows the correlation between the combined bacterial count (cfu/m3) with temperature (°C) and relative humidity (%) of the SK Bayan Lepas. Temperature correlates with bacterial count by a Pearson correlation with 0.738. The two tailed P value is 0.000468, considered significant (P<0.05). Relative humidity correlates with bacterial count by a Pearson correlation with -0.639. The two tailed P value is

0.004309, considered significant (P<0.05). From correlation terms (Townend, 2002), this was a weak correlation for temperature and relative humidity with bacterial count.

Table 4‎ .18: Pearson‟s correlation for SK Bayan Lepas Relative Humidity Temperature Bacterial Count (RH) (T) (BC) Pearson Correlation 1 -0.962** -0.639** RH Sig. (2-tailed) 0.000468 0.004309 N 18 18 18 Pearson Correlation -0.962** 1 0.738** T Sig. (2-tailed) 0.000 0.000 N 18 18 18 Pearson Correlation -0.639** 0.738** 1 BC Sig. (2-tailed) 0.004309 0.000468 N 18 18 18 **. Correlation is significant at the 0.01 level (2-tailed).

4.11.3 SK Tasek Gelugor

Table 4.19 shows the correlation between the combined bacterial count (cfu/m3) with temperature (°C) and relative humidity (%) of the SK Tasek Gelugor. Temperature correlates with bacterial count by a Pearson correlation with 0.106. The two tailed P value is 0.676, considered not significant (P>0.05). Relative humidity correlates with bacterial count by a Pearson correlation with -0.069. The two tailed P value is 0.786, considered not significant (P>0.05). From correlation terms (Townend, 2002), this was a little or no correlation for temperature and relative humidity with bacterial count.

Table 4‎ .19: Pearson‟s correlation for SK Tasek Gelugor Bacterial Temperature Relative Count Humidity Bacterial Pearson Correlation 1 0.106 -0.069 Count Sig. (2-tailed) 0.676 0.786 N 18 18 18 Temperature Pearson Correlation 0.106 1 -0.997** Sig. (2-tailed) 0.676 0.000 N 18 18 18 Relative Pearson Correlation -0.069 -0.997** 1 Humidity Sig. (2-tailed) 0.786 0.000 N 18 18 18 ** Correlation is significant at the 0.01 level (2-tailed).

4.11.4 SK Machang Bubok

Table 4.20 shows the correlation between the combined bacterial count (cfu/m3) with temperature (°C) and relative humidity (%) of the SK Machang Bubok.

Temperature correlates with bacterial count by a Pearson correlation with 0.052. The two tailed P value is 0.839, considered not significant P>0.05. Relative humidity correlates with bacterial count by a Pearson correlation with -0.231. The two tailed P value is 0.356, considered not significant at P>0.05. From correlation terms (Townend,

2002), this was a little or no correlation for temperature and relative humidity with bacterial count.

Table 4‎ .20: Pearson‟s correlation for SK Machang Bubok Bacterial Temperature Relative Count Humidity Bacterial Pearson Correlation 1 -0.052 -0.231 Count Sig. (2-tailed) 0.839 0.356 N 18 18 18 Temperature Pearson Correlation -0.052 1 -0.791** Sig. (2-tailed) 0.839 0.000 N 18 18 18 Relative Pearson Correlation -0.231 -0.791** 1 Humidity Sig. (2-tailed) 0.356 0.000 N 18 18 18 **. Correlation is significant at the 0.01 level (2-tailed).

4.11.5 SMK Mutiara Impian

Table 4.21 shows the correlation between the combined bacterial count (cfu/m3) with temperature (°C) and relative humidity (%) of the SMK Mutiara Impian.

Temperature correlates with bacterial count by a Pearson correlation with 0.417. The two tailed P value is 0.085, considered not significant (P>0.05). However, relative humidity correlates with bacterial count by a Pearson correlation with -0.526. The two tailed P value is 0.025, considered significant at P<0.05. From correlation terms

(Townend, 2002), this was a little or no correlation for temperature and relative humidity with bacterial count.

Table 4‎ .21: Pearson‟s correlation for SMK Mutiara Impian Bacterial Temperature Relative Count Humidity Bacterial Pearson Correlation 1 0.417 -0.526* Count Sig. (2-tailed) 0.085 0.025 N 18 18 18 Temperature Pearson Correlation 0.417 1 -0.949** Sig. (2-tailed) 0.085 0.000 N 18 18 18 Relative Pearson Correlation -0.526* -0.949** 1 Humidity Sig. (2-tailed) 0.025 0.000 N 18 18 18

*. Correlation is significant at the 0.05 level (2-tailed). **. Correlation is significant at the 0.01 level (2-tailed).

Most of the people spend the greater part of their day indoors, away from the heat and pollution from the concrete jungle and often spend most of their time at home, in school or at the office in relative comfort (Luksamijarulkul, 2011; Kodama & McGee,

1986). Respiratory disease is a major cause of illness and absence from school for children (Marbury et al., 1997).

The number of students per classroom in relation to the classroom area, temperature and relative humidity was measured at the time of this study might be responsible for the level of bacterial count recorded in this study. In this study, the number of students per classroom is not equal. Some classrooms have too many students. The highest number of students in a classroom is 38 at level 1 of SK Tasek Gelugor while the least number of students is 18 at level 2 of SMK Mutiara Impian. This might be because of location of school with residential area. From this study, the number of bacterial count was higher for normal condition (with presence of student) compared to background study.

Some data presented in this work provides evidence that people visiting closed to agar media increased the number of bacterial count. It means that overcrowded places will extremely expose to risk of high microbial contamination. Würtz et al. (1999) reported that the relationship between the density of occupants and the concentration of indoor microbes. However, in this study, there was no significant correlation between classroom occupancy and bacterial counts. But the activities by the occupancy gave effect on bacterial counts.

In the SMK Mutiara Impian, the highest bacterial count might be due to activity of occupants during sampling whereas the lowest concentration was recorded at SK Bayan

Lepas. This increased the shedding of bacteria and agitation of air. Meadow et al.

(2014) revealed that the presence of bacteria was associated to the presence of personnel into the air of the partially closed premises. The structural design and less activity from students might be responsible for low bacteria burden of SK Bayan

Lepas. Therefore, to improve a healthy of indoor air quality in the building would be avoid the overcrowding.

The classrooms of SK Bayan Lepas, SK Tasek Gelugor, SK Machang Bubok and SMK

Mutiara Impian had all windows open and 3 ceiling fans except to classroom level 3 of

SMK Mutiara Impian with 4 ceiling fans. With regards to ventilation, all school open all windows and ceiling fans during sampling. Inadequate ventilation has been reported to be one of the causes of poor indoor air quality of classrooms (Daisey et al., 2013).

This leads to the accumulation of pollutants from different sources and might increase the incidence of symptoms among building occupants. The presence of good

74 ventilation systems inside the classrooms eliminates some extent the influence of sources (Filipiak, 2007).

CHAPTER 5

CONCLUSIONS

5.1 Conclusion

The first objective of this research is to determine the concentration of bacteria using settle plate method for fifteen minutes for each classroom of selected school in

Penang. The acceptable limits of total bacteria count from ICOP on Indoor Air Quality

2010 is 500 cfu/m3. However, from the combined mean bacterial colony counts per sampling period, SMK Mutiara Impian has the higher bacterial counts (1339 cfu/m3) at

12:45 p.m. compared to another three schools. The poor microbial indoor air quality at the schools could have a harmful effect on children‟s health.

Furthermore, the second objective of this research is to compare the concentration of bacteria in background condition with presence of student and activities. The mean bacterial counts when there was a presence of students is higher than mean bacterial counts for background condition. Activity of students affected the concentration of bacteria. The layout of the classrooms itself affect the concentration of bacteria. Factors affecting concentration of bacterial counts are the presence of book shelves, the use of curtains and tablecloths preventing airflow in the classroom.

For the third objective is to investigate the relationship between concentration of bacteria with relative humidity and temperature. The relative humidity and temperature inside the classroom is measured using formaldemeter. The relative humidity and temperature effect the bacterial growth. When the temperature higher, the relative humidity decreased and the bacterial count was increased. Overall, the

76 temperature for each school shown the value is over limit of indoor air temperature range suggested by the ICOP on Indoor Air Quality 2010. Therefore, the comfort in classroom for each school is decrease. Meanwhile, the relative humidity also over limit if indoor relative humidity range suggested by the ICOP on Indoor Air Quality 2010.

From the observations, temperature at SK Tasek Gelugor with the presence of student is the lowest compare to another three schools. The ventilation systems use in the classroom is natural when no presence of students and mechanical during the presence of student. The location of classroom that have tree outside made the classroom become a bit cooler than other classroom. The observation on relative humidity during the sampling shown that relative humidity with the presence of student at SMK Mutiara Impian is higher than another three schools. Overall, relative humidity and temperature affect the bacterial count for each school classrooms.

5.2 Recommendations

5.2.1 Air Movement

The good air movement in the classrooms can help to reduce the concentration of bacteria problems. Sitting at the classroom with windows close every day is unhealthy because the contaminant air is trapped at the classroom and cannot outflow.

Therefore, windows must be open in order to let the air movement in and out.

The use of mechanical system such as fan, not only cool the air but also recycle air from outside. If the air enters is less, so contaminant will gather and cause occupant not comfort to stay at the classroom. Therefore, every school is advised to install an air cleaner and is fully utilized during teaching and learning sessions. This fan allows the changes of indoor air with outside air that is more fresh. 77

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APPENDIX

Appendix A School: Date of Sampling: Time of Sampling: Weather:  Name of Classrooms: Classroom layout and sampling location:

Result:

 24 hours Location 1 2 3 4 5 Average Sampling Time Number of bacteria count (cfu/m3) 0715-0730 1040-1055 1245-1300

 48 hours Location 1 2 3 4 5 Average Sampling Time Number of bacteria count (cfu/m3) 0715-0730 1040-1055 1245-1300

 72 hours Location 1 2 3 4 5 Average Sampling Time Number of bacteria count (cfu/m3) 0715-0730 1040-1055 1245-1300

Note:

Appendix B

Hot Plate Autoclave

Laminar flow Cool Box

Colony Counter 37 °C Incubator

Appendix C

PREPARATION OF AGAR (Prepared two days or a day before sampling)

Suspend 28 g of agar in one litter of distilled water and then heat to dissolve completely

Mixture was sterilized by autoclaving at 121°C for 15 minutes

20 ml of the mixture were poured to 9 cm of petri dishes at the laminar flow to avoid any contaminant

The agar were then cooled at room temperature and keep in cool box

Appendix D

Microorganisms formed on an agar plate after 24-hours incubation at SK Bayan Lepas for background condition (without the presence of students)

Time 0715H – 0730H 1040H – 1055H 1245H – 1300H

LEVEL 2 LEVEL

24 HOURS 24

LEVEL 3 LEVEL

Microorganisms formed on an agar plate after incubation at SK Bayan Lepas for normal condition (with the presence of students)

Time 0715H – 0730H 1040H – 1055H 1245H – 1300H

LEVEL 2 LEVEL

24 HOURS 24

LEVEL 3 LEVEL

LEVEL 2 LEVEL

48 HOURS 48

LEVEL 3 LEVEL

LEVEL 2 LEVEL

72 HOURS 72

LEVEL 3 LEVEL

Microorganisms formed on an agar plate after incubation at SK Tasek Gelugor for normal condition (with the presence of students)

Time 0715H – 0730H 1040H – 1055H 1245H – 1300H

LEVEL 1 LEVEL

24 HOURS 24 LEVEL 3 LEVEL

LEVEL 1 LEVEL

48 HOURS 48 LEVEL 3 LEVEL

LEVEL 1 LEVEL

72 HOURS 72

LEVEL 3 LEVEL

Microorganisms formed on an agar plate after incubation at SK Machang Bubok for normal condition (with the presence of students)

Time 0715H – 0730H 1040H – 1055H 1245H – 1300H

LEVEL 2 LEVEL

24 HOURS 24

LEVEL 3 LEVEL

LEVEL 2 LEVEL

48 HOURS 48

LEVEL 3 LEVEL

LEVEL 2 LEVEL

72 HOURS 72 LEVEL 3 LEVEL

Microorganisms formed on an agar plate after incubation at SMK Mutiara Impian for normal condition (with the presence of students)

Time 0715H – 0730H 1040H – 1055H 1245H – 1300H

LEVEL 2 LEVEL

24 HOURS 24 LEVEL 3 LEVEL

LEVEL 2 LEVEL

48 HOU 48

LEVEL 3 LEVEL

LEVEL 2 LEVEL

72 HOURS 72

LEVEL 3 LEVEL