Indoor-Outdoor Volatile Organic Compounds (VOCs) levels in Urban and Industrial Area of Dhaka City, Bangladesh

iv LIST OF ABBREVIATIONS . v TABLE OF CONTENTS . vii CHAPTER ONE: GENERAL INTRODUCTION . 1 1.1 Background of the study . 1 1.2 Study scope and objectives . 3 CHAPTER TWO: LITERATURE REVIEW . 5 2.1 Volatile organic compounds . 5 2.2 Definitions. 5 2.3 Sources . 6 2.3.1 Natural sources . 6 2.3.2 Anthropogenic sources . 6 2.3.2.1 Stationary sources . 6 2.3.2.2 Mobile sources . 6 2.3.2.3 Indoor sources . 7 2.4 Indoor to Outdoor concentration ratio (I/O) . 7 2.5 Source identification . 8 2.6 Effects of VOCs . 8 2.6. 1 Health effects . 8 2.6. 2 Environmental effects . 9 2.6. 2.1 Stratospheric ozone depletion . 9 2.6. 2.2 Tropospheric ozone formation . 9 2.6. 2.3 Global warming through Greenhouse effect . 9 2.7 Estimation of ozone formation potential. 9 CHAPTER THREE: MATERIALS AND METHODS . 12 3.1 Sample Preparation . 12 3.1.1 Tenax TA tube description . 12 3.1.2 Conditioning of Tenax TA tubes . 12 3.1.3 Preparation of closed two-phase system (CTS) . 12 3.1. 4 Loading with internal standard (Tol-d8) . 12 3.1. 5 Calculation of mass of the internal standard (IS) . 13 3.1. 6 Pump calibration . 14 3.1. 7 Sampling technique . 14 3.2 Sampling Campaigns . 15 3.2.1 Urban sampling campaign . 17 3.2.1.1 Urban indoor house . 18 3.2.1.2 Urban outdoor roadside . 19 3.2.1.3 Urban outdoor park . 19 3.2.2 Industrial sampling campaign . 20 Indoor-Outdoor Volatile Organic Compounds (VOCs) levels in Urban and Industrial Area of Dhaka City, Bangladesh Page viii 3.2.2.1 Industrial indoor house . 21 3.2.2.2 Industrial outdoor roadside . 22 3.2.2.3 Industrial outdoor ambient . 22 3.3 Sample Analysis. 23 3.3.1 Loading of calibration mixture . 23 3.3.2 Calibration of the TD-GC-MS . 23 3.3.3 Analysis of Tenax TA sampling tubes . 24 3.3. 4 Determination of RSRF . 25 3.3. 5 Quantification . 25 3.3. 5.1 Mass of the analyte . 25 3.3. 5.2 Concentration of the analyte . 26 3.3. 5.3 Determination of LOD and LOQ . 26 3.3. 6 Statistical Analysis . 26 3.3. 7 Quantitative concentration profiles . 27 CHAPTER FOUR: RESULTS AND DISCUSSIONS . 28 4.1Qualitative analysis . 28 4.2 Quantitative Analysis . 29 4.2.1 Concentration levels of VOCs . 29 4.2.2 Ambient mean TVOCs in urban and industrial environment . 30 4.2.3 Box plot of TVOCs . 31 4.3 Individual groups in TVOCs . 33 4.3.1 Mean of individual groups in TVOCs . 33 4.3.2 Stacked column (100%) contribution of each group to TVOCs . 34 4.4 TVOCs individual subgroups . 36 4.4. 1 Mean concentration of total (cyclo)-alkanes in TVOCs . 37 4.4.2 Stacked column (100%) contribution of subgroups to total (cyclo)-alkanes . 38 4.4.3 Mean concentration of total oxygenated compounds in TVOCs . 38 4.4.4 Stacked column (100%) contribution of subgroups to total oxygenated compounds39 4.5 Total Aromatic Compounds in TVOCs . 40 4.5.1 Mean concentration of total aromatic compounds in TVOCs . 40 4.5.2 Stacked column (100%) contribution of each compound to total aromatic compounds . 41 4.6 Mean of sum of BTEX (∑BTEX) level . 42 4.7 Mean benzene concentration level . 43 4.8 Indoor to outdoor concentration ratio (I/O) . 45 4.9 Source Identification . 47 4.9. 1 Diagnostic ratios . 47 4.9. 2 Correlation coefficients of all aromatic compounds . 48 4.10 Ozone Formation Potential . 50 4.10. 1 Total ozone formation potential . 50 4.10. 2 Stacked column percentage (100%) contribution per group in TOFP . 51 4.10. 3 Influence of update MIR in OFP . 52 4.10. 3.1 Influence of