Aerosol Sampling: Science, Standards, Instrumentation and Applications

Aerosol Sampling......Page 3
Contents......Page 9
Preface......Page 19
A SCIENTIFIC FRAMEWORK FOR AEROSOL SAMPLING......Page 23
1.1 Aerosols......Page 25
1.2 Particle size......Page 26
1.3 Elementary particle size statistics......Page 27
1.4 Aerosol measurement......Page 30
1.5 Sampler performance characteristics......Page 31
References......Page 34
2.1.2 Equations of fluid motion......Page 35
2.1.3 Streamlines and streamsurfaces......Page 37
2.1.4 Boundary layers......Page 38
2.1.5 Stagnation......Page 40
2.1.7 Turbulence......Page 42
2.2.2 Drag coefficient......Page 44
2.2.3 Slip......Page 45
2.2.4 General equation of motion under the in.uence of an external force......Page 46
2.2.5 Particle motion without external forces......Page 47
2.2.6 Particle aerodynamic diameter......Page 49
2.2.7 Impaction......Page 50
2.2.8 Molecular diffusion......Page 52
2.2.9 Turbulent diffusion......Page 54
References......Page 55
3.2.1 The direct (trajectory) method......Page 57
3.2.2 The indirect (comparison) method......Page 58
3.2.3 Critique of the alternative methods......Page 59
3.3 Scaling relationships for aerosol samplers......Page 60
3.4 Test facilities......Page 61
3.4.1 Moving air......Page 62
3.4.2 Calm air......Page 67
3.4.3 Slowly moving air......Page 70
3.5.1 Idealised test aerosols......Page 72
3.5.2 Dry-dispersed dusts......Page 74
3.5.3 Aerosol materials......Page 79
3.5.4 Electric charge effects......Page 81
3.7 Assessment of collected aerosol......Page 82
3.8 Aerosol sampler test protocols and procedures......Page 83
References......Page 90
4.2 Line and point sink samplers......Page 93
4.3.1 Facing the freestream......Page 95
4.3.2 Other orientations......Page 96
4.4 Thick-walled tubes......Page 97
4.5.1 Two-dimensional blunt sampling systems......Page 98
4.5.2 Axially symmetric blunt sampling systems......Page 102
4.6.1 A cylindrical blunt sampler......Page 104
4.6.2 Flow stability......Page 106
4.6.3 A spherical blunt sampler......Page 108
4.7 More complex sampling systems......Page 111
References......Page 112
5.1 Introduction......Page 115
5.2.1 Qualitative picture of aerosol transport......Page 116
5.2.2 Impaction model for a thin-walled tube facing the freestream......Page 118
5.2.4 Experimental studies for thin-walled tubes facing the freestream......Page 120
5.2.5 Experimental studies for thin-walled tubes at other orientations......Page 126
5.2.6 Impaction model for other orientations......Page 127
5.2.7 Mathematical models......Page 131
5.2.8 Conditions for ‘acceptable’ isokinetic sampling......Page 136
5.3.1 Impaction model for a blunt sampler facing the freestream......Page 138
5.3.2 Experimental investigations of blunt samplers of simple shape facing the wind......Page 142
5.3.3 Blunt samplers at other orientations......Page 145
5.3.4 Mathematical and numerical approaches to blunt samplers......Page 147
5.3.5 Orientation-averaged conditions......Page 148
References......Page 149
6.2.1 Qualitative description......Page 153
6.2.2 Experimental studies for sampling in perfectly calm air......Page 157
6.2.3 Analytical models for aspiration efficiency in calm air......Page 160
6.2.4 Descriptive modeling of aspiration efficiency......Page 166
6.2.5 Criteria for ‘representative sampling’ in calm air......Page 169
6.3 Slowly moving air......Page 171
6.3.1 Definition of calm air......Page 172
6.3.2 Intermediate conditions......Page 174
References......Page 177
7.2 Interferences during aspiration......Page 179
7.2.1 Effects of turbulence on aspiration......Page 180
7.2.2 Effects of electrostatic forces on aspiration......Page 184
7.2.3 External wall effects......Page 187
7.3.1 Deposition losses inside a straight sampling tube......Page 195
7.3.2 Deposition losses inside a bent sampling tube......Page 202
7.3.3 Deposition inside a thin-walled tube facing into the wind......Page 203
7.3.4 Deposition inside a thin-walled tube at other orientations......Page 206
7.3.5 Rebound of particles from internal walls......Page 207
7.3.7 Electrostatic effects......Page 208
References......Page 210
8.1 Introduction......Page 215
8.2.1 Vertical elutriation......Page 216
8.2.2 Horizontal elutriation......Page 217
8.3 Filtration by porous foam media......Page 219
8.4 Centrifugation......Page 223
8.5.1 Conventional impaction......Page 227
8.5.3 Virtual impaction......Page 231
8.6.1 Deposition by diffusion in laminar flow through tubes......Page 233
8.6.2 Deposition by diffusion in flow through screens......Page 234
8.7.1 Electrostatic precipitation......Page 235
8.7.2 Thermal precipitation......Page 236
References......Page 237
B STANDARDS FOR AEROSOLS......Page 241
9.1 Introduction......Page 243
9.2 Exposure to aerosols......Page 244
9.2.1 The human respiratory tract......Page 245
9.2.2 Definitions of exposure......Page 247
9.3.1 Criteria......Page 249
9.3.3 Analytical methods......Page 250
9.3.4 Sampling strategies......Page 251
9.3.5 Exposure limits......Page 254
9.4 Non-health-related aerosol standards......Page 255
References......Page 257
10.2.1 Early experimental measurements of inhalability......Page 259
10.2.2 Physical basis of inhalability......Page 263
10.2.3 Inhalability for very large particles......Page 264
10.2.4 Inhalability at very low wind speeds......Page 266
10.3 Particle size-selective criteria for the inhalable fraction......Page 269
10.3.1 Early recommendations......Page 270
10.3.2 Modern criteria for the inhalable fraction......Page 271
10.4 Overview......Page 274
References......Page 275
11.2.1 Framework......Page 277
11.2.2 Theories, simulations and models......Page 280
11.2.3 Experiments for studying regional deposition......Page 281
11.2.4 Results for total deposition......Page 282
11.2.5 Results for extrathoracic deposition......Page 283
11.2.6 Results for tracheobronchial deposition......Page 284
11.2.7 Results for deposition in the alveolar region......Page 286
11.2.8 Results for the deposition of fibrous aerosols......Page 287
11.2.9 Results for the deposition of very .ne and ultra.ne aerosols......Page 288
11.3.1 Historical overview......Page 290
11.3.2 Modern criteria for the thoracic and respirable aerosol fractions......Page 295
11.3.3 Criteria for the extrathoracic aerosol fraction......Page 297
11.3.4 Criteria for the tracheobronchial and alveolar aerosol fractions......Page 298
11.3.5 Criteria for very fine aerosol fractions......Page 300
11.3.6 Criteria for fibrous aerosols......Page 301
11.3.7 Criteria for ultrafine aerosols......Page 302
11.4.1 Summary......Page 304
11.4.2 Precision and tolerance bands......Page 305
11.4.3 International harmonisation of sampling criteria......Page 306
References......Page 307
12.2 Aerosol-related health effects......Page 311
12.2.1 Diseases of the respiratory tract......Page 312
12.2.2 Diseases beyond the respiratory tract......Page 313
12.4 Occupational exposure limits (OELs)......Page 314
12.4.2 Regulatory exposure limits......Page 315
12.4.3 OELs for aerosols......Page 316
12.5.1 Black smoke and fine particles......Page 319
12.5.2 Establishment of the EPA PM NAAQS limit values......Page 320
12.5.3 Limits for non-health-related aerosols......Page 322
12.6 Special cases......Page 323
12.6.1 Fibrous aerosols......Page 324
12.6.2 Bioaerosols......Page 325
12.6.3 Ultrafine aerosols......Page 326
References......Page 327
C AEROSOL SAMPLING INSTRUMENTATION......Page 331
13.1 Introduction......Page 333
13.2.1 Sampling strategies and philosophies......Page 334
13.2.3 Early gravimetric samplers for ‘total’ aerosol......Page 335
13.2.4 Particle count samplers......Page 336
13.2.5 Emergence of gravimetric samplers for the respirable fraction......Page 338
13.2.8 Sampling to measure aerosol particle size distribution......Page 339
13.2.9 Direct-reading instruments......Page 340
13.3.1 Sampling strategies and philosophies......Page 341
13.3.2 Indices of health-related aerosol exposure......Page 342
13.3.5 Overview......Page 344
References......Page 345
14.2.1 ‘Total’ aerosol......Page 349
14.2.2 Inhalable aerosol......Page 350
14.3.1 ‘Total’ aerosol......Page 355
14.3.2 Inhalable aerosol......Page 366
14.3.3 Other samplers......Page 373
14.4.2 Modeling......Page 374
14.5 Passive aerosol samplers......Page 376
References......Page 378
15.2 Samplers for the respirable fraction......Page 381
15.2.1 Early samplers......Page 382
15.2.2 Horizontal elutriators......Page 386
15.2.3 Cyclones......Page 390
15.2.4 Impactors......Page 398
15.2.5 Porous plastic foam filter samplers......Page 400
15.2.6 Other samplers......Page 405
15.3 Samplers for the thoracic fraction......Page 407
15.3.2 Cyclones......Page 408
15.3.3 Impactors......Page 409
15.3.4 Porous plastic foam filter samplers......Page 410
15.4 Samplers for PM2.5......Page 413
15.5 Thoracic particle size selection for fibrous aerosols......Page 415
15.6.2 Combustion-related aerosols......Page 416
15.7 Simultaneous sampling for more than one aerosol fraction......Page 417
References......Page 420
16.2 Basic considerations......Page 425
16.3 Stack sampling methods......Page 426
16.3.1 United States of America......Page 427
16.3.2 United Kingdom and elsewhere......Page 431
16.4.1 Standard probes......Page 432
16.4.2 Velocity-sensing probes......Page 433
16.4.4 Self-compensating probes......Page 434
16.4.5 Dilution......Page 435
16.5 Sampling for determining particle size distribution in stacks......Page 436
References......Page 437
17.2 Sampling for coarse ‘nuisance’ aerosols......Page 439
17.3 Sampling for ‘black smoke’......Page 445
17.4.1 ‘Total’ aerosol......Page 447
17.4.2 Inhalable aerosol......Page 453
17.5.1 PM10......Page 454
17.5.2 PM2.5......Page 457
17.5.3 Ultrafine aerosols......Page 461
17.6 Meteorological sampling......Page 462
References......Page 464
18.2 Rationale......Page 469
18.3.1 Horizontal elutriators......Page 470
18.3.3 Inertial spectrometers......Page 472
18.4.1 Outline......Page 474
18.4.3 Static cascade impactor-based samplers......Page 476
18.4.4 Personal cascade impactors......Page 481
18.4.5 Cascade impactors for stack sampling......Page 484
18.4.6 Inversion procedures for cascade impactors......Page 485
18.5.1 Parallel impactors......Page 487
18.5.2 Cascade cyclones......Page 488
18.5.3 Diffusion batteries......Page 489
18.6 Particle size distribution analysis by microscopy......Page 491
References......Page 492
19.1 Introduction......Page 495
19.3 Technical issues for bioaerosol sampling......Page 496
19.4 Early bioaerosol sampling......Page 498
19.6 Inertial samplers......Page 499
19.6.2 Single-stage impactors......Page 500
19.6.3 Cascade impactors......Page 503
19.6.4 Impingers......Page 504
19.7.2 Centrifuges......Page 507
References......Page 508
20.1 Introduction......Page 511
20.2.1 Physical background......Page 512
20.2.2 Transmission/extinction monitoring......Page 514
20.2.3 Light scattering photometry......Page 516
20.2.4 Optical particle counters......Page 520
20.3 Electrical particle measurement......Page 525
20.4 Condensation nuclei/particle counters......Page 526
20.5 Mechanical aerosol mass measurement......Page 527
20.6 Nuclear mass detectors......Page 531
20.7 Surface area monitoring......Page 532
20.9.1 Fluorescence technology......Page 533
20.9.3 Hybrid systems......Page 534
References......Page 535
D AEROSOL SAMPLE APPLICATIONS AND FIELD STUDIES......Page 539
21.2 Air moving systems......Page 541
21.2.1 Pumps......Page 542
21.2.2 Personal sampling pumps......Page 544
21.2.3 Pulsation damping......Page 545
21.3 Flow rate......Page 546
21.3.2 Flow measurement......Page 547
21.4.1 Filters......Page 548
21.4.2 Filtration efficiency......Page 549
21.4.3 Mass stability......Page 550
21.4.4 Choices and applications......Page 553
21.4.5 Substrates......Page 554
21.5.1 Handling and transport of samples......Page 555
21.5.3 Chemical analysis......Page 556
References......Page 557
22.1 Introduction......Page 559
22.2 Personal and static (or area) sampling......Page 560
22.3 Relationship between ‘total’ and inhalable aerosol......Page 561
22.3.1 Side-by-side comparative studies......Page 562
22.3.2 The practical impact of changes from ‘total’ to inhalable aerosol measurement......Page 570
22.4.1 Respirable aerosol exposures in the coal industry......Page 571
22.4.2 Respirable aerosol exposures in hard rock mining......Page 574
22.4.3 Inhalable aerosol exposures in the nickel industry......Page 576
22.5.1 Gravimetric mass sampling......Page 580
22.5.2 Workplace comparisons between optical and gravimetric aerosol samplers......Page 581
22.6.1 Particle size distribution......Page 584
22.6.2 Combined particle size measurement and chemical speciation......Page 588
22.7 Diesel particulate matter......Page 590
22.8 The future of workplace aerosol measurement......Page 591
References......Page 592
23.1 Introduction......Page 597
23.2 ‘Nuisance’ dust......Page 598
23.3 Total suspended particulate and black smoke......Page 599
23.4 Black smoke and particle size fractions (PM10 and PM2.5)......Page 602
23.5 Transition to particle size-selective sampling......Page 604
23.6 PM10......Page 607
23.8 Personal exposures to PM10 and PM2.5......Page 611
23.9.1 Particle size distribution......Page 615
23.9.2 Chemical composition......Page 616
References......Page 618
Index......Page 621