Aerosol Science History – Willeke And Baron (2001) Ch

aerosol science history – willeke and baron (2001), ch. 1 romans – foul air of rome → aerosol science intrinsically linked to air pollution

Aerosol science history – Willeke and Baron (2001), Ch. 1
Romans – foul air of Rome → Aerosol science intrinsically linked to
air pollution
1273 – Coal burning banned in London.
1500 – Leonardo da Vinci – first recorded use of laboratory aerosols.
1661 – Tract on air pollution in England submitted to Charles II -
Fumifugium
1700s – High mortality of hard rock miners.
1841 – Epsy invented ‘nephelescope’ and observed water cloud formation
in lab. He was not aware that condensation occurred on particles.
1847 – Becquerel hypothesized about existence of fine particles in
air,
1850s – Tyndall used ‘sunbeams’ to determine indoor air pollution,
1860s – Tyndall detected fine particles by dark field illumination.
Invented the tyndallometer, nephelometer, ultra microscope, optical
particle counter, and indirectly thermal precipitator – noted dark
region above a heated body, later observed by Rayleigh, Lodge, Aitken
– discovery of thermophoresis
1875 – Coulier the first to show condensation in unfiltered air,
1880 – John Aitken developed an expansion type portable dust (CN)
counter with full credit to Coulier. First portable aerosol counter.
1897 – Wilson used cloud chamber to study homogeneous nucleation.
1880s – Electrostatic precipitation – electric discharge into smoke
laden atmosphere coagulated the smoke – electrophoresis.
1881 – ultramicroscopy of smoke
1900s – First attempts at using filters and gravimetry which were
dominated by large particles. Silicotic lung tissue – 70% of particles
< 1.0 µm → fine dust counters. First aerosol diffusion battery.
1918 – “Aerosol” coined in analogy with hydrosol – Donnan,
1920s – Silica (quartz) recognized as producing pulmonary diseases,
silicosis, pneumoconiosis → dust counters in industry.
1919 – Konimeter – dust collected by impaction on glass slides and
counted with microscopy → fine dust counters. Number concentration
more important than mass.
Fibrous aerosol:
1920s – Medical proof of a causal effect between asbestos fibers and
fatality of asbestos workers.
1927 – Peribronchial fibrosis fully recognized – asbestosis.
1935 – Bronchial carcinoma → Need for measure and control of
asbestosis officially recognized.
1970s – Optical fiber counter – Baron, 1980s – improvements, 1990s –
satisfactory instrumentation available.
1940s – Cascade impactors, precipitators (thermal/electrical) –
Problems were many – rebound, re-entrainment, deagglomeration,
sampling and collection efficiencies varied widely with differences of
± 100%. Isokinetic sampling not recognized or understood until after
1960. Thermal precipitators (instruments of choice) were discovered to
be size selective.
> 1960 – Although all essential aerosol sampling techniques had been
discovered and applied, no instruments survive to be useful today.
This period preceded lasers, computers, spectroscopic analysis tools.
Sampling methods:
Filtration: 1950 – membrane filters most important standard
1960 – pore filters developed (nucleopore filters).
Elutriators, Centrifuges: Particles sorted by sized based on settling
velocity (elutriators) or centrifugal force (centrifuge).
Condensation nuclei (CN) counting: Aitken’s methods improved upon.
Junge (1935) used a camera in place of a microscope. 1950s – GE lab
automated CN counters (CNCs) – Vonnegut (1947).
Ultra microscopy: Tyndall’s phenomenon used to count flashes of light
passing a slit, which is used to define the sample volume.
Tyndallometry: Measure of light scattered from all particles in a
sample volume through an angle of 30º. Nephelometer – angle increased
to ~ 170º.
Optical particle counters (OPCs): 1940s – Gucker refined the light
detector on an ultra microscope to count particles > 0.3 µm. 1960s –
commercial development – the Royco counter. 1970s - Rosen developed
the Wyoming OPC.
Mineralogical and chemical analysis – microscopy, x-ray diffraction.
Now mass spectrometers.