Health risks associated with the inhalation of airborne particles are known to
be influenced by particle size. Studies have shown that certain nanoparticles,
with diameters <100 nm, have increased toxicity relative to larger particles of
the same substance. A reliable, size-resolving sampler able to collect a wide
range of particle sizes, including particles with sizes in the nanometre range,
would be beneficial in investigating health risks associated with the
inhalation of airborne particles.
An article in the latest edition of The Annals of Occupational Hygiene
discusses this problem. A review of current aerosol samplers used for
size-resolved collection of airborne particles highlighted a number of
limitations. These could be overcome by combining an inertial deposition
impactor with a diffusion collector in a single device. Verified theories of
diffusion and inertial deposition suggested an optimal design and operational
regime. The instrument was designed for analysing mass distribution functions.
Calibration was carried out using a number of recognized techniques.
The sampler was tested in the field by collecting size-resolved samples of lead
containing aerosols present at workplaces in factories producing crystal glass.
The mass deposited on each screen proved sufficient to be detected and measured
by an appropriate analytical technique. Mass concentration distribution
functions of lead were produced. The nanofraction of lead in air varied from 10
to 70% by weight of total lead.
AplusA-online.de - Source: Annals of Occupational Hygiene