August 7, 2002

A: FROM MENTOR MOLLY WILLIAMS. To read bio. click here.
There are several areas in which small particles are of interest.
Some of these particles are pollen, dust, soil or other debris that
comes from the wear or abrasion of surfaces (sidewalks or streets or
carpets) and from the degradation of organisms. Do you know that
we're shedding skin cells all the time? All of these little bits
contribute to the makeup of dust.

The McCrone Group was one of the first businesses devoted to
identifying small particles. The founder, Walter McCrone just died
within the last month. The website of McCrone Associates is at
http://www.mccrone.com/ma/index.html It has several case studies
that show the kinds of detective work they've done, for example
investigating the authenticity of historical relics.

Identifying small particles is of interest in some forensic
investigations. For example your clothing will pick up pollen and
other particles that are characteristic of the region you've been
in. Or there may be a need to identify particles that have
contaminated a food or pharmaceutical product in order to figure out
where the contamination occurred.

Besides optical and electron microscopy, there are other ways of
identifying particles through light scattering or spectroscopy. To
get into this area, a good background would be in chemistry and
physics.