768: Eugenia Mirica, PhD, EMSL Labs - Laboratory Methods for Wildfire Impact Assessment

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12:01:09 From Don Weekes : Hello, Eugenia! I have worked with EMSL for many years.
13:01:37 From Don Weekes : Semi-volatile soot refers to carbonaceous particles that are partially burned and can dissolve in solvents used in analytical methods. These particles are often found in the combustion of hydrocarbon fuels and can contain various organic compounds.
Composition: Semi-volatile soot can dissolve in solvents during analysis, which can lead to significant losses in sample integrity.
13:03:29 From Don Weekes : https://eaalab.com/wp-content/uploads/2 ... -14-21.pdf THE LIMITATIONS OF USING THE ASTM 6602-13 METHOD FOR THE ANALYSIS OF WILDFIRE AND STRUCTURE FIRE RESIDUES
13:09:30 From Spurgeon : The example zone A & B data are lognormally distributed, do GM & GSD are the descriptive parameters.

[Brad Prezant]

Not much discussion around reflected darkfield microscopy. It is pretty much garbage if a lab is only looking at transmitted light and not looking at reflected dark field light in judging whether something is char or ash. No mention of assemblage analysis (though that is in the AIHA 2nd edirtion), which at least from the article by Crutcher and Kovar suggests is a more reliable method than soot and char estimated % analysis (chart from article attached). I would guess EMSL and many other labs do not do assemblage analysis nor has the skills in their microscopy group to identify what AIHA calls "fire-indicator signature particles" - didn't hear that term in this webinar...

I don't know if Dan Baxter's statistical approach is valid, as far as I know it hasn't been published for peer review other than AIHA 2nd edition, but it is a good start at making sense of the data and should not be dismissed just because it is "hard to understand" So is control banding and Bayesian statistics.

Every lab wants to jump on bandwagon of doing this type of analysis but few really seem to understand the more reliable ways of doing this and technical requirements, and experience, primarily because the skills required are at a very high level and do not lend themselves to quick turnaround by persons of limited training (e.g., asbestos labs and asbestos analysts).