Page 16 - CleanScience_Fall22

16 | The Cleaning Industry Research Institute
FALL 2022
Characterization of Wildfire Smoke Residues in Residential Properties
By Joe C. Spurgeon, PhD, Franco Seif, and Euginia Mirica, PhD
INTRODUCTION
T􏰀􏰁 􏰃􏰄􏰅􏰃􏰆􏰇􏰁 􏰆􏰈 􏰉􏰀􏰁 􏰇􏰉􏰄􏰊􏰋 􏰌􏰍􏰇 􏰉􏰆 􏰎􏰀􏰍􏰅􏰍􏰎􏰉􏰁􏰅􏰏􏰐􏰁 􏰉􏰀􏰁 effects of selected parameters on the evaluation of 􏰌ild􏰑re smo􏰒e residues 􏰌hen evaluatin􏰓 their
impact on structures, primarily residential properties 􏰔ut other structures as 􏰌ell􏰕 The study included 􏰌ild􏰑re smoke residue samples that were collected from houses that were potentially impacted 􏰔y various wild􏰑res in northern California. The parameters included the frequency with which a residue was detected, the distance of the site from the wild􏰑re, the elapsed time 􏰔etween the inspection and the wild􏰑re, the effect of samplin􏰓 location in the structure, the effects of sampling method, and the numerical guideline for evaluating if a structure had 􏰔een impacted 􏰔y wild􏰑re smoke residues.
Rationale for Sampling Method
In practice, wet wipes may perform better than tape lifts for sampling hard surfaces.1 In addition, wet wipes may be the preferred residue sampling method within the industry.2 􏰖bout 􏰗􏰘􏰙 of the wild􏰑re smoke residue samples submitted to the EMSL facility in Cinnaminson, 􏰚􏰛 were wipes, 1􏰘􏰙 were tape lifts, and 1􏰘􏰙 were micro􏰜vacuum samples. 􏰖t EMSL􏰝s 􏰞asadena, C􏰖 facility, 􏰟􏰘􏰙 of the samples were wipes, 2􏰠􏰙 were tape lifts, and 􏰠􏰙 were micro􏰜vacuums.
The wet􏰜wipe sampling method offered several poten􏰜 tial advantages for collecting wild􏰑re smoke residues, especially since char was expected to be the dominant wild􏰑re smoke residue.1
First, the method could be applied to both smooth and intricate hard surfaces, as well as heavily loaded surfaces. Second, the sample preparation step increased homogeneity of subsamples for analysis by optical microscopy, which reduced analytical