Developing and Demonstrating a Lab Method for Quantifying Hair Exposure to Environmental Tobacco Smoke with a...

Area of Science:

• Forensic Science
• Chemistry
• Analytical Chemistry

Background:

• Forensic science curricula often lack practical experiments simulating environmental tobacco smoke (ETS) or marijuana exposure on trace evidence like hair.
• Hair is valuable trace evidence for assessing long-term environmental pollutant exposure, including ETS.

Purpose of the Study:

• To present a novel, noninvasive forensic laboratory module for evaluating ETS exposure on diverse human hair types.
• To assess the impact of hair's physical and chemical properties on its adsorption of ETS residues.

Main Methods:

• Controlled cigarette smoke exposure on untreated, dyed, and bleached human hair.
• Analysis using UV-visible spectroscopy, FTIR spectroscopy, and zeta potential measurements.
• A three-week lab module involving thirteen students with pre- and postlab assessments.

Main Results:

• Students demonstrated improved understanding of how chemical treatments affect hair's adsorption capacity for ETS.
• Measurable gains in student knowledge, technical skills, and appreciation for forensic applications were observed.
• The module effectively illustrated the influence of hair's altered properties on ETS residue adsorption.

Conclusions:

• The developed lab module is a valuable tool for teaching forensic hair analysis and assessing ETS exposure.
• This experiment enhances forensic chemistry education by connecting theoretical knowledge to practical, real-world applications.
• The findings highlight the importance of considering hair's chemical and physical characteristics in forensic investigations involving environmental pollutants.