Temporal Assessment of DNA Shedding from Human Hands After Handwashing: Implications for Touch DNA Recovery

Abstract

This study examines the temporal dynamics of DNA shedding from human hands following handwashing, with a focus on its implications for forensic touch DNA recovery. The research investigates fluctuations in DNA levels over time post-handwashing and highlights significant individual differences in shedding patterns. Statistical analysis revealed that DNA recovery levels at 30 minutes post-handwashing were significantly higher than those at 5 minutes (p < 0.01), demonstrating rapid DNA reaccumulation. Male participants shed significantly more DNA than female participants on average (p < 0.01), underscoring a potential influence of gender on DNA shedding tendencies.

Results further emphasized the challenges of accurately categorizing individuals as "high," "medium," or "low" shedders, although the methodology provided a robust framework for assessing shedding abilities. This variability in DNA shedding rates has critical forensic implications, particularly regarding the timing of evidence collection and the interpretation of touch DNA evidence. By accounting for these individual differences, forensic professionals can improve the accuracy and reliability of DNA analysis, ultimately strengthening forensic investigations.

Future research should explore additional factors influencing DNA shedding, including skin type, ethnicity, and long-term activity levels. Investigating the effects of different handwashing agents, environmental conditions, and extended timelines on DNA recovery could further refine forensic methodologies, enhancing the utility of touch DNA evidence in forensic science.