External Post Mortem Artefact: A Key Issue in Hair Result Interpretation

The study highlighted the challenges in interpreting hair test results due to potential external contamination, particularly in post mortem cases. It presented three cases where drugs were detected in hair samples, despite no history of drug use, suggesting contamination from environmental sources or body fluids. The research demonstrated that standard decontamination procedures were insufficient to remove such contamination, as evidenced by homogenous drug concentrations across hair segments. The study concluded that single hair test results should not be used to infer long-term drug exposure, and the presence of metabolites should not be relied upon for discrimination, as they can also originate from putrefactive material.