5. Conclusion

Hair analysis is an interesting alternative to urine and blood analysis. It widens the window of detection, and can also differentiate between single and chronic exposure. However, it is not systematic, and the reliability of hair analysis results remains controversial, due to the risk of external contamination, hair coloring biases and cosmetic treatments that can modify the incorporation and retention of molecules in the hair. This variability often leads to over-interpretation of results and differences of opinion between experts, calling into question the contribution of hair analysis as forensic evidence. ...