Revealing details of stays abroad by sequential stable isotope analyses along human hair strands
Multi-element stable isotope analyses of δ13C, δ15N, δ34S and δ2H values were performed along scalp hair strands to detect isotopic changes resulting from different stays abroad. One hair strand with a hair length of more than 50 cm originated from a German woman, who frequently made long-distance travels of 1 to 4 weeks. The second hair strand with a length of 15 cm was taken from a Japanese woman who went to Germany for a period of some months. Stable isotopic influences due to the stays abroad were clearly reflected in the 5-mm segments along the proximal part of the hair strand; whereas in the more distal parts, the isotopic influences were blurred. This can be regarded as the result of the highly variable intra-individual hair growth rate of single hairs of at least ± 30% compared to the mean growth rate. Consequently, the initial isotope signal obtained by short stays abroad became rapidly attenuated in the more distal parts of the hair strand. Furthermore, decreasing sulphur content associated with higher sulphur isotope values was observed with increasing hair length. The isotope shifts along the scalp hair strand, provoked by dietary changes at new locations, appeared at such points of hair length, which correspond well with the maximum growth rate of single hairs. Consequently, the exact date for any changes coming along with isotopic shifts may be calculated by best approach considering a hair growth value of 1.4 cm per 30 days, instead of the commonly used mean monthly hair growth rate of 1.1 cm. This may be important in forensics, if detailed information about a person’s recent lifetime should be figured out by segmental scalp hair analyses.
KeywordsStable isotopes Human scalp hair Sequential analyses Stay abroad Unknown individuals
We are deeply thankful to the two women who were taking part in our study by donating their hair strands and providing information about the travels they had undertaken.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- 10.Petzke KJ, Lemke S (2009) Hair protein and amino acid 13C and 15N abundances take more than 4 weeks to clearly prove influences of animal protein intake in young women with a habitual daily protein consumption of more than 1 g per kg body weight. Rapid Commun Mass Spectrom 23(16):2411–2420CrossRefGoogle Scholar
- 12.Pragst F, Rothe M, Spiegel K, Sporkert F (1998) Illegal and therapeutic drug concentrations in hair segments-a timetable of drug exposure? Forensic Sci Rev 10(2):81–111Google Scholar
- 17.Wilson AS (2005) Hair as a bioresource in archaeological study. Hair Toxicol: Important bio-monitor:321–344Google Scholar
- 24.Lehn C, Graw M (2017) Haare, Zähne und Knochen – Über Isotopenanalysen zu Lebensdaten. In: Rosendahl W, Madea B (eds) Tatorte der Vergangenheit. Archäologie und Forensik, Konrad Theiss Verlag, Darmstadt, pp 85–91Google Scholar
- 28.Britton K, McManus-Fry E, Nehlich O, Richards M, Ledger PM, Knecht R (2016) Stable carbon, nitrogen and sulphur isotope analysis of permafrost preserved human hair from rescue excavations (2009, 2010) at the precontact site of Nunalleq, Alaska. J Archaeol Sci: ReportsGoogle Scholar
- 30.Meier-Augenstein W (2018) Stable isotope forensics: methods and forensic applications of stable isotope analysis, 2nd edn. Wiley, pp 333–400Google Scholar
- 32.Remien CH, Sussman NL, Adler FR (2013) Mathematical modelling of chronic acetaminophen metabolism and liver injury. Math Med Biol (3):302–317Google Scholar
- 35.Sieper HP, Kupka HJ, Williams T, Rossmann A, Rummel S, Tanz N, Schmidt HL (2006) A measuring system for the fast simultaneous isotope ratio and elemental analysis of carbon, hydrogen, nitrogen and sulfur in food commodities and other biological material. Rapid Commun Mass Spectrom 20(17):2521–2527CrossRefGoogle Scholar
- 43.Bowen G. Waterisotopes.org. Accessed 16 January 2018
- 46.Robbins CR (2012) Chemical composition of different hair types. In: Chemical and physical behavior of human hair. Springer, pp 105–176Google Scholar