Dating human skeletal remains using 90Sr and 210Pb: case studies

Area of Science:

• Forensic Science
• Radiometric Dating
• Anthropology

Background:

• Determining post mortem interval (PMI) for skeletal remains is crucial in legal medicine, often relying on forensic anthropologist experience.
• Existing radiometric methods like carbon-14 (14C) and strontium-90 (90Sr) bomb pulse dating, thorium-232 (232Th) series dating, and lead-210 (210Pb) dating have limitations.
• The PMI of interest in legal medicine typically covers the last 50 years.

Purpose of the Study:

• To determine the PMI of 29 forensic cases using strontium-90 (90Sr) bomb pulse dating.
• To enhance PMI accuracy by combining 90Sr dating with lead-210 (210Pb) dating in 12 cases.
• To compare radiometric results with traditional anthropological investigations in 15 cases.

Main Methods:

• Application of strontium-90 (90Sr) bomb pulse dating to 29 human skeletal remains.
• Utilized lead-210 (210Pb) dating as a supplementary method to narrow PMI uncertainty.
• Conducted anthropological investigations on 15 cases to validate radiometric findings.

Main Results:

• Strontium-90 (90Sr) bomb pulse dating successfully excluded 10 cases from forensic interest due to a PMI exceeding 50 years.
• The addition of lead-210 (210Pb) dating reduced PMI uncertainty to within a few years for 10 cases.
• Anthropological assessments corroborated the radiometric PMI results in 15 investigated cases.

Conclusions:

• Radiometric dating, particularly 90Sr bomb pulse dating, is effective in assessing PMI for skeletal remains within the last 60 years.
• Combining 90Sr and 210Pb dating offers improved accuracy for PMI determination in forensic contexts.
• Diagenesis and individual variations in radionuclide uptake are key factors influencing the uncertainty of radiometric PMI estimations.