Elemental composition of ancient Japanese bones

Area of Science:

• Archaeometry
• Paleochemistry
• Bioarchaeology

Background:

• Investigating elemental composition of human skeletal remains provides insights into past environments and human activities.
• Japanese prehistoric and historic eras offer distinct chronological markers for analyzing long-term environmental changes.

Observation:

• Rib bone samples from 50 Japanese sites, spanning five eras (Jomon to Edo), were analyzed for 19 elements using ICP-AES and AAS.
• Calcium (Ca) and Phosphorus (P) concentrations indicate well-preserved bone mineral matrices across most samples.
• Elemental concentrations of Aluminum (Al), Boron (B), and Chromium (Cr) remained consistent across all eras.

Findings:

• Edo-era bones exhibited significantly elevated concentrations of Lead (Pb), Iron (Fe), Cobalt (Co), and Manganese (Mn).
• Kofun-era bones displayed a unique elemental profile, with the highest Cadmium (Cd), Zinc (Zn), and Magnesium (Mg), and lowest Copper (Cu), Potassium (K), Nickel (Ni), and Strontium (Sr).
• The Calcium/Phosphorus (Ca/P) ratio was lowest in the Edo group (1.48) compared to earlier periods (1.54-1.66).

Implications:

• Elevated lead levels in Edo bones suggest significant environmental lead pollution linked to human activities during that period.
• Distinct elemental profiles across Japanese historical periods highlight changes in diet, environment, and potentially industrial practices.
• This study demonstrates the utility of bone elemental analysis in reconstructing past environmental conditions and human impact.