Permanent signatures of birth and nursing initiation are chemically recorded in teeth

• DOI: 10.1016/j.jas.2022.105564
• Publication Date: 2022-02-14T11:35:49Z
• Authors: Tanya M. Smith; Christine Austin; Janaína N. Ávila; Wendy Dirks; Daniel R. Green; Ian S. Williams; Manish Arora
• Keywords: Barium

In 2013 we presented a model for identifying nursing behavior from primate teeth based on rapid postnatal concentration changes in the non-essential trace element barium. Here leverage permanent neonatal (birth) line enamel of several dozen M1 cusps to compare pre- and trends barium, zinc, strontium, oxygen, as each is believed evince developmental patterning. Barium zinc are most consistent biomarkers initiation; majority shows increases prenatal enamel, whereas strontium decreases or no change with similar frequency. Exceptions pattern barium increase occurred that had been mineralizing less than three weeks, suggesting subsequent maturation has only minor impact detecting real time events. Oxygen isotope compositions (δ18O) show marked fluctuations (∼1–2‰) within two weeks birth 93% (n = 27/29). This likely due measurements hypomineralized perinatal physiological body water newborn infants. Ongoing work integrating elemental gradients isotopic variation will help establish degree which milk intake may cause elevated δ18O teeth. We chemical identification pre-to transitions be robust slight planar deviations commonly obscure growth increments under light microscopy, could validate potential lines, making this approach useful complement bioarchaeological studies public health investigations.