Baby teeth may hold more than childhood memories; they store chemical clues about our earliest exposures to the environment. A groundbreaking PhD thesis from the University of Bergen, authored by Synnøve Stokke Jensen, reveals how primary teeth can act as biomarkers for toxic and essential elements during critical developmental windows. The research, based on Norway’s extensive Mother, Father and Child Cohort Study (MoBa) and the MoBaTooth Biobank, offers insights that could reshape public health policy, industry standards, and academic research on neurodevelopmental disorders.
“Baby teeth are more than keepsakes—they’re chemical diaries of early life.”
The Science Behind the Smile
Traditional biomarkers like maternal blood or cord blood provide only snapshots of exposure. Jensen’s work demonstrates that primary teeth, which begin forming in the second month of foetal life and mineralize incrementally, can reconstruct exposure histories week by week. Using laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS), the study analysed 18 elements, including lead (Pb), manganese (Mn), zinc (Zn), copper (Cu), and molybdenum (Mo), in dentine from nearly 100 Norwegian children.
“Maternal blood lead levels can predict a child’s prenatal exposure, offering a new tool for prevention.”
The findings are striking. Girls showed higher postnatal levels of Mn and Zn compared to boys, suggesting sex-specific absorption patterns. Lead exposure stood out: maternal blood Pb concentrations during mid-pregnancy strongly correlated with dentine Pb levels in children (r ≈ 0.5–0.58, p < .001). This means a simple blood test during pregnancy could predict a child’s prenatal lead exposure—a breakthrough for preventive health strategies.
Autism and Environmental Clues
Perhaps the most provocative aspect of Jensen’s research is its link to autism spectrum disorder (ASD). In a nested case-control study of 170 children, time-varying differences in elemental uptake were observed between ASD cases and controls. For boys, prenatal magnesium levels were higher in ASD cases, while postnatal levels were lower. Lithium and lead also showed critical windows of divergence, with ASD cases exhibiting distinct patterns before and after birth. These findings suggest that environmental exposures, interacting with genetic predispositions, may influence neurodevelopment in ways previously underestimated.
“Environmental exposures may interact with genetics in autism risk, timing is everything.”
Implications for Policy and Industry
The policy implications are profound. If maternal blood Pb can predict foetal exposure, routine screening during pregnancy could become a cornerstone of preventive care. For industries, particularly those dealing with metals, this research underscores the urgency of minimizing environmental contamination. Regulatory bodies may need to revisit permissible exposure limits for pregnant women, while manufacturers could face pressure to reduce trace metal content in consumer products.
Academia, too, stands to benefit. The MoBaTooth Biobank, now the world’s largest repository of primary teeth linked to health data, opens new avenues for longitudinal studies on environmental health. International collaborations could leverage this resource to explore global patterns of exposure and disease.
The Road Ahead
While the study’s sample size limits generalizability, its methodological rigor sets a new standard for biomarker research. Future studies with larger cohorts and diverse populations could validate these findings and inform global health guidelines. As Jensen notes, understanding the “precise timing of toxic exposures” is key to preventing disease, a goal that resonates across public health, clinical practice, and environmental policy.
References
- Arora, M., Austin, C. (2013). Teeth as a biomarker of past chemical exposure. Current Opinion in Pediatrics, 25(2), 261–267.
- Jensen, S. S., et al. (2023). Toxic and essential trace elements in human primary teeth: A baseline study within The MoBaTooth Biobank. Environmental Advances, 13, 100418.
- Jensen, S. S., et al. (2025). Toxic and essential elements in primary teeth and maternal blood during pregnancy. Environmental Research, 274, 121316.
- Tvinnereim, H. M., et al. (2012). A biobank of primary teeth within the Norwegian Mother and Child Cohort Study. Paediatric and Perinatal Epidemiology, 26(3), 264–271.
