Baby Teeth, Environmental Chemicals, and Autism: What Does the Research Really Tell Us?
Recent scientific literature evaluates a pilot case-control study exploring the connection between environmental chemicals and autism spectrum disorder through the analysis of shed baby teeth. While researchers detected higher concentrations of various substances like plasticizers and pesticides in the dental tissues of autistic children, experts emphasize that this small observational study only shows an association rather than definitive causation. The texts explain how primary teeth serve as valuable biological archives of early life exposure, yet caution against jumping to conclusions due to methodological limitations and small sample sizes. Ultimately, the reviews urge parents and educators to focus on reasonable precautionary steps to reduce hazard exposures without creating unnecessary fear, blaming families, or misinterpreting neurodiversity.
A Reading Sage Literature Review on Early-Life Chemical Exposure, Developmental Neuroscience, and the Limits of a Small Pilot Study
By Sean Taylor, M.Ed. | Reading Sage
Introduction: What Can a Baby Tooth Tell Us About Early Childhood Development?
A child's shed baby tooth may look like an ordinary childhood keepsake. To an environmental health researcher, however, it can serve as a remarkable biological archive.
As primary teeth develop during pregnancy and early childhood, some substances circulating in the body can become incorporated into dental tissues. Researchers can analyze these tissues years later to investigate aspects of a child's earlier environmental exposures. Unlike a single blood or urine sample, which typically reflects a more limited period, a developing tooth can preserve evidence of exposure across a longer developmental window.
This approach has become particularly relevant to research into autism spectrum disorder (ASD), a complex neurodevelopmental condition influenced by multiple genetic and developmental factors.
In August 2026, researchers affiliated with the University of Texas at San Antonio published a pilot case-control study titled A Pilot Autism Case-Control Study of Pesticides and Plasticizers in Shed Baby Teeth in the journal Neurotoxicology and Teratology. The findings attracted attention because researchers detected higher concentrations of most of the chemicals examined in teeth from children with autism than in teeth from typically developing children.
The study raises important questions about early-life exposure to pesticides, plasticizers, flame-retardant-related compounds, fragrance ingredients, and other substances found in everyday environments.
But an important scientific distinction must guide the discussion:
An association between chemical concentrations and autism is not proof that the chemicals caused autism.
The results are a reason to investigate environmental exposures more carefully—not a reason to blame parents, stigmatize autistic children, or conclude that ordinary household products have been shown to cause autism.
This literature review examines the study, the science of tooth-based exposure biomarkers, the broader environmental-health literature, the limitations of current evidence, and practical implications for parents, teachers, and early-childhood professionals.
1. The 2026 UT San Antonio Study: What Did Researchers Find?
The study by Lynne P. Heilbrun and colleagues examined shed primary teeth donated by families of 38 children. The sample included 22 children with autism and 16 typically developing controls.
Researchers used two-dimensional gas chromatography coupled with time-of-flight mass spectrometry, an analytical technique that can identify and measure numerous chemical compounds within complex samples.
Rather than testing only a small, predetermined list of chemicals, the researchers used a broad analytical approach to investigate chemical exposure patterns.
Key findings
| Finding | What the researchers reported |
|---|---|
| Participants | 38 children: 22 with autism and 16 controls |
| Compounds examined in the main comparison | 60 compounds detected in more than half of participants |
| Compounds with higher concentrations in the autism group | 57 of 60, or 95% |
| Compounds significantly higher in the autism group | 19 of 60 |
| Compounds classified as developmental toxicants or endocrine disruptors | 39 of 60 |
| Compounds lacking EPA developmental-toxicity data | 21 of 60 |
| Notable potential exposure sources | Baby-product materials, food-contact materials, PEX tubing, fragrances, and flame-retardant-related products |
Source: Heilbrun et al., 2026, Neurotoxicology and Teratology. DOI: 10.1016/j.ntt.2026.107710.
The distinction between the 57 compounds with higher measured concentrations and the 19 statistically significant differences is important. The first figure describes the direction of the observed differences; the second identifies the subset meeting the study's statistical significance threshold.
The findings suggest a possible difference in early-life chemical exposure profiles between the two groups. They do not demonstrate that every compound was harmful at the measured concentration, nor that every child with autism experienced the same exposures.
Why the results deserve attention
The study's significance lies partly in its examination of multiple chemicals together. Children do not encounter environmental substances one at a time in carefully controlled laboratory conditions. They live in environments containing mixtures of substances from food, air, water, household products, building materials, and personal care products.
Researchers need better methods to understand these combined exposure patterns, particularly during periods of rapid development.
Nevertheless, this was a small exploratory study. Its findings should be interpreted as preliminary evidence requiring replication, not as a definitive explanation for autism.
2. Baby Teeth as Biological Archives: The Science of Exposure Biomarkers
One of the most interesting aspects of this research is its use of deciduous teeth as biological exposure records.
Primary teeth begin developing before birth. Different teeth form and mineralize on different schedules, with development continuing into early childhood. During this process, certain substances or their metabolites can become incorporated into dental tissues.
After the tooth is shed, researchers can examine those retained chemical signatures.
How this differs from blood and urine testing
Blood and urine testing remain valuable tools for measuring chemical exposure. However, many substances are metabolized and eliminated relatively quickly. A sample collected today may not reliably reconstruct exposure that occurred months or years earlier.
Tooth analysis offers a different perspective:
Blood and urine: Often provide information about relatively recent exposure, depending on the substance and test.
Baby teeth: Can preserve information about certain exposures during the period when the tooth formed.
Repeated or time-resolved measurements: When validated methods are available, these may help researchers distinguish exposure patterns across developmental periods.
A tooth is not a perfect chemical diary. The substances that can be detected depend on the analytical method, their chemical properties, the tissue examined, and how the tooth was collected and processed. Some measurements may reflect exposure over a broad period rather than identify a precise day or month.
The researchers' description of teeth as a long-term exposure record is therefore useful, provided we do not interpret it as a complete record of every chemical a child encountered.
Why timing matters in developmental research
Prenatal and early-childhood development involve rapid changes in the brain, nervous system, immune system, and endocrine system. Environmental-health researchers investigate whether exposure to particular substances during sensitive developmental periods can alter biological processes.
A tooth-based biomarker can help researchers ask more precise questions about timing and exposure. It cannot, by itself, establish what happened in the brain or whether a particular exposure caused a later developmental outcome.
That distinction is central to interpreting this study responsibly.
3. Which Chemical Groups Were Identified?
The 2026 investigation examined compounds associated with several broad categories of products and environmental sources. These categories are not interchangeable: chemicals within the same category can have very different properties, exposure levels, and toxicological profiles.
A. Phthalates and other plasticizers
Plasticizers are substances added to some materials to change flexibility, durability, or other physical properties. Phthalates are one group of plasticizers, although not all plasticizers are phthalates.
Some phthalates have been investigated for their potential to interfere with endocrine signaling and affect reproductive or developmental processes. Research has also examined associations between prenatal exposure to certain phthalates and childhood neurodevelopmental outcomes.
However, evidence varies by individual chemical, exposure level, developmental window, and outcome measured. An association involving one phthalate cannot automatically be applied to every plasticizer or every plastic product.
B. Pesticides and related compounds
Certain pesticides are established toxicants, and some can affect the developing nervous system. The potential health effects depend on the particular compound, dose, route of exposure, and timing.
Observational research has investigated whether prenatal exposure to certain pesticides is associated with an increased likelihood of autism or other developmental differences. These studies contribute to an important research field, but they do not establish that all pesticides have the same effects or that pesticide exposure explains autism in an individual child.
C. Organophosphate esters and flame-retardant-related compounds
Organophosphate esters are a broad chemical group used in some flame retardants, plasticizers, and other applications. Some compounds in this group have attracted attention because of possible effects on neurodevelopment, hormones, or other biological systems.
Finding a compound associated with a product category does not necessarily identify the exact product from which a child was exposed. Several sources can contribute to exposure, and a chemical may have multiple uses.
D. Fragrance ingredients, preservatives, and other household chemicals
The study also identified compounds associated with fragrances, food preservatives, personal care products, and cleaning-product ingredients or their manufacturing processes.
The presence of a chemical in a fragrance or preservative does not establish that its use in every product is dangerous. Safety depends on the individual substance, concentration, route of exposure, and relevant toxicological evidence.
A further challenge is that chemical databases do not contain equally complete developmental-toxicity information for every compound. Missing data mean that uncertainty remains; they do not automatically establish that a substance is either safe or harmful.
E. Benzyl benzoate and baby-product materials
Benzyl benzoate was among the compounds receiving attention in media coverage because its measured concentration was substantially higher in the autism group.
The study and its accompanying reporting also identified compounds previously reported to migrate from baby-bottle components. Five of the nine compounds that best differentiated the groups were associated with migration from baby bottles.
These observations are scientifically interesting, but they do not prove that baby bottles were the source of the chemicals in any particular child's teeth. Similar compounds can occur in multiple products and environments, and the study was not a controlled experiment assigning children to different products.
The appropriate conclusion is that potential exposure pathways warrant further investigation.
4. What Does the Broader Scientific Literature Say?
The 2026 findings should not be evaluated in isolation. They belong to a broader body of research examining environmental exposures, early development, autism, and the usefulness of biological samples for reconstructing exposure histories.
A. Earlier research using primary teeth
Palmer's 2024 study, An Exploratory Investigation of Organic Chemicals Detected in Baby Teeth: Differences in Children with and without Autism, examined teeth from 22 children with autism and 20 typically developing children.
The researchers reported a higher average number of identified compounds in the autism group. Many of the chemicals belonged to categories such as plasticizers, pesticides, preservatives, and substances associated with fragranced products.
The study supports the feasibility of using primary teeth to investigate organic chemical exposure. It also shares important limitations with the newer research: small samples, observational comparisons, and uncertainty about why the groups differed.
The 2024 and 2026 investigations should be treated as separate studies rather than as interchangeable reports of the same sample. Their analytical approaches and study populations differ.
B. Earlier tooth studies of metals
Research has also used baby teeth to investigate exposure to metals, including lead, manganese, and zinc.
The National Institute of Environmental Health Sciences summarizes research comparing children with autism with their unaffected twins. Some studies have reported differences in the timing or levels of metal deposition in primary teeth.
This literature is relevant because it demonstrates how teeth can help researchers investigate developmental exposure patterns that may be difficult to reconstruct using a single blood sample.
However, metals and organic compounds are different chemical classes. Findings about lead, manganese, or zinc cannot be used as direct proof of a causal relationship between pesticides or plasticizers and autism.
C. Environmental exposure and neurodevelopment
The broader environmental-health literature has investigated several possible contributors to developmental outcomes, including particular pesticides, air pollutants, endocrine-disrupting chemicals, and certain metals.
The strength of evidence differs considerably across exposures. Some substances are established developmental hazards under particular conditions; evidence connecting a specific exposure to autism is often less conclusive.
It is important to distinguish three questions:
Can a chemical affect a biological system under certain conditions?
Is a particular exposure associated with a developmental outcome in human populations?
Does that exposure cause the outcome, independently or in combination with other factors?
The answer to the first question does not automatically answer the second or third.
A chemical's ability to harm the nervous system at a particular dose is important toxicological information. It does not establish that the dose experienced by a particular child was sufficient to produce an effect, or that the effect would specifically be autism.
D. Genetic and environmental contributions
Autism is a heterogeneous neurodevelopmental condition with substantial genetic contributions and complex developmental pathways. Researchers continue to investigate how genetic susceptibility and environmental factors may interact.
A gene-environment interaction is a scientific hypothesis that some exposures may have different effects depending on an individual's genetic or biological characteristics. It is not evidence that the 2026 tooth study identified such an interaction.
To demonstrate one, researchers would need appropriate genetic information, reliable exposure measurements, adequately powered analyses, and independent replication.
The National Institute of Environmental Health Sciences provides a useful overview of current research on autism and environmental factors: https://www.niehs.nih.gov/health/topics/conditions/autism.
5. The Critical Question: Association or Causation?
The central scientific limitation of the 2026 study is that it compared chemical measurements in children with and without autism after their teeth had formed. It did not experimentally manipulate exposure, and it cannot establish that the measured differences preceded the developmental processes associated with autism.
Several explanations remain possible.
Hypothesis 1: Some exposures may contribute to developmental risk. Certain environmental substances may influence biological processes relevant to neurodevelopment. This possibility deserves careful investigation for individual chemicals and exposure levels.
Hypothesis 2: Children may differ in chemical metabolism or elimination. If individuals process particular substances differently, concentrations measured in biological tissues may differ even when their external exposures are similar. This is a hypothesis, not an established explanation for the findings.
Hypothesis 3: The groups may differ in exposure sources or circumstances. Diet, housing, geography, household products, occupational exposures affecting parents, and other factors can influence environmental exposure patterns.
Hypothesis 4: Multiple factors may contribute to the observed differences. Chemical mixtures, individual biological differences, socioeconomic circumstances, and other unmeasured variables may influence the results.
Hypothesis 5: Some differences may reflect chance or analytical uncertainty. When researchers compare many compounds in a small sample, the possibility of false-positive findings increases. Independent replication and appropriate statistical methods are essential.
These explanations are not mutually exclusive. The present study cannot determine which, if any, account for the observed pattern.
Why 19 statistically significant findings are not 19 proven causes
Statistical significance is a measure of how compatible observed data are with a specified statistical model. It does not establish causation, clinical importance, or the probability that a chemical caused autism.
When many compounds are tested, multiple-comparison issues become particularly important. Unless adequately addressed, testing many substances can increase the likelihood that some will appear statistically significant by chance.
The study's findings should therefore be viewed as a set of signals to investigate, rather than a list of 19 established autism-causing chemicals.
The size of a difference also needs careful interpretation. A large percentage difference between two groups can attract attention, but without adequate information about the absolute concentration, measurement uncertainty, toxicological threshold, and relevant exposure period, it cannot independently tell us whether a measured level was harmful.
6. What the Study Cannot Tell Us
A responsible review must make the limitations explicit.
First, the sample was small. Thirty-eight children are not enough to establish that the observed chemical patterns apply broadly to all autistic children or to different populations.
Second, the research was observational. It cannot show that exposure caused autism, and it cannot establish the direction of the relationship between the measured concentrations and the developmental outcome.
Third, the study did not identify the source of every chemical. Detecting a substance that can migrate from a baby bottle does not establish that a particular child used a bottle containing that substance or that the bottle was the source of the measured exposure.
Fourth, exposure measurements are not equivalent to measurements of harm. Detection establishes that a substance or chemical signature was present in the analyzed sample. It does not establish that the concentration caused injury or affected a child's development.
Fifth, the study does not identify an individual diagnostic test. Baby-tooth chemical analysis is a research method, not a validated clinical test for diagnosing autism, determining its cause, or guiding treatment.
Finally, the findings cannot be generalized to all plastics, pesticides, fragrances, or preservatives. Each compound requires its own evidence-based assessment.
These limitations do not make the study unimportant. They define what researchers need to do next.
7. Why This Research Matters to Parents and Educators
Environmental health is relevant to early childhood education because children grow and learn within physical environments that influence their health and well-being.
Teachers and parents can reasonably support efforts to reduce established environmental hazards, improve indoor air quality, prevent unsafe pesticide exposure, and ensure access to clean drinking water. Such measures benefit children's health without requiring claims that a specific chemical causes autism.
At the same time, educators should be careful not to interpret an autistic child's behavior, communication differences, sensory preferences, or learning profile as evidence of toxic exposure.
Autism is not a diagnosis that can be inferred from a child's behavior in a classroom, nor can it be attributed to a household product based on this research.
For Reading Sage, the educational implication is straightforward: developmental science should encourage better questions, more careful observation, and informed decision-making—not fear-based explanations of children's differences.
A practical, proportionate approach to reducing exposure
Families who want to reduce avoidable chemical exposures can consider reasonable precautions:
Follow public-health guidance for pesticide use, including label instructions and appropriate re-entry intervals.
Avoid heating food in containers not designed for that use, and follow the manufacturer's instructions for food-contact products.
Use fragrance-free personal care or cleaning products when preferred, particularly if fragrance causes irritation or symptoms.
Follow local drinking-water advisories and use appropriately certified treatment systems when testing identifies a problem.
Wash produce under running water and follow food-safety guidance rather than relying on unproven detoxification methods.
Ask healthcare professionals or public-health agencies about specific, credible exposure concerns instead of ordering unvalidated commercial toxin tests.
These steps are precautionary measures, not proven methods of preventing autism. Families should not feel compelled to discard every plastic item, purchase expensive specialty products, or undertake restrictive diets based on this pilot study.
Most importantly, parents should never be blamed for a child's autism because they used a particular bottle, lotion, food container, or household product. The research does not support that conclusion.
8. What Should Researchers Do Next?
The next stage of this research should move beyond identifying differences and begin testing explanations for them.
Priority 1: Replicate the findings in larger populations
Independent research teams should examine larger, more diverse groups of children. Replication would help determine whether the same chemicals and exposure patterns consistently differ between groups.
Priority 2: Improve the timing of exposure measurements
Researchers should use validated methods to determine which developmental periods the chemical signatures represent. When possible, tooth measurements could be combined with pregnancy records, repeated biological samples, and environmental monitoring.
Priority 3: Measure relevant confounding variables
Studies should collect information about diet, housing, geography, socioeconomic circumstances, parental occupational exposures, medication use, and other factors that could influence chemical exposure patterns.
These variables must be considered carefully rather than assuming that the chemical differences themselves explain the developmental outcome.
Priority 4: Improve chemical identification and toxicological assessment
Researchers should distinguish confirmed chemical identities from tentative analytical matches, report measurement uncertainty, and evaluate the biological relevance of measured concentrations.
They should also clarify when a compound has demonstrated developmental toxicity, when evidence is limited to laboratory studies, and when relevant data are missing.
Priority 5: Examine mixtures rather than isolated substances alone
Children encounter combinations of chemicals, and the effects of mixtures may differ from those of individual compounds. More advanced statistical and toxicological approaches can help identify exposure patterns that deserve further study.
Priority 6: Investigate possible biological mechanisms
Research can examine whether particular exposures influence pathways involved in neurodevelopment, hormone signaling, inflammation, or cellular energy metabolism. Such work must connect laboratory findings with realistic human exposures and well-designed population studies.
Priority 7: Separate autism risk research from individual diagnosis
Even if future studies identify an environmental exposure that contributes to autism risk at a population level, that would not mean the exposure explains every autistic person's development.
Research should improve prevention of established hazards, deepen understanding of developmental biology, and support autistic people and their families—not create a search for blame.
9. The Reading Sage Perspective: Protect Children's Health Without Pathologizing Difference
The most useful response to emerging environmental-health research is neither dismissal nor alarmism.
We should not dismiss evidence that children encounter numerous environmental chemicals or that some exposures can harm development. Public health has a legitimate role in identifying hazards, evaluating exposure, and reducing preventable harm.
But we must also resist the temptation to turn a small observational study into a simple explanation for a complex neurodevelopmental condition.
Autistic children are not a uniform group. They have different strengths, support needs, communication styles, sensory experiences, and developmental trajectories. Their educational needs cannot be understood through a chemical exposure profile.
For teachers, the immediate responsibility remains to create learning environments that are safe, responsive, and accessible. That means observing the individual child, adapting instruction, providing communication supports, and helping children participate meaningfully in school and community life.
Environmental research can complement that work. It should never replace individualized educational planning or respectful understanding of neurodiversity.
A thoughtful public conversation can hold two ideas at once: reducing harmful environmental exposures is a worthwhile public-health goal, and autistic children deserve support and acceptance regardless of what future research discovers about the causes of autism.
Conclusion: A Promising Research Tool, Not a Final Answer
The 2026 University of Texas at San Antonio study offers an intriguing contribution to environmental-health research. In a small sample of shed baby teeth, researchers observed higher concentrations of 57 out of 60 frequently detected compounds in the autism group, with 19 differences reaching statistical significance.
The use of primary teeth provides a potentially valuable way to investigate chemical exposures across early developmental periods. The findings also highlight gaps in knowledge about the chemicals found in everyday environments and the need for more comprehensive exposure assessment.
However, the study does not demonstrate that the identified compounds caused autism, that baby bottles were responsible for individual children's exposures, or that reducing exposure to these compounds would prevent autism.
Those are questions for future research.
For parents and educators, the sensible response is to support evidence-based environmental health protections, seek reliable information about specific hazards, and avoid unnecessary fear or blame.
For researchers, the task is to replicate the findings, improve exposure measurements, account for alternative explanations, and investigate the biological significance of the observed differences.
For schools, the responsibility remains clear: protect children's health, respect developmental differences, and provide every child with the opportunity to learn and thrive.
Reading Sage takeaway: Follow the evidence, reduce established environmental hazards, and follow the child. Good science should expand our understanding—not narrow our compassion.
This is an important topic for Reading Sage, especially because it sits at the intersection of developmental neuroscience, environmental health, early childhood development, and the need to distinguish scientific evidence from popular claims. The strongest version of this article will examine the baby-teeth study alongside the broader literature, explain what the findings do and do not establish, and give parents and educators practical guidance without creating unnecessary fear or implying that autism is caused by a particular product or parenting choice.
One important distinction up front: finding higher chemical concentrations in the teeth of children with autism does not establish that those chemicals caused autism. Researchers must still determine when exposure occurred, whether it preceded the development of autism-related traits, how the chemicals affect the developing brain, and whether the findings can be replicated in larger populations.
Reading Sage · Research review · October 2026
References and Further Reading
Heilbrun, L. P., Han, I., Rodriguez, A., Shay, L. A., & Gimeno Ruiz de Porras, D. (2026). A pilot autism case-control study of pesticides and plasticizers in shed baby teeth. Neurotoxicology and Teratology, 117, 107710. https://doi.org/10.1016/j.ntt.2026.107710
Palmer, R. F. (2024). An Exploratory Investigation of Organic Chemicals Detected in Baby Teeth: Differences in Children with and without Autism. Journal of Xenobiotics, 14(1), 404–415. https://doi.org/10.3390/jox14010025
National Institute of Environmental Health Sciences. Autism. https://www.niehs.nih.gov/health/topics/conditions/autism
Heilbrun, L. P., et al. (2015). Organic Compounds Detected in Deciduous Teeth: A Replication Study from Children with Autism in Two Samples. PubMed record: https://pubmed.ncbi.nlm.nih.gov/26290670/
Editorial note: This article is an educational review of published research, not medical advice. The 2026 tooth study is preliminary and does not establish causation. Families with specific concerns about environmental exposures should consult qualified healthcare or public-health professionals.
Research sources verified for this review
Original 2026 study: A Pilot Autism Case-Control Study of Pesticides and Plasticizers in Shed Baby Teeth — the peer-reviewed paper published in Neurotoxicology and Teratology.
ScienceDirect+1University research summary: UT Health San Antonio's report on the findings.
UT Health San AntonioEarlier research: 2024 exploratory study of organic chemicals in baby teeth.
PMCEnvironmental health background: National Institute of Environmental Health Sciences: Autism.
NIEHS
The article is structured as a literature review rather than a sensational news recap, with the central findings, earlier research, methodological limitations, implications for families and educators, future research priorities, and references.
One editorial recommendation for Reading Sage: keep the headline focused on what researchers found and what remains unknown. That framing will help the article reach parents and educators while maintaining scientific credibility.
