Related Experiment Video
Updated: Aug 5, 2026
Long-term Behavioral and Reproductive Consequences of Embryonic Exposure to Low-dose Toxicants
Published on: March 6, 2018
A pilot autism case-control study of pesticides and plasticizers in shed baby teeth
Lynne P Heilbrun1, Inkyu Han2, Anabel Rodriguez3
1Department of Environmental and Occupational Health, Kate Marmion School of Public Health, The University of Texas at San Antonio, 8403 Floyd Curl Drive, San Antonio, TX 78229, USA.
Insights
Long-term pesticide and plasticizer exposure, measured in baby teeth, was higher in children with autism. These chemicals, including flame retardants and fragrance compounds, are linked to developmental toxicity and may contribute to autism.
Area of Science:
- Environmental Health
- Toxicology
- Developmental Pediatrics
Background:
- Pesticides and plasticizers are linked to neurotoxicity and autism characteristics.
- Teeth provide a unique window into long-term chemical exposures from in-utero through early childhood, unlike short-term urine or blood samples.
Purpose of the Study:
- To investigate cumulative pesticide and plasticizer exposures in shed baby teeth of children with and without autism.
- To identify specific toxicants associated with autism spectrum disorder (ASD).
Main Methods:
- Utilized two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GCxGC-TOFMS) for comprehensive targeted and non-targeted analysis.
- Analyzed shed baby teeth from 38 children (cases and controls).
- Confirmed compound identification using standards and spectral library matching.
Main Results:
- Sixty compounds were detected in over 50% of participants.
- Ninety-five percent (57/60) of detected compounds were higher in children with autism (cases) compared to controls.
- Nineteen compounds were statistically significantly elevated in cases, including known developmental toxicants and endocrine-disrupting compounds like benzyl benzoate and organophosphate esters.
Conclusions:
- Elevated levels of specific pesticides and plasticizers detected in baby teeth suggest a link between long-term exposure and autism.
- Many identified compounds are common in consumer products and migrate from items like baby bottles.
- Further large-scale case-control studies are needed to confirm these findings and understand the impact of long-term toxicant exposure on autism development.
Abstract:
Even moderate exposures to pesticides and plasticizers have been associated with neurotoxicity and autism characteristics; however, most studies of urine and blood provide a short-term exposure window compared to teeth, which capture long-term exposures from 13-14 weeks in-utero through early childhood. We investigated cumulative pesticide and plasticizer exposures in shed baby teeth from children with and without autism using a comprehensive targeted and non-targeted analysis with two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GCxGC-TOFMS). Compound identification was confirmed with standards and high-fidelity spectral library matches. Sixty compounds were detected in more than 50% of participants (n = 38). Of these, 95% (57/60) were higher in cases compared to controls, and 19/60 were statistically significantly elevated. Thirty-nine of the 60 compounds detected are known developmental toxicants or endocrine-disrupting compounds. To date, 21/60 compounds lack Environmental Protection Agency (EPA) developmental toxicity data. Compounds exhibiting higher levels in cases than in controls include benzyl benzoate (fragrance and food preservative) and organophosphate esters, which are frequently found in flame retardants and other baby products, PEX tubing, food contact materials, and products applied to the skin. Interestingly, five of the top nine compounds that differentiated cases from controls migrate from baby bottles. Elevated levels of toxicants in autism cases in our pilot study highlight a need for larger case-control studies to understand the effects of long-term exposure on autism.
