An Exploratory Investigation of Organic Chemicals Detected in Baby Teeth: Differences in Children with and without Autism

Abstract

Autism spectrum disorder (ASD) is a behaviorally defined neurodevelopmental disorder characterized by deficits in language, communication, and social function with an estimated prevalence rate of between 1 in 30 and 44 U.S. births. Gene/environment (G × E) interactions are widely regarded as the most probable explanation for idiopathic ASD, especially because some genes are selectively targeted by various environmental xenobiotics. Because deciduous teeth are a likely biomarker of in utero exposure, the present study investigated if the quantity of chemicals found in deciduous teeth differs between children with and without ASD. Twenty-two deciduous teeth from children with ASD and 20 teeth from typically developed children were prepared and analyzed using THE Two-Dimensional Gas Chromatography Time-of-Flight Mass Spectrometer (GC × GC-TOF MS) with ChromaTOF version 23H2 software and Agilent 7890 gas chromatograph. The autism sample had significantly more chemicals in their teeth than the typical developing sample (99.4 vs. 80.7, respectively) (p < 0.0001). The majority of chemicals were identified as phthalates, plasticizers, pesticides, preservatives, or intermediary solvents used in the production of fragranced personal care or cleaning products or flavoring agents in foods. The known toxic analytes reported in this study are likely biomarkers of developmental exposure. Why there were greater concentrations of toxic chemicals in the teeth that came from children with ASD is unclear. A further understanding of the cavalcade of multiple biological system interactions (Interactome) could help with future efforts to reduce risks. Notwithstanding, the avoidance of pesticides, plastics, and scented personal care products may be warranted under the precautionary principle rule.

Keywords: autism; deciduous teeth; environmental toxic exposure; pesticides.

Figure 1

Distribution of the number of chemicals in the primary teeth of children with and without autism. Solid lines represent the population distribution, and the dashed lines indicate the sample distribution. Given they are a close match signifies that the sample is sufficiently well represents the population.

Figure 2

Distribution of micrograms (μg/g) of chemicals distinguishing children with and without autism. Solid lines represent the population distribution, and the dashed lines indicate the sample distribution. Given they are a close match signifies that the sample is sufficiently well represents the population.