Research Article Organic Compounds Detected in Deciduous Teeth: A Replication Study from Children with Autism in Two Samples Raymond F. Palmer, 1 Lynne Heilbrun, 1 David Camann, 2 Alice Yau, 2 Stephen Schultz, 1 Viola Elisco, 1 Beatriz Tapia, 1 Noe Garza, 1 and Claudia Miller 1 1 Department of Family and Community Medicine, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA 2 Department of Analytical and Environmental Chemistry, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238-5166, USA Correspondence should be addressed to Raymond F. Palmer; palmerr@uthscsa.edu Received 4 May 2015; Accepted 2 July 2015 Academic Editor: Chit Ming Wong Copyright © 2015 Raymond F. Palmer et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Biological samples are an important part of investigating toxic exposures and disease outcomes. However, blood, urine, saliva, or hair can only refect relatively recent exposures. Alternatively, deciduous teeth have served as a biomarker of early developmental exposure to heavy metals, but little has been done to assess organic toxic exposures such as pesticides, plastics, or medications. Te purpose of our study was to determine if organic chemicals previously detected in a sample of typically developing children could be detected in teeth from a sample of children with autism. Eighty-three deciduous teeth from children with autism spectrum disorders (ASD) were chosen from our tooth repository. Organic compounds were assessed using liquid chromatography tandem mass spectrometry and gas chromatography methods. Consistent with a prior report from Camann et al., (2013), we have demonstrated that specifc semivolatile organic chemicals relevant to autism etiology can be detected in deciduous teeth. Tis report provides evidence that teeth can be useful biomarkers of early life exposure for use in epidemiologic case-control studies seeking to identify diferential unbiased exposures during development between those with and without specifc disorders such as autism. 1. Introduction Biological samples are an important part of epidemiological investigations of toxic exposures and their disease out- comes. Blood, urine, saliva, or hair has ofen been utilized to assess risk factors for a specifc disease by comparing the concentrations of some environmental toxic substances between afected and unafected individuals. While this is a useful approach in some endeavors, these biosamples are only measures of recent exposure and cannot inform about distant past exposures. Terefore, the use of these types of biomarkers is limited. Alternatively, the use of deciduous teeth has served as a biomarker of early developmental exposure to heavy metals. Te mineralization of primary teeth begins prenatally between 14-and 16-week gestation and concludes postnatally at 1.5 to 3 months for incisors, 9 months for canines, and 5.5 to 11 months for molars [1]. It has been demonstrated that metals in circulation, which are present during the period of tooth formation, become incorporated into forming dental tissue and are stored in the mineral component of teeth [2–4]. Deciduous teeth have been used as biomarkers of heavy metal exposure in disease outcome studies for some time. Needleman et al. [5] demonstrated that lead measured in deciduous teeth was associated with lowered cognitive performance in children. Since that landmark study, the concentrations of lead in deciduous teeth have been widely used as a biomarker for lead exposure and body burden in a variety of other studies [6]. Along with lead, other heavy metals such as cadmium, zinc, and copper have also been measured in deciduous teeth [7]. A major development in the assessment of heavy metals using deciduous teeth has been the use of Laser Ablation Electrospray Ionization (LAESI) methods [8]. Tese methods Hindawi Publishing Corporation Journal of Environmental and Public Health Volume 2015, Article ID 862414, 9 pages http://dx.doi.org/10.1155/2015/862414