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Indika NLR, Senarathne UD, Malvaso A, Darshana D, Owens SC, Mansouri B, Semenova Y, Bjørklund G. Abnormal Porphyrin Metabolism in Autism Spectrum Disorder and Therapeutic Implications. Mol Neurobiol 2024; 61:3851-3866. [PMID: 38032468 DOI: 10.1007/s12035-023-03722-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 10/17/2023] [Indexed: 12/01/2023]
Abstract
Autism spectrum disorder (ASD) is a mosaic of neurodevelopmental conditions composed of early-onset social interaction and communication deficits, along with repetitive and/or restricted patterns of activities, behavior, and interests. ASD affects around 1% of children worldwide, with a male predominance. Energy, porphyrin, and neurotransmitter homeostasis are the key metabolic pathways affected by heavy metal exposure, potentially implicated in the pathogenesis of ASD. Exposure to heavy metals can lead to an altered porphyrin metabolism due to enzyme inhibition by heavy metals. Heavy metal exposure, inborn genetic susceptibility, and abnormal thiol and selenol metabolism may play a significant role in the urinary porphyrin profile anomalies observed in ASD. Altered porphyrin metabolism in ASD may also be associated with, vitamin B6 deficiency, hyperoxalemia, hyperhomocysteinemia, and hypomagnesemia. The present review considers the abnormal porphyrin metabolism in ASD in relation to the potential pathogenic mechanism and discusses the possible metabolic therapies such as vitamins, minerals, cofactors, and antioxidants that need to be explored in future research. Such targeted therapeutic therapies would bring about favorable outcomes such as improvements in core and co-occurring symptoms.
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Affiliation(s)
- Neluwa-Liyanage R Indika
- Department of Biochemistry, Faculty of Medical Sciences, University of Sri Jayewardenepura, Nugegoda, 10250, Sri Lanka.
| | - Udara D Senarathne
- Department of Biochemistry, Faculty of Medical Sciences, University of Sri Jayewardenepura, Nugegoda, 10250, Sri Lanka
- Department of Chemical Pathology, Monash Health Pathology, Monash Health, Clayton, Victoria, Australia
| | - Antonio Malvaso
- IRCCS "C. Mondino" Foundation, National Neurological Institute, Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Dhanushka Darshana
- Department of Pharmacy, Faculty of Allied Health Sciences, University of Ruhuna, Galle, Sri Lanka
| | - Susan C Owens
- Autism Oxalate Project, Autism Research Institute, San Diego, CA, USA
| | - Borhan Mansouri
- Substance Abuse Prevention Research Center, Research Institute for Health, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Yuliya Semenova
- Nazarbayev University School of Medicine, Astana, Kazakhstan
| | - Geir Bjørklund
- Council for Nutritional and Environmental Medicine, Toften 24, 8610, Mo i Rana, Norway.
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Yu X, Rahman MM, Wang Z, Carter SA, Schwartz J, Chen Z, Eckel SP, Hackman D, Chen JC, Xiang AH, McConnell R. Evidence of susceptibility to autism risks associated with early life ambient air pollution: A systematic review. ENVIRONMENTAL RESEARCH 2022; 208:112590. [PMID: 34929192 DOI: 10.1016/j.envres.2021.112590] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 12/14/2021] [Accepted: 12/16/2021] [Indexed: 06/14/2023]
Abstract
BACKGROUND Many studies have found associations between early life air pollution exposure and subsequent onset of autism spectrum disorder (ASD). However, characteristics that affect susceptibility remain unclear. OBJECTIVE This systematic review examined epidemiologic studies on the modifying roles of social, child, genetic and maternal characteristics in associations between prenatal and early postnatal air pollution exposure and ASD. METHODS A systematic literature search in PubMed and Embase was conducted. Studies that examined modifiers of the association between air pollution and ASD were included. RESULTS A total of 19 publications examined modifiers of the associations between early life air pollution exposures and ASD. In general, estimates of effects on risk of ASD in boys were larger than in girls (based on 11 studies). Results from studies of effects of family education (2 studies) and neighborhood deprivation (2 studies) on air pollution-ASD associations were inconsistent. Limited data (1 study) suggest pregnant women with insufficient folic acid intake might be more susceptible to ambient particulate matter less than 2.5 μm (PM2.5) and 10 μm (PM10) in aerodynamic diameter, and to nitrogen dioxide (NO2). Children of mothers with gestational diabetes had increased risk of ozone-associated ASD (1 study). Two genetic studies reported that copy number variations may amplify the effect of ozone, and MET rs1858830 CC genotype may augment effects of PM and near-roadway pollutants on ASD. CONCLUSIONS Child's sex, maternal nutrition or diabetes, socioeconomic factors, and child risk genotypes were reported to modify the effect of early-life air pollutants on ASD risk in the epidemiologic literature. However, the sparsity of studies on comparable modifying hypotheses precludes conclusive findings. Further research is needed to identify susceptible populations and potential targets for preventive intervention.
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Affiliation(s)
- Xin Yu
- Spatial Science Institute, University of Southern California, Los Angeles, CA, USA
| | - Md Mostafijur Rahman
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Zhongying Wang
- Spatial Science Institute, University of Southern California, Los Angeles, CA, USA
| | - Sarah A Carter
- Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, CA, USA
| | - Joel Schwartz
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Zhanghua Chen
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Sandrah P Eckel
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Daniel Hackman
- USC Suzanne Dworak-Peck School of Social Work, University of Southern California, Los Angeles, CA, USA
| | - Jiu-Chiuan Chen
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Anny H Xiang
- Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, CA, USA
| | - Rob McConnell
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
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Öztürk ME, Yirün A, Erdemli-Köse SB, Balcı-Özyurt A, Çakır DA, Oral D, Erkekoğlu P. Evaluation of the toxic effects of thimerosal and/or aluminum hydroxide in SH-SY5Y cell line. Hum Exp Toxicol 2022; 41:9603271221136206. [DOI: 10.1177/09603271221136206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In this study, we aimed to evaluate possible toxic effects of thimerosal, aluminum and combination of thimerosal and aluminum in SH-SY5Y cells. Inhibitory concentrations were determined by MTT assay; reactive oxygen species (ROS) were determined by a fluorometric kit and antioxidant/oxidant parameters were measured by spectrophotometric kits. Nuclear factor erythroid 2-associated factor 2 (Nrf2), norepinephrine (NE), dopamine transporter (DAT) and dopamine beta β-hydroxylase (DBH) levels were measured by sandwich ELISA kits while 8-hydroxy deoxyguanosine (8-OHdG) and dopamine levels were determined by competitive ELISA kits. Thimerosal (1.15 μM) and aluminum (362 μM) were applied to cells at inhibitory concentrations 20 (IC20s) for 24 h. ROS increased significantly in cells aluminum- and aluminum+thimerosal-treated cells. Glutathione levels decreased in aluminum group while total antioxidant capacity and protein oxidation levels increased significantly in aluminum and aluminum+thimerosal groups. Lipid peroxidation increased significantly in groups treated with aluminum and aluminum+thimerosal. Nrf2 levels and DNA damage were significantly higher in all groups while dopamine levels significantly increased in cells treated with thimerosal and aluminum+thimerosal, DAT levels were found to be higher in all experimental groups compared to the control. These findings showed that both thimerosal and aluminum can change oxidant/antioxidant status, cause DNA damage, alter dopamine and DAT levels. Changes seen in cells treated with combined exposure to aluminum and thimerosal are more pronounced. Special care should be taken while vaccinating sensitive populations and safer alternatives for aluminum and thimerosal should used.
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Affiliation(s)
- Mehmet Evren Öztürk
- Department of Pharmaceutical Toxicology, Hacettepe University Faculty of Pharmacy, Ankara, Turkey
| | - Anıl Yirün
- Department of Pharmaceutical Toxicology, Hacettepe University Faculty of Pharmacy, Ankara, Turkey
- Department of Pharmaceutical Toxicology, Çukurova University Faculty of Pharmacy, Adana, Turkey
| | - Selinay Başak Erdemli-Köse
- Department of Pharmaceutical Toxicology, Hacettepe University Faculty of Pharmacy, Ankara, Turkey
- Department of Chemistry, Burdur Mehmet Akif Ersoy University Faculty of Arts and Sciences, Burdur, Turkey
| | - Aylin Balcı-Özyurt
- Department of Pharmaceutical Toxicology, Hacettepe University Faculty of Pharmacy, Ankara, Turkey
- Department of Pharmaceutical Toxicology, Bahçeşehir University Faculty of Pharmacy, İstanbul, Turkey
| | - Deniz Arca Çakır
- Department of Pharmaceutical Toxicology, Hacettepe University Faculty of Pharmacy, Ankara, Turkey
- Department of Vaccine Technology, Hacettepe University Vaccine Institute, Ankara, Turkey
| | - Didem Oral
- Department of Pharmaceutical Toxicology, Hacettepe University Faculty of Pharmacy, Ankara, Turkey
- Department of Pharmaceutical Toxicology, Düzce University Faculty of Pharmacy, Düzce, Turkey
| | - Pınar Erkekoğlu
- Department of Pharmaceutical Toxicology, Hacettepe University Faculty of Pharmacy, Ankara, Turkey
- Department of Pharmaceutical Toxicology, Bahçeşehir University Faculty of Pharmacy, İstanbul, Turkey
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4
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Baj J, Flieger W, Flieger M, Forma A, Sitarz E, Skórzyńska-Dziduszko K, Grochowski C, Maciejewski R, Karakuła-Juchnowicz H. Autism spectrum disorder: Trace elements imbalances and the pathogenesis and severity of autistic symptoms. Neurosci Biobehav Rev 2021; 129:117-132. [PMID: 34339708 DOI: 10.1016/j.neubiorev.2021.07.029] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 07/22/2021] [Accepted: 07/26/2021] [Indexed: 02/08/2023]
Abstract
The identification of biomarkers as diagnostic tools and predictors of response to treatment of neurological developmental disorders (NDD) such as schizophrenia (SZ), attention deficit hyperactivity disorder (ADHD), or autism spectrum disorder (ASD), still remains an important challenge for clinical medicine. Metallomic profiles of ASD patients cover, besides essential elements such as cobalt, chromium, copper, iron, manganese, molybdenum, zinc, selenium, also toxic metals burden of: aluminum, arsenic, mercury, lead, beryllium, nickel, cadmium. Performed studies indicate that children with ASD present a reduced ability of eliminating toxic metals, which leads to these metals' accumulation and aggravation of autistic symptoms. Extensive metallomic studies allow a better understanding of the importance of trace elements as environmental factors in the pathogenesis of ASD. Even though a mineral imbalance is a fact in ASD, we are still expecting relevant tests and the elaboration of reference levels of trace elements as potential biomarkers useful in diagnosis, prevention, and treatment of ASD.
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Affiliation(s)
- Jacek Baj
- Department of Anatomy, Medical University of Lublin, Jaczewskiego Street 8b, 20-400, Lublin, Poland.
| | - Wojciech Flieger
- Faculty of Medicine, Medical University of Lublin, Aleje Racławickie 1, 20-059, Lublin, Poland
| | - Michał Flieger
- Faculty of Medicine, Medical University of Lublin, Aleje Racławickie 1, 20-059, Lublin, Poland
| | - Alicja Forma
- Chair and Department of Forensic Medicine, Medical University of Lublin, Jaczewskiego Street 8b, 20-090, Lublin, Poland
| | - Elżbieta Sitarz
- Chair and 1st Department of Psychiatry, Psychotherapy and Early Intervention, Medical University of Lublin, Gluska Street 1, 20-439, Lublin, Poland
| | - Katarzyna Skórzyńska-Dziduszko
- Chair and Department of Human Physiology, Medical University of Lublin, Radziwillowska Street 11, Lublin, 20-080, Poland
| | - Cezary Grochowski
- Laboratory of Virtual Man, Chair of Anatomy, Medical University of Lublin, Jaczewskiego Street 8b, 20-400, Lublin, Poland
| | - Ryszard Maciejewski
- Department of Anatomy, Medical University of Lublin, Jaczewskiego Street 8b, 20-400, Lublin, Poland
| | - Hanna Karakuła-Juchnowicz
- Chair and 1st Department of Psychiatry, Psychotherapy and Early Intervention, Medical University of Lublin, Gluska Street 1, 20-439, Lublin, Poland; Department of Clinical Neuropsychiatry, Medical University of Lublin, Gluska Street 1, 20-439, Lublin, Poland
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5
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Raciti M, Salma J, Spulber S, Gaudenzi G, Khalajzeyqami Z, Conti M, Anderlid BM, Falk A, Hermanson O, Ceccatelli S. NRXN1 Deletion and Exposure to Methylmercury Increase Astrocyte Differentiation by Different Notch-Dependent Transcriptional Mechanisms. Front Genet 2019; 10:593. [PMID: 31316548 PMCID: PMC6610538 DOI: 10.3389/fgene.2019.00593] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Accepted: 06/05/2019] [Indexed: 01/11/2023] Open
Abstract
Controversial evidence points to a possible involvement of methylmercury (MeHg) in the etiopathogenesis of autism spectrum disorders (ASD). In the present study, we used human neuroepithelial stem cells from healthy donors and from an autistic patient bearing a bi-allelic deletion in the gene encoding for NRXN1 to evaluate whether MeHg would induce cellular changes comparable to those seen in cells derived from the ASD patient. In healthy cells, a subcytotoxic concentration of MeHg enhanced astroglial differentiation similarly to what observed in the diseased cells (N1), as shown by the number of GFAP positive cells and immunofluorescence signal intensity. In both healthy MeHg-treated and N1 untreated cells, aberrations in Notch pathway activity seemed to play a critical role in promoting the differentiation toward glia. Accordingly, treatment with the established Notch inhibitor DAPT reversed the altered differentiation. Although our data are not conclusive since only one of the genes involved in ASD is considered, the results provide novel evidence suggesting that developmental exposure to MeHg, even at subcytotoxic concentrations, induces alterations in astroglial differentiation similar to those observed in ASD.
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Affiliation(s)
- Marilena Raciti
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Jahan Salma
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Stefan Spulber
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Giulia Gaudenzi
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | | | - Mirko Conti
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Britt-Marie Anderlid
- Centre for Molecular Medicine, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Falk
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Ola Hermanson
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Sandra Ceccatelli
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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6
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Street ME, Angelini S, Bernasconi S, Burgio E, Cassio A, Catellani C, Cirillo F, Deodati A, Fabbrizi E, Fanos V, Gargano G, Grossi E, Iughetti L, Lazzeroni P, Mantovani A, Migliore L, Palanza P, Panzica G, Papini AM, Parmigiani S, Predieri B, Sartori C, Tridenti G, Amarri S. Current Knowledge on Endocrine Disrupting Chemicals (EDCs) from Animal Biology to Humans, from Pregnancy to Adulthood: Highlights from a National Italian Meeting. Int J Mol Sci 2018; 19:E1647. [PMID: 29865233 PMCID: PMC6032228 DOI: 10.3390/ijms19061647] [Citation(s) in RCA: 138] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 05/23/2018] [Accepted: 05/31/2018] [Indexed: 02/07/2023] Open
Abstract
Wildlife has often presented and suggested the effects of endocrine disrupting chemicals (EDCs). Animal studies have given us an important opportunity to understand the mechanisms of action of many chemicals on the endocrine system and on neurodevelopment and behaviour, and to evaluate the effects of doses, time and duration of exposure. Although results are sometimes conflicting because of confounding factors, epidemiological studies in humans suggest effects of EDCs on prenatal growth, thyroid function, glucose metabolism and obesity, puberty, fertility, and on carcinogenesis mainly through epigenetic mechanisms. This manuscript reviews the reports of a multidisciplinary national meeting on this topic.
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Affiliation(s)
- Maria Elisabeth Street
- Department of Obstetrics, Gynaecology and Paediatrics, Azienda USL-IRCCS, Viale Risorgimento 80, 42123 Reggio Emilia, Italy.
| | - Sabrina Angelini
- Department of Pharmacy and Biotechnology, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy.
| | - Sergio Bernasconi
- Former Department of Medicine, University of Parma, Via A. Catalani 10, 43123 Parma, Italy.
| | - Ernesto Burgio
- ECERI European Cancer and Environment Research Institute, Square de Meeus, 38-40, 1000 Bruxelles, Belgium.
| | - Alessandra Cassio
- Pediatric Endocrinology Programme, Pediatrics Unit, Department of Woman, Child Health and Urologic Diseases, AOU S. Orsola-Malpighi, Via Massarenti, 11, 40138 Bologna, Italy.
| | - Cecilia Catellani
- Department of Obstetrics, Gynaecology and Paediatrics, Azienda USL-IRCCS, Viale Risorgimento 80, 42123 Reggio Emilia, Italy.
| | - Francesca Cirillo
- Department of Obstetrics, Gynaecology and Paediatrics, Azienda USL-IRCCS, Viale Risorgimento 80, 42123 Reggio Emilia, Italy.
| | - Annalisa Deodati
- Department of Pediatrics (DPUO), Bambino Gesù Children's Hospital, Tor Vergata University, Piazza S. Onofrio 4, 00165 Rome, Italy.
| | - Enrica Fabbrizi
- Department of Pediatrics and Neonatology, Augusto Murri Hospital, Via Augusto Murri, 17, 63900 Fermo, Itlay.
| | - Vassilios Fanos
- Neonatal Intensive Care Unit, Neonatal Pathology and Neonatal Section, AOU and University of Cagliari, via Ospedale, 54, 09124 Cagliari, Italy.
| | - Giancarlo Gargano
- Department of Obstetrics, Gynaecology and Paediatrics, Azienda USL-IRCCS, Viale Risorgimento 80, 42123 Reggio Emilia, Italy.
| | - Enzo Grossi
- Villa Santa Maria Institute, Neuropsychiatric Rehabilitation Center, Via IV Novembre 15, 22038 Tavernerio (Como), Italy.
| | - Lorenzo Iughetti
- Department of Medical and Surgical Sciences of the Mother, Children and Adults, Pediatrics Unit, University of Modena and Reggio Emilia, via del Pozzo, 71, 41124 Modena, Italy.
| | - Pietro Lazzeroni
- Department of Obstetrics, Gynaecology and Paediatrics, Azienda USL-IRCCS, Viale Risorgimento 80, 42123 Reggio Emilia, Italy.
| | - Alberto Mantovani
- Department of Veterinary Public Health and Food Safety, Food and Veterinary Toxicology Unit ISS⁻National Institute of Health, Viale Regina Elena 299, 00161 Rome, Italy.
| | - Lucia Migliore
- Department of Traslational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma, 55, 56123 Pisa, Italy.
| | - Paola Palanza
- Unit of Neuroscience, Department of Medicine and Surgery, University of Parma, Via Gramsci, 14, 43126 Parma, Italy.
| | - Giancarlo Panzica
- Laboratory of Neuroendocrinology, Department of Neuroscience Rita Levi Montalcini, University of Turin, Via Cherasco 15, 10126 Turin, Italy.
- Neuroscience Institute Cavalieri-Ottolenghi (NICO), Regione Gonzole, 10, 10043 Orbassano (Turin), Italy.
| | - Anna Maria Papini
- Department of Chemistry 'Ugo Schiff', University of Florence, Via della Lastruccia, 3-13, 50019 Sesto Fiorentino, Florence, Italy.
| | - Stefano Parmigiani
- Unit of Evolutionary and Functional Biology-Department of Chemistry, Life Sciences and Environmental Sustainability (SCVSA)-University of Parma⁻11/a, 43124 Parma, Italy.
| | - Barbara Predieri
- Department of Medical and Surgical Sciences of the Mother, Children and Adults, Pediatrics Unit, University of Modena and Reggio Emilia, via del Pozzo, 71, 41124 Modena, Italy.
| | - Chiara Sartori
- Department of Obstetrics, Gynaecology and Paediatrics, Azienda USL-IRCCS, Viale Risorgimento 80, 42123 Reggio Emilia, Italy.
| | - Gabriele Tridenti
- Department of Obstetrics, Gynaecology and Paediatrics, Azienda USL-IRCCS, Viale Risorgimento 80, 42123 Reggio Emilia, Italy.
| | - Sergio Amarri
- Department of Obstetrics, Gynaecology and Paediatrics, Azienda USL-IRCCS, Viale Risorgimento 80, 42123 Reggio Emilia, Italy.
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Geier DA, Kern JK, Sykes LK, Geier MR. Mercury-associated diagnoses among children diagnosed with pervasive development disorders. Metab Brain Dis 2018; 33:949-960. [PMID: 29512044 DOI: 10.1007/s11011-018-0211-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 02/25/2018] [Indexed: 12/27/2022]
Abstract
Nelson and Bauman (Pediatrics 111:674-679, 2003) previously hypothesized that pervasive developmental disorder (PDD) was not associated with mercury (Hg) exposure because the medical conditions associated with Hg exposure were not associated with PDD. A hypothesis-testing longitudinal case-control study evaluated the frequency of medically diagnosed conditions previously associated with Hg poisoning, including: epilepsy, dysarthria, failure to thrive, cerebral palsy, or contact dermatitis and other eczema among children preceding their eventual PDD diagnosis (cases) compared to controls. A retrospective examination of medical records within the Vaccine Safety Datalink (VSD) was undertaken. Cases diagnosed with PDD (n = 534) were born from 1991 to 2000 and continuously enrolled until their PDD diagnosis. Controls (n = 26,367) were born from 1991 to 1993 and continuously enrolled from birth for 7.22 years. Within the first 5 years of life, cases compared to controls were significantly (p < 0.0001) more likely to be assigned a diagnosis of contact dermatitis and other eczema (odds ratio (OR) = 2.033), dysarthria (OR = 23.992), epilepsy (OR = 5.351), failure to thrive (OR = 25.3), and cerebral palsy (OR = 4.464). Similar results were observed when the data were separated by gender. Overall, the results of the present study and recently published studies provide direct evidence supporting a link in twelve of twelve categories (100%) of Hg poisoning associated symptoms as defined by Nelson and Bauman (Pediatrics 111:674-679, 2003) and symptoms observed in those with a PDD diagnosis. The results of this study support the biological plausibility of Hg poisoning to induce PDD diagnoses and rejection of the Nelson and Bauman (Pediatrics 111:674-679, 2003) hypothesis because those with a PDD diagnosis have an increased frequency of conditions previously associated with Hg poisoning.
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Affiliation(s)
- David A Geier
- The Institute of Chronic Illnesses, Inc, 14 Redgate Ct, Silver Spring, MD, USA
| | - Janet K Kern
- The Institute of Chronic Illnesses, Inc, 14 Redgate Ct, Silver Spring, MD, USA.
- CoMeD, Inc, Silver Spring, MD, USA.
- CONEM US Autism Research Group, Allen, TX, USA.
| | | | - Mark R Geier
- The Institute of Chronic Illnesses, Inc, 14 Redgate Ct, Silver Spring, MD, USA
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8
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Fordyce TA, Leonhard MJ, Chang ET. A critical review of developmental exposure to particulate matter, autism spectrum disorder, and attention deficit hyperactivity disorder. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2018; 53:174-204. [PMID: 29157090 DOI: 10.1080/10934529.2017.1383121] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Autism spectrum disorder (ASD) and attention deficit (hyperactivity) disorder (ADD/ADHD) are key focuses of current health research due to their increasing prevalence. The objective of this systematic literature search and critical review was to evaluate whether the human epidemiologic data indicate a pattern of association between ASD or ADD/ADHD and developmental exposure to particulate matter (PM), with a focus on exposures encountered before the age of three. A MEDLINE and EMBASE search was conducted; following preliminary and full-text screening, 14 relevant articles were identified for review. Three of the 14 studies were prospective cohort studies evaluating exposure to PM10; 11 studies had a case-control design. There was no consistent association between developmental PM exposure and ASD across the three of the cohort studies. Seven of the case-control studies examined the relationship between PM2.5 and/or PM10 and ASD; four examined the relationship between developmental diesel PM exposure and ASD. Overall, there was low external consistency in results among studies of PM2.5/PM10 and ASD, with some reporting high internal consistency without significant associations, others showing associations with high internal consistency for specific exposure windows only (e.g., third trimester), and still others showing high consistency for moderate to strong associations between PM and ASD. The majority of studies reporting significant results had low effect sizes in conjunction with small sample sizes. The four studies of diesel PM and ASD also had low external consistency of results. Only one study evaluated associations with ADD/ADHD, and it found no significant associations with PM10. The inconsistent findings across studies of developmental exposure to PM and ASD may be attributed to differences in the study populations, exposure assessments, outcome assessments, or chance. Further research is needed to understand the underlying biological mechanisms that lead to ASD and ADD/ADHD and how PM might be involved in those mechanisms, if at all. High-quality epidemiologic studies are also needed to conclusively determine whether developmental PM exposure is a causal factor for ASD or ADD/ADHD, with focus on a well-developed exposure assessment.
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Affiliation(s)
- Tiffani A Fordyce
- a Exponent, Inc., Center for Health Sciences , Menlo Park , California , USA
| | - Megan J Leonhard
- b Exponent, Inc., Center for Health Sciences , Bellevue , Washington , USA
| | - Ellen T Chang
- a Exponent, Inc., Center for Health Sciences , Menlo Park , California , USA
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9
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Kern JK, Geier DA, Deth RC, Sykes LK, Hooker BS, Love JM, Bjørklund G, Chaigneau CG, Haley BE, Geier MR. RETRACTED ARTICLE: Systematic Assessment of Research on Autism Spectrum Disorder and Mercury Reveals Conflicts of Interest and the Need for Transparency in Autism Research. SCIENCE AND ENGINEERING ETHICS 2017; 23:1689-1690. [PMID: 26507205 PMCID: PMC5705728 DOI: 10.1007/s11948-015-9713-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 10/19/2015] [Indexed: 06/05/2023]
Affiliation(s)
- Janet K. Kern
- Institute of Chronic Illnesses, Inc., 14 Redgate Court, Silver Spring, MD 20905 USA
| | - David A. Geier
- Institute of Chronic Illnesses, Inc., 14 Redgate Court, Silver Spring, MD 20905 USA
| | | | | | | | | | - Geir Bjørklund
- Council for Nutritional and Environmental Medicine, Mo i Rana, Norway
| | | | | | - Mark R. Geier
- Institute of Chronic Illnesses, Inc., 14 Redgate Court, Silver Spring, MD 20905 USA
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10
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Kern JK, Geier DA, Deth RC, Sykes LK, Hooker BS, Love JM, Bjørklund G, Chaigneau CG, Haley BE, Geier MR. Systematic Assessment of Research on Autism Spectrum Disorder (ASD) and Mercury Reveals Conflicts of Interest and the Need for Transparency in Autism Research. SCIENCE AND ENGINEERING ETHICS 2017; 23:1691-1718. [PMID: 29119411 PMCID: PMC5705731 DOI: 10.1007/s11948-017-9983-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Historically, entities with a vested interest in a product that critics have suggested is harmful have consistently used research to back their claims that the product is safe. Prominent examples are: tobacco, lead, bisphenol A, and atrazine. Research literature indicates that about 80-90% of studies with industry affiliation found no harm from the product, while only about 10-20% of studies without industry affiliation found no harm. In parallel to other historical debates, recent studies examining a possible relationship between mercury (Hg) exposure and autism spectrum disorder (ASD) show a similar dichotomy. Studies sponsored and supported by industry or entities with an apparent conflict of interest have most often shown no evidence of harm or no "consistent" evidence of harm, while studies without such affiliations report positive evidence of a Hg/autism association. The potentially causal relationship between Hg exposure and ASD differs from other toxic products since there is a broad coalition of entities for whom a conflict of interest arises. These include influential governmental public health entities, the pharmaceutical industry, and even the coal burning industry. This review includes a systematic literature search of original studies on the potential relationship between Hg and ASD from 1999 to August 2015, finding that of the studies with public health and/or industry affiliation, 86% reported no relationship between Hg and ASD. However, among studies without public health and/or industry affiliation, only 21% find no relationship between Hg and ASD. The discrepancy in these results suggests a bias indicative of a conflict of interest.
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Affiliation(s)
- Janet K. Kern
- Institute of Chronic Illnesses, Inc, 14 Redgate Court, Silver Spring, MD 20905 USA
| | - David A. Geier
- Institute of Chronic Illnesses, Inc, 14 Redgate Court, Silver Spring, MD 20905 USA
| | | | | | | | | | - Geir Bjørklund
- Council for Nutritional and Environmental Medicine, Mo i Rana, Norway
| | | | | | - Mark R. Geier
- Institute of Chronic Illnesses, Inc, 14 Redgate Court, Silver Spring, MD 20905 USA
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Yang C, Zhao W, Deng K, Zhou V, Zhou X, Hou Y. The association between air pollutants and autism spectrum disorders. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:15949-15958. [PMID: 28540549 DOI: 10.1007/s11356-017-8928-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 03/23/2017] [Indexed: 04/15/2023]
Abstract
Autism spectrum disorders are a member of the pervasive developmental disorders (PDDs) that have been increasing dramatically since described by Leo Kanner in 1943. In the past decade, the number of epidemiological publications addressing air pollution exposures and autism has grown correspondingly, but the association is still unclear. Whether air pollutants play a causal role and which substances are related with autism requires further study. We systematically reviewed the literature from 2005 to 2016 in MEDLINE (National Library of Medicine), Web of Science, and PubMed and summarized the association between different air pollutants and autism. Furthermore, we further discussed the exposure time window and potential confounders that should be considered in the association analysis studies. Our objective is to summarize the association between different air pollutants and autism with literature, which has been published since 2005, and explore whether the exposure time window and potential confounders have influence on this association. These results could provide more comprehensive information about the association between air pollutants and autism and be helpful towards further validation study. Graphical abstract ᅟ.
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Affiliation(s)
- Chunyan Yang
- Department of Epidemiology and Biostatistics, School of Public Health, Harbin Medical University, 157 Baojian Road, Harbin, 150081, China
| | - Weiwei Zhao
- Department of Epidemiology and Biostatistics, School of Public Health, Harbin Medical University, 157 Baojian Road, Harbin, 150081, China
| | - Kui Deng
- Department of Epidemiology and Biostatistics, School of Public Health, Harbin Medical University, 157 Baojian Road, Harbin, 150081, China
| | - Vanessa Zhou
- School of Public Health and Community Medicine, University of Washington Autism Center, University of Washington, Seattle, USA
| | - Xiaohua Zhou
- Department of Biostatistics, School of Public Health and Community Medicine, University of Washington, Seattle, WA, 98195, USA.
| | - Yan Hou
- Department of Epidemiology and Biostatistics, School of Public Health, Harbin Medical University, 157 Baojian Road, Harbin, 150081, China.
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Adams J, Howsmon DP, Kruger U, Geis E, Gehn E, Fimbres V, Pollard E, Mitchell J, Ingram J, Hellmers R, Quig D, Hahn J. Significant Association of Urinary Toxic Metals and Autism-Related Symptoms-A Nonlinear Statistical Analysis with Cross Validation. PLoS One 2017; 12:e0169526. [PMID: 28068407 PMCID: PMC5222512 DOI: 10.1371/journal.pone.0169526] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 11/16/2016] [Indexed: 01/25/2023] Open
Abstract
Introduction A number of previous studies examined a possible association of toxic metals and autism, and over half of those studies suggest that toxic metal levels are different in individuals with Autism Spectrum Disorders (ASD). Additionally, several studies found that those levels correlate with the severity of ASD. Methods In order to further investigate these points, this paper performs the most detailed statistical analysis to date of a data set in this field. First morning urine samples were collected from 67 children and adults with ASD and 50 neurotypical controls of similar age and gender. The samples were analyzed to determine the levels of 10 urinary toxic metals (UTM). Autism-related symptoms were assessed with eleven behavioral measures. Statistical analysis was used to distinguish participants on the ASD spectrum and neurotypical participants based upon the UTM data alone. The analysis also included examining the association of autism severity with toxic metal excretion data using linear and nonlinear analysis. “Leave-one-out” cross-validation was used to ensure statistical independence of results. Results and Discussion Average excretion levels of several toxic metals (lead, tin, thallium, antimony) were significantly higher in the ASD group. However, ASD classification using univariate statistics proved difficult due to large variability, but nonlinear multivariate statistical analysis significantly improved ASD classification with Type I/II errors of 15% and 18%, respectively. These results clearly indicate that the urinary toxic metal excretion profiles of participants in the ASD group were significantly different from those of the neurotypical participants. Similarly, nonlinear methods determined a significantly stronger association between the behavioral measures and toxic metal excretion. The association was strongest for the Aberrant Behavior Checklist (including subscales on Irritability, Stereotypy, Hyperactivity, and Inappropriate Speech), but significant associations were found for UTM with all eleven autism-related assessments with cross-validation R2 values ranging from 0.12–0.48.
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Affiliation(s)
- James Adams
- Arizona State University, Tempe, AZ, United States of America
- * E-mail:
| | - Daniel P. Howsmon
- Rensselaer Polytechnic Institute, Troy, NY, United States of America
| | - Uwe Kruger
- Rensselaer Polytechnic Institute, Troy, NY, United States of America
| | - Elizabeth Geis
- Arizona State University, Tempe, AZ, United States of America
| | - Eva Gehn
- Arizona State University, Tempe, AZ, United States of America
| | - Valeria Fimbres
- Arizona State University, Tempe, AZ, United States of America
| | - Elena Pollard
- Arizona State University, Tempe, AZ, United States of America
| | - Jessica Mitchell
- Southwest College of Naturopathic Medicine, Tempe, AZ, United States of America
| | - Julie Ingram
- Arizona State University, Tempe, AZ, United States of America
| | - Robert Hellmers
- Arizona Allergy Associates, Phoenix, AZ, United States of America
| | - David Quig
- Doctor’s Data, St. Charles, IL, United States of America
| | - Juergen Hahn
- Rensselaer Polytechnic Institute, Troy, NY, United States of America
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Lam J, Sutton P, Kalkbrenner A, Windham G, Halladay A, Koustas E, Lawler C, Davidson L, Daniels N, Newschaffer C, Woodruff T. A Systematic Review and Meta-Analysis of Multiple Airborne Pollutants and Autism Spectrum Disorder. PLoS One 2016; 11:e0161851. [PMID: 27653281 PMCID: PMC5031428 DOI: 10.1371/journal.pone.0161851] [Citation(s) in RCA: 146] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 08/14/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Exposure to ambient air pollution is widespread and may be detrimental to human brain development and a potential risk factor for Autism Spectrum Disorder (ASD). We conducted a systematic review of the human evidence on the relationship between ASD and exposure to all airborne pollutants, including particulate matter air pollutants and others (e.g. pesticides and metals). OBJECTIVE To answer the question: "is developmental exposure to air pollution associated with ASD?" METHODS We conducted a comprehensive search of the literature, identified relevant studies using inclusion/exclusion criteria pre-specified in our protocol (registered in PROSPERO, CRD # 42015017890), evaluated the potential risk of bias for each included study and identified an appropriate subset of studies to combine in a meta-analysis. We then rated the overall quality and strength of the evidence collectively across all air pollutants. RESULTS Of 1,158 total references identified, 23 human studies met our inclusion criteria (17 case-control, 4 ecological, 2 cohort). Risk of bias was generally low across studies for most domains; study limitations were related to potential confounding and accuracy of exposure assessment methods. We rated the quality of the body of evidence across all air pollutants as "moderate." From our meta-analysis, we found statistically significant summary odds ratios (ORs) of 1.07 (95% CI: 1.06, 1.08) per 10-μg/m3 increase in PM10 exposure (n = 6 studies) and 2.32 (95% CI: 2.15, 2.51) per 10-μg/m3 increase in PM2.5 exposure (n = 3 studies). For pollutants not included in a meta-analysis, we collectively evaluated evidence from each study in rating the strength and quality of overall evidence considering factors such as inconsistency, imprecision, and evidence of dose-response. All included studies generally showed increased risk of ASD with increasing exposure to air pollution, although not consistently across all chemical components. CONCLUSION After considering strengths and limitations of the body of research, we concluded that there is "limited evidence of toxicity" for the association between early life exposure to air pollution as a whole and diagnosis of ASD. The strongest evidence was between prenatal exposure to particulate matter and ASD. However, the small number of studies in the meta-analysis and unexplained statistical heterogeneity across the individual study estimates means that the effect could be larger or smaller (including not significant) than these studies estimate. Our research supports the need for health protective public policy to reduce exposures to harmful airborne contaminants among pregnant women and children and suggests opportunities for optimizing future research.
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Affiliation(s)
- Juleen Lam
- Department of Obstetrics, Gynecology & Reproductive Sciences, Program on Reproductive Health and the Environment, University of California, San Francisco, CA, United States of America
| | - Patrice Sutton
- Department of Obstetrics, Gynecology & Reproductive Sciences, Program on Reproductive Health and the Environment, University of California, San Francisco, CA, United States of America
| | - Amy Kalkbrenner
- Joseph J. Zilber School of Public Health, University of Wisconsin-Milwaukee, Milkwaukee, WI, United States of America
| | - Gayle Windham
- Division of Environmental and Occupational Disease Control, California Department of Public Health, Richmond, CA, United States of America
| | - Alycia Halladay
- Autism Science Foundation, New York, NY, United States of America
- Department of Pharmacology and Toxicology, Rutgers University, New Brunswick, NJ, United States of America
| | - Erica Koustas
- Scientific consultant to the University of California, San Francisco, CA, United States of America
| | - Cindy Lawler
- Division of Extramural Research and Training, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States of America
| | - Lisette Davidson
- Department of Obstetrics and Gynecology, Kaiser Permanente, Oakland, CA, United States of America
| | - Natalyn Daniels
- Department of Obstetrics, Gynecology & Reproductive Sciences, Program on Reproductive Health and the Environment, University of California, San Francisco, CA, United States of America
| | - Craig Newschaffer
- Department of Epidemiology and Biostatistics, Drexel University, Philadelphia, PA, United States of America
| | - Tracey Woodruff
- Department of Obstetrics, Gynecology & Reproductive Sciences, Program on Reproductive Health and the Environment, University of California, San Francisco, CA, United States of America
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14
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Kern JK, Geier DA, Sykes LK, Haley BE, Geier MR. The relationship between mercury and autism: A comprehensive review and discussion. J Trace Elem Med Biol 2016; 37:8-24. [PMID: 27473827 DOI: 10.1016/j.jtemb.2016.06.002] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 05/17/2016] [Accepted: 06/01/2016] [Indexed: 12/28/2022]
Abstract
The brain pathology in autism spectrum disorders (ASD) indicates marked and ongoing inflammatory reactivity with concomitant neuronal damage. These findings are suggestive of neuronal insult as a result of external factors, rather than some type of developmental mishap. Various xenobiotics have been suggested as possible causes of this pathology. In a recent review, the top ten environmental compounds suspected of causing autism and learning disabilities were listed and they included: lead, methyl-mercury, polychorinated biphenyls, organophosphate pesticides, organochlorine pesticides, endocrine disruptors, automotive exhaust, polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers, and perfluorinated compounds. This current review, however, will focus specifically on mercury exposure and ASD by conducting a comprehensive literature search of original studies in humans that examine the potential relationship between mercury and ASD, categorizing, summarizing, and discussing the published research that addresses this topic. This review found 91 studies that examine the potential relationship between mercury and ASD from 1999 to February 2016. Of these studies, the vast majority (74%) suggest that mercury is a risk factor for ASD, revealing both direct and indirect effects. The preponderance of the evidence indicates that mercury exposure is causal and/or contributory in ASD.
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Affiliation(s)
- Janet K Kern
- Institute of Chronic Illnesses, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA; Council for Nutritional and Environmental Medicine, Mo i Rana, Norway; CoMeD, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA.
| | - David A Geier
- Institute of Chronic Illnesses, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA; CoMeD, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA
| | - Lisa K Sykes
- CoMeD, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA
| | - Boyd E Haley
- University of Kentucky, 410 Administration Drive, Lexington, KY, 40506 USA
| | - Mark R Geier
- Institute of Chronic Illnesses, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA; CoMeD, Inc., 14 Redgate Court, Silver Spring, MD, 20905 USA
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15
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Liu L, Zhang D, Rodzinka-pasko JK, Li YM. Environmental risk factors for autism spectrum disorders. DER NERVENARZT 2016; 87:55-61. [DOI: 10.1007/s00115-016-0172-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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16
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Dickerson AS, Rahbar MH, Bakian AV, Bilder DA, Harrington RA, Pettygrove S, Kirby RS, Durkin MS, Han I, Moyé LA, Pearson DA, Wingate MS, Zahorodny WM. Autism spectrum disorder prevalence and associations with air concentrations of lead, mercury, and arsenic. ENVIRONMENTAL MONITORING AND ASSESSMENT 2016; 188:407. [PMID: 27301968 DOI: 10.1007/s10661-016-5405-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Accepted: 06/02/2016] [Indexed: 06/06/2023]
Abstract
Lead, mercury, and arsenic are neurotoxicants with known effects on neurodevelopment. Autism spectrum disorder (ASD) is a neurodevelopmental disorder apparent by early childhood. Using data on 4486 children with ASD residing in 2489 census tracts in five sites of the Centers for Disease Control and Prevention's Autism and Developmental Disabilities Monitoring (ADDM) Network, we used multi-level negative binomial models to investigate if ambient lead, mercury, and arsenic concentrations, as measured by the US Environmental Protection Agency National-Scale Air Toxics Assessment (EPA-NATA), were associated with ASD prevalence. In unadjusted analyses, ambient metal concentrations were negatively associated with ASD prevalence. After adjusting for confounding factors, tracts with air concentrations of lead in the highest quartile had significantly higher ASD prevalence than tracts with lead concentrations in the lowest quartile (prevalence ratio (PR) = 1.36; 95 '% CI: 1.18, 1.57). In addition, tracts with mercury concentrations above the 75th percentile (>1.7 ng/m(3)) and arsenic concentrations below the 75th percentile (≤0.13 ng/m(3)) had a significantly higher ASD prevalence (adjusted RR = 1.20; 95 % CI: 1.03, 1.40) compared to tracts with arsenic, lead, and mercury concentrations below the 75th percentile. Our results suggest a possible association between ambient lead concentrations and ASD prevalence and demonstrate that exposure to multiple metals may have synergistic effects on ASD prevalence.
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Affiliation(s)
- Aisha S Dickerson
- Biostatistics/Epidemiology/Research Design (BERD) Core, Center for Clinical and Translational Sciences (CCTS), University of Texas Health Science Center at Houston, 6410 Fannin Street, UT Professional Building Suite 1100.05, Houston, TX, 77030, USA.
| | - Mohammad H Rahbar
- Biostatistics/Epidemiology/Research Design (BERD) Core, Center for Clinical and Translational Sciences (CCTS), University of Texas Health Science Center at Houston, 6410 Fannin Street, UT Professional Building Suite 1100.05, Houston, TX, 77030, USA
- Division of Clinical and Translational Sciences, Department of Internal Medicine, McGovern Medical School The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
- Division of Epidemiology, Human Genetics, and Environmental Sciences (EHGES), University of Texas School of Public Health at Houston, University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Amanda V Bakian
- Division of Child Psychiatry, Department of Psychiatry, University of Utah School of Medicine, Salt Lake City, UT, 84108, USA
| | - Deborah A Bilder
- Division of Child Psychiatry, Department of Psychiatry, University of Utah School of Medicine, Salt Lake City, UT, 84108, USA
| | - Rebecca A Harrington
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | - Sydney Pettygrove
- Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, 85721, USA
| | - Russell S Kirby
- Department of Community and Family Health, College of Public Health, University of South Florida, Tampa, FL, 33612, USA
| | - Maureen S Durkin
- Waisman Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, 53726, USA
| | - Inkyu Han
- Division of Epidemiology, Human Genetics, and Environmental Sciences (EHGES), University of Texas School of Public Health at Houston, University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Lemuel A Moyé
- Division of Biostatistics, University of Texas School of Public Health at Houston, Houston, TX, 77030, USA
| | - Deborah A Pearson
- Department of Psychiatry and Behavioral Sciences, University of Texas Medical School, Houston, TX, 77054, USA
| | - Martha Slay Wingate
- Department of Health Care Organization and Policy, School of Public Health, University of Alabama at Birmingham, Birmingham, AL, 35205, USA
| | - Walter M Zahorodny
- Department of Pediatrics, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA
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17
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Dickerson AS, Rahbar MH, Han I, Bakian AV, Bilder DA, Harrington RA, Pettygrove S, Durkin M, Kirby RS, Wingate MS, Tian LH, Zahorodny WM, Pearson DA, Moyé LA, Baio J. Autism spectrum disorder prevalence and proximity to industrial facilities releasing arsenic, lead or mercury. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 536:245-251. [PMID: 26218563 PMCID: PMC4721249 DOI: 10.1016/j.scitotenv.2015.07.024] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 06/09/2015] [Accepted: 07/06/2015] [Indexed: 05/22/2023]
Abstract
Prenatal and perinatal exposures to air pollutants have been shown to adversely affect birth outcomes in offspring and may contribute to prevalence of autism spectrum disorder (ASD). For this ecologic study, we evaluated the association between ASD prevalence, at the census tract level, and proximity of tract centroids to the closest industrial facilities releasing arsenic, lead or mercury during the 1990s. We used 2000 to 2008 surveillance data from five sites of the Autism and Developmental Disabilities Monitoring (ADDM) network and 2000 census data to estimate prevalence. Multi-level negative binomial regression models were used to test associations between ASD prevalence and proximity to industrial facilities in existence from 1991 to 1999 according to the US Environmental Protection Agency Toxics Release Inventory (USEPA-TRI). Data for 2489 census tracts showed that after adjustment for demographic and socio-economic area-based characteristics, ASD prevalence was higher in census tracts located in the closest 10th percentile compared of distance to those in the furthest 50th percentile (adjusted RR=1.27, 95% CI: (1.00, 1.61), P=0.049). The findings observed in this study are suggestive of the association between urban residential proximity to industrial facilities emitting air pollutants and higher ASD prevalence.
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Affiliation(s)
- Aisha S Dickerson
- Biostatistics/Epidemiology/Research Design (BERD) Core, Center for Clinical and Translational Sciences (CCTS), University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
| | - Mohammad H Rahbar
- Biostatistics/Epidemiology/Research Design (BERD) Core, Center for Clinical and Translational Sciences (CCTS), University of Texas Health Science Center at Houston, Houston, TX 77030, USA; Division of Epidemiology, Human Genetics, and Environmental Sciences (EHGES), University of Texas School of Public Health at Houston, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
| | - Inkyu Han
- Division of Epidemiology, Human Genetics, and Environmental Sciences (EHGES), University of Texas School of Public Health at Houston, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
| | - Amanda V Bakian
- Division of Child Psychiatry, Department of Psychiatry, University of Utah School of Medicine, Salt Lake City, UT 84108, USA.
| | - Deborah A Bilder
- Division of Child Psychiatry, Department of Psychiatry, University of Utah School of Medicine, Salt Lake City, UT 84108, USA.
| | - Rebecca A Harrington
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA.
| | - Sydney Pettygrove
- Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ 85721, USA.
| | - Maureen Durkin
- Waisman Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53726, USA.
| | - Russell S Kirby
- Department of Community and Family Health, College of Public Health, University of South Florida, Tampa, FL 33612, USA.
| | - Martha Slay Wingate
- Department of Health Care Organization and Policy, School of Public Health, University of Alabama at Birmingham, Birmingham, AL 35205, USA..
| | - Lin Hui Tian
- National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
| | - Walter M Zahorodny
- Department of Pediatrics, Rutgers New Jersey Medical School, Newark, NJ 07103, USA.
| | - Deborah A Pearson
- Department of Psychiatry and Behavioral Sciences, University of Texas Medical School, Houston, TX 77054, USA.
| | - Lemuel A Moyé
- Division of Biostatistics, University of Texas School of Public Health at Houston, Houston, TX 77030, USA.
| | - Jon Baio
- National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
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Yoshimasu K, Kiyohara C, Takemura S, Nakai K. A meta-analysis of the evidence on the impact of prenatal and early infancy exposures to mercury on autism and attention deficit/hyperactivity disorder in the childhood. Neurotoxicology 2014; 44:121-31. [DOI: 10.1016/j.neuro.2014.06.007] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 05/14/2014] [Accepted: 06/11/2014] [Indexed: 10/25/2022]
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19
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Yau VM, Green PG, Alaimo CP, Yoshida CK, Lutsky M, Windham GC, Delorenze G, Kharrazi M, Grether JK, Croen LA. Prenatal and neonatal peripheral blood mercury levels and autism spectrum disorders. ENVIRONMENTAL RESEARCH 2014; 133:294-303. [PMID: 24981828 DOI: 10.1016/j.envres.2014.04.034] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 04/22/2014] [Accepted: 04/25/2014] [Indexed: 05/22/2023]
Abstract
BACKGROUND Prenatal and early-life exposures to mercury have been hypothesized to be associated with increased risk of autism spectrum disorders (ASDs). OBJECTIVES This study investigated the association between ASDs and levels of total mercury measured in maternal serum from mid-pregnancy and infant blood shortly after birth. METHODS The study sample was drawn from the Early Markers for Autism (EMA) Study. Three groups of children who were born in Orange County, CA in 2000-2001 were identified: children with ASD (n=84), children with intellectual disability or developmental delay (DD) (n=49), and general population controls (GP) (n=159). Maternal serum specimens and newborn bloodspots were retrieved from the California Department of Public Health prenatal and newborn screening specimen archives. Blood mercury levels were measured in maternal serum samples using mass spectrometer and in infant bloodspots with a 213 nm laser. RESULTS Maternal serum and infant blood mercury levels were significantly correlated among all study groups (all correlations >0.38, p<0.01). Adjusted logistic regression models showed no significant associations between ASD and log transformed mercury levels in maternal serum samples (ASD vs. GP: OR [95% CI]=0.96 [0.49-1.90]; ASD vs. DD: OR [95% CI]=2.56 [0.89-7.39]). Results for mercury levels in newborn blood samples were similar (ASD vs. GP: OR [95% CI]=1.18 [0.71-1.95]; ASD vs. DD: OR [95% CI]=1.96 [0.75-5.14]). CONCLUSIONS Results indicate that levels of total mercury in serum collected from mothers during mid-pregnancy and from newborn bloodspots were not significantly associated with risk of ASD, though additional studies with greater sample size and covariate measurement are needed.
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Affiliation(s)
- Vincent M Yau
- Division of Research, Kaiser Permanente, Oakland, CA, USA
| | - Peter G Green
- Department of Civil & Environmental Engineering, University of California Davis, Davis, CA, USA
| | - Christopher P Alaimo
- Department of Civil & Environmental Engineering, University of California Davis, Davis, CA, USA
| | | | - Marta Lutsky
- Division of Research, Kaiser Permanente, Oakland, CA, USA
| | - Gayle C Windham
- Division of Environmental and Occupational Disease Control, California Department of Public Health, Richmond, CA, USA
| | | | - Martin Kharrazi
- Genetic Disease Screening Program, California Department of Public Health, Richmond, CA, USA
| | - Judith K Grether
- Division of Environmental and Occupational Disease Control, California Department of Public Health, Richmond, CA, USA
| | - Lisa A Croen
- Division of Research, Kaiser Permanente, Oakland, CA, USA.
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20
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Rossignol DA, Genuis SJ, Frye RE. Environmental toxicants and autism spectrum disorders: a systematic review. Transl Psychiatry 2014; 4:e360. [PMID: 24518398 PMCID: PMC3944636 DOI: 10.1038/tp.2014.4] [Citation(s) in RCA: 292] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 12/15/2013] [Accepted: 01/06/2014] [Indexed: 11/21/2022] Open
Abstract
Although the involvement of genetic abnormalities in autism spectrum disorders (ASD) is well-accepted, recent studies point to an equal contribution by environmental factors, particularly environmental toxicants. However, these toxicant-related studies in ASD have not been systematically reviewed to date. Therefore, we compiled publications investigating potential associations between environmental toxicants and ASD and arranged these publications into the following three categories: (a) studies examining estimated toxicant exposures in the environment during the preconceptional, gestational and early childhood periods; (b) studies investigating biomarkers of toxicants; and (c) studies examining potential genetic susceptibilities to toxicants. A literature search of nine electronic scientific databases through November 2013 was performed. In the first category examining ASD risk and estimated toxicant exposures in the environment, the majority of studies (34/37; 92%) reported an association. Most of these studies were retrospective case-control, ecological or prospective cohort studies, although a few had weaker study designs (for example, case reports or series). Toxicants implicated in ASD included pesticides, phthalates, polychlorinated biphenyls (PCBs), solvents, toxic waste sites, air pollutants and heavy metals, with the strongest evidence found for air pollutants and pesticides. Gestational exposure to methylmercury (through fish exposure, one study) and childhood exposure to pollutants in water supplies (two studies) were not found to be associated with ASD risk. In the second category of studies investigating biomarkers of toxicants and ASD, a large number was dedicated to examining heavy metals. Such studies demonstrated mixed findings, with only 19 of 40 (47%) case-control studies reporting higher concentrations of heavy metals in blood, urine, hair, brain or teeth of children with ASD compared with controls. Other biomarker studies reported that solvent, phthalate and pesticide levels were associated with ASD, whereas PCB studies were mixed. Seven studies reported a relationship between autism severity and heavy metal biomarkers, suggesting evidence of a dose-effect relationship. Overall, the evidence linking biomarkers of toxicants with ASD (the second category) was weaker compared with the evidence associating estimated exposures to toxicants in the environment and ASD risk (the first category) because many of the biomarker studies contained small sample sizes and the relationships between biomarkers and ASD were inconsistent across studies. Regarding the third category of studies investigating potential genetic susceptibilities to toxicants, 10 unique studies examined polymorphisms in genes associated with increased susceptibilities to toxicants, with 8 studies reporting that such polymorphisms were more common in ASD individuals (or their mothers, 1 study) compared with controls (one study examined multiple polymorphisms). Genes implicated in these studies included paraoxonase (PON1, three of five studies), glutathione S-transferase (GSTM1 and GSTP1, three of four studies), δ-aminolevulinic acid dehydratase (one study), SLC11A3 (one study) and the metal regulatory transcription factor 1 (one of two studies). Notably, many of the reviewed studies had significant limitations, including lack of replication, limited sample sizes, retrospective design, recall and publication biases, inadequate matching of cases and controls, and the use of nonstandard tools to diagnose ASD. The findings of this review suggest that the etiology of ASD may involve, at least in a subset of children, complex interactions between genetic factors and certain environmental toxicants that may act synergistically or in parallel during critical periods of neurodevelopment, in a manner that increases the likelihood of developing ASD. Because of the limitations of many of the reviewed studies, additional high-quality epidemiological studies concerning environmental toxicants and ASD are warranted to confirm and clarify many of these findings.
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Affiliation(s)
- D A Rossignol
- Family Medicine, Rossignol Medical Center, Irvine, CA, USA
| | - S J Genuis
- Faculty of Medicine, University of Alberta, Edmonton, AB, Canada
| | - R E Frye
- Arkansas Children's Hospital Research Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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Persico AM, Merelli S. Environmental Factors in the Onset of Autism Spectrum Disorder. CURRENT DEVELOPMENTAL DISORDERS REPORTS 2014. [DOI: 10.1007/s40474-013-0002-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kern JK, Haley BE, Geier DA, Sykes LK, King PG, Geier MR. Thimerosal exposure and the role of sulfation chemistry and thiol availability in autism. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2013; 10:3771-800. [PMID: 23965928 PMCID: PMC3774468 DOI: 10.3390/ijerph10083771] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 07/10/2013] [Accepted: 07/11/2013] [Indexed: 01/22/2023]
Abstract
Autism spectrum disorder (ASD) is a neurological disorder in which a significant number of the children experience a developmental regression characterized by a loss of previously acquired skills and abilities. Typically reported are losses of verbal, nonverbal, and social abilities. Several recent studies suggest that children diagnosed with an ASD have abnormal sulfation chemistry, limited thiol availability, and decreased glutathione (GSH) reserve capacity, resulting in a compromised oxidation/reduction (redox) and detoxification capacity. Research indicates that the availability of thiols, particularly GSH, can influence the effects of thimerosal (TM) and other mercury (Hg) compounds. TM is an organomercurial compound (49.55% Hg by weight) that has been, and continues to be, used as a preservative in many childhood vaccines, particularly in developing countries. Thiol-modulating mechanisms affecting the cytotoxicity of TM have been identified. Importantly, the emergence of ASD symptoms post-6 months of age temporally follows the administration of many childhood vaccines. The purpose of the present critical review is provide mechanistic insight regarding how limited thiol availability, abnormal sulfation chemistry, and decreased GSH reserve capacity in children with an ASD could make them more susceptible to the toxic effects of TM routinely administered as part of mandated childhood immunization schedules.
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Affiliation(s)
- Janet K. Kern
- Institute of Chronic Illnesses, Inc., Silver Spring, MD 20905, USA; E-Mails: (D.A.G.); (M.R.G.)
| | - Boyd E. Haley
- Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA; E-Mail:
| | - David A. Geier
- Institute of Chronic Illnesses, Inc., Silver Spring, MD 20905, USA; E-Mails: (D.A.G.); (M.R.G.)
| | - Lisa K. Sykes
- CoMeD, Inc., Silver Spring, MD 20905, USA; E-Mails: (L.K.S.); (P.G.K.)
| | - Paul G. King
- CoMeD, Inc., Silver Spring, MD 20905, USA; E-Mails: (L.K.S.); (P.G.K.)
| | - Mark R. Geier
- Institute of Chronic Illnesses, Inc., Silver Spring, MD 20905, USA; E-Mails: (D.A.G.); (M.R.G.)
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23
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Etiopathogenesis of autism spectrum disorders: fitting the pieces of the puzzle together. Med Hypotheses 2013; 81:26-35. [PMID: 23622947 DOI: 10.1016/j.mehy.2013.04.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 03/26/2013] [Accepted: 04/01/2013] [Indexed: 12/19/2022]
Abstract
Autism spectrum disorders (ASD) are disorders of the central nervous system characterized by impairments in communication and social reciprocity. Despite thousands of studies on this topic, the etiopathogenesis of these disorders remains unclear, apart from a general belief that they derive from an interaction between several genes and the environment. Given the mystery surrounding the etiopathogenesis of ASD it is impossible to plan effective preventive and treatment measures. This is of particular concern due to the progressive increase in the prevalence of ASD, which has reached a figure as high as 1:88 children in the USA. Here we present data corroborating a novel unifying hypothesis of the etiopathogenesis of ASD. We suggest that ASD are disorders of the immune system that occur in a very early phase of embryonic development. In a background of genetic predisposition and environmental predisposition (probably vitamin D deficiency), an infection (notably a viral infection) could trigger a deranged immune response which, in turn, results in damage to specific areas of the central nervous system. If proven, this hypothesis would have dramatic consequences for strategies aimed at preventing and treating ASD. To confirm or refute this hypothesis, we need a novel research approach, which unlike former approaches in this field, examine the major factors implicated in ASD (genetic, infections, vitamin D deficiency, immune system deregulation) not separately, but collectively and simultaneously.
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St-Hilaire S, Ezike VO, Stryhn H, Thomas MA. An ecological study on childhood autism. Int J Health Geogr 2012; 11:44. [PMID: 23051560 PMCID: PMC3504530 DOI: 10.1186/1476-072x-11-44] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 10/07/2012] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND AND METHODS Idiopathic autism, suspected to be caused by exposure of genetically susceptible individuals to unknown environmental triggers, has increased dramatically in the past 25 years. The objectives of our study were to determine, using a linear regression model, whether the county prevalence of autism in the Pacific Northwest of the United States was associated with the source of drinking water for that county and whether this relationship was dependent on the level of environmental pollutants and meteorological factors in the county. RESULTS We found the previously reported relationship between precipitation and autism in a county was dependent on the amount of drinking water derived from surface sources in the county. We also found a positive association between the EPA's risk of neurological disease and autism, but this relationship was only present in warm areas. CONCLUSIONS Our study provides evidence for the hypothesis that environmental factors are associated with autism and that meteorological factors play a role in this relationship.
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Affiliation(s)
- Sophie St-Hilaire
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE C1A 4P3, Canada.
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