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Meta-Analysis
. 2024 Sep 3;24(1):2388.
doi: 10.1186/s12889-024-19742-w.

Environmental pollutants as risk factors for autism spectrum disorders: a systematic review and meta-analysis of cohort studies

Tatiana Duque-Cartagena  1   2 , Marcello Dala Bernardina Dalla  3   4   5 , Eduardo Mundstock  6   7 , Felipe Kalil Neto  8 , Sergio Angelo Rojas Espinoza  2 , Sara Kvitko de Moura  9 , Gabriele Zanirati  1   10 , Alexandre Vontobel Padoin  1 , Juan Gabriel Piñeros Jimenez  11 , Airton Tetelbom Stein  12 , Wilson Cañon-Montañez  13 , Rita Mattiello  14
Affiliations
Meta-Analysis

Environmental pollutants as risk factors for autism spectrum disorders: a systematic review and meta-analysis of cohort studies

Tatiana Duque-Cartagena et al. BMC Public Health. .

Abstract

Background: Autism Spectrum Disorder (ASD) is a lifelong neurodevelopmental condition affecting communication, social interaction, and behavior. Evidence suggests that environmental pollutants are associated with ASD incidence. This review aimed to analyze the effect of environmental pollutants on ASD.

Methods: Systematic review and meta-analysis of cohort studies evaluated the association between exposure to environmental pollutants and ASD. We searched COCHRANE CENTRAL, MEDLINE, CINAHL, LILACS, EMBASE, PsycINFO, Web of Science, SciELO, and gray literature from inception to January 2023. The model used for meta-analysis was inverse variance heterogeneity (IVhet). The effect measures were the beta coefficient (β) and the relative risk (RR) with their 95% confidence intervals (95% CI). Sensitivity analyses were carried out using an instrument to screen or diagnose autism.

Results: A total of 5,780 studies were identified; 27 were included in the systematic review, and 22 were included in the meta-analysis. These studies included 1,289,183 participants and 129 environmental pollutants. Individual meta-analyses found a significant association between nitrogen dioxide RR = 1.20 (95% CI: 1.03 to 1.38; I2: 91%), copper RR = 1.08 (95% CI: 1.03 to 1.13; I2: 0%), mono-3-carboxy propyl phthalate β = 0.45 (95% CI: 0.20 to 0.70; I2: 0%), monobutyl phthalate β = 0.43 (95% CI: 0.13 to 0.73; I2: 0%) and polychlorinated biphenyl (PCB) 138 RR = 1.84 (95% CI: 1.14 to 2.96; I2:0%) with ASD. Subgroup meta-analyses found a significant association with carbon monoxide RR = 1.57 (95% CI: 1.25 to 1.97; I2: 0%), nitrogen oxides RR = 1.09 (95% CI: 1.04 to 1.15; I2: 34%) and metals RR = 1.13 (95% CI: 1.01 to 1.27; I2:24%).

Conclusion: This study found positive associations nitrogen dioxide, copper, mono-3-carboxypropyl phthalate, monobutyl phthalate, and PCB 138, and the development of ASD, likewise, with subgroups of pollutants carbon monoxide, nitrogen oxides, and metals. Therefore, it is important to identify these risk factors in children and adolescents to contribute to ASD and identify prevention strategies effectively.

Keywords: Autism; Cohort studies; Environmental pollutants; Systematic review.

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Conflict of interest statement

The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Flowchart of the study selection process
Fig. 2
Fig. 2
Meta-analysis association between nitrogen dioxide and ASD
Fig. 3
Fig. 3
Meta-analysis association (A) copper; B mono-3-carboxypropyl phthalate; C monobutyl phthalate; D PCB 138 with ASD
Fig. 4
Fig. 4
Meta-analysis association of (A) carbon monoxide, B nitrogen oxides, and (C) metals with ASD
Fig. 5
Fig. 5
Meta-analysis association between organophosphates and carbamates and ASD
See this image and copyright information in PMC

References

    1. Zeidan J, Fombonne E, Scorah J, Ibrahim A, Durkin MS, Saxena S, et al. Global prevalence of autism: A systematic review update. Autism Res. 2022;15(5):778–90. 10.1002/aur.2696 - DOI - PMC - PubMed
    1. Maenner MJ, Warren Z, Williams AR, Amoakohene E, Bakian AV, Bilder DA, et al. Prevalence and Characteristics of Autism Spectrum Disorder Among Children Aged 8 Years — Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2020. MMWR Surveill Summ. 2023;72(2):1–14. 10.15585/mmwr.ss7202a1 - DOI - PMC - PubMed
    1. Lavelle TA, Weinstein MC, Newhouse JP, Munir K, Kuhlthau KA, Prosser LA. Economic burden of childhood autism spectrum disorders. Pediatrics. 2014;133(3):e520–9. - PMC - PubMed
    1. Chowdhury A, Naz A, Maiti SK. Bioaccumulation of potentially toxic elements in three mangrove species and human health risk due to their ethnobotanical uses. Environ Sci Pollut Res. 2021;28(25):33042–59. 10.1007/s11356-021-12566-w - DOI - PubMed
    1. Saghazadeh A, Rezaei N. Systematic review and meta-analysis links autism and toxic metals and highlights the impact of country development status: Higher blood and erythrocyte levels for mercury and lead, and higher hair antimony, cadmium, lead, and mercury. Prog Neuro-Psychopharmacology Biol Psychiatry. 2017;79:340–68. 10.1016/j.pnpbp.2017.07.011 - DOI - PubMed

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