EXPOSITION TO PLASTIC AND ASSOCIATED-CHEMICALS IN NEURODEVELPMENTAL DISORDER: AN OVERVIEW

Along with the increased production and use of plastic, scientific research on its potential negative effects on human health has also increased exponentially. The literature reports several studies on animal models, highlighting the negative effects of exposure to micro- and nanoplastics and associated chemical on various aspects of global health. However, few studies specifically explore the impact of these substances on human populations. In particular, in recent years, growing interest has focused on evaluating their effects on pediatric populations, whose central nervous system is still developing. We performed an overview on the effects of micro- and nanoplastics, plasticizers, flame retardants, bisphenols, and perfluoroalkyl and polyfluoroalkyl substances on development of clinical conditions of neuropsychiatric interest, particularly regarding neurodevelopmental disorder in childhood. We considered observational studies in which pre- or postnatal exposure measurements were performed directly on human biological samples. Phthalates are associated with spontaneous pregnancy loss, low birth weight, and neurodevelopmental disorders such as decreased intelligence quotient (IQ) and difficulties in fine-motor and psychomotor development. Some polychlorinated biphenyls, polybrominated diphenyl ethers, and some PFAS (perfluoroalkyl and polyfluoroalkyl substances) have been associated with low birth weight. Exposure to PFAS has also been associated with attention deficit hyperactivity disorder (ADHD) in male children. Polybrominated diphenyl ethers (PBDEs) were negatively associated with cognitive development and decreased IQ in male children. The specific effects of micro- and nanoplastics have not yet been enough explored. The mechanisms of action, bioavailability, and long-term accumulation of these substances in tissues remain poorly understood. Furthermore, existing studies do not sufficiently explore the interactions between these substances and other environmental contaminants, which could mediate their effects. Exposure to Plastics and their associated chemicals appears to be associated with adverse outcomes across a wide range of human health domains, and recent evidence suggests a role in neurodevelopmental disorders. Future research should focus on understanding the underlying mechanisms, including epigenetic and transgenerational ones, focusing also on emerging chemicals. New epidemiological studies on human populations are needed to confirm and further explore these findings. Meanwhile reducing plastic use during pregnancy and childhood, particularly of tableware, cups, and baby bottles, could be a targeted measure to mitigate potential developmental toxicity. References 1. Symeonides  C et al. An Umbrella Review of Meta-Analyses Evaluating Associations between Human Health and Exposure to Major Classes of Plastic-Associated Chemicals. Ann Glob Health. 2024 Aug 19;90(1):52. 2. Radke EG et al. Phthalate exposure and neurodevelopment: a systematic review and meta-analysis of human epidemiological evidence. Environ Int. 2020;137:105408.3. Forns J et al. Early life exposure to perfluoroalkyl substances (PFAS) and ADHD: a meta-analysis of nine European population-based studies. Environ Health Perspect. 2020;128(5):057002