Impact of Early‑Life Exposure to Environmental Neurotoxicants on Brain Development and Risk of Neurodevelopmental Disorders in Children

Environmental neurotoxicants pose significant risks to the developing brain, particularly during foetal and early postnatal periods when the blood-brain barrier is immature and highly permeable. Exposure during these critical windows of development can result in long-lasting structural and functional alterations to the nervous system, potentially leading to adverse neurodevelopmental and cognitive outcomes later in life. To synthesise current evidence on major environmental neurotoxicants, their mechanisms of action, neurodevelopmental effects, vulnerability factors, and implications for prevention and policy. A narrative review of published epidemiological, experimental, neuroimaging, and meta-analytic studies examining exposure to heavy metals, pesticides, industrial solvents, air pollutants, and endocrine-disrupting chemicals, with emphasis on developmental neurotoxicity and associated health outcomes. Environmental neurotoxicants disrupt neurodevelopment through oxidative stress, inflammation, excitotoxicity, apoptosis, epigenetic modifications, and neurotransmitter dysregulation. Prenatal and early-life exposures are associated with increased risks of autism spectrum disorder, attention-deficit/hyperactivity disorder, intellectual disabilities, behavioural disorders, reduced intelligence quotient (IQ), and structural brain abnormalities. Susceptibility is influenced by genetic factors, socioeconomic conditions, nutritional status, and combined exposures to multiple toxicants. Environmental neurotoxicants remain a major threat to child neurodevelopment, while current regulatory frameworks are insufficient to adequately protect vulnerable populations. Strengthened preventive measures, child-specific regulations, coordinated international testing, and equitable public health interventions are urgently needed to reduce exposure and safeguard brain health.