REVIEW ARTICLE Environmental neurotoxic pollutants: review Ashif Iqubal 1 & Musheer Ahmed 2 & Shahnawaz Ahmad 1 & Chita Ranjan Sahoo 3 & Mohammad Kashif Iqubal 2 & Syed Ehtaishamul Haque 1 Received: 21 March 2020 /Accepted: 16 August 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract Environmental pollutants are recognized as one of the major concerns for public health and responsible for various forms of neurological disorders. Some of the common sources of environmental pollutants related to neurotoxic manifestations are industrial waste, pesticides, automobile exhaust, laboratory waste, and burning of terrestrial waste. Among various environmen- tal pollutants, particulate matter, ultrafine particulate matter, nanoparticles, and lipophilic vaporized toxicant (acrolein) easily cross the blood–brain barrier, activate innate immune responses in the astrocytes, microglia, and neurons, and exert neurotoxicity. Growing shreds of evidence from human epidemiological studies have correlated the environmental pollutants with neuroin- flammation, oxidative stress, endoplasmic reticulum stress, mitochondrial dysfunction, myelin sheath disruption, and alterations in the blood–brain barrier anatomy leading to cognitive dysfunction and poor quality of life. These environmental pollutants also considerably cause developmental neurotoxicity, exhibit teratogenic effect and mental growth retardance, and reduce IQ level. Until now, the exact mechanism of pollutant-induced neurotoxicity is not known, but studies have shown interference of pollutants with the endogenous antioxidant defense system, inflammatory pathway (Nrf2/NF-kB, MAPKs/PI3K, and Akt/ GSK3β), modulation of neurotransmitters, and reduction in long-term potentiation. In the current review, various sources of pollutants and exposure to the human population, developmental neurotoxicity, and molecular mechanism of different pollutants involved in the pathogenesis of different neurological disorders have been discussed. Keywords Heavy metals . Nanoparticles . Blood . brain barrier . Microglia . Alzheimer’s disease and dementia Introduction Neurotoxicity is an etiological phenomenon of alteration in the structure and function of the central nervous systems (CNS) via a biological, chemical, or physical agent (Salvi et al. 2020). Diseases resulting due to neurotoxicity include Alzheimer’s disease (AD), Parkinson’s disease (PD), cog- nitive disorders, neurovascular diseases such as brain aneu- rysms, neurodevelopmental diseases such as attention deficit hyperactive disorder (ADHD), intellectual disability, and autism spectrum disorder (ASD) (Diaz-Ortiz and Chen- Plotkin 2020). Major factors contributing to neurotoxicity are trauma, genetic defect, mental stress, co-existing disease conditions, environmental contaminants, heavy metals, air pollution, and organotins (Bertotto et al. 2020). Out of all these aforementioned contributing factors, environmental pollutants are one of the major players in the event of neu- rotoxicity. Illegal or legal mining, wrong agriculture prac- tices, and ungoverned manufacturing practice in the phar- maceutical, beverage, and food industry are the various sources from where environmental pollutants are released (Bharagava et al. 2020; Vargas and Ponce-Canchihuamán 2017). Intensive agriculture practices generate new risk as more amount of herbicides, pesticides, fertilizers, and hor- mones are used for germination and growth. These practices are more common in the developing countries since laws for the environment are not very stringent or practically non- existent (Putra et al. 2020). All these activities have a sim- ilarity, i.e., use and discrete used and non-guided discharge of toxicants/pollutants such as lead, pesticides, herbicides, Responsible editor: Mohamed M. Abdel-Daim * Syed Ehtaishamul Haque haquepharm@gmail.com 1 Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India 2 Department of Pharmaceutics, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India 3 Central Research Laboratory, Institute of Medical Sciences & Sum Hospital, Siksha ‘O’ Anusandhan (Deemed to be University), Bhubaneswar, Odisha 751003, India Environmental Science and Pollution Research https://doi.org/10.1007/s11356-020-10539-z