Citation: Shehata, S.A.; Toraih, E.A.; Ismail, E.A.; Hagras, A.M.; Elmorsy, E.; Fawzy, M.S. Vaping, Environmental Toxicants Exposure, and Lung Cancer Risk. Cancers 2023, 15, 4525. https://doi.org/10.3390/ cancers15184525 Academic Editors: Abhijit Chakraborty, Faisal Aziz and Sandro Arguelles Received: 30 April 2023 Revised: 18 June 2023 Accepted: 22 June 2023 Published: 12 September 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). cancers Review Vaping, Environmental Toxicants Exposure, and Lung Cancer Risk Shaimaa A. Shehata 1 , Eman A. Toraih 2,3 , Ezzat A. Ismail 4 , Abeer M. Hagras 1 , Ekramy Elmorsy 5,6 and Manal S. Fawzy 7, * 1 Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Suez Canal University, Ismailia 41522, Egypt; shaimaa_shehata@med.suez.edu.eg (S.A.S.); abeerhagras@med.suez.edu.eg (A.M.H.) 2 Division of Endocrine and Oncologic Surgery, Department of Surgery, School of Medicine, Tulane University, New Orleans, LA 70112, USA; etoraih@tulane.edu 3 Genetics Unit, Department of Histology and Cell Biology, Faculty of Medicine, Suez Canal University, Ismailia 41522, Egypt 4 Department of Urology, Faculty of Medicine, Suez Canal University, Ismailia 41522, Egypt; boezzat@med.suez.edu.eg 5 Department of Pathology, Faculty of Medicine, Northern Border University, Arar 73213, Saudi Arabia; ekramy.elmorsy@nbu.edu.sa 6 Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt 7 Department of Biochemistry, Faculty of Medicine, Northern Border University, Arar 73213, Saudi Arabia * Correspondence: manal.darwish@nbu.edu.sa Simple Summary: Lung cancer (LC) is considered one of the most common cancers globally. Numer- ous studies have determined the relations between E-cigarette, or vaping, products (EVPs) and many proven environmental toxicants in LC development. Even though tobacco smoke remains the chief cause of LC, there is increasing concern that EVPs use could also increase LC risk. Consumption of EVPs has been dramatically increasing world-wide, particularly among younger people and non- smokers. This review seeks to consolidate the known environmental toxicants and EVPs contributing to LC to ensure that future research endeavors may identify key focus areas. Thus, EVPs are a highly potential risk factor for LC and an area of significant concern for the future. Since these factors have been linked to the development of LC, more research is needed to determine the mechanisms by which they affect lung pathology. Discovering the pathophysiology of EVPs use and environmental toxicant exposure in LC development can facilitate the adoption of exposure reduction strategies. Abstract: Lung cancer (LC) is the second-most prevalent tumor worldwide. According to the most recent GLOBOCAN data, over 2.2 million LC cases were reported in 2020, with an estimated new death incident of 1,796,144 lung cancer cases. Genetic, lifestyle, and environmental exposure play an important role as risk factors for LC. E-cigarette, or vaping, products (EVPs) use has been dramatically increasing world-wide. There is growing concern that EVPs consumption may increase the risk of LC because EVPs contain several proven carcinogenic compounds. However, the relationship between EVPs and LC is not well established. E-cigarette contains nicotine derivatives (e.g., nitrosnornicotine, nitrosamine ketone), heavy metals (including organometal compounds), polycyclic aromatic hydro- carbons, and flavorings (aldehydes and complex organics). Several environmental toxicants have been proven to contribute to LC. Proven and plausible environmental carcinogens could be physical (ionizing and non-ionizing radiation), chemicals (such as asbestos, formaldehyde, and dioxins), and heavy metals (such as cobalt, arsenic, cadmium, chromium, and nickel). Air pollution, especially particulate matter (PM) emitted from vehicles and industrial exhausts, is linked with LC. Although extensive environmental exposure prevention policies and smoking reduction strategies have been adopted globally, the dangers remain. Combined, both EVPs and toxic environmental exposures may demonstrate significant synergistic oncogenicity. This review aims to analyze the current publications on the importance of the relationship between EVPs consumption and environmental toxicants in the pathogenesis of LC. Cancers 2023, 15, 4525. https://doi.org/10.3390/cancers15184525 https://www.mdpi.com/journal/cancers