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It traces discovery history, Earth’s N2-rich atmosphere evolution, and links to oxygen, then explores N2 quantum state properties to explain inertness and physiologic lethality when excessive, especially without O2.",{"@graph":14,"@context":73},[15,34,56],{"@type":16,"itemListElement":17},"BreadcrumbList",[18,23,27,31],{"item":19,"name":20,"@type":21,"position":22},"https://docshare.wps.com","Home","ListItem",1,{"item":24,"name":25,"@type":21,"position":26},"https://docshare.wps.com/document/","Document",2,{"item":28,"name":29,"@type":21,"position":30},"https://docshare.wps.com/document/healthcare/","Healthcare",3,{"item":32,"name":10,"@type":21,"position":33},"https://docshare.wps.com/document/physiology-of-nitrogen-a-life-or-death-matter/414837/",4,{"url":32,"name":10,"@type":35,"image":36,"author":41,"headline":10,"publisher":44,"fileFormat":47,"inLanguage":8,"description":12,"dateModified":48,"datePublished":49,"encodingFormat":47,"isAccessibleForFree":50,"interactionStatistic":51},"DigitalDocument",{"url":37,"@type":38,"width":39,"height":40},"https://docshare.wps.com/thumbnails/physiology-of-nitrogen-a-life-or-death-matter/414837.png","ImageObject",300,407,{"name":42,"@type":43},"Aurelia","Person",{"url":19,"name":45,"@type":46},"DocShare","Organization","application/pdf","2026-10-23","2026-09-28",true,{"@type":52,"interactionType":53,"userInteractionCount":55},"InteractionCounter",{"@type":54},"ViewAction",7,{"@type":57,"mainEntity":58},"FAQPage",[59,65,69],{"name":60,"@type":61,"acceptedAnswer":62},"Why is nitrogen (N2) abundant in inspired air?","Question",{"text":63,"@type":64},"In each breath, most inspired molecules are N2 because it constitutes roughly 80% of the atmospheric air surrounding us.","Answer",{"name":66,"@type":61,"acceptedAnswer":67},"Why has N2 traditionally received less attention from physiologists?",{"text":68,"@type":64},"N2 has been viewed as metabolically inert since it is relatively nonreactive and cannot support combustion or life compared with molecular oxygen (O2).",{"name":70,"@type":61,"acceptedAnswer":71},"What does the review argue about the physiology of N2 in excess or in the exclusion of O2?",{"text":72,"@type":64},"The review explains that N2’s unique physiochemical properties help account for why it can be metabolically inert under normal conditions yet physiologically deadly when present in excess and especially without O2.","https://schema.org",{"og:url":32,"og:type":75,"og:title":10,"og:site_name":45,"og:description":12},"article",{"robots":77,"canonical":32},"index,follow",{"doc_id":79,"site_id":7},414837,1791309776,{"code":4,"msg":82,"data":83},"success",[84,88,92,96,101,106,109,114,119,122,126],{"id":22,"doc_module":4,"doc_module_name":25,"category_name":85,"show_sort_weight":86,"slug":87},"Story & Novel",90,"story-novel",{"id":26,"doc_module":4,"doc_module_name":25,"category_name":89,"show_sort_weight":90,"slug":91},"Literature",80,"literature",{"id":33,"doc_module":4,"doc_module_name":25,"category_name":93,"show_sort_weight":94,"slug":95},"Exam",70,"exam",{"id":97,"doc_module":4,"doc_module_name":25,"category_name":98,"show_sort_weight":99,"slug":100},5,"Comic",60,"comic",{"id":102,"doc_module":4,"doc_module_name":25,"category_name":103,"show_sort_weight":104,"slug":105},6,"Technology",50,"technology",{"id":55,"doc_module":4,"doc_module_name":25,"category_name":29,"show_sort_weight":107,"slug":108},40,"healthcare",{"id":110,"doc_module":4,"doc_module_name":25,"category_name":111,"show_sort_weight":112,"slug":113},8,"Research & Report",30,"research-report",{"id":115,"doc_module":4,"doc_module_name":25,"category_name":116,"show_sort_weight":117,"slug":118},9,"Religion & Spirituality",20,"religion-spirituality",{"id":117,"doc_module":4,"doc_module_name":25,"category_name":120,"show_sort_weight":117,"slug":121},"World Cup","world-cup",{"id":123,"doc_module":4,"doc_module_name":25,"category_name":124,"show_sort_weight":123,"slug":125},10,"Lifestyle","lifestyle",{"id":127,"doc_module":4,"doc_module_name":25,"category_name":128,"show_sort_weight":97,"slug":129},19,"General","general",{"code":4,"msg":82,"data":131},{"doc_id":79,"user_id":132,"nickname":42,"user_avatar":133,"doc_module":4,"category_id":55,"category_name":29,"doc_title":10,"doc_description":12,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":55,"is_deleted":4,"is_public":22,"is_downloadable":22,"audit_status":22,"page_count":139,"language":140,"language_code":8,"site_id":7,"html_lang":8,"table_of_contents":141,"faqs":142,"seo_title":143,"seo_description":12,"update_tm":144,"read_time":145,"preview_page_count":4},1099514068365,"https://ap-avatar.wpscdn.com/avatar/10000253d8d9f28188e?_k=1776742907772140068","DOI: 10.1113/EP092946  \nRESEARCH ARTICLE  \nPhysiology of nitrogen: A life or death matter  \nDamian M. Bailey1   Vaughan G. Macefield2   David C. Poole3,4   \n1 Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, UK  \n2 Department of Neuroscience, School of Translational Medicine, Monash University, Melbourne, Victoria, Australia  \n3 Department of Kinesiology, Kansas State University, Manhattan, Kansas, USA  \n4 Department of Anatomy & Physiology, Kansas State University, Manhattan, Kansas, USA  \nCorrespondence  \nDamian M. Bailey, Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Alfred Russel Wallace Building, Pontypridd CF37 4AT, [UK. Email:](UK. Email: damian.bailey@southwales.ac.uk)[ damian.bailey@southwales.ac.uk](UK. Email: damian.bailey@southwales.ac.uk)  \nFunding information  \nD. M. B. is supported by a Royal Society Wolfson Research Fellowship (Grant No. WM170007).  \nD.C. P. is funded by the Elizabeth Chapin Burke Chair in Health and Human Sciences.  \nHandling Editor: Ronan Berg  \nAbstract  \nWith each breath, four out of every five molecules we inspire are nitrogen (N2 ), since this gas constitutes ∼80% of the atmospheric air that surrounds us. Despite its abundance and unlike molecular oxygen, N2 has traditionally held less appeal among physiologists given its lack of reactivity and corresponding inability to support combustion or life, rendering it metabolically nugatory. The controversial application of N2 asphyxiation for the inhumane purposes of human execution of convicted criminals and assisted suicide of a terminally ill patient has thrust this important gas into the scientific and public spotlight, sparking widespread condemnation. In the current review, we take an opportunity to explore the molecular bases and clinical consequences linked to the Janus-faced physiology of N2 to better explain its lifeand-death qualities. We highlight the complex history that led to its discovery and the physio-geochemical evolution of Earth’s uniquely N2-rich atmosphere, including intimate links with oxygen (O2 ), another life-and-death homonuclear diatomic gas that preceded aerobic respiration and the emergence of complex multicellular life. Diving deep into N2’s quantum state, we expose its unique physiochemical properties to better understand why this gas is metabolically inert and physiologically deadly when in excess and especially to the exclusion of O2. We apply this integrated physiological knowledge to further inform the controversial public debate and directly challenge themisconceived notion that N2 gas asphyxiation offers a quick, indolent and dignified death for the inhumane purposes of human execution and assisted suicide.  \nKEYWORDS  \nasphyxiation, assisted suicide, execution, inert, nitrogen gas  \n‘Neither will I administer a poison to anybody when asked to do so, nor will I suggest such a course.’Hippocrates, 460–370 BCE.  \n1  INTRODUCTION  \nWith every resting breath, we inspire a staggering ∼1.6 × 1021 molecules of dinitrogen gas (N2 ), comprising ∼78% of the ∼2.0 × 1021 (sextillion) molecules of atmospheric air that surrounds us (Box 1). To put the magnitude of this number into clearer context, convert the 4. 54 (± 0.05) billion years that reflects the geological age of Earth into seconds: you will still fall short by more than four orders of magnitude! Yet, remarkably, of the sextillion molecules of N2 that enter our lungs  \nThis is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.  \n© 2025 The Author(s). Experimental Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.  \nBAILEY ET AL.  \n271  \nBOX 1 Every breath you take.  \nCalculating how much N2 we inspire with each breath:  \nAssuming 0.5 L tidal volume and 37◦ C body tem","cbCaibbIpzb0nyTb","https://ap.wps.com/l/cbCaibbIpzb0nyTb","pdf",2255176,13,"English","# Abstract\n# Key words\n# 1 INTRODUCTION\n## Box 1 Every breath you take.\n# Calculating how much N2 we inspire with each breath","[{\"question\":\"Why is nitrogen (N2) abundant in inspired air?\",\"answer\":\"In each breath, most inspired molecules are N2 because it constitutes roughly 80% of the atmospheric air surrounding us.\"},{\"question\":\"Why has N2 traditionally received less attention from physiologists?\",\"answer\":\"N2 has been viewed as metabolically inert since it is relatively nonreactive and cannot support combustion or life compared with molecular oxygen (O2).\"},{\"question\":\"What does the review argue about the physiology of N2 in excess or in the exclusion of O2?\",\"answer\":\"The review explains that N2’s unique physiochemical properties help account for why it can be metabolically inert under normal conditions yet physiologically deadly when present in excess and especially without O2.\"}]","Physiology of nitrogen: A life or death matter | PDF",1790598831,33]