Patrick Fenichel ^1* Emiko Todaka ² Ruth Etzel ³ Chang-chuan Chan ⁴ Robert Barouki ⁵ Nicolas Chevalier ¹ Jean-Baptiste Fini ⁶ kirsten poore ⁷ kou Sakabe ² Valérie Siroux ⁸ midori yamamoto ² chisato mori ²

• ¹ Université Côte d'Azur, Nice, France
• ² Center for Preventive Medical Sciences, Chiba University, Chiba, Japan
• ³ Milken Institute School of Public Health, George Washington University, Washington, D.C., District of Columbia, United States
• ⁴ College of Public Health, National Taiwan University, Taipei, Taiwan
• ⁵ University Paris-Descartes, Paris/France, France
• ⁶ Centre National de la Recherche Scientifique (CNRS), Paris, France
• ⁷ Faculty of Medicine, University of Southampton, Southampton, Hampshire, United Kingdom
• ⁸ INSERM U1209 Institut pour l'Avancée des Biosciences (IAB), La Tronche, Rhône-Alpes, France

Non-communicable diseases including neuro-developmental, reproducWve, metabolic, cardiovascular, oncologic, allergic/immune and neurodegeneraWve diseases have become more frequent worldwide than infecWous diseases 1 . Since 1990, there has been a marked shi_ in the global burden due to years lived with disability from communicable diseases to noncommunicable diseases and injuries. 2 Non-communicable diseases kill 41 million people each year, equivalent to 74% of all deaths globally. 3 Adults with NCDs had an increased risk of death during the COVID pandemic and could be similarly at risk during future epidemics. 4 Diseases of pure geneWc origin with single germinal mutaWons are found only in a very small proporWon of chronic diseases. Chronic, non-communicable diseases are now considered to result from a combinaWon of geneWc suscepWbility and a variety of environmental exposures. Among these environmental exposures, air and chemical polluWon play a major role, but lifestyle factors, nutriWon, psychological stress and socioeconomic condiWons also are involved. To improve environmental exposure assessment, Christopher Wild proposed the concept of the exposome in 2005: "At its most complete, the exposome encompasses life-course environmental exposures (including lifestyle factors), from the prenatal period onwards" 5 . The rapid environmental changes of the Anthropocene have resulted in harms to human and veterinary health that can no longer be isolated from harms to Earth's environment, including air 6 , chemical 7 and ocean 8 polluWon, the decrease in biodiversity or climate change, an approach known as "One Health". 9 Despite calls from researchers 10 , the curriculum of most medical schools in the world does not yet incorporate concepts concerning the impact of the environment on human health and the consequences for public health policy and prevenWve medical pracWce 11 . Medical students themselves have recognized this, as recently reported in a French naWonal survey which showed they considered the topic of prevenWve and environmental medicine to be insufficiently taught. 12 While there have been some student-led iniWaWves 13 , our aim was to establish a faculty-led educaWon program on environmental prevenWve medicine in the medical school curriculum. This medical field includes individual paWent care, populaWon health management, and nonmedical risk management intervenWons, such as product subsWtuWon and paWent educaWon. The field draws on both One Health 9 and Planetary Health 14 concepts. 15 We report here our posiWve experience in enhancing student understanding of environmental prevenWve medicine. An official collaboraWon between Chiba University in Japan and University of Côte d'Azur in Nice, France, was established in 2016, following iniWal meeWngs between the teams of Professor Chisato Mori, Director of the Research Center for PrevenWve Medical Sciences in Chiba University, and Professor Patrick Fénichel, Director of the Endocrine and ReproducWve Medicine Department of the University Hospital of Nice (University of Côte d'Azur). A_er iniWally collaboraWng around the theme of human exposure to endocrine disrupWng chemicals, this expanded to a wider goal of exchanging scienWfic research and educaWon of students about prevenWve environmental medicine, both in Nice and beyond. An educaWon course was designed a_er extensive discussions that would cover topics that newly trained doctors would likely face in their pracWces, all core to the pracWce of environmental prevenWve medicine. 16 There was a parWcular focus on the effect of environmental exposures during criWcal periods of early life to, as a foundaWon to reduce the life-Wme risk of non-communicable disease. Two iniWal iteraWons of this course took place in 2017 and 2018 at the University Hospital of Nice, which included a small group of students from Chiba University and a larger cohort of about 80 Year 3-5 medical students from University of Côte d'Azur, who amended on a voluntary basis. In 2018, a brief student evaluaWon of the course was undertaken that showed it was posiWvely received (overall approval raWng of 4.4 out of 5, n = 26 respondents). Informed by these iniWal experiences of the educaWon course, since 2022, every student at University of Côte d'Azur's Faculty of Medicine has benefited from environmental health teaching. In Year 1, 6 hours of teaching are dedicated to global concepts: One Health, major health issues linked to environmental issues, methodologies for quanWfying hazards and risks, and the concept of endocrine disruptors. In Year 3, 12 hours of teaching are devoted to environmental health and climate change. These efforts have been shaped by a requirement within the French naWonal program for medical faculWes to include environmental medicine in Year 2 of the curriculum. The most recent ediWon of the environmental prevenWve medicine course took place in November 2023 at the Faculty of Medicine of University of Côte d'Azur in Nice. This course was organized for final year (Year 6) students who thus had a higher general background scienWfic knowledge and ability to embed environmental medicine in their clinical experience. In addiWon, following a proposal from the Faculty of Medicine's Dean, the course was mandatory, with students registering their amendance twice a day before each half-day session. Those who were not able to amend were required to take a test a_er watching a recording of the course. Students compleWng the course were given an advantage for the final compeWWon leading to the naWonal choice for the future student's specialty. A cohort of 180 students, along with 10 invited students from Chiba University amended the course, which was given in English with simultaneous translaWon to French throughout. The program of the course is shown in Table 1 and included 30 minute lecture-style presentaWons followed by 15 minutes of quesWons and discussion with the students. A preand post-course knowledge quiz was delivered via an online plaporm (Vevox) based on the topics in each presentaWon (12 mulWple choice quesWons) at the start and end of the course. The learning outcomes of the course were to ensure students understood several environmental prevenWve medicine concepts, including how to take an environmental history, environmental injusWce, the Developmental Origins of Health and Disease (DOHaD) 17 , the role of epigeneWcs in the occurrence of chronic diseases, epidemiological transiWon, exposome 18 and mechanisms of endocrine disrupWng chemicals. 19 All topics were supported by epidemiological and experimental studies and were delivered by a mulWdisciplinary team of clinicians and scienWsts. Our objecWve was to help students to understand the physiopathological origins of non-communicable diseases, the concepts of One Health and planetary health, and the importance of educaWon and prevenWon at criWcal periods of development. 20,21 This involved discussion of the individual and collecWve public health responsibiliWes, as well as the role of general pracWWoners as public health actors at the prevenWve medical level. 22 The expert internaWonal speakers provided students with a pracWcal understanding of the environmental health problems experienced by different cultures and socieWes and the common threats to human health caused by environmental changes. This allowed the students to think more broadly than through their own cultural lens. We believe this approach is necessary to give students the cultural sensiWvity to understand environmental injusWce across generaWons, race, wealth and poverty, in the global north and south. Most students stayed unWl the end of the course; they remained amenWve and interacWve, asking many perWnent quesWons at the end of each lecture. They explained that they had not previously received much teaching on these topics but we were impressed by their ability to understand, integrate, synthesize these new data and concepts and to realize the implicaWons at the individual and collecWve point of view. When comparing student knowledge before and a_er the course, the percentage of students answering each quesWon correctly was increased for all quesWons, showing effecWveness of the teaching and learning during the course (Table 2). All students were asked for their evaluaWon of the course on compleWon: 38 students provided numerical (on a scale of 1 to 5) and qualitaWve feedback. Students found the course intellectually sWmulaWng (score 4.4 out of 5), clinically relevant (score 4.4 out of 5) and would recommend the course to other students (score 4.7 out of 5). Students clearly understood the aims of the course (score 4.8 out of 5) and found the material covered was appropriate (score 4.6 out of 5), given their prior knowledge as Year 6 students. The overall course raWng was 4.6 out of 5 (95% giving a raWng of 4 or 5). Crucially, 74% of students who responded agreed that the course would influence their future pracWce as a doctor. We believe that bringing French students together with Japanese students for this course helped to create a collaborative learning environment to foster the development of students who will be equipped to respond to global problems through effective collaboration and transdisciplinarity. 23 Although some students found the course too intensive at Wmes, with some sessions too long and overly scienWfic in nature, their level of interacWon with the course suggested they were conscious it was important to them as future doctors. We explained to them that we deliberately presented original epidemiological and experimental data during the lectures to support the conclusions, following an evidence-based medicine approach. Students suggested that the course should dedicate more Wme to providing pracWcal advice and methods to educate their paWents. Some students were worried about not being able to advise paWents in their medical pracWce due to lack of Wme, pracWcal soluWons and knowledge. We understood that they wanted more pracWcal advice, paWent-focused sources of informaWon, quesWonnaires, applicaWons, and pedagogical methods to use with their paWent consultaWons. Students were also conscious that the course content was important for their own lives and for humanity in general, developing philosophical reflecWons and quesWons. Some even quesWoned whether it was reasonable or perWnent to start a family given the many environmental and climate pressures facing them. They could not understand why poliWcians and policy makers did not care more about the link between the environment and health. Our ongoing educa*on approach The feedback from the 2023 course and its earlier iteraWons were overwhelmingly posiWve and this is now shaping the future of the medical curriculum at University of Côte d'Azur's Faculty of Medicine. In addiWon to content in Years 1-3, in 2024 a social responsibility and the ecodesign of healthcare theme has been added to the curriculum (15 hours of workshop teaching). In Year 4, students are trained to provide pracWcal advice on prevenWon and promoWon of environmental health, for use with secondary school students and staff in vocaWonal training, directly responding to students' request for pracWcal advice to help their paWents. In addiWon, the Faculty is proposing 6-12 hours of teaching on environmental medicine in Year 6, based on the model of our 2023 course, to reinforce specific knowledge they have achieved throughout the curriculum. All medical schools have a crowded curriculum and there is considerable compeWWon for Wme to be allocated to new topics. We argue that future doctors need to be prepared to deal with the health challenges of our changing environment. Including new content about environmental prevenWve medicine could be done using various methods, such as the course presented here, but need not be burdensome for students. Others have used an 'infusion' approach to gently reinforce concepts over many years of study and in a variety of contexts. 24 This is aligned with the new approach at University of Côte d'Azur which begins in Year 1 and is reinforced in Year 6 following recent naWonal recommendaWons. We conclude that this original and innovaWve teaching experience should not only be a recommendaWon but an absolute necessity to introduce and develop environmental prevenWve medicine into the curriculum in worldwide medical faculWes. We have proposed one model based on a final year course that has been effecWve and well-received. This may have three posiWve general consequences for future health care pracWWoners: 1) to bring more amenWon to the impact of environment on health in clinical pracWce, 2) to give perWnent prevenWve medical advice to paWents and 3) to enable future specialists in environment health to inform policymakers on ways to reduce harmful environmental exposures at local, naWonal and internaWonal level. We believe this is a universal competence that all medical students need before they enter clinical pracWce in our increasingly complex and inter-connected world. We declare no compeWng interests. Acknowledgments This viewpoint received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.