The Exposome: A Primer

By Gary W. Miller

The Exposome: A Primer is the first book dedicated to exposomics, detailing the purpose and scope of this emerging field of study, its practical applications and how it complements a broad range of disciplines. Genetic causes account for up to a third of all complex diseases. (As genomic approaches improve, this is likely to rise.) Environmental factors also influence human disease but, unlike with genetics, there is no standard or systematic way to measure the influence of environmental exposures. The exposome is an emerging concept that hopes to address this, measuring the effects of life-long environmental exposures on health and how these exposures can influence disease.

This systematic introduction considers topics of managing and integrating exposome data (including maps, models, computation, and systems biology), "-omics"-based technologies, and more. Both students and scientists in disciplines including toxicology, environmental health, epidemiology, and public health will benefit from this rigorous yet readable overview.

• Language: English
• Publisher: Academic Press
• Release date: Nov 16, 2013
• ISBN: 9780124172180

Gary W. Miller

Gary W. Miller, PhD is the Vice Dean for Research Strategy and Innovation and Professor of Environmental Health Sciences at the Mailman School of Public Health at Columbia University. He was founding director of the HERCULES Exposome Research Center at Emory University, the first exposome-based center in the U.S. In addition to his work on the exposome, his research interests include the role of environmental factors in neurodegenerative disorders, such as Parkinson’s disease and Alzheimer’s disease, and the regulation of dopamine signaling in the brain. He served as Editor-in-Chief of Toxicological Sciences, the official journal of the Society of Toxicology, from 2013-2019.

Book preview

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Preface

The idea for this book was conceived as the author organized and directed a course on the topic (Genome, Exposome, and Health) at Emory University in 2013. The course was based upon the research of faculty members at Emory University and published work from the primary literature. Students expressed an interest in having access to more background information about the course material. At the time no such material was available. A brief discussion with the editorial staff at Elsevier at a Society of Toxicology meeting led to a book proposal and a rapid turnaround of the text before you.

Dean Jones at Emory University, Eberhard Voit at Georgia Tech, and I have been involved in a series of collaborations over the past several years that touched on many of the same questions and challenges that surround the exposome. Dr. Jones and I were slowly emerging from our mechanistic biochemical and toxicological studies and embracing the computational, bioinformatic, and systems biology tools that were becoming necessary to unravel the scientific questions we were pursuing. Dr. Voit was especially helpful in opening my eyes to the importance of computational and systems biology. Many of these early discussions provided the impetus for the development of the course, as well as the proposal we developed for a center grant focused on the exposome. That proposal was ultimately funded by the US National Institute of Environmental Health Sciences in 2013. HERCULES: Health and Exposome Research Center at Emory provides conceptual and technical infrastructure for exposome-related research. A website, humanexposomeproject.com, has also been established to provide information to the lay and scientific public.

I would like to thank the scientists who participated in the inaugural course. Dr. Jones, Michael Zwick, Matthew Strickland, Jennifer Mulle, Lance Waller, Yang Liu, Yan Sun, Jeremy Sarnat, Dana Barr, Eberhard Voit (Georgia Tech), and Chirag Patel (Stanford). I am especially thankful to the students who participated in this inaugural course. They were very patient as we developed the course de novo. Their willingness to sign up for a course that included a word not even found in a dictionary or Wikipedia (at that time) is a testament to their inquisitiveness and openness to new ideas. An additional thanks goes out to Chandresh Ladva, a doctoral student in Environmental Health Sciences at Emory, for reading the manuscript and providing insightful feedback. I also want to thank the group of students in the Pharmacology and Toxicology Program at the University of Montana who viewed and critiqued the introductory lecture. Getting feedback from a group of students not associated with our institution helped with the further development of the course.

To faculty members attempting to integrate exposome-based concepts into their curriculum, I believe that you will find the topic to be one that engages and challenges the students (and yourselves). I hope that this introductory text makes it easier to do so. Even though it is in its primordial stage from a scientific perspective, the exposome has the potential to play a critical role in advancing our understanding of the environment in human health. Introducing the concept to the upcoming generation of scientists should instill a desire to better understand how the environment impacts health and hopefully inspire them to pursue the challenging questions surrounding the exposome. My hope is that you use the exposome to shamelessly and unabashedly promote the importance of the environment in health and disease.

I do not presume to be an authority on the exposome per se, but rather an environmental health scientist who is exceedingly interested in the concept. I undertook this project as a sole author because I thought it was more important to provide a focused and consistent, albeit idealistic, mindset throughout the book rather than provide an overwhelming, and potentially fractured, compilation on the topic. Given the early stage of the development of the exposome, it would be difficult, if not impossible, to generate such an authoritative tome at this time, even though such a work will be a welcome addition to the field. Certainly, such treatises about the exposome are forthcoming by those that are experts in particular aspects of the exposome, but at this stage it was my view that an introduction, or primer, was the most appropriate tack, that is, a course of action meant to minimize opposition to the attainment of a goal. This is necessary because there has been some reluctance, skepticism, and opposition to this topic. When one considers the potential utility of the exposome it becomes clear that this is, indeed, something that must be pursued. I have chosen to use the first person in those sections where I espouse my views and opinions that may not be consistent with others in the field, and I take responsibility for these thoughts. My goal is to engage trainees and colleagues so that they contemplate and critically analyze the exposome-related concepts and approaches.

Chapter 1

The Exposome

Purpose, Definition, and Scope

The exposome is a recently introduced concept aimed at explaining the complex exposures we face as humans. It can be viewed as the environmental equivalent of the human genome. The exposome represents the totality of exposures we face throughout our lives and includes the food we ingest, the air we breathe, the objects we touch, the psychological stresses we face, and the activities in which we engage. This chapter provides a detailed definition of the term, an overview of the concept, and its potential utility. It also introduces the challenges the scientific community must overcome to make the exposome a useful tool in public health.

Keywords

Genome; environment; exposures; pollution; public health

1.1 Why a Primer?

Let me begin by explaining the title of this book. The exposome, which one can view as the environmental equivalent of the genome and an all-encompassing view of the exposures we encounter throughout our lives, is obviously the topic of the book, but why a primer? A primer is a small introductory book on a subject. The word, which has a short or soft i, comes from the Medieval Latin word for first. It was not intended to be haughty or presumptuous, but rather exactly what it is—a small, introductory book. The connotation is distinct from that used when referring to paint (long i), but interestingly, that definition is also appropriate—the first coat. This book is for people who are interested in taking a first look at the exposome, to set the initial foundation for further study. The goal of this text is to provide an overview of the concept of the exposome and to explain how it can be used by students, scientists, physicians, and the general public to better understand the importance of the environment in health. Each chapter provides suggested readings for further study and discussion questions for further