The exposome is a concept used to describe environmental exposures that an individual encounters throughout life, and how these exposures impact biology and health. It encompasses both external and internal factors, including chemical, physical, biological, and social factors that may influence human health. [1] [2] [3]
The study of the exposome has become a useful tool in understanding the interplay between genetics and environmental factors in the development of diseases, with a particular focus on chronic conditions. [4] The concept has been widely applied in fields such as epidemiology, toxicology, and public health, among others, and has led to significant advances [5] in our understanding of disease etiology and prevention.
By considering the cumulative effect of multiple exposures, it provides a holistic approach to the study of gene-environment interactions, allowing for a more accurate assessment [6] of disease risk and the identification of potential intervention strategies. [7]
Environmental exposures can have a significant impact on an individual's health. Exposure to air pollution, for example, has been linked to an increased risk of respiratory disease, heart disease, and even premature death. Similarly, exposure to certain chemicals in consumer products has been linked to an increased risk of cancer and other health problems. [5] In addition to external factors, the internal exposome can also influence an individual's health outcomes. For example, genetics can play a role in how an individual's body processes and responds to environmental exposures, [7] while the gut microbiome can affect an individual's immune system and overall health. As our understanding of the exposome continues to evolve, it is likely that we will gain new insights into the complex interplay between our environment and our health.
The term "exposome" was first coined in 2005 by Dr. Christopher Wild, [1] then-director of the International Agency for Research on Cancer (IARC), in a seminal paper published in Cancer Epidemiology, Biomarkers & Prevention. Wild's concept was initially proposed to complement the human genome, as he recognized the limitations of genetic research in explaining the etiology of chronic diseases. By suggesting a systematic approach to measuring environmental exposures, the exposome aimed to fill this knowledge gap. [8]
Various definitions of the exposome have been proposed over time, but most emphasize three main components: the external exposome, the internal exposome, and the biological response. [6] The external exposome includes general external factors, such as air pollution, diet, and socioeconomic factors, as well as specific external factors like chemicals and radiation. The internal exposome comprises endogenous factors, such as hormones, inflammation, oxidative stress, and gut microbiota. Finally, the biological response refers to the complex interactions between the external and internal exposome factors and their influence on an individual's physiology and health [9]
The field of exposome research is relatively new, rapidly evolving, and is still being developed and refined [10] by researchers in a variety of fields, including epidemiology, environmental health, and genomics. Understanding the exposome is important because it can help researchers identify the environmental factors that contribute to disease, and develop strategies for prevention and treatment.[ citation needed ]
The exposome concept presents several challenges for researchers. One of the main challenges is the complexity and diversity of exposures that individuals experience throughout their lifetime. [11] There are thousands of chemicals in the environment, [12] and individuals are exposed to different combinations of chemicals depending on their location, occupation, and lifestyles. [6] Besides this, a lack of standardized methods for measuring exposures is also challenging. [13] Traditional approaches to measuring environmental exposures have relied on individual exposure assessments, which are often expensive and time-consuming. [14] New technologies, such as high-throughput methods for measuring multiple exposures simultaneously, [15] are being developed [16] to address this challenge.
Understanding exposomes has significant implications for public health [17] and the development of more effective strategies for prevention and treatment of disease. [18] For example, if research shows that exposure to a certain chemical is linked to an increased risk of cancer, [19] policymakers can take steps to regulate or ban the use of that chemical. [20]
In addition to informing public health policies, the study of the exposome can also help individuals make more informed choices about their own health. [5] By understanding the environmental factors that contribute to disease, individuals can take steps to reduce their exposure to harmful substances and improve their overall health. [6] [21] [22] [12]
The exposome concept holds great promise [23] for advancing our understanding of the complex interplay between environmental exposures and human health. [24] As researchers continue to refine exposure assessment methods, identify novel biomarkers, and develop sophisticated computational approaches, the exposome framework is poised to revolutionize the fields of epidemiology, toxicology, and public health. [25] [26]
There have been several research initiatives aimed to better understand the exposome. One such initiative was the "Enhanced exposure assessment and omic profiling for high priority environmental exposures in Europe", [27] a program by the Imperial College of Science, Technology and Medicine in the UK. A current initiative is EXIMIOUS [28] - a 5 year Research and Innovation Action funded by the European Union's Horizon 2020 program, aimed at introducing a new approach to mapping exposure-induced immune effects by combining exposomics and immunomics in a unique toolbox. Another is the National Institutes of Health's Environmental Influences on Child Health Outcomes (ECHO) program, [29] which is studying the impact of these factors on children's health. We also have the Human Exposome Project, [30] a collaborative effort between researchers from around the world to develop tools and techniques to measure and analyze the exposome.
Furthermore, several European countries, including Sweden, France, Austria, and Czechia, have been actively involved in establishing dedicated research infrastructures for exposomics. In Sweden, the National Facility for Exposomics [31] was approved in November 2020 and is hosted by the University of Stockholm. The facility is currently operational in Solna, providing resources and expertise for exposomics research. France has also established a dedicated research infrastructure, France Exposome, [32] a new National Research Infrastructure that focuses on environmental health. It has been included in the 2021 roadmap for the research infrastructure of the Ministry of Higher Education and Research, indicating its significance in the country's research landscape.[ citation needed ]
Additionally, the Environmental Exposure Assessment Research Infrastructure (EIRENE) [33] is a collaborative effort consisting of 17 National Nodes representing around 50 institutions with complementary expertise. EIRENE aims to fill the gap in the European infrastructural landscape and pioneer the first EU infrastructure on the human exposome. The consortium has a geographically balanced network, covering Northern (Finland, Iceland, Norway, Sweden), Western (Belgium, France, Germany, Netherlands, UK), Southern (Greece, Italy, Slovenia, Spain), and Central and Eastern (Austria, Czech Republic, Slovakia) Europe, as well as the US. The EIRENE RI team consists of scientists leading exposome research on an international level.
These initiatives reflect the growing recognition of the importance of exposomics research and the commitment of these countries to advancing the field. The establishment of dedicated research infrastructures ensures the availability of resources and expertise required to uncover crucial insights into the impact of exposomes [10] on human health.
The study of the exposome requires a multi-disciplinary approach that combines advances in exposure assessment, bioinformatics, and systems biology. As such, researchers have developed a range of key methodologies to measure and analyze the exposome – from exposure assessment techniques, analytical tools, to computational approaches.[ citation needed ]
These methods are designed to capture and analyze the diverse and dynamic nature of environmental exposures across a person's lifespan.[ citation needed ]
The assessment of environmental exposures is a critical aspect of exposome research. Traditional methods, such as questionnaires and environmental monitoring, provide useful information on external factors but may not adequately capture the complexity and variability of exposures over time. [7]
Consequently, researchers have increasingly turned to personal monitoring devices, such as wearable sensors, personal monitoring devices, and smartphone applications, which can collect real-time data on an individual's exposure to various environmental factors, such as air pollution, noise, and ultraviolet radiation. [21] [34] The data collected by these devices can help researchers understand how personal behaviors and microenvironments contribute to overall exposome profiles. [35] [36] [37]
Biomarkers (measurable indicators of biological processes or conditions) play an essential role in characterizing the internal exposome and biological response. This approach involves the measurement of chemicals or their metabolites in biological specimens such as blood, urine, or tissues. [22] [38] [39] Advances in high-throughput -omics technologies such as genomics, transcriptomics, proteomics, and metabolomics, have revolutionized our ability to measure thousands of biomarkers simultaneously. This can provide a detailed snapshot of an individual's molecular profile at a given time, as well as a comprehensive view of the individual's biological response to environmental exposures. [14] These technologies yield a direct and quantitative assessment of an individual's exposure to specific compounds and have been increasingly incorporated into exposome research and epidemiological studies. [39]
GIS tools can be used to estimate an individual's exposure to environmental factors based on spatial data, such as air pollution or proximity to hazardous waste sites. [40] GIS-based exposure assessment has been applied in numerous epidemiological studies to investigate the relationship between environmental exposures and health outcomes. [41] [42]
The vast amounts of data generated by exposome research require advanced computational methods for storage, analysis, and interpretation. Machine learning [43] and other data mining techniques [44] have emerged as valuable tools for identifying patterns and relationships within complex exposome data sets. Furthermore, systems biology approaches, which integrate data from multiple -omics platforms [45] can help elucidate the complex interactions between exposures and biological pathways that contribute to disease development. [46]
Exposome research has had a significant impact on the field of epidemiology, providing new insights into the complex relationships between environmental exposures, genetic factors, and human health. [47] By comprehensively assessing the totality of exposures, epidemiologists can better understand the etiology of chronic diseases, such as cancer, cardiovascular disease, and neurodegenerative disorders, and identify modifiable risk factors that may be targets for intervention. [48]
Large-scale exposome projects, such as the Human Early-Life Exposome (HELIX) project [7] and the European Exposome Cluster, have been established to investigate these relationships and generate new knowledge on disease etiology and prevention. [49]
The exposome has also influenced the field of toxicology, leading to the development of new methods for assessing the cumulative effects of multiple environmental exposures on human health. By integrating exposure data with molecular profiling techniques, [50] toxicologists can better understand the mechanisms through which environmental chemicals and other factors contribute to adverse health outcomes. This knowledge can inform the development of more effective strategies for chemical risk assessment and regulation. [11]
Public health research and practice have greatly benefited from the insights gained through exposome research. By elucidating the complex interactions between environmental exposures and human health, the exposome framework can inform the design of targeted interventions to reduce disease risk and promote health equity. [18]
Moreover, the development of exposome-based tools, such as biomonitoring and personal exposure monitoring devices, can help public health practitioners better track population exposures [51] and evaluate the effectiveness of interventions.
Despite significant advances in exposome research, several challenges remain, including the development of more accurate exposure assessment techniques, the identification of novel biomarkers, and the management of large- scale and complex data sets. [3]
One of the main challenges in exposome research is the accurate assessment of exposures across an individual's lifetime. [26] While recent technological advancements have improved our ability to measure environmental exposures in real-time, there is still a need for methods that can retrospectively assess historical exposures, [2] particularly in the context of chronic disease research. [52]
Another challenge lies in the identification of novel and informative biomarkers that can provide insights into the biological pathways underlying exposure-disease relationships. [14] While omics technologies have greatly expanded the number of measurable biomarkers, researchers must still determine [53] which of these markers are most relevant to specific health outcomes and how they may be affected by various exposures.
Exposome research generates vast amounts of complex data, [54] posing challenges related to data storage, analysis, and interpretation. As the field continues to grow, the development of standardized data formats, data sharing platforms, and advanced computational methods for data integration will be crucial [46] to maximizing the potential of exposome research.
Toxicology is a scientific discipline, overlapping with biology, chemistry, pharmacology, and medicine, that involves the study of the adverse effects of chemical substances on living organisms and the practice of diagnosing and treating exposures to toxins and toxicants. The relationship between dose and its effects on the exposed organism is of high significance in toxicology. Factors that influence chemical toxicity include the dosage, duration of exposure, route of exposure, species, age, sex, and environment. Toxicologists are experts on poisons and poisoning. There is a movement for evidence-based toxicology as part of the larger movement towards evidence-based practices. Toxicology is currently contributing to the field of cancer research, since some toxins can be used as drugs for killing tumor cells. One prime example of this is ribosome-inactivating proteins, tested in the treatment of leukemia.
Environmental health is the branch of public health concerned with all aspects of the natural and built environment affecting human health. In order to effectively control factors that may affect health, the requirements that must be met in order to create a healthy environment must be determined. The major sub-disciplines of environmental health are environmental science, toxicology, environmental epidemiology, and environmental and occupational medicine.
Endocrine disruptors, sometimes also referred to as hormonally active agents, endocrine disrupting chemicals, or endocrine disrupting compounds are chemicals that can interfere with endocrine systems. These disruptions can cause numerous adverse human health outcomes including, alterations in sperm quality and fertility, abnormalities in sex organs, endometriosis, early puberty, altered nervous system function, immune function, certain cancers, respiratory problems, metabolic issues, diabetes, obesity, cardiovascular problems, growth, neurological and learning disabilities, and more. Found in many household and industrial products, endocrine disruptors "interfere with the synthesis, secretion, transport, binding, action, or elimination of natural hormones in the body that are responsible for development, behavior, fertility, and maintenance of homeostasis ."
An environmental factor, ecological factor or eco factor is any factor, abiotic or biotic, that influences living organisms. Abiotic factors include ambient temperature, amount of sunlight, air, soil, water and pH of the water soil in which an organism lives. Biotic factors would include the availability of food organisms and the presence of biological specificity, competitors, predators, and parasites.
Toxicogenomics is a subdiscipline of pharmacology that deals with the collection, interpretation, and storage of information about gene and protein activity within a particular cell or tissue of an organism in response to exposure to toxic substances. Toxicogenomics combines toxicology with genomics or other high-throughput molecular profiling technologies such as transcriptomics, proteomics and metabolomics. Toxicogenomics endeavors to elucidate the molecular mechanisms evolved in the expression of toxicity, and to derive molecular expression patterns that predict toxicity or the genetic susceptibility to it.
Xenoestrogens are a type of xenohormone that imitates estrogen. They can be either synthetic or natural chemical compounds. Synthetic xenoestrogens include some widely used industrial compounds, such as PCBs, BPA, and phthalates, which have estrogenic effects on a living organism even though they differ chemically from the estrogenic substances produced internally by the endocrine system of any organism. Natural xenoestrogens include phytoestrogens which are plant-derived xenoestrogens. Because the primary route of exposure to these compounds is by consumption of phytoestrogenic plants, they are sometimes called "dietary estrogens". Mycoestrogens, estrogenic substances from fungi, are another type of xenoestrogen that are also considered mycotoxins.
Gene–environment interaction is when two different genotypes respond to environmental variation in different ways. A norm of reaction is a graph that shows the relationship between genes and environmental factors when phenotypic differences are continuous. They can help illustrate GxE interactions. When the norm of reaction is not parallel, as shown in the figure below, there is a gene by environment interaction. This indicates that each genotype responds to environmental variation in a different way. Environmental variation can be physical, chemical, biological, behavior patterns or life events.
In biomedical contexts, a biomarker, or biological marker, is a measurable indicator of some biological state or condition. Biomarkers are often measured and evaluated using blood, urine, or soft tissues to examine normal biological processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention. Biomarkers are used in many scientific fields.
Spatial epidemiology is a subfield of epidemiology focused on the study of the spatial distribution of health outcomes; it is closely related to health geography.
Exposure science is the study of the contact between humans and harmful agents within their environment – whether it be chemical, physical, biological, behavioural or mental stressors – with the aim of identifying the causes and preventions of the adverse health effects they result in. This can include exposure within the home, workplace, outdoors or any other environment an individual may encounter. The term ‘exposure’ is the umbrella term for many different types, ranging from ultraviolet exposure, exposure to the chemicals in the food we eat, to exposure to long working hours being the occupational factor most attributable to the burden of disease.
Exposure assessment is a branch of environmental science and occupational hygiene that focuses on the processes that take place at the interface between the environment containing the contaminant of interest and the organism being considered. These are the final steps in the path to release an environmental contaminant, through transport to its effect in a biological system. It tries to measure how much of a contaminant can be absorbed by an exposed target organism, in what form, at what rate and how much of the absorbed amount is actually available to produce a biological effect. Although the same general concepts apply to other organisms, the overwhelming majority of applications of exposure assessment are concerned with human health, making it an important tool in public health.
Environmental epidemiology is a branch of epidemiology concerned with determining how environmental exposures impact human health. This field seeks to understand how various external risk factors may predispose to or protect against disease, illness, injury, developmental abnormalities, or death. These factors may be naturally occurring or may be introduced into environments where people live, work, and play.
Molecular epidemiology is a branch of epidemiology and medical science that focuses on the contribution of potential genetic and environmental risk factors, identified at the molecular level, to the etiology, distribution and prevention of disease within families and across populations. This field has emerged from the integration of molecular biology into traditional epidemiological research. Molecular epidemiology improves our understanding of the pathogenesis of disease by identifying specific pathways, molecules and genes that influence the risk of developing disease. More broadly, it seeks to establish understanding of how the interactions between genetic traits and environmental exposures result in disease.
In analytical chemistry, biomonitoring is the measurement of the body burden of toxic chemical compounds, elements, or their metabolites, in biological substances. Often, these measurements are done in blood and urine. Biomonitoring is performed in both environmental health, and in occupational safety and health as a means of exposure assessment and workplace health surveillance.
"Envirome" is a concept that relates the core of environmental conditions with the successful biological performance of living beings. This concept was created in genetic epidemiology, in which an envirome is defined as the total set of environmental factors, both present, and past, that affect the state, and in particular the disease state, of an organism. The study of the envirome and its effects is termed enviromics. The term was first coined in the field of psychiatric epidemiology by J.C. Anthony in 1995. More recently, use of the term has been extended to the cellular domain, where cell functional enviromics studies both the genome and envirome from a systems biology perspective. In plants, enviromics is directly related to complex ecophysiology, in which the wide environment of the plants, into an omics scale, can be dissected and understood as a mosaic of possible growing factors and the balance of diverse resources available. In ecology, this concept can be related to the Shelford's law of tolerance. The enviromics is conceived as a pillar of the Modern Plant Breeding, capable to connect the design and development of breeding goals concealing it with the agronomic targets for a climate-smart agriculture. It also has the ability to bridge the knowledge gaps between the different levels of systems biology and phenomics in the context of Gene–environment interaction.
Occupational toxicology is the application of toxicology to chemical hazards in the workplace. It focuses on substances and conditions that people may be exposed to in workplaces, including inhalation and dermal exposures, which are most prevalent when discussing occupational toxicology. These environmental and individual exposures can impact health, and there is a focus on identifying early adverse affects that are more subtle than those presented in clinical medicine.
E-SCREEN is a cell proliferation assay based on the enhanced proliferation of human breast cancer cells (MCF-7) in the presence of estrogen active substances. The E-SCREEN test is a tool to easily and rapidly assess estrogenic activity of suspected xenoestrogens. This bioassay measures estrogen-induced increase of the number of human breast cancer cell, which is biologically equivalent to the increase of mitotic activity in tissues of the genital tract. It was originally developed by Soto et al. and was included in the first version of the OECD Conceptual Framework for Testing and Assessment of Endocrine Disrupters published in 2012. However, due to failed validation, it was not included in the updated version of the framework published in 2018.
Frederica Perera is an American environmental health scientist and the founder of the Columbia Center for Children's Environmental Health at the Columbia University Mailman School of Public Health. Her research career has focused on identifying and preventing harm to children from prenatal and early childhood exposure to environmental chemicals and pollutants. She is internationally recognized for pioneering the field of molecular epidemiology, incorporating molecular techniques into epidemiological studies to measure biologic doses, preclinical responses and susceptibility to toxic exposure.
Kelly K. Ferguson is an American public health researcher who is a Senior Investigator in the National Institute of Environmental Health Sciences. She leads the Perinatal and Early Life Epidemiology Group, which studies how maternal exposure to chemicals impacts pregnancy and development. In 2021, she was awarded the inaugural Lou Guillette Jr. Outstanding Young Investigator Award.
{{cite book}}
: CS1 maint: location missing publisher (link){{cite book}}
: CS1 maint: location missing publisher (link)