Lab Matters Summer 2021 | Page 12


Assessing and Advancing Public Health Research and Practice Through Exposomics

by Mark D . Hoover , PhD , CHP , CIH , health and safety scientist
The exposome was proposed in 2005 by Dr . Chris Wild as a complement to the genome and has been defined as the totality of exposures that individuals experience over their lives and how those exposures affect health . 1 The premise was that interactions of an individual ’ s exposures with their unique individual characteristics leads to their health status . Understanding an exposure and the role of genetics , lifestyle and other factors in disease has also been called “ exposure biology ” ( Figure 1 ).
Figure 2 : Genomics and the other “ omics ” play a role in the many events and activities leading to disease . Improving our understanding of the influence of ” omic ” -related processes on the progression of exposure to disease can lead to more effective disease prevention and treatment . 3 ( Figure adapted from Decker et al . 2010 )
Exposomics is the study of the exposome and relies on fields such as genomics , adductomics , metabonomics , lipidomics , transcriptomics , and proteomics ( Figure 2 ). These omic fields involve collective characterization and quantification of pools of biological molecules that translate into the structure , function and dynamics of an organism . Common threads are :
1 . Use of biomarkers to determine exposure , effect of exposure , disease progression , and susceptibility factors .
2 . Use of technologies that result in large amounts of data .
Figure 1 : An individual ’ s exposure begins before birth and includes contributions from all manner of endogenous , environmental and occupational sources . Tools in exposomic studies include biomarkers , sensors , geographic information systems and epidemiological surveys . 2 ( Figure adapted from DeBord et al . 2016 )
3 . Use of data mining techniques to find statistical associations between exposures , effect of exposures , and other factors such as genetics with disease .
Exposomics potentially includes the study of exposures in the environment that might improve or enhance health or the opportunity to attain health in greater measure . 2
Challenges and Responding Steps
Obvious challenges limit progress in the field of exposomics . The exposome is highly variable and dynamic as it evolves throughout the lifetime of an individual . Ultimately , the impact of a specific exposure — regardless of its origin — may be different at the individual level for different people . Relating a disease to an exposure that occurred in the past can be challenging , and even present exposures are difficult or impossible to quantify .
As part of the exposome component of its exposure assessment program , the National Institute for Occupational Safety and Health has identified some specific steps that can help meet the exposomic challenges : 4
1 . Develop more sensitive exposure assessment methods and tools to improve the ability to measure exposures .
2 . Develop and characterize biomarkers to improve measurement of exposure , effect of exposure and susceptibility for determination of disease relationships , including identification of “ legacy biomarkers ” that could quantify past exposures or effects from past exposures .
3 . Develop improved statistical tools and data sharing to help evaluate the relationship of disease to the many facets of exposure , increase statistical power and provide a more thorough analysis of all exposures , including through improved bioinformatics tools , pattern matching techniques and artificial neural network models .
4 . Develop gene expression matrices to assess and understand the interrelationships of environmental , occupational , dietary , lifestyle and other exposures .
5 . Develop standardized criteria for designing studies and reporting results to improve the collection and storage of data that incorporates information on epidemiology , genetics and other omics ; enable more holistic exposure assessment ; make the information more accessible for data mining ; and enhance the interpretation and reproduction of experimental results .
10 LAB MATTERS Summer 2021
PublicHealthLabs @ APHL APHL . org