Exploring the Exposome: A New Era in Environmental Health Science
WHAT IS EXPOSOME?
Despite the general acknowledgement by the scientific community that ‘Genetics load the gun, but environment pulls the trigger’ there is persistent uncertainty as to the global burden of disease attributable to environmental factors.
Throughout our lives, we are exposed to a variety of factors, both internal and external, which are a function of our lifestyle, behavior, and environment. All these exposures form a concept called “the exposome”.
The exposome was conceived by the scientist Christopher Wild in 2005 to represent the environmental, nongenetic, drivers of health and disease. These exposures are not restricted to the thousands of chemicals that enter our bodies through the air, water, or food, for example, but also our body’s response to our environment, including the built environment and social circumstances, through inflammation, oxidative stress, infections, and gut flora, for example (Figure 1).
Unlike the genome, which is relatively stable throughout life, the exposome is a moving target depending on your current and past environment, as well as your activity, health state, nutrition, and stress, and consumption of food.
So, why do we care about such a complicated and moving target?
The WHO estimates that approximately 25% of diseases are related to these non-genetic factors, which could be avoided. Therefore, it provides extremely valuable information in the design of preventive, diagnostic, and therapeutic strategies in the medicine of the future.
Figure 1. The Exposome Concept. The exposome can be divided into three categories: the general external exposome, the specific external exposome and the internal exposome that interact with each other.
HOW TO MEASURE EXPOSOME?
Several research efforts have pioneered different approaches for the systematic mapping of the exposome, taking advantage of developments in mass spectrometry, sensors, wearables, study design, biostatistics, and bioinformatics — advances that now position us to pursue Dr. Wild’s original vision of the exposome.
A key challenge for the field is to produce a testing approach that is suitable for regular use by large numbers of people in a wide range of contexts, including at-risk populations such as children, the elderly and those with underlying conditions. Since these tests would ideally be administered frequently to people who have no symptoms, they also need to be appropriately ‘non-medical’, meaning non-invasive, pain-free and requiring no specialist expertise. Systems that provide speed, cost, and large data gathering capacities are also preferable.
Exhaled breath is more than just air, it contains over 1,000 volatile organic compounds (VOCs) as well as microscopic aerosol particles, also known as respiratory droplets, originating from the lungs and airways. Both VOCs and breath aerosol represent rich sources of biological information (Figure 2).
In contrast to blood or urine, exhaled breath has strategic advantages in that sample collection is noninvasive, does not require medical personnel, privacy, or a clinical environment, and does not typically generate potentially infectious waste. These features are especially important when collecting many hundreds of samples to foster simplicity in the field and acceptance by individuals.
Figure 2. Biomarkers on breath include volatile organic compounds (VOCs) and respiratory droplets. Both can be rich sources of exposure and health information.
QUADROCORE’S AerX FOR ENVIRONMENTAL EXPOSURE RESEARCH
From an analytical point of view, breath analysis is quite challenging. Analysis demands ultra-low detection limits, broad dynamic range, and fast time response. With unmatched sensitivity and mass resolving power, the QuadroCore’s AerX is a cutting-edge solution for online analysis of VOCs and non-volatiles in breath.
Real-Time Chemical Analysis of Air
QuadroCore’s direct analysis triple quadrupole mass spectrometers directly sample air, ionize molecules by unique patented plasma ionization source and measure the ions by mass spectrometry. Composition is instantaneously reported with part-per-trillion (ppt) limits of detection (LOD).
Direct sample introduction allows real time characterization of complex mixtures without chromatography, resulting in fast response time (1-5s)
Small footprint enables deployment anywhere within laboratory or processing facilities