Revealing the Chemistry Around Us Through Mass Spectrometry

Health is increasingly viewed through the lens of family history and genetics, nutrition and fitness, and, for many, medications and treatments for various conditions. However, public perception is waking up to another factor: the chemistry of our environment.

From air quality and drinking water to clothing and cookware, there is growing skepticism surrounding the multitude of synthetic materials that coat and comprise our environment. This realization that the world around us has an impact on our growth, development, and well-being follows a century of industrial expansion in which the chemistry of the world changed far faster than the means to measure or understand its impacts. A scientific field concerned with this frontier of research has been quietly maturing for twenty years. It is called exposomics.

Exposomics, a modern omics approach to understanding environmental impact, is still an emerging science, but it is already changing how we think about the relationship between the environment and our health. This article explores how researchers can now study the chemistry of the world around us and the body’s response to it with unprecedented breadth, increasingly bringing both into a common analytical framework. The growing attention to the chemistry around us is well founded. It is also now matched by the means to investigate it.

What is the exposome?

The exposome as a term was introduced in 2005 as a deliberate complement to the genome. It refers to external factors that have an impact on an organism’s biology (in our case, on human health). Across a person’s lifetime, these will include environmental, lifestyle, occupational, dietary, biological and social influences, each capable of imparting (alone or together via complex interactions) measurable molecular signatures and provoking equally measurable biological responses. Exposomics is the science of measuring it and its impacts.

Today, scientists are gaining a clearer understanding of how much the exposome matters. Working with UK Biobank data, researchers compared what genetic risk scores and environmental exposures each contribute to ageing and early death. Set against age and sex alone, polygenic risk scores across 22 major diseases added less than two percentage points to the explained variation in mortality. The exposome added seventeen.¹ The two are not rivals, however. Inherited risk still explained more for dementias and for breast, prostate, and colorectal cancers, while environment explained more for diseases of the lung, heart, and liver.¹ The difference is that while genomics is a mature science, exposomics remains emergent, operating across a much broader chemical landscape.

Technology for exposomics research

For most of the twentieth century, environmental health science was concerned with identifying potential health concerns, testing them, and regulating them if needed, one at a time. This approach shaped our view on the dangers of lead, asbestos, and tobacco, slowly over decades. However, exposures are not always singular concerns. The chemical world around us is complex, with a stunning diversity of components interacting with biology and each other in ways that isolated testing cannot capture or represent. Even modern environmental monitoring only concentrates on a short list of regulated pollutants, despite inhalation exposure spanning thousands of organic compounds, numerous inorganic substances, and a large biological component.² Exposomics takes a different approach. As a modern “omics” science, it measures molecular signals broadly rather than selectively (both the exposures themselves and the body’s biochemical responses) and relies on data-driven statistical analysis to find the patterns that matter.

Here, high-resolution mass spectrometry is a key enabling technology. It separates and detects molecules according to their mass with enough precision and selectivity to distinguish compounds that differ only slightly and, critically, without being told in advance what to look for. And importantly, the same technology is as applicable to studying the chemistry of living systems (e.g. biofluids and tissues) as it is to environmental samples (e.g. air, water, dust, soil, food and consumer products). Using mass spectrometry, a single analysis of blood or urine can measure hundreds or thousands of signals at once, including those from pollutants, drugs, dietary compounds, molecules produced by gut bacteria, and the body’s own metabolic responses to all of it. When applied to air analysis, measurements of diverse and unexpected components can be made continuously and in real time, capturing short-lived compounds and brief exposure events that a filter sample collected over hours would average away.

Enabling understanding and action

Measuring the chemistry around us is valuable, but measurement alone does not explain how an exposure influences health. These measurements become most useful when they can be connected. The objective of exposomics is to link the source of an exposure, the amount that enters the body, the biological responses it provokes, and ultimately any impact on health.

Completing that chain remains difficult, and the field is clear-eyed about where the challenges lie. Detecting a signal in a mass spectrometer is not the same as knowing what chemical produced it, and many of the signals detected remain unannotated, collectively constituting what researchers often refer to as the dark matter of the chemical exposome.³ Their identification depends on reference libraries that are still underdeveloped for environmental chemicals, and workflows vary enough between laboratories that studies can be difficult to compare.³ However, progress is being made, for example, in artificial intelligence methods that predict chemical behavior to improve confidence in identification,⁴ and in the prioritization of harmonized workflows throughout the field.³ Still, for today, mass spectrometry-based exposomics is a powerful approach that can see more than it can readily interpret. And therein lies its promise as a tool for novel discovery.

The challenges extend beyond identifying individual chemicals. Researchers must also account for the sheer scale of environmental exposure and how sharply it can vary among places and people. The World Health Organization reports that 99% of the world’s population breathes air exceeding its guideline limits.⁵ At the same time, we know that the exposome is geospatially linked, with recent mobile monitoring studies showing that pollutant concentrations can vary dramatically over surprisingly short distances.⁶ Finally, it has been suggested that exposure profiles can differ markedly even between neighbors in the same building,² together making the exposome an individual and community matter as much as a population one. As a result, exposomics research is increasingly being pursued across all three scales through multidisciplinary collaborations that combine environmental science, analytical chemistry, epidemiology and clinical research.

Matthew Lewis, PhD, is vice president of metabolomics and lipidomics at Bruker Daltonics.

References

1. Argentieri MA, Amin N, Nevado-Holgado AJ, et al. Integrating the environmental and genetic architectures of aging and mortality. Nature Medicine. 2025;31(3):1016-1025. doi:10.1038/s41591-024-03483-9.
2. Gao P. The human airborne exposome. Nature Health. 2026;1:26-34. doi:10.1038/s44360-025-00026-5.
3. Talavera Andújar B, Schymanski EL. High Resolution Mass Spectrometry To Investigate the Human Exposome: Where Are We? Exposome. 2025. doi:10.1093/exposome/osaf017.
4. Sillé FCM, Prasse C, Luechtefeld T, Hartung T. AI redefines mass spectrometry chemicals identification: retention time prediction in metabolomics and for a Human Exposome Project. Frontiers in Public Health. 2025;13:1687056. doi:10.3389/fpubh.2025.1687056.
5. World Health Organization. Air Pollution. Accessed 7 May 2026.
6. Robinson ES, Tehrani MW, Yassine A, et al. Ethylene Oxide in Southeastern Louisiana’s Petrochemical Corridor: High Spatial Resolution Mobile Monitoring during HAP-MAP. Environmental Science & Technology. 2024;58(25):11084–11095. doi:10.1021/acs.est.3c10579.

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