SUMMARY

Lifelong exposure to environmental factors — especially air pollution — significantly affects the risk and progression of chronic lung diseases, and understanding these interactions is key for early intervention and personalized prevention strategies.

Chronic respiratory diseases, such as asthma and chronic obstructive pulmonary disease (COPD), are among the most prevalent non-communicable diseases globally. The risk of getting these conditions is highly influenced by lifelong exposure to multiple environmental factors that affect human biology and health—collectively referred to as exposome factors. These exposures interact in complex ways, making it challenging to fully understand their cumulative impact. During the Sunday morning session at ERS 2025, experts explored how the exposome contributes to both the prevention and progression of chronic lung diseases.

Understanding exposome: a holistic view of environmental influences

Environmental exposures are, according to the exposome concept, categorized into three main domains¹:

• General external exposome are factors affecting populations, such as climate, air pollution, societal changes and chemicals in our environment.
• Specific external exposome are factors that influence individuals such as diet, water, physical activity and personal behaviors.
• Internal exposome reflects what happens inside our body biologically, such as DNA mutations and disruptions in cellular pathways.

Challenges in capturing the full picture

A key challenge identified by speakers was the complexity of measuring the exposome in its entirety. Most studies focus on isolated exposures, which limits our understanding of how multiple factors interact. Some exposures may even begin to influence health before conception, highlighting the need for a life-course perspective.²

Overcoming barriers in exposome research

Exosome research faces multiple challenges, such as variability in measurements across populations, temporal issues, heterogeneity in measurements and the practicality of capturing biomarkers over large populations. The Exposome prevention of lung diseases, an international interdisciplinary translational network (EXPLAIN-IT), is working to address these challenges through interdisciplinary collaboration. Check it out at https://www.ersnet.org/science-and-research/clinical-research-collaboration-application-programme/explain-it-exposome-and-prevention-of-lung-diseases-an-international-interdisciplinary-translational-network/

Epigenetics and critical windows of vulnerability

Although the underlying mechanisms are not yet fully understood, it is clear that environmental exposures can alter gene expression through epigenetic modifications. These changes may persist over generations. Critical windows—such as the preconception and prenatal periods—are particularly sensitive, with exposures during these times potentially affecting fetal development and long-term respiratory health. ³

Air pollution- a modifiable and urgent risk factor

One modifiable exposome factor discussed in detail was air pollution. It not only contributes to climate change but is strongly linked to increased respiratory disease risk. Studies consistently show associations between air pollution and hospital admissions in children.⁴ In addition, exposure to air pollution during pregnancy does also effect lung function of children in mid childhood (5). Not only does air pollution influences our respiratory health directly but also indirectly through its impact on climate changes. When global temperatures rise, thunderstorms become more frequent and they can trigger hospital admissions related to asthma.⁶ Further, the increase in temperature results in more heavy rain periods with more humid weather that our houses are not designed for. This increases the risk of exposure to fungi that is associated with reduced lung function in some children with asthma.⁷

From research to action – a new paradigm in prevention

The exposome framework represents a shift in how we approach chronic lung disease prevention. By understanding the interaction between exposures better we can identify at-risk populations and implement early interventions. As research advances, integrating exposomic insights into clinical practice will be essential for personalized care and long-term disease prevention. The ERS 2025 session underscored the urgency of addressing modifiable exposures like air pollution and the importance of interdisciplinary collaboration to translate exposome science into actionable healthcare strategies.

Reference

1. Wan M, Simonin EM, Johnson MM, Zhang X, Lin X, Gao P, et al. Exposomics: a review of methodologies, applications, and future directions in molecular medicine. EMBO Mol Med. 2025 Jan 27;17(4):599–608.
2. López-Cervantes JP, Lønnebotn M, Jogi NO, Calciano L, Kuiper IN, Darby MG, et al. The Exposome Approach in Allergies and Lung Diseases: Is It Time to Define a Preconception Exposome? Int J Environ Res Public Health. 2021 Dec 1;18(23):12684.
3. Klibaner-Schiff E, Simonin EM, Akdis CA, Cheong A, Johnson MM, Karagas MR, et al. Environmental exposures influence multigenerational epigenetic transmission. Clin Epigenet. 2024 Oct 17;16(1):145.
4. Docherty R, Gill M, Shankar S, Turner S, Dick S. Update of a systematic review on associations between environmental exposures and asthma control and exacerbations in young children. BMJ Open. 2025 Aug 31;15(8):e091855.
5. Cai Y, Hansell AL, Granell R, Blangiardo M, Zottoli M, Fecht D, et al. Prenatal, Early-Life, and Childhood Exposure to Air Pollution and Lung Function: The ALSPAC Cohort. Am J Respir Crit Care Med. 2020 July 1;202(1):112–23.
6. Diver S, Symon F, Satchwell J, Lipscombe H, Green RH, Woltmann G, et al. Under the weather: an epidemic thunderstorm asthma event in Leicester, June 2023. BMJ Open Resp Res. 2025 Apr;12(1):e002588.
7. Welsh KG, Holden KA, Wardlaw AJ, Satchwell J, Monteiro W, Pashley CH, et al. Fungal sensitization and positive fungal culture from sputum in children with asthma are associated with reduced lung function and acute asthma attacks respectively. Clin Experimental Allergy. 2021 June;51(6):790–800.