A new study published inEnvironment Internationalreveals that better indoor air quality, proximity to natural spaces, healthy diets, and strong social networks are associated with reduced and better-regulatedinflammationin children. The findings, which form part of the Human Early Life Exposome (HELIX) cohort under the ATHLETE project, provide valuable insight into how early-life environmental exposures influence long-term immune health. The environment in which children grow up plays a critical role in shaping their lifelong health. The study focuses on the exposome—a concept that captures the totality of environmental exposures from conception onward, includingair pollution, nutrition,stress, and social factors. The study analyzed data from 845 children across six European birth cohorts in the UK, France, Spain, Lithuania, Norway, and Greece. Researchers assessed 91 environmental exposures grouped into 13 categories, including air pollution, chemical agents, diet, physical activity, sleep, tobacco exposure, and socioeconomic indicators. “To assess immune health, we analyzed blood samples from each child using three biological layers: white blood cell composition, plasma protein concentrations and genome-wideDNAmethylation of white blood cells,” says Ines Amine, the study’s first author. Using advanced statistical models and a high-dimensional reduction algorithm called Regularized Generalized Canonical Correlation Analysis (RGCCA), the team identified immune “signatures” associated with better composite health outcomes. Three such signatures—two protein-based and one involving white blood cells—were linked to reduced inflammation and improved immune regulation. “Our findings emphasize the importance of these environmental factors in mitigating immunotoxicity related to child health,” concludes Léa Maitre, coordinator of the Exposome Hub at ISGlobal and last author of the study. “Improving indoor air quality, supporting healthy diets, preserving access to natural spaces, and strengthening community support systems are actionable strategies that can promote better key inflammatory processes, which hold significant clinical relevance for cardiometabolic, respiratory and neurodevelopmental health in children.” Reference:Amine, I., Anguita-Ruiz, A., Guillien, A., Basagaña, X., Bustamante, M., Borràs, E., Cirach, M., Dedele, A., Dobaño, C., Garcia-Aymerich, J., Granum, B., Grazuleviciene, R., González, J. R., Julvez, J., Keun, H., López-Vicente, M., McEachan, R., Moncunill, G., Nieuwenhuijsen, M., … Maitre, L. (2025). Early-life exposome and health-related immune signatures in childhood. Environment International, 202(109668), 109668. https://doi.org/10.1016/j.envint.2025.109668