Telomere length is a molecular marker of biological aging. OBJECTIVE: Here we investigated whether early-life exposure to residential air pollution was associated with leukocyte telomere length (LTL) at 8 y of age. METHODS: In a multicenter European birth cohort study, HELIX (Human Early Life Exposome) (n= 1,396), we estimated prenatal and 1-y childhood exposure to nitrogen dioxide (NO2), particulate matter with aerodynamic diameter ≤2:5 lm (PM2:5), and proximity to major roads. Average relative LTL was measured using quantitative real-time polymerase chain reaction (qPCR). Effect estimates of the association between LTL and prenatal, 1-y childhood air pollution, and proximity to major roads were calculated using multiple linear mixed models with a random cohort effect and adjusted for relevant covariates. RESULTS: LTL was inversely associated with prenatal and 1-y childhood NO2 and PM2:5 exposures levels. Each standard deviation (SD) increase in prenatal NO2 was associated with a −1:5% (95% CI: −2:8, −0:2) change in LTL. Prenatal PM2:5 was nonsignificantly associated with LTL (−0:7% per SD increase; 95% CI: −2:0, 0.6). For each SD increment in 1-y childhood NO2 and PM2:5 exposure, LTL shortened by −1:6% (95% CI: −2:9, −0:4) and −1:4% (95% CI: −2:9, 0.1), respectively. Each doubling in residential distance to nearest major road during childhood was associated with a 1.6% (95% CI: 0.02, 3.1) lengthening in LTL. CONCLUSION: Lower exposures to air pollution during pregnancy and childhood were associated with longer telomeres in European children at 8 y of age. These results suggest that reductions in traffic-related air pollution may promote molecular longevity, as exemplified by telomere length, from early life onward.

Published Oct 25, 2019

Clemente, D. B. P., Vrijheid, M., Martens, D. S., Bustamante, M., Chatzi, L., Danileviciute, A., De Castro, M., Grazuleviciene, R., Gutzkow, K. B., Lepeule, J., Maitre, L., McEachan, R. R. C., Robinson, O., Schwarze, P. E., Tamayo, I., Vafeiadi, M., Wright, J., Slama, R., Nieuwenhuijsen, M., & Nawrot, T. S. (2019). Prenatal and childhood traffic-related air pollution exposure and telomere length in european children: The HELIX project. Environmental Health Perspectives, 127(8), 1–8. https://doi.org/10.1289/EHP4148