Prenatal Air Pollution and Newborns' Predisposition to Accelerated Biological Aging

Abstract

Importance Telomere length is a marker of biological aging that may provide a cellular memory of exposures to oxidative stress and inflammation. Telomere length at birth has been related to life expectancy. An association between prenatal air pollution exposure and telomere length at birth could provide new insights in the environmental influence on molecular longevity. Objective To assess the association of prenatal exposure to particulate matter (PM) with newborn telomere length as reflected by cord blood and placental telomere length. Design, Setting, and Participants In a prospective birth cohort (ENVIRONAGE [Environmental Influence on Ageing in Early Life]), a total of 730 mother-newborn pairs were recruited in Flanders, Belgium between February 2010 and December 2014, all with a singleton full-term birth (≥37 weeks of gestation). For statistical analysis, participants with full data on both cord blood and placental telomere lengths were included, resulting in a final study sample size of 641. Exposures Maternal residential PM2.5 (particles with an aerodynamic diameter ≤2.5 μm) exposure during pregnancy. Main Outcomes and Measures In the newborns, cord blood and placental tissue relative telomere length were measured. Maternal residential PM2.5 exposure during pregnancy was estimated using a high-resolution spatial-temporal interpolation method. In distributed lag models, both cord blood and placental telomere length were associated with average weekly exposures to PM2.5 during pregnancy, allowing the identification of critical sensitive exposure windows. Results In 641 newborns, cord blood and placental telomere length were significantly and inversely associated with PM2.5 exposure during midgestation (weeks 12-25 for cord blood and weeks 15-27 for placenta). A 5-μg/m3 increment in PM2.5 exposure during the entire pregnancy was associated with 8.8% (95% CI, −14.1% to −3.1%) shorter cord blood leukocyte telomeres and 13.2% (95% CI, −19.3% to −6.7%) shorter placental telomere length. These associations were controlled for date of delivery, gestational age, maternal body mass index, maternal age, paternal age, newborn sex, newborn ethnicity, season of delivery, parity, maternal smoking status, maternal educational level, pregnancy complications, and ambient temperature. Conclusions and Relevance Mothers who were exposed to higher levels of PM2.5 gave birth to newborns with shorter telomere length. The observed telomere loss in newborns by prenatal air pollution exposure indicates less buffer for postnatal influences of factors decreasing telomere length during life. Therefore, improvements in air quality may promote molecular longevity from birth onward.

Spatiotemporal Variations in Ambient Ultrafine Particles and the Incidence of Childhood Asthma

“…weekly exposures during pregnancy and monthly exposures during childhood) (49). Recent studies have used DLNMs in the context of air pollution and birth outcomes in order to identify sensitive windows of exposure and simultaneously account for potential confounding by other time periods of exposure (50,51). For each pollutant, DLNMs were defined through two "cross-basis" matrices, one for exposures during gestational weeks 1 to 40 and one for childhood exposures from the first month after birth until the end of follow-up.…”

Timescales of developmental toxicity impacting on research and needs for intervention

“…Telomere length is considered a biomarker of biological ageing and has been associated with age‐related diseases and premature mortality . While telomere lengths in newborns are highly variable, mothers exposed to higher levels of air pollution within EU limits gave birth to newborns with shorter telomere length . The implications of changes in telomere lengths for long‐term health deserve further scrutiny.…”

Ageing at the level of telomeres in association to residential landscape and air pollution at home and work: a review of the current evidence

“…shorter cord blood and 13.2% (95%CI, -19.3 to -6.7%) shorter placental TL with the strongest effects during second trimester. 87 Interestingly, also a positive association was observed between cord blood TL and PM2.5 exposure late in gestation (32-34 weeks), this adding to the evidence of short-term exposure in relation with longer TL. Up to now, only one study evaluated TL during childhood in relation with PM exposure.…”