Ambient exposure and fetal black carbon load in association with telomere length in cord blood

Abstract

Background: Ambient particulate matter (PM) is an important factor that is associated with telomere length (TL) at birth. A recent study has shown that translocation of black carbon (BC), one of the most toxic components of PM, towards the fetus is possible, but it is not yet linked to biological outcomes. In this study, we investigated whether 1) ambient BC is associated with cord blood TL, 2) fetal BC load relates to ambient BC exposure and 3) fetal BC load is related to newborn TL. Methods: In 247 mother-newborn pairs from the ENVIRONAGE (Environmental Influence On Early Ageing) study, which is a population-based birth cohort study located in Limburg, Belgium, maternal residential exposure to BC during pregnancy was estimated using a spatial-temporal interpolation model. BC particles were detected in cord blood by the generation of white-light under femtosecond pulsed laser illumination. Cord blood TL was measured using qPCR. We applied Pearson correlations and distributed lag models to associate BC exposure with cord blood TL. Results: An IQR increment (0.85 µg/m3) in ambient BC was associated with a -12% (95% CI: −21% to −2.8%) decrease and a 20% (95% CI: 7.6% to 34%) increase in cord blood TL during the second and third trimester of pregnancy respectively. Secondly, fetal BC load showed the highest correlation with ambient BC during trimester 3 (r=0.28, p<0.0001). Thirdly, fetal BC load was positively correlated with TL in cord blood (r=0.15, p=0.023). Conclusion: Our findings show that mothers with a higher exposure to ambient BC had more BC particles in cord blood. The positive correlation between both ambient and fetal BC exposure during trimester 3 and cord blood TL may suggest the possibility of an acute protective response, but additional studies are needed to investigate the underlying mechanisms. Keywords: Telomere Length, Particulate Matter, Black Carbon, Ageing