The association between prenatal exposure to thallium and shortened telomere length of newborns

Abstract

Thallium is a widely known toxic heavy metal that has been reported have embryo toxicity. We aimed to investigate the relationship of prenatal thallium exposure with neonatal telomere length. A total of 746 mother-newborn pairs were recruited from Wuhan Children Hospital between November 2013 and March 2015 in Wuhan City, China. Maternal thallium exposure levels were measured in spot urine samples collected during the three trimesters and during hospital delivery using inductively coupled plasma mass spectrometry. Neonatal relative telomere length (rTL) was measured by a real-time quantitative polymerase chain reaction assay in cord blood. Multiple informant models were used to evaluate the association of maternal thallium exposure with neonatal rTL. After adjustment for multiple potential confounders, each 25% incremental increase of maternal thallium exposure, measured in urine samples collected during hospital delivery, was associated with a 1.85% shortened neonatal rTL (95% CI:-3.62%,-0.05%; P=0.044). Similarly, mothers in the highest quartile of urinary thallium exposure had a 11.74% (95% CI:-21.57%,-0.68%; P=0.038) shorter cord blood leukocyte rTL than those in the lowest quartile. However, no significant association was found between neonatal rTL and maternal thallium exposure measured in urine samples collected during the three trimesters of pregnancy. This study reveals that prenatal thallium exposure was related to shortened neonatal telomere length in Chinese population, pointing to the important role of thallium exposure in accelerating biological aging.