Polycyclic aromatic hydrocarbons exposures and telomere length: A cross-sectional study on preschool children

Area of Science:

• Environmental Health
• Pediatric Toxicology
• Molecular Epidemiology

Background:

• Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants linked to adverse health outcomes.
• Telomere length (TL) is a biomarker of cellular aging, and shorter TL is associated with various health issues.
• Evidence on the association between PAH exposure and TL in children remains limited.

Purpose of the Study:

• To investigate the relationship between urinary 1-hydroxypyrene (1-OHP), a marker of PAH exposure, and relative leukocyte telomere length (LTL) in preschool-aged children.
• To assess potential differences in this association based on sex and parental education level.

Main Methods:

• A cross-sectional study involving 200 preschool children from Sabzevar, Iran.
• Urinary 1-OHP levels were quantified using solid phase extraction (SPE) and high-performance liquid chromatography (HPLC).
• Relative leukocyte telomere length (LTL) was measured using real-time PCR.
• Linear mixed effects models were employed to analyze the association between 1-OHP and LTL, adjusting for covariates.

Main Results:

• The median relative LTL was 0.83 and the median urinary 1-OHP was 257 ng/L.
• An interquartile range (IQR) increase in urinary 1-OHP was significantly associated with a decrease in relative LTL (-0.05; 95% CI: -0.09, -0.01; P=0.02).
• The association was consistent between boys and girls, with a potential trend towards a stronger effect in children of parents with university education.

Conclusions:

• This study suggests an inverse relationship between PAH exposure, indicated by urinary 1-OHP, and telomere length in preschool children.
• PAH exposure may be associated with accelerated cellular aging in young children.
• Further longitudinal studies are warranted to confirm these findings and explore the long-term implications.