Mitochondrial DNA
(mtDNA) content and telomere length are putative
aging biomarkers and are sensitive to environmental stressors, including
pollutants. Our objective was to identify, from a set of environmental
exposures, which exposure is associated with leukocyte mtDNA content
and telomere length in adults. This study includes 175 adults from
50 to 65 years old from the cross-sectional Flemish Environment and
Health study, of whom leukocyte telomere length and mtDNA content
were determined using qPCR. The levels of exposure of seven metals,
11 organohalogens, and four perfluorinated compounds (PFHxS, PFNA,
PFOA, PFOS) were measured. We performed sparse partial least-squares
regression analyses followed by ordinary least-squares regression
to assess the multipollutant associations. While accounting for possible
confounders and coexposures, we identified that urinary cadmium
(6.52%, 95% confidence interval, 1.06, 12.28), serum hexachlorobenzene
(2.89%, 018, 5.68), and perfluorooctanesulfonic acid (11.38%, 5.97,
17.08) exposure were positively associated (p <
0.05) with mtDNA content, while urinary copper (−9.88%, −14.82,
−4.66) and serum perfluorohexanesulfonic acid (−4.75%,
−8.79, −0.54) exposure were inversely associated with
mtDNA content. Urinary antimony (2.69%, 0.45, 4.99) and mercury (1.91%,
0.42, 3.43) exposure were positively associated with leukocyte telomere
length, while urinary copper (−3.52%, −6.60, −0.34)
and serum perfluorooctanesulfonic acid (−3.64%, −6.60,
−0.60) showed an inverse association. Our findings support
the hypothesis that environmental pollutants interact with molecular
hallmarks of aging.