Exposure to Environmental Pollutants and Their Association with Biomarkers of Aging: A Multipollutant Approach

Abstract

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.

Towards Therapeutic Alternatives for Mercury Neurotoxicity in the Amazon: Unraveling the Pre-Clinical Effects of the Superfruit Açaí (Euterpe oleracea, Mart.) as Juice for Human Consumption

“…Literature about the possible influence of the metal is extremely scarce. Only two recent studies with exposed human populations demonstrated contradictory results in the analysis of telomere length in blood [69,70]. However, blood is not the main target organ for MeHg and confounding factors in these studies are still an open question.…”

Application of the Key Characteristics of Carcinogens to Per and Polyfluoroalkyl Substances

“…To date, only a few studies have examined the influence of PFAS on endpoints related to DNA stability and immortalization. Leukocyte telomere length was inversely associated with elevated PFOS and PFDA levels in female but not male newborns [197] and with serum PFOA levels in adults 50-65 years old [198]. In the same adult study, serum PFOS and PFHxS levels were positively and negatively associated with mitochondrial DNA content respectively [198].…”

“…Leukocyte telomere length was inversely associated with elevated PFOS and PFDA levels in female but not male newborns [197] and with serum PFOA levels in adults 50-65 years old [198]. In the same adult study, serum PFOS and PFHxS levels were positively and negatively associated with mitochondrial DNA content respectively [198]. Intriguingly, a study of PFAS in wild Arctic seabirds found a positive relationship between PFAS and elongated telomere length in birds bearing the highest concentrations of six PFAS; PFOS (linear), PFNA, PFDA, PFUnA, PFDoA and PFTrDA [199].…”

Associations between polyfluoroalkyl substance and organophosphate flame retardant exposures and telomere length in a cohort of women firefighters and office workers in San Francisco

“…Huang et al, 2019 examined PFAS and TL in National Health and Nutrition Examination Survey (NHANES) data and reported a strong positive association between PFOS and leukocyte TL in adults and null associations for other PFAS and TL(17). Vriens et al, 2019 found a negative association between PFOA and leukocyte TL in adults aged 50 to 65 years using multipollutant models(18). Zota et al, 2018 similarly used multipollutant models and found no significant associations between prenatal PFAS exposure and repeated measures of leukocyte TL in overweight and obese low-income mothers with an average age of 27.9 years(98).…”

“…In addition to studying cancer, researchers have begun to examine associations between exposures to environmental chemicals and biomarkers of effect with potential relevance for cancer, including telomere length (TL) (15)(16)(17)(18)(19). Telomeres are complexes of repetitive DNA sequences and proteins that cap the ends of chromosomes to protect against degradation and fusion during cell division (20,21).…”