Particulate matter air pollution, neighborhood socio-economic status, and leukocyte telomere length

Abstract

Background: Telomeres cap and protect chromosomes from degradation and risk factors for telomere attrition include aging and environmental factors. Although exposure to some air pollutants and neighborhood socio-economic factors (nSES) have been associated with telomere length, evidence of associations between exposure to particulate matter (PM) air pollution, nSES, and the interaction between the two in relation to telomere length is limited and inconclusive. Our objective was to examine the associations between exposure to short-, intermediate-, and long-term (1-, 3-, and 12-month) exposure to different size fractions of PM (<2.5 microns [PM2.5], 2.5-10 microns [PM10-2.5], and <10 microns [PM10]) and nSES at blood draw, and leukocyte telomere length.Methods: We used generalized linear regression models to examine the associations between each of the PM exposure metrics, nSES, and z-scores of log-transformed telomere length in 10,212 female participants of the nationwide Nurses’ Health Study, after adjusting for demographics and telomere attrition risk factors. Using participants’ address history, we applied spatio-temporal prediction models to estimate monthly PM exposures.Results: In adjusted models, PM2.5 exposure per 10 μg/m3 increase was not associated with relative telomere length: 1-month exposure: β: 0.01, standard error (SE): 0.01, p: 0.40; 3-month exposure: β: 0.01, SE: 0.01, p: 0.37; 12-month exposure: β: 0.01, SE: 0.01, p: 0.34. Results for exposure to PM10-2.5, and PM10 were similar. nSES at blood draw was also not associated with telomere length: β: -0.001, SE: 0.001, p: 0.28. We observed no multiplicative interactions between 1-, 3-, and 12-month PM exposures and nSES.Conclusions: In this study of U.S. women, short-, intermediate-, and long-term PM exposures were not associated with telomere attrition for any size fraction of PM; nSES was also not associated with telomere length. Additionally, we observed no interactions between PM exposures and nSES in association with telomere length.