Air pollution exposure and telomere length in highly exposed subjects in Beijing, China: a repeated-measure study

Environ Int. 2012 Nov 1;48:71-7. doi: 10.1016/j.envint.2012.06.020. Epub 2012 Aug 5.

Abstract

Background: Ambient particulate matter (PM) exposure has been associated with short- and long-term effects on cardiovascular disease (CVD). Telomere length (TL) is a biomarker of CVD risk that is modified by inflammation and oxidative stress, two key pathways for PM effects. Whether PM exposure modifies TL is largely unexplored.

Objectives: To investigate effects of PM on blood TL in a highly-exposed population.

Methods: We measured blood TL in 120 blood samples from truck drivers and 120 blood samples from office workers in Beijing, China. We measured personal PM(2.5) and Elemental Carbon (EC, a tracer of traffic particles) using light-weight monitors. Ambient PM(10) was obtained from local monitoring stations. We used covariate-adjusted regression models to estimate percent changes in TL per an interquartile-range increase in exposure.

Results: Covariate-adjusted TL was higher in drivers (mean=0.87, 95%CI: 0.74; 1.03) than in office workers (mean=0.79, 95%CI: 0.67; 0.93; p=0.001). In all participants combined, TL increased in association with personal PM(2.5) (+5.2%, 95%CI: 1.5; 9.1; p=0.007), personal EC (+4.9%, 95%CI: 1.2; 8.8; p=0.01), and ambient PM(10) (+7.7%, 95%CI: 3.7; 11.9; p<0.001) on examination days. In contrast, average ambient PM(10) over the 14 days before the examinations was significantly associated with shorter TL (-9.9%, 95%CI: -17.6; -1.5; p=0.02).

Conclusions: Short-term exposure to ambient PM is associated with increased blood TL, consistent with TL roles during acute inflammatory responses. Longer exposures may shorten TL as expected after prolonged pro-oxidant exposures. The observed TL alterations may participate in the biological pathways of short- and long-term PM effects.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Air Pollution / statistics & numerical data*
  • Biomarkers / blood
  • Cardiovascular Diseases / epidemiology
  • Cardiovascular Diseases / metabolism
  • China
  • Female
  • Humans
  • Inhalation Exposure / statistics & numerical data*
  • Male
  • Middle Aged
  • Particulate Matter / analysis
  • Reactive Oxygen Species / metabolism
  • Telomere / physiology*
  • Telomere Shortening / physiology*

Substances

  • Biomarkers
  • Particulate Matter
  • Reactive Oxygen Species