title: Influence of ambient air pollution on global DNA methylation in healthy adults: a seasonal follow-up.
abstract: BACKGROUND
  DNA methylation changes are potential pathways of environmentally induced health effects. We investigated whether exposure to ambient concentrations of NO2, PM10, PM2.5 and O3 and traffic parameters were associated with global DNA methylation in blood of healthy adults.
  
  
  METHODS
  48 non-smoking adults (25 males) with a median age of 39years were sampled in winter and summer. Global DNA methylation in whole blood (% 5-methyl-2'-deoxycytidine, %5mdC) was analyzed with HPLC. Exposure to air pollutants at the home address was assessed using interpolated NO2, PM10, PM2.5 and O3 concentrations for various exposure windows (60- to 1-day moving average exposures and yearly averages) and GIS-based traffic parameters. Associations between pollutants and %5mdC were tested with multiple mixed effects regression models.
  
  
  RESULTS
  Average %5mdC (SD) was 4.30 (0.08) in winter and 4.29 (0.08) in summer. Men had higher %5mdC compared to women both in winter (4.32 vs. 4.26) and summer (4.31 vs. 4.27). When winter and summer data were analyzed together, various NO2, PM10 and PM2.5 moving average exposures were associated with changes in %5mdC (95% CI) ranging from -0.04 (-0.09 to 0.00) to -0.14 (-0.28 to 0.00) per IQR increase in pollutant. NO2, PM10, PM2.5 and O3 moving average exposures were associated with decreased %5mdC (95% CI) varying between -0.01 (-0.03 to 0.00) and -0.17 (-0.27 to -0.06) per IQR increase in pollutant in summer but not in winter.
  
  
  CONCLUSIONS
  Decreased global DNA methylation in whole blood was associated with exposure to NO2, PM10, PM2.5 and O3 at the home addresses of non- adults. Most effects were observed for the 5- to 30-day moving average exposures.
authors.affiliation: Environmental Risk and Health unit, VITO (Flemish Institute for Technological Research), Boeretang 200, B-2400 Mol, Belgium. sofie.deprins@vito.be
authors.forename: Sofie
authors.initials: S
authors.lastname: De Prins
authors.forename: Gudrun
authors.initials: G
authors.lastname: Koppen
authors.forename: Griet
authors.initials: G
authors.lastname: Jacobs
authors.forename: Evi
authors.initials: E
authors.lastname: Dons
authors.forename: Els
authors.initials: E
authors.lastname: Van de Mieroop
authors.forename: Vera
authors.initials: V
authors.lastname: Nelen
authors.forename: Frans
authors.initials: F
authors.lastname: Fierens
authors.forename: Luc
authors.initials: L
authors.lastname: Int Panis
authors.forename: Patrick
authors.initials: P
authors.lastname: De Boever
authors.forename: Bianca
authors.initials: B
authors.lastname: Cox
authors.forename: Tim S
authors.initials: TS
authors.lastname: Nawrot
authors.forename: Greet
authors.initials: G
authors.lastname: Schoeters
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000032:analysis* / Q000633:toxicity; D000397:Air Pollution / Q000032:analysis*; D002980:Climate; D019175:DNA Methylation / Q000187:drug effects*; D003841:Deoxycytidine / Q000031:analogs & derivatives / Q000032:analysis / Q000633:toxicity; D005260:Female; D005500:Follow-Up Studies; D015386:Hazardous Substances / Q000032:analysis / Q000633:toxicity; D006801:Humans; D008297:Male; D008875:Middle Aged; D052638:Particulate Matter / Q000032:analysis* / Q000633:toxicity; D012621:Seasons; D013997:Time Factors
chemical_list: D000393:Air Pollutants; D015386:Hazardous Substances; D052638:Particulate Matter; D003841:Deoxycytidine; C016569:5-methyldeoxycytidine
keywords: %5mdC; 2′-deoxycytidine; 5-hydroxymethyl-cytosine; 5-methyl-2′-deoxycytidine; 5-methyl-cytosine; 5hmC; 5mC; 5mdC; Air pollution; BC; BMI; CI; DNA methylation; Epigenetics; GIS; GSH; Human biomonitoring; IQR; LINE-1; NO; NO(2); O(3); Ozone; PM; PM(10); PM(2.5); S-adenosylmethionine; SAM; SD; WBC; black carbon; body mass index; confidence interval; dC; geographical information system; glutathione; iNOS; inducible nitric oxide synthase; interquartile range; long interspersed nucleotide elements; nitric oxide; nitrogen dioxide; ozone; particulate matter with aerodynamic diameter≤10μm; particulate matter with aerodynamic diameter≤2.5μm; percentage 5mdC; standard deviation; white blood cells