title: Variations in arsenic methylation capacity and oxidative DNA lesions over a 2-year period in a high arsenic-exposed population.
abstract: OBJECTIVE
  To assess long-term variations in arsenic methylation and oxidative DNA lesions of chronic high arsenic-exposed populations.
  
  
  METHODS
  A follow-up study was conducted in 64 chronic high arsenic-exposed subjects from 2004 to 2006. Urinary arsenic species and 8-hydroxydeoxyguanine were measured.
  
  
  RESULTS
  Percentages of urinary inorganic arsenic, monomethylarsonate and urinary 8-hydroxydeoxyguanine (8-OHdG) level were significantly higher, but the percentage of dimethylarsinate, the primary methylation index (PMI) and secondary methylation index (SMI) was lower in the ninth year of arsenic exposure compared with the seventh year. Substantial differences in relative arsenic methylation capacity were observed between the seventh and ninth year. Percentages of arsenic species, PMI and SMI were significantly correlated between siblings, and between parents and children.
  
  
  CONCLUSIONS
  Arsenic methylation may decrease, but oxidative DNA lesions may increase with the increase of cumulative arsenic exposure level. Both genetic and environmental factors may contribute to variability in arsenic methylation.
authors.affiliation: Department of Occupational and Environmental Health, College of Public Health, China Medical University, Heping District, Shenyang, Liaoning, People's Republic of China.
authors.forename: Yuan-yuan
authors.initials: YY
authors.lastname: Xu
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Miao
authors.initials: M
authors.lastname: He
authors.forename: Peng
authors.initials: P
authors.lastname: Xue
authors.forename: Jing-qi
authors.initials: JQ
authors.lastname: Fu
authors.forename: Hui-hui
authors.initials: HH
authors.lastname: Wang
authors.forename: Gui-fan
authors.initials: GF
authors.lastname: Sun
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine / Q000031:analogs & derivatives; D000293:Adolescent; D000328:Adult; D020261:Arsenic Poisoning / Q000235:genetics / Q000378:metabolism*; D001152:Arsenicals / Q000009:adverse effects* / Q000378:metabolism; D002648:Child; D004247:DNA / Q000187:drug effects; D004249:DNA Damage; D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000378:metabolism / Q000633:toxicity*; D005260:Female; D006147:Guanine / Q000031:analogs & derivatives / Q000652:urine; D006801:Humans; D008297:Male; D008745:Methylation; D008875:Middle Aged; D018384:Oxidative Stress; D013548:Sweden; D055815:Young Adult
chemical_list: D001152:Arsenicals; D004785:Environmental Pollutants; D006147:Guanine; C078307:8-oxo-7,8-dihydrodeoxyguanine; D000080242:8-Hydroxy-2'-Deoxyguanosine; D004247:DNA