title: Sex ratios in the Arctic--do man-made chemicals matter?
abstract: OBJECTIVE
  The objective was to analyze the variation of secondary sex ratios across the Arctic and to estimate the time trend. The rationale for this was claims in news media that, in the Arctic, sex ratios have become reduced due to exposure to anthropogenic contaminants in the environment.
  
  
  METHODS
  Data was collected from 27 circumpolar jurisdictions from public websites of the eight Arctic countries. Sex ratios at birth were calculated for each jurisdiction and each available year. Linear regression models of the sex ratios across time were fit within each jurisdiction to estimate the change in sex ratio over time.
  
  
  RESULTS
  All male:female sex ratios were close to 1.05 with time trends close to 0. In a Bayesian hierarchical model overall sex ratio was estimated at 1.054 (95% confidence interval 1.048, 1.058). The estimate for the 10-year slope across all jurisdictions was 0.0010 (95% confidence interval -0.0021, 0.0046). Separate analyses of indigenous populations in Alaska and Greenland gave similar results and similar sex ratios were found among Greenland Inuit in 1900 and today.
  
  
  CONCLUSIONS
  The absence of deviation of the secondary sex ratio in any of the Arctic jurisdictions indicates that the contaminants that are present are not disrupting endocrine systems to the extent that sex ratios are being affected.
authors.affiliation: Centre for Health Research in Greenland, National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark. pb@sdu.dk
authors.forename: Peter
authors.initials: P
authors.lastname: Bjerregaard
authors.forename: Susan
authors.initials: S
authors.lastname: Chatwood
authors.forename: Bryany
authors.initials: B
authors.lastname: Denning
authors.forename: Lawrence
authors.initials: L
authors.lastname: Joseph
authors.forename: T Kue
authors.initials: TK
authors.lastname: Young
mesh_terms: D001110:Arctic Regions; D004703:Endocrine System / Q000187:drug effects; D004784:Environmental Monitoring; D005260:Female; D015386:Hazardous Substances / Q000494:pharmacology*; D006801:Humans; D016014:Linear Models; D008297:Male; D012744:Sex Ratio
chemical_list: D015386:Hazardous Substances