title: Increase in selenium status of Christchurch adults associated with deregulation of the wheat market.
abstract: OBJECTIVE
  to determine whether there have been changes in the plasma selenium status of Christchurch adults between 1981 and 1992, and likely causes of any such changes.
  
  
  METHODS
  selenium analyses were performed on plasma samples collected during the period. Changes in agricultural practices and importation policies were also examined.
  
  
  RESULTS
  mean plasma selenium levels ranged between 46 and 54 micrograms/L (0.59-0.69 mumol/L) until 1987, after which there was a dramatic and sustained increase to between 66 and 70 micrograms/L (0.84-0.88 mumol/L) for 1988-91, with a 1992 mean of 80 micrograms/L (1.01 mumol/L). This increase closely follows the deregulation of the New Zealand wheat market and greater South Island consumption of wheat imported from Australia and the United States. Whereas flour was made from South Island wheat prior to 1988 and contained about 15 micrograms/kg selenium, flour manufactured by Christchurch mills in 1991 contained between 80 and 140 micrograms/kg.
  
  
  CONCLUSIONS
  these results imply that as a result of current government policy, the population of Christchurch no longer has particularly low selenium levels. It follows that if there is an association between low selenium and any form of ill health, a declining incidence or severity in this population might be expected.
authors.affiliation: Department of Pathology, Christchurch School of Medicine, New Zealand.
authors.forename: C C
authors.initials: CC
authors.lastname: Winterbourn
authors.forename: D J
authors.initials: DJ
authors.lastname: Saville
authors.forename: P M
authors.initials: PM
authors.lastname: George
authors.forename: T A
authors.initials: TA
authors.lastname: Walmsley
mesh_terms: D000328:Adult; D003132:Commerce; D006801:Humans; D009520:New Zealand; D011640:Public Policy; D012643:Selenium / Q000032:analysis / Q000097:blood*; D014908:Triticum / Q000737:chemistry
chemical_list: D012643:Selenium