title: Correlations between mercury concentration, and stable isotope ratios of carbon and nitrogen of amino acids in scalp hair from whale meat eaters and heavy fish eaters.
abstract: BACKGROUND
  As mercury (Hg) accumulation in marine animals generally increases with increased trophic level (δ15N values) through the food web, predators accumulate higher levels of Hg. The main source of human Hg intake is the consumption of fish and other marine animals, and Hg concentration in scalp hair is the preferred marker for evaluating consumption of marine animals. Difference in δ15N values between trophic and source amino acids of human consumers could enable us to estimate the trophic level of the consumer without knowing the bulk δ15N value of their prey.
  
  
  METHODS
  We measured the δ15N values of 15 amino acids in scalp hair from heavy fish eaters and whale meat eaters using isotope ratio monitoring gas chromatography/mass spectrometry (irm-GC/MS), and investigated the correlations between Hg concentrations in the hair and the δ15N values of the individual constituent amino acids.
  
  
  RESULTS
  The δ15N values for all trophic amino acids (Ala, Val, Leu, Ile, Pro, Asx and Glx) increased with increases in Hg concentration (p < 0.01), with the highest correlation being with Glx (R2= 0.725). In contrast, the δ15N value for Thr decreased with increases in Hg concentration (R2= 0.663, p < 0.01). The difference in δ15N values between Glx and Thr was positively correlated with Hg concentration, showing the highest correlation coefficient (R2= 0.773, p < 0.01) among the various combinations for amino acids.
  
  
  CONCLUSIONS
  The difference in δ15N values between Glx and Thr appears to be the best proxy for the estimation of Hg concentration in scalp hair. Copyright © 2017 John Wiley & Sons, Ltd.
authors.affiliation: School of Pharmaceutical Science, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu, Hokkaido, 061-0293, Japan.
authors.forename: Tetsuya
authors.identifier: http://orcid.org/0000-0003-4278-5689
authors.initials: T
authors.lastname: Endo
authors.affiliation: Sapporo Minami-Seishu Hospital, 1-2-20, Satozuka, Kiyota-ku, Sapporo, Hokkaido, 004-0501, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Ogasawara
authors.affiliation: Sapporo Higashi-Tokushukai Hospital, N33-E14, Higashi-ku, Sapporo, Hokkaido, 065-0033, Japan.
authors.forename: Moriaki
authors.initials: M
authors.lastname: Hayasaka
authors.affiliation: Hokusei Hospital, W3-2-10-1, Shinkawa, Kita-Ku, Sapporo, Hokkaido, 001-0933, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Hotta
authors.affiliation: School of Pharmaceutical Science, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu, Hokkaido, 061-0293, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Kimura
authors.affiliation: German Institute of Human Nutrition, Potsdam-Rehbruecke (DIfE), D-14558, Nuthetal, Germany.
authors.forename: Klaus J
authors.initials: KJ
authors.lastname: Petzke
mesh_terms: D000596:Amino Acids / Q000032:analysis / Q000737:chemistry*; D000818:Animals; D002247:Carbon Isotopes / Q000032:analysis*; D004032:Diet / Q000706:statistics & numerical data*; D005399:Fishes; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006197:Hair / Q000737:chemistry*; D006801:Humans; D008460:Meat / Q000032:analysis; D008628:Mercury / Q000032:analysis*; D009587:Nitrogen Isotopes / Q000032:analysis*; D012535:Scalp / Q000502:physiology; D014907:Whales
chemical_list: D000596:Amino Acids; D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D008628:Mercury