Abstract
The Yupik people of St. Lawrence Island, Alaska have a traditional
subsistence lifestyle with the majority of their diet consisting
of
local birds, fish, seal, walrus, and whale. Diets based on
fish
and marine mammals, such as the Yupik diet, are potential pathways
for
exposure to mercury and other toxic metals. At St. Lawrence
Island,
metal contaminants may come from local sources such as weathered
rock
or two abandoned U.S. military bases or remote sources through
atmospheric deposition or seasonal migration of animals to the
island.
The main goals of this study are to determine the total
concentrations
of copper (Cu), arsenic (As), selenium (Se), cadmium (Cd), mercury
(Hg), and lead (Pb) and the Se:Hg ratios in foodstuffs of
the
traditional Yupik diet. A secondary goal is to use C stable
isotope
ratios to quantify trophic levels and biomagnification within the
ecosystem. For this study, 216 samples from 28 different
species
and 14 different types of tissue were collected by Yupik hunters
at the
time of kill or shortly thereafter during the years of 2005, 2006,
and
2007. . The majority of samples represent fat, kidney,
liver, and muscle tissues of bearded seal, polar bear, reindeer,
and
walrus. The data show no significant differences among
muscle
tissues of the walrus, seal, polar bear, or reindeer for any of
the
metals analyzed. Among the different tissues sampled, however,
walrus,
seal, and polar bear liver and reindeer liver and kidney have
significantly higher concentrations of Cu, Cd, Hg, and Pb compared
to
all other tissue types. In contrast, Se is more concentrated in
muscle
tissue than in liver. Arsenic in walrus is concentrated in
blubber,
oil, and skin relative to other tissues. In most animals and
tissues, the Se:Hg ratio is significantly greater than 10:1 with
only
polar bear, seal, reindeer, and some sea bird tissues less than
10:1
and approaching 1:1.
The Se:Hg ratio is believed to affect the bioavailablity of both
elements with higher Se:Hg ratios considered advantageous to both
mitigating the negative effects of Hg and promoting the effects of
Se,
a vial nutrient.
The results, together with dietary surveys, can be used to
determine
how much of the Yupik’s exposure to environmental contaminants is
from
traditional foods, and to provide a basis for the members of the
Yupik
community to make informed decisions about dietary choices.
Kricheff, J., 2009. Metal concentrations in native Yupik
foodstuffs
from St. Lawrence Island, Alaska.
Unpublished MSc. thesis, State University of New York at
Albany.
52 pp., +vii
University at Albany Science Library call number: SCIENCE
Oversize
(*) QE 40 Z899 2009 K75
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