Enclosure (1) TO COMDTINST 16478.12
BIOLOGICAL SAMPLING:
The intent of the biological sampling and analysis program was to determine
the potential uptake and bioaccumulation of mercury in animals in close
promixity discarded batteries.
Aquatic Sites
In the Chesapeake and Tampa Bays, organisms attached to batteries or other
hard surfaces associated with AtoNs were collected and analyzed, to determine
whether mercury concentrations in such biota exceeded concentrations in
similar organisms in other portions of the estuary. Attached organisms were
studied because they are immobile. Their immobility removes the possibility
that any elevated mercury concentrations found in the organisms could have
been accumulated at a different location. Similarly, if the levels were not
elevated (for animals which had been attached to batteries for their entire
life) it would be unlikely that more transient animals, like fish or crabs,
would accumulate mercury from batteries. The biological collection procedures
used were designed specifically for the particular environments in which they
were implemented. In the Chesapeake Bay, blue mussels (Mytilus edulis) were
collected, where possible, because NOAA (NOAA 1989) and the EPA have used this
mussel to evaluate national trends in water pollution, and there is a wealth
of information on mercury concentrations in that species. Application of this
planned procedure was limited by the absence of this species in sufficient
numbers in the Chesapeake and Tampa Bays, and was modified for the Tennessee
River study. In Tennessee and Puget Sound, organisms dwelling within the
sediments were analyzed. Total mercury concentrations in biological tissue
were measured as an upper bound on the methyl mercury concentration. Methyl
mercury persists much longer than elemental mercury in tissue (Riisgard and
Hansen, 1990; Surma-Aho and Passivirta, 1986), therefore, if detected, mercury
is more likely to be in methyl form in tissue than in elemental form. The
total mercury concentration is, therefore, a conservative estimate of the
total methyl mercury in biota.
Terrestrial Sites
In addition to the aquatic effort in the Tampa area, land-based (or
terrestrial) AtoNs were evaluated. Two representative locations were
examined: an active AtoN surrounded by dry land on Egmont Key and an inactive
light surrounded by wetlands on Anclotte Key. Terrestrial locations were
included in the study due to the multiple exposure pathways to humans that can
be encountered at this type of location.
The additional possibility of exposure to contaminants through inhalation
exists at terrestrial location, whereas the exposure pathways at aquatic
locations are
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