Enclosure (1) TO COMDTINST 16478.12
Summary of Results
Sediment and biological sampling was conducted in four locations, as part of
the prototype investigation program. The results of these investigations
revealed a pattern which indicates little, if any, detectable risk due to
spent primary AtoN batteries.
While the results of the prototype investigations varied by location, some
common trends were noted. A full description of each study is available in
individual reports for each prototype investigation. In general the findings
were:
The extremely low percentage of methyl mercury, and thus low risk
potential, was common at all of the characteristic aquatic environments
examined. Very low mercury concentrations were detected in the aquatic
organisms, even those attached to batteries. These findings indicate no
significant risk to human health or the aquatic food chain.
The limited spatial distribution of mercury within the sediment was
another common pattern detected during the prototype program. In most
cases elevated sediment concentrations, if any, were confined to the
immediate vicinity (less than one meter) of batteries and in all cases if
there were any slightly elevated concentrations detected beyond one
meter, the condition was limited to 10 meters or less from the AtoN.
In almost all cases, even the highest mercury concentrations measured
around AtoNs was within the range of backgrounnd concentrations measured
as part of the investigation reported in the literature for the general
prototype investigation area.
There appear to be elevated sediment concentrations of mercury associated
with high density of discarded batteries, and also with broken batteries.
When both of these conditions occur, the sediment levels approach and in
some cases even exceed levels associated with adverse effects on sediment
dwelling organisms. However, even in the areas of highest battery
concentrations and greatest percentage of broken batteries methyl mercury
concentrations and levels in aquatic organisms are well below those which
pose a potential risk to humans or the aquatic food chain.
There are special circumstances and conditions which can occur at an AtoN,
such as high biological productivity, hard sea bottom, and high number of
broken batteries, which in combination can produce relatively high
mercury concentrations and sensitive exposure pathways and thus potential
environmental risk.
The prototype and demonstration programs estimated the risk associated
with spent primary batteries in terrestrial and aquatic environments.
Risk indicators included.
3-17
Previous Page
