Changes in HTO and OBT activity concentrations in the Perch Lake aquatic ecosystem.
Perch Lake, a small shallow shield lake located on the Chalk River Laboratories (CRL) site, contains elevated levels of tritium due to inputs from a nearby nuclear waste management area. The releases have been going on for many years but tritium levels in Perch Lake have been gradually decreasing since about year 2000. Lake water, sediments, aquatic plants, clams and fish were collected during the summer and fall of 2003 and 2013 at three locations in the lake. HTO activity concentrations were measured in all samples and OBT activity concentrations were measured in sediments, plants, clams and fish. In 2003, 2013, HTO activity concentrations in lake water were roughly uniform in time and space, except close to the shoreline where concentrations were fluctuating according to stream water and groundwater tritium levels in streams entering the lake. HTO activity concentrations of biota were similar to concentrations in lake water at the site where they were collected. OBT activity concentrations in biota were not always correlating with the lake water HTO levels. OBT to HTO ratios were found to be less than 1 for aquatic plants, around 1 for clams and fish and above 1 for birds reared on the shore of the lake.
Environmental Technologies Branch, Canadian Nuclear Laboratories, Chalk River, Ontario, K0J 1J0, Canada. Electronic address: sangbog.kim@cnl.ca.
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Kim
Environmental Technologies Branch, Canadian Nuclear Laboratories, Chalk River, Ontario, K0J 1J0, Canada.
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Farrow
Environmental Technologies Branch, Canadian Nuclear Laboratories, Chalk River, Ontario, K0J 1J0, Canada.
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Bredlaw
Environmental Technologies Branch, Canadian Nuclear Laboratories, Chalk River, Ontario, K0J 1J0, Canada.
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Stuart
D000818:Animals; D017753:Ecosystem; D060106:Lakes / Q000737:chemistry*; D010471:Perches; D011834:Radiation Monitoring; D014316:Tritium / Q000032:analysis*; D014875:Water Pollutants, Radioactive / Q000032:analysis*
D014875:Water Pollutants, Radioactive; D014316:Tritium
HTO activity concentration; OBT activity concentration; Perch lake