Concentrations of toxaphene (CHB) and 2-exo,3-endo,5-exo,6-endo,8,9,10-heptachlorobornane (B7-1001; Hp-Sed), a major toxaphene component known to be present in the sediment of toxaphene treated lakes, were determined in water, sediment, and fish from 13 lakes to examine the relationship between chlorobornane levels in fish and environmental variables. The lakes were situated in either the boreal plain, montane, or subalpine ecozones in western Canada. Five of the lakes had been treated with toxaphene between 1958 and 1962. Mean concentration of CHB (all chlorobornane congeners) in fish from the lakes ranged from 1.9 to 303 μg/kg with the maximum concentration occurring in lake trout from Bow Lake, an oligotrophic glacial fed lake with no record of toxaphene usage. CHB and in particular B7-1001 levels, were higher in water, sediment, and fish from treated relative to matched untreated lakes selected as “control” sites. CHB concentra tions in sediment were not related to the levels measured in fish; however, levels of atmospheric CHBAtm (CHBAtm = CHB − [B7-1001]) in fish, from both treated and untreated lakes combined, were inversely related to indicators of lake productivity (p < 0.05, dissolved phosphorus r = −0.64, percent organic content of lake sediment r = −0.84, and mid-summer water temperature r = −0.68). These relationships suggest that the process and pathway of CHBAtm accumulation in fish is mediated by limnological and perhaps physiological factors in addition to exposure levels. B7-1001 concentrations in fish were not related to indicators of lake productivity or the characteristics of fish from the lakes (weight, age, lipid content), but were related to B7-1001 concentration in sediments (r = 0.74, p < 0.05).
This study examines the effects of sequential filtration on the particle abundance and lead concentrations in ground water from four monitoring wells in New Jersey with a history of high turbidity, elevated metal concentrations, or where differences in metal concentrations exist between filtered and unfiltered samples. In these monitoring wells, both transportable suspended particles, such as colloidal particles that are suspended in solution, and nontransportable particles that are disturbed during sample collection but not considered mobile transportable species may be present in solution with potential overlap in particle size distribution. Filtration, particularly the operational pore size (25 to 0.45 μm) of the filter, was evaluated as a method to obtain a representative sample of the transportable metal, as defined by the dissolved phase and particles that are persistently suspended in solution. Two monitoring wells at the Denzer‐Schaefer site, a silty/clay aquifer with high particle concentrations (>8900 mg/L) from samples taken with bailers and a low‐flow purge (LFP) pump, showed that a filter of pore size 25 μm could remove 60% to 90% of soil‐derived particles, with minimal loss of suspended particles from solution. The two monitoring wells within the highly conductive Picatinny Arsenal sand aquifer provided higher particle abundance with the samples collected with bailers (4300 to 6500 mg/L) than with the LFP pump (4 to 11 mg/L), indicating greater artificial particle disruption with a bailer. At Picatinny Arsenal, the major portion of nontransportable particles in the ground water samples could be removed by filtration through a 25–μm pore size filter, with a minimal loss in suspended particles. Filtration of ground water through a 25–μm pore size filter followed by acidification at the sampling site would provide investigators a tool to examine particle transport in aquifers where there exists the potential for artificial particle disruption during sampling.
935Tables I and 11, in which they have been compared with the values of Ramsay and Young. All determinations were carried out in duplicate and agreed within 1 mm.The vapor pressures of the various special systems were then measured. The data appear in Tables I11 and VI, and have also been plotted in the form of pressure-temperature curves in the accompanying charts. All determinations were carried out in duplicate.
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