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1 <br />1 <br />1 <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />Results <br />Toxicant solutions and analytical procedures <br />Exposure and tissue concentrations were adjusted for recovery of selenium in spiked <br />samples (water: 106%, SE = 1.36; algae: 90.0%, 5E=8.61; rotifer: 77.5%, SE= 5.80; fish: 87.7%, <br />5E=11.9). Mean and standard error measured concentrations in exposure water, algae, rotifer, <br />and fish are presented in Tables 1-3. Chemical analysis revealed that the well water used for <br />controls contained traces of selenium at an average concentration of 5.35 (5E=0.153) µg/L. The <br />well water was used as dilution water for all experimental treatments, consequently the selenium <br />that it contained increased target exposure concentrations by approximately 5.35 µg/L. To <br />account for the additional selenium, all data and analysis are presented based on measured <br />Analyses conducted during this study suggest that selenium levels in the water are relatively <br />concentrations. Previous analysis of the well water over several years did not detect selenium. <br />constant and that previous analyses were either in error or did not have sufficient detection limits <br />to quantify existing levels. <br />Measured selenium concentrations before and after pasteurization in the lowest and <br />highest water exposure concentrations were 8.60 (5E=0.306) and 7.6 (SE=0.665), and 26.7 <br />(5E=0.333) and 27.7 (SE=0.667), respectively. The average selenium concentration was about <br />4% higher after pasteurization. This relatively small increase was probably a result of analytical <br />error during measurement of selenium concentrations and shows that pasteurization did not <br />reduce toxicant concentrations. <br />10 <br />