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FACTORS INFLUENCING THE DESIGN OF BIOACCUMULATION FACTOR AND BIOTA-SEDIMENT ACCUMULATION FACTOR FIELD STUDIES
Citation:
Burkhard, L P. FACTORS INFLUENCING THE DESIGN OF BIOACCUMULATION FACTOR AND BIOTA-SEDIMENT ACCUMULATION FACTOR FIELD STUDIES. Presented at Ecological Risk Assessment Forum Meeting, Washington, DC, January 31, 2003.
Description:
General guidance for designing field studies to measure bioaccumulation factors (BAFs) and biota-sediment accumulation factors (BSAFs) is not available. To develop such guidance, a series of modeling simulations were performed to evaluate the underlying factors and principles that drive the uncertainty in measured BAFs and BSAFs for fish, and to determine which sampling designs minimize those uncertainties. Temporal variability of chemical concentrations in the water column, and the metabolism rate and n-octanol/water partition coefficient (Kow) for the chemical were determined to be the dominant factors influencing the field sampling design. Spatial variability of the chemical concentrations, food web structure, and the sediment-water column concentration quotient, had a lesser importance upon the overall design. The simulations also demonstrated that collection of composite water samples in comparison to grab water samples resulted in reductions in the uncertainties associated with measured BAFs. Some illustrative sampling design structures for BAF and BSAF measurements based upon the temporal variability of chemical concentrations in the water column, and the metabolism rate and Kow for the chemical will be presented. These illustrative designs will provide a sense of how sampling design structures, i.e., the number and spacing over time of sampling events, might be influenced by differences in temporal variabilities, metabolism rates and Kow. Although the importance of spatial variability was discounted as a major factor in the design process, sampling of water and sediment across the immediate home range of the sampled organism will be required for successful measurements because poor spatial coordination of organism, water and/or sediments samples will yield BAFs and BSAFs with large and unknown biases.