Burkhard Lawrence P
U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, 6201 Congdon Boulevard, Duluth, Minnesota 55804, USA.
Environ Toxicol Chem. 2003 Feb;22(2):351-60.
A series of modeling simulations was performed to evaluate the underlying factors and principles that drive the uncertainty in measured bioaccumulation factors (BAFs) and biota-sediment accumulation factors (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 that influenced 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 were developed. These illustrative designs provided a sense of how sampling design structures, that is, 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 is required for successful measurements because poor spatial coordination of organism, water, or sediment samples will yield BAFs and BSAFs with large and unknown biases.
进行了一系列建模模拟，以评估导致鱼类实测生物累积因子（BAFs）和生物群落 - 沉积物累积因子（BSAFs）存在不确定性的潜在因素和原理，并确定哪种采样设计可将这些不确定性降至最低。水柱中化学物质浓度的时间变异性、化学物质的代谢率和正辛醇 - 水分配系数（Kow）被确定为影响现场采样设计的主要因素。化学物质浓度的空间变异性、食物网结构以及沉积物 - 水柱浓度商对总体设计的重要性较小。模拟还表明，与采集瞬时水样相比，采集混合水样可降低与实测BAFs相关的不确定性。基于水柱中化学物质浓度的时间变异性以及化学物质的代谢率和Kow，开发了一些用于BAF和BSAF测量的示例性采样设计结构。这些示例性设计展示了采样设计结构，即采样事件的数量和时间间隔，可能如何受到时间变异性、代谢率和Kow差异的影响。尽管空间变异性的重要性在设计过程中被视为次要因素，但为了成功进行测量，需要在被采样生物的直接活动范围内对水和沉积物进行采样，因为生物、水或沉积物样本的空间协调性差会导致BAFs和BSAFs产生大的且未知的偏差。
