Evaluation of Two Methods for Prediction of Bioaccumulation Factors

Abstract

Two methods for deriving bioaccumulation factors (BAFs) used by the U.S. Environmental Protection Agency in development of water quality criteria were evaluated using polychlorinated biphenyl (PCB) data from the Hudson River and Green Bay ecosystems. One method predicts BAF(L)fd values (BAFs based upon concentrations of freely dissolved chemical in ambient water and in the lipid fraction of tissue) using field-measured biota-sediment accumulation factors (BSAFs): greater than 90% of the predicted BAF(L)fd values were within a factor of 5 of their measured values for both ecosystems. The second method predicts BAF(L)fd values as the chemical's 1-octanol/water partition coefficient (Kow) times a food chain multiplier: greater than 90% of the predicted BAF(L)fd values were within a factor of 5 of their measured values for the Green Bay ecosystem and for three of the six sampling locations on the Hudson River. Poorer predictive ability with the Kow method for the other three sampling locations was believed to be due to the existence of environmental conditions not representative of the longer term ecosystem conditions assumed for the method. BAF(L)fd and BAF(T)t values (BAFs based upon concentrations of total chemical in ambient water and in wet tissue) were compared. The within ecosystem and across ecosystems comparisons demonstrated a 2-5-fold decrease in variability (expressed as ratios of coefficients of variation, percentile ranges, and confidence ranges) for predicted BAF(L)fd values in comparison to BAF(T)t values.

The Modulation of Fibrosis in Scleroderma by 3-Deoxyglucosone

“…41 Section 6.1.5, pp. 6-6-6-7: Similarly, PRAM systematically underestimated lipid-based BAFs in comparison to the data set reported by Burkhard et al (2003) (Figure 26), although the general patterns across Kow agree reasonably well. EPA concurs with the Navy's suggestion that "some model tuning may be warranted" (p. 6-6) to add confidence in the accuracy of PRAM predictions.…”

A hybrid empirical-mechanistic modeling approach for extrapolating biota–sediment accumulation factors and bioaccumulation factors across species, time, and/or ecosystems

“… a Values for Lake Michigan, midlake off of Saugatuck (MI, USA) are from Burkhard et al [16]. Values from Green Bay (WI, USA) are from Burkhard et al [17]. …”

“…In this example, the model was run with the food web described in Materials and Methods , a 30:70 benthic/pelagic food web for Lake Michigan [18] and a default 50:50 benthic/pelagic food web for Green Bay. The sediment‐water disequilibria values were based on measurements for the individual PCBs in the two ecosystems [17,19]. The predicted BSAFs are listed in Table 2 along with the calculated ER BSAF,∏ values (using Eqn.…”

Ex-ORISKANY Artificial Reef Project: Ecological Risk Assessment

“…These include differences in the actual trophic level and the nominal or measured (with δN 13 and δC 13 isotopes), the fact that most ecosystems are in disequilibria with chemical inputs and losses, errors and biases in sampling and analytical chemistry, and difference in age, size, gender, growth rate, and reproductive status of the specimens sampled (Burkhard et al 2003.…”