Bioaccumulation of Polycyclic Aromatic Compounds: 2. Modeling Bioaccumulation in Marine Organisms Chronically Exposed to Dispersed Oil

Abstract

Within the frame of a large environmental study, we report on a research program that investigated the potential for bioaccumulation and subsequent effect responses in several marine organisms exposed to chronic levels of dispersed crude oil. Body burden can be estimated from kinetic parameters (rate constants for uptake and elimination), and appropriate body burden-effect relationships may improve assessments of environmental risks or the potential for such outcomes following chronic discharges at sea. We conducted a series of experiments in a flow-through system to describe the bioaccumulation kinetics of polycyclic aromatic hydrocarbons (PAH) at low concentrations of dispersed crude oils. Mussels (Mytilus edulis) and juvenile turbot (Scophthalmus maximus) were exposed for periods ranging from 8 to 21 d. Postexposure, the organisms were kept for a period of 9 to 10 d in running seawater to study elimination processes. Rate constants of uptake (k1) and elimination (k2) of the PAHs during and following exposure were calculated using a first-order kinetic model that assumed a decrease of the substances in the environment over time. The estimated bioconcentration factor was calculated from the ratio of k1/k2. The kinetic parameters of two-, three-, and four-ring PAHs in mussel and fish are compared with estimates based on hydrophobicity alone, expressed by the octanol-water partition coefficient, Kow (partitioning theory). A combination of reduced bioavailability of PAHs from oil droplets and degradation processes of PAHs in body tissues seems to explain discrepancies between kinetic rates based on Kow and actual kinetic rates measured in fish. Mussels showed a pattern more in compliance with the partitioning theory.

Development and Application of an Oil Toxicity and Exposure Model, Oiltoxex

“…Elimination rates for aromatic hydrocarbons in several studies [16,18,29,31,34] are consistent with the Spacie-Hamelink regression for Equation 12 [49]. Measured elimination rates for naphthalene, methylnaphthalene (C1-naphthalene), C2-naphthalene, acenathene, and acenaphthylene from dispersed crude oil were in agreement with Equation 12, while for higher-K ow compounds the uptake rates were lower and elimination rates higher than expected from the model [51]. This may be due in part to the flow-through design of these experiments, where time was insufficient for dissolution of the higher-K ow compounds, and so they were not bioavailable.…”

“…This may be due in part to the flow-through design of these experiments, where time was insufficient for dissolution of the higher-K ow compounds, and so they were not bioavailable. From Equation 12, LC50 t reaches 95% of LC50 ϱ at t ϭ 3/⑀ [21,50,51]. Thus, as ⑀ decreases with increasing log(K ow ), the time to reach 95% of LC50 ϱ increases from 1 d at log(K ow ) ϭ 2 (benzene) to 12 d at log(K ow ) ϭ 5 (C3-naphthalenes).…”

“…where ⑀ 1 ϭ 1.47 and ⑀ 2 ϭ 0.414 [21,[49][50][51]. This regression is used in the Organization for Economic Cooperation and Development (OECD) bioconcentration test guidelines (flowthrough fish test) [21,50].…”

Study of environmental risks incurred by leakage of lithium cells to the food chain in a freshwater ecosystem

“…Hence, we can conclude that nNi(OH)2 bioaccumulation in fish is significantly aftccted by the fast metabolic clearance. These results are consistent with previous studies; for example, some organic chemicals such as organochlorine pesticides and polychlorinated biphenyls can be greatly accumulated by organisms (Zhou et al 1999), and other organic chemicals like polycyclic aromatic hydrocarbons can not only be bioaccumulated but also be metabolized (Baussant et al 2001).…”

Atmospherically Deposited PBDEs, Pesticides, PCBs, and PAHs in Western U.S. National Park Fish: Concentrations and Consumption Guidelines

“…Concentrations for only 28 of the most frequently detected SOCs are presented here. Concentrations of PAHs and other SOCs measured are not shown here because they were detected in less than 50% of samples, likely due to low ambient concentrations and rapid transformation and/or elimination from fish (39).…”