Normalizing the Biomagnification Factor.

Following a recent proposal of normalizing the experimentally derived biomagnification factor to a 5% lipid content fish, we explore the normalization of the biomagnification factor (BMF) of lipophilic chemicals in fish. We illustrate with theoretical models and experimental data that the biomagnification factor of lipophilic chemicals is a function of the lipid content of the diet and that poorly metabolizable, lipophilic chemicals biomagnify in organisms to a greater degree when present in higher lipid content food. The proposed normalization of the laboratory BMF to a 5% lipid content fish, which is numerically identical to normalizing the biomagnification factor to a 5% dietary lipid content, has the potential to underestimate the biomagnification potential of lipophilic substances in aquatic food-webs. The biomagnification factor normalized to both the lipid content of the fish and the lipid content of the diet, which is the biomagnification metric included in the OECD-305 bioaccumulation testing guidelines, better represents real world biomagnification than the biomagnification factor normalized to a 5% lipid content fish. This article is protected by copyright. All rights reserved.