Bioaccumulation and Occurrence of Endocrine-Disrupting Chemicals (EDCs), Persistent Organic Pollutants (POPs), and Other Organic Compounds in Fish and Other Organisms Including Humans

Abstract

Bioaccumulation of chemicals by aquatic organisms, especially fish, mussels and Daphnia, is an important criterion in risk assessment. Bioconcentration from water must be considered in context with toxicity, biotic and abiotic degradation and other physical-chemical factors in order to protect the freshwater and marine environments with their organisms. Furthermore, it is necessary to prevent human exposure from contaminated aquatic food, such as fish, mussels, and oysters. This review outlines the factors such as toxic effects, bioavailability, chemical concentration in the water, pH of the water, and lipid content of the organisms, which are known to affect the bioconcentration of chemicals in aquatic organisms. Quantitative structure-activity relationships (QSARs) for predicting the bioconcentration potential of chemicals in algae, Daphnia, mussels, and fish are presented. Specific classes of organic chemicals, such as endocrine-disrupting chemicals (EDCs), super-hydrophobic persistent organic pollutants (POPs) (2,3,7,8-tetrachlorodibenzo-p-dioxin, octachlorodibenzo-p-dioxin, Mirex, and Toxaphene), tetrachlorobenzyltoluenes (TCBTs), polybrominated benzenes (PBBz), polybrominated biphenyls (PBBs), polybrominated diphenyl ethers (PBDEs), polychlorinated diphenylethers (PCDEs), nitro musk compounds (NMCs), polycyclic musk fragrances (PMFs), and sun screen agents (SSAs) are critically reviewed and discussed. Furthermore, predictions for some metabolites, especially hydroxylated aromatics, of these chemical classes which may have endocrine-disrupting effects are made. The selected bioconcentration factors on a wet weight basis (BCF_w) and on a lipid basis (BCF_L) in aquatic organisms, such as algae (Chlorella sp.), water fleas (Daphnia sp.), mussels (Mytilus edulis), oysters (Crassostrea virginica), and different fish species, of these chemicals are presented in tables. Furthermore, the chemical structure, physico-chemical properties, such as selected log K_OW values, and other data are compiled. In the cases where no bioconcentration factors (BCFs) were published the BCF values of chemicals in fish and mussels were predicted from QSARs using the n-octanol/water partition coefficient (K_OW) as the basic parameter. A new classification scheme for organic chemicals by their hydrophobicity (log K_OW) and by their worst-case bioconcentration factors on a lipid basis (BCF_L) is also presented.