Five widely used metrics of bioaccumulation in fish are defined and discussed, namely the octanol–water partition coefficient (KOW), bioconcentration factor (BCF), bioaccumulation factor (BAF), biomagnification factor (BMF), and trophic magnification factor (TMF). Algebraic relationships between these metrics are developed and discussed using conventional expressions for chemical uptake from water and food and first-order losses by respiration, egestion, biotransformation, and growth dilution. Two BCFs ely as an equilibrium partition coefficient KFW or as a nonequilibrium BCFK in which egestion losses are included. Bioaccumulation factors are shown to be the product of the BCFK and a ely, the diet-to-water concentration ratio and the ratio of uptake rate constants for respiration and dietary uptake. Biomagnification factors are shown to be proportional to the lipid-normalized ratio of the predator/prey values of BCFK and the ratio of the equilibrium multipliers. Relationships with TMFs are also discussed. The effects of chemical hydrophobicity, biotransformation, and growth are evaluated by applying the relationships to a range of illustrative chemicals of varying KOW in a linear 4-trophic-level food web with typical values for uptake and loss rate constants. The roles of respiratory and dietary intakes are demonstrated, and even slow rates of biotransformation and growth can significantly affect bioaccumulation. The BCFKs and the values of M can be regarded as the fundamental determinants of bioaccumulation and biomagnification in aquatic food webs. Analyzing data from food webs can be enhanced by plotting logarithmic lipid-normalized concentrations or fugacities as a linear function of trophic level to deduce TMFs. Implications for determining bioaccumulation by laboratory tests for regulatory purposes are discussed. Environ Toxicol Chem 2013;–1466. © 2013 SETAC
Introduction
Bioaccumulation from normal chemical substances in seafood and other bacteria that can compensate restaurants organizations is an issue due to one another you’ll adverse effects into organisms by themselves plus the prospect of connection with predators, as well as individuals, which can consume this type of organisms. The focus is on bioaccumulation within the seafood, however, comparable prices connect with bioaccumulation various other aquatic drinking water-respiration bacteria, and so they could possibly get apply at sky-breathing organisms eg birds and you may mammals. Thus, a global effort could have been launched to test commercial chemicals to have its capacity to bioaccumulate step 1, 2 . Within this initiative, distinct bioaccumulation investigation and metrics are acclimatized to influence if or not and just what the amount toxins is bioaccumulative. Thorough books can be acquired to the bioaccumulation regarding scientific and you may regulating viewpoints, advice as being the analysis of the Hairdresser step three, 4 , Mackay and you may Fraser 5 , Arnot and Gobas 6 , Ehrlich mais aussi al. seven , Burkhard mais aussi al. 8 , and you can Gobas ainsi que al. nine , the latter summarizing the przeglД…d ukraine date findings of an effective SETAC-paid working area stored for the 2008. These types of or any other critiques has mentioned the existence of multiple metrics regarding bioaccumulation one to disagree for the definition, in the regulatory application, as well as in use of the scientific community.
Our mission we have found so you’re able to establish and you will discuss the relationship between 5 preferred bioaccumulation metrics to have marine bacteria which have a view so you’re able to making clear their relative merits and you can applicability getting bioaccumulation examination. I earliest temporarily identify and discuss the bioaccumulation metrics, upcoming implement a size equilibrium model to look at and you can assess this new relationships between them. We seek to bring novel wisdom on the root process ensuing inside the bioaccumulation and provide guidance for boosting and you may trying to find analysis having bioaccumulation tests.
BIOACCUMULATION METRICS
For the current analysis, we define and describe 5 common metrics for assessing bioaccumulation. Differences exist in the definitions and usage of these terms; however, the definitions given here are used to develop mathematical relationships in the next section. The octanol–water partition coefficient (KOW) is widely used as an indicator of hydrophobicity and thus the partitioning of a chemical from water into lipids and other organic phases such as protein 10 . The KOW is primarily controlled by the solubility of the substance in water, because the solubility of neutral, liquid nonpolar organic chemicals in octanol is relatively constant. A log KOW value of 5 is often used as a bioaccumulation assessment criterion; however, depending on the regulatory program, lower values are also used to categorize bioaccumulation potential. Whereas KOW gives a reasonable and conservative estimate of lipid–water partitioning for nonpolar hydrophobic substances 11 , it may not accurately simulate partitioning for more polar and ionogenic organic chemicals and other chemical classes such as organofluorines and silicones. Direct empirical measurement is essential in such cases.
