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 chatiw phone number 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
Inclusion
Bioaccumulation out-of normal chemical compounds during the fish or any other bacteria that compensate dining chains is an issue on account of one another possible adverse consequences for the organisms by themselves additionally the possibility of connection with predators, together with humans, that consume this type of organisms. The focus we have found towards bioaccumulation inside seafood, however, similar prices connect with bioaccumulation various other aquatic drinking water-respiration organisms, and so they can get affect sky-respiration organisms for example birds and you may mammals. Consequently, a worldwide effort could have been circulated to check on commercial chemical to have their power to bioaccumulate step one, 2 . Within which initiative, several types of bioaccumulation study and you may metrics are widely used to dictate if or not and to exactly what the amount chemical compounds are bioaccumulative. Extensive literary works can be obtained on the bioaccumulation out-of medical and you will regulating perspectives, examples as being the critiques by the Barber 3, 4 , Mackay and you will Fraser 5 , Arnot and you will Gobas six , Ehrlich et al. eight , Burkhard mais aussi al. 8 , and you may Gobas ainsi que al. nine , aforementioned summarizing the newest conclusions of a SETAC-sponsored working area stored for the 2008. These or other feedback provides pointed out the current presence of several metrics off bioaccumulation one disagree inside the definition, during the regulatory app, plus use of the medical people.
Our very own mission here’s to help you determine and you can discuss the relationships between 5 well-known bioaccumulation metrics getting marine organisms with a view so you’re able to making clear its relative merits and applicability getting bioaccumulation tests. We first temporarily determine and you may discuss the bioaccumulation metrics, upcoming apply a bulk harmony design to examine and quantify brand new relationships among them. We seek to give novel insights toward hidden process resulting during the bioaccumulation and gives guidance having improving and you may trying to find studies having bioaccumulation assessments.
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.
