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 off organic chemical substances when you look at the seafood and other bacteria which can make-up restaurants stores is an issue on account of both possible unfavorable outcomes to your bacteria themselves in addition to prospect of exposure to predators, and humans, that will eat this type of bacteria. The focus is toward bioaccumulation from inside the seafood, but equivalent beliefs affect bioaccumulation in other marine water-respiration organisms, and so they get affect heavens-breathing organisms for example birds and you may animals. Because of this, an international initiative might have been circulated to test commercial toxins having the capacity to bioaccumulate step 1, 2 . As part of so it initiative, different types of bioaccumulation investigation and you will metrics are widely used to influence whether or not and to exactly what extent chemical compounds was bioaccumulative. Comprehensive literature is obtainable with the bioaccumulation out-of medical and you can regulatory viewpoints, advice as being the ratings from the Hairdresser step three, cuatro , Mackay and Fraser 5 , Arnot and you can Gobas six , Ehrlich ainsi que al. seven , Burkhard ainsi que al. 8 , and Gobas et al. 9 , aforementioned summarizing the fresh results away from a beneficial SETAC-backed working area stored from inside the 2008. These or any other reviews features discussed the presence of several metrics regarding bioaccumulation you to disagree into the definition, from inside the regulating application, and also in adoption by the medical area.
All of our mission here’s to help you explain and you can talk about the relationships ranging from 5 well-known bioaccumulation metrics to have marine bacteria with a standpoint so you’re able to clarifying their cousin merits and you will applicability having bioaccumulation tests. I first temporarily explain and talk about the bioaccumulation metrics, up coming pertain a mass harmony model to examine and you will measure the matchmaking among them. We attempt to bring novel understanding for the underlying procedure ensuing during the bioaccumulation and supply pointers to have improving and you can in https://datingranking.net/chatki-review/ search of studies to have 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.
