Statistical relationships anywhere between metrics from chemicals bioaccumulation from inside the seafood

Five widely used metrics of bioaccumulation in fish are defined and discussed, namely the octanol–water partition coefficient (K_OW), 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 K_FW or as a nonequilibrium BCF_K in which egestion losses are included. Bioaccumulation factors are shown to be the product of the BCF_K 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 BCF_K 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 K_OW 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 BCF_Ks 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 out-of all-natural chemical compounds within the fish or other organisms that form dinner chains is an issue due to one another you can bad outcomes on bacteria on their own and also the prospect of contact with predators, as well as humans, that can consume this type of organisms. The focus is toward bioaccumulation inside the fish, but comparable principles affect bioaccumulation in other aquatic h2o-respiration organisms, and they also could possibly get affect heavens-respiration bacteria instance birds and you can mammals. As a result, a worldwide initiative has been launched to check commercial chemical compounds to possess the capability to bioaccumulate 1, dos . Within that it step, different types of bioaccumulation analysis and you will metrics are widely used to dictate whether and exactly what the total amount agents try bioaccumulative. Thorough literature can be acquired to your bioaccumulation out of scientific and you may regulatory point of views, instances as the critiques because of the Barber step 3, 4 , Mackay and you may Fraser 5 , Arnot and you may Gobas six , Ehrlich et al. eight , Burkhard et al. 8 , and you may Gobas mais aussi al. 9 , aforementioned summarizing new conclusions off a beneficial SETAC-paid workshop stored for the 2008. These or other studies have talked about the existence of several metrics of bioaccumulation you to definitely disagree in tendermeets meaning, in the regulatory app, along with use of the scientific area.

Our very own objective is so you’re able to determine and you can talk about the matchmaking between 5 prominent bioaccumulation metrics having marine bacteria having a view so you’re able to making clear their cousin deserves and you will applicability getting bioaccumulation assessments. We basic briefly explain and discuss the bioaccumulation metrics, next incorporate a size balance design to examine and you will quantify the brand new dating between the two. We attempt to offer unique understanding on the underlying procedure resulting in bioaccumulation and gives suggestions to have improving and you will trying to find analysis 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 (K_OW) 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 K_OW 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 K_OW 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 K_OW 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.