background: aquatic ecosystems are frequently subjected to contamination by toxic heavy metals and pesticides, yet very little is known about the influence of pesticides on bioaccumulation of heavy metals in aquatic organisms. mercury is a toxic metal with no known biological benefit to organisms. bioavailability of mercury in aquatic environments depends on biological and non-biological parame...

The present study examines a new bioaccumulation model for hydrophobic organic chemicals in aquatic food webs. The purpose of the model is to provide site-specific estimates of chemical concentrations and associated bioconcentration factors, bioaccumulation factors, and biota-sediment accumulation factors in organisms of aquatic food webs using a limited number of chemical, organism, and site-s...

We investigated the potential of the South African high-biomass Ni hyperaccumulator Berkheya coddii to phytoextract Co and/or Ni from artificial metalliferous media. Plant accumulation of both metals from single-element substrates indicate that the plant/media metal concentration quotient (bioaccumulation coefficient) increases as total metal concentrations increase. Cobalt was readily taken up...

Organic contaminant and total mercury concentrations were compared in four species of lamniform sharks over several age classes to examine bioaccumulation patterns and gain insights into trophic ecology. Contaminants found in young of the year (YOY) sharks were assumed to be derived from maternal sources and used as a proxy to investigate factors that influence maternal offloading processes. YO...

PCBs are mixtures of chlorinated biphenyls with different degrees of chlorination, are hydrophobic chemicals, very persistent and bioaccumulative in aquatic organisms, especially in fishes that are at the end of the food chain and are the final receptors of toxicants. PCBs can be classified as narcotics: they produce no change in the biophase and elicit anesthetic reversible effects. Bioaccumul...

Chemical management programs strive to protect human health and the environment by accurately identifying persistent, bioaccumulative, toxic substances and restricting their use in commerce. The advance of these programs is challenged by the reality that few empirical data are available for the tens of thousands of commercial substances that require evaluation. Therefore, most preliminary asses...

Many studies have investigated bioaccumulation and metabolism of polycyclic aromatic hydrocarbons (PAHs) in aquatic organisms. However, lack of studies investigated both processes simultaneously, and the interaction between these two processes is less understood so far. This study investigated the bioaccumulation kinetics of PAHs and metabolic enzyme activities, including total cytochrome P450 ...

Bioaccumulation and biotransformation are key toxicokinetic processes that modify toxicity of chemicals and sensitivity of organisms. Bioaccumulation kinetics vary greatly among organisms and chemicals; thus, we investigated the influence of biotransformation kinetics on bioaccumulation in a model aquatic invertebrate using fifteen (14)C-labeled organic xenobiotics from diverse chemical classes...

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 w...

Title of Dissertation: THE IMPORTANCE OF PHYSICAL MIXING AND SEDIMENT CHEMISTRY IN MERCURY AND METHYLMERCURY BIOGEOCHEMICAL CYCLING AND BIOACCUMULATION WITHIN SHALLOW ESTUARIES Eun-Hee Kim, Doctor of Philosophy, 2004 Dissertation Directed By: Professor Robert P. Mason, Marine Estuarine Environmental Science The objective of this study was to examine, using mesocosm experiments, the long-term ef...