Food webs biomagnification

Biomagnification Along Aquatic Food Chains and Food Webs Biomagnification Along Terrestrial Food Chains... 

Kay SH. 1984. Potential for biomagnification of contaminants within marine and freshwater food webs. Vicksburg, MS Department of the Army, Waterways Experiment Station, Corps of Engineers. D-84-7. 

No observed adverse effect level with uncertainty factor of 20. s Based on food chain biomagnification in aquatic webs. 

Bargagli, R., F. Monaci, J.C. Sanchez-Hemandez, and D. Cateni. 1998. Biomagnification of mercury in an Antarctic marine coastal food web. Mar. Ecol. Prog. Ser. 169 65-76. 

Cyanide biomagnification in food webs has not been reported, possibly due to rapid detoxification of sublethal doses by most species, and death at higher doses. 

Evans, M.S., G.E. Noguchi, and C.P. Rice. 1991. The biomagnification of polychlorinated biphenyls, toxaphene, and DDT compounds in a Lake Michigan offshore food web. Arch. Environ. Contam. Toxicol. 20 87-93. 

Biomagnification, which is the phenomenon that a chemical accumulates in species through different trophic levels in a food web, may cause toxic effects on mammals and birds as a secondary poisoning. Next to direct effects on soil organisms (see above), these indirect effects cam be considered in deriving critical limits for soil, by the use of simple food web models. 

MMHg is UpophiUc, causing it to bioaccumulate and biomagnify through the marine food web. About 85 to 95% of the total mercury in fish is MMHg, most of which is the result of biomagnification. Marine fish consumption accoimts far most of the mercury burden in... 

Bioaccumulation is generally referred to as a process in which the chemical concentration in an organism achieves a level that exceeds that in the respiratory medium (e.g., water for a fish or air for a mammal), the diet, or both. The extent to which chemicals bioaccumulate is expressed by several quantities, including the bioconcentration factor (BCF), bioaccumulation factor (BAF), biomagnification factor (BMF), and trophic or food web magnification factor (TMF) [6]. The ecological, biological and chemical parameters involved in the transfer and accumulation of contaminants in food webs are complex. 

As early as 1961 scientists looked for and found measurable levels of POCs, indeed POCs that would become classified as POPs, in human fat and by 1965 in human breast milk [77]. While something of a surprise at the time, the current understanding of bioaccumulation and biomagnification explain this, as humans tend to eat high in the food web. For people reliant on alpine sources for food then, it is possible that they are exposed to higher levels of certain POCs, i.e. those that are subject to efficient mountain cold-trapping, than are people nearer to the POC sources. 

H., Solomon, K.R. and Muir, D.C.G. (2003) Enantiomer-specific biomagnification of alpha-hexachlorocyclohexane and selected chiral chlordane-related compounds within an Arctic marine food web. Environ Toxicol Chem, 22, 2482-2491. 

Tomy et al. [57] published a study on the biomagnification of HBCD in Lake Ontario s food web. Using liquid chromatographic techniques, they were able to differentiate the three isomers from one another. In general, the ft... 

For many organic compounds that accumulate in lipids, bio accumulation potential can be estimated from the Kow. Since perfluoroalkyl compounds are inherently oleophobic, and do not partition preferentially to lipid rich tissues [67], the K0w is not a useful predictor of bioaccumulation and direct evidence derived from the laboratory or field is required. Additionally, tissue concentrations of perfluoroalkyl substances should never be lipid normalized. The dietary accumulation, bioconcentration, and biomagnification potential of various perfluoroalkyl carboxylates and sulfonates have been assessed in the laboratory and in the Great Lakes food web (Table 4). 

This factor is applied to bioconcentration factors to account for chemical biomagnification and bioaccumulation in the food web. The US-EPA uses it to derive bioaccumulation factors of very hydrophobic organic chemicals. 

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