Bioconcentration Effects

Settling particulates/water in Lake Ontario logKgg = 4.57 

Calculated from octanol/water coefficient logKgg = 2.99 

Generally, variations of trace metal discharge are mainly caused by the changes in suspended matter concentrations. The relative importance of the particulate forms in the decreasing sequence Al Fe Mn Co Zn Ni Cu Cd has been found by Yeats Bewers (1982) from St. Lawrence River in Canada. According to these authors the lower proportions of the metals in particulate phases from St. Lawrence compared ato the data from the Amazon (Gibbs, 1977) or the Mississippi (Trefry Presley, 1976) rivers are a direct reflection of the contrasting levels of suspended matter in the St. Lawrence (10 mg/1), Amazon (65 mg/1) and Mississippi (580 mg/1). 

Changes of Metal Load (Particulate and Dissolved) in the Rhine River at the Dutch-German Border from 1971 to 1983 (after Malle, 1985) 

This development is due to various factors, such as high water flow in wet years and the effects of the economic crisis, particularly at the end of the 1970 s. However, a significant portion of the reduction should be affected by improvement of wastewater treatment and by the partial replacement of metals in critical applications. It is indicated from these data, that the major decrease for cadmium occurred in the dissolved phases, whereas - until 1979 - the reduction of mercury concentrations mainly took place in the solid phases. This is an indication that equilibria between solid and aqueous phases have not completely established, and clearly shows the difficulties involved in the modeling such processes (see review by Honeyman Santschi, 1988). 

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The PCB concentration of eels in this river is a factor of 26 300 higher than the PCB concentration in the river water. The very simple phase equilibrium model for the distribution of the chemical used here is able to predict this very large bioconcentration effect to within a factor of2.. ... 

DDT is highly toxic to fish (LC q for trout and blue gill, 0.002—0.008 ppm), and it is only moderately toxic to birds (oral LD q mallard 1300 and pheasant >2240 mg/kg). However, widespread bird kills have resulted from bioconcentration of DDT through food chains, ie, from fish or earthworms. A significant environmental problem has resulted from the specific effects of DDE on eggshell formation in raptorial birds where accumulation has caused decreases in shell thickness of 10—15%, resulting in widespread breakage. 

PAHs can be bioconcentrated or bioaccumulated by certain aquatic invertebrates low in the food chain that lack the capacity for effective biotransformation (Walker and Livingstone 1992). Mollusks and Daphnia spp. are examples of organisms that readily bioconcentrate PAH. On the other hand, fish and other aquatic vertebrates readily biotransform PAH so, biomagnification does not extend up the food chain as it does in the case of persistent polychlorinated compounds. As noted earlier, P450-based monooxygenases are not well represented in mollusks and many other aquatic invertebrates (see Chapter 4, Section 4.2) so, this observation is not surprising. Oxidation catalyzed by P450 is the principal (perhaps the only) effective mechanism of primary metabolism of PAH. 

Examples of differences in the responses of wildlife organisms to EDCs include the differences in sensitivity to phthalates and bisphenols among mollusks, crustaceans, and amphibians compared to fish. In invertebrates, biological effects are observed at exposures in the ng/L to low pg/L range, compared to high pg/L for most effects in fish (reviewed in Oehtmann et al. 2008). In addition, aquatic mollusks tend to bioconcentrate and bioaccumulate pollutants to a greater level than hsh, possibly owing to poorer capabilities for metabolic detoxification (see Chapter 4, Section 4.3). 

Non-volatile silicones do not bioconcentrate in aquatic media. Their large molecular size prevents them from passing through the membranes of fish or other aquatic creatures. They readily become attached to particulate matter and are effectively... 

Haitzer, M., Hoss, S., Traunspurger, W., Steinberg, C. (1999) Relationship between concentration of dissolved organic matter (DOM) and the effect of DOM on the bioconcentration of benzo[a]pyrene. Aqua. Toxicol. 45, 147-158. 

In aquatic environments, waterborne lead was the most toxic form. Adverse effects were noted on daphnid reproduction at 1.0 pg Pb+2/L, on rainbow trout survival at 3.5 pg tetraethyllead/L, and on growth of marine algae at 5.1 pg Pb+2/L. High bioconcentration factors were recorded for filter-feeding bivalve molluscs and freshwater algae at 5.0 pg Pb+2/L. 

Muir, D.C.G., B.R. Hobden, and M.R. Servos. 1994. Bioconcentration of pyrethroid insecticides and DDT by rainbow trout uptake, depuration, and effect of dissolved organic carbon. Aquat. Toxicol. 29 223-240. 

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