Bioaccumulation coefficient

Another example is Lake Baikal, where the water is cleaner than other bodies of water. In this case, the bioaccumulation coefficient for DDT in the water => zooplankton => fish => seal chain exceeded one million (Table 4.2). 

To distinguish these very remarkable capabilities from the multitude of plant species that accumulate only a little Cd while being Cd-sensitive, but stiU are sometimes called Cd hyperaccumulators based on the old definition of Cd hyperaccumulation ( >100 ppm in shoot dry weight in the natural habitat [31]), it might be useful to re-define Cd hyperaccumulation as >500 ppm in shoots under enviroimientally relevant conditions with less than 20% growth reduction until the stage of maturity and a bioaccumulation coefficient >5 at a Cd concentration leading to >500 ppm in shoots. 

The toxicological or cumulative effect of illicit drugs on the ecosystems has not been studied yet. Moreover, their fate and transport in the environment is to a big extent still unknown. Due to their physical-chemical properties (octanol-water partition coefficient, solubility, etc.) some of them, such as cannabinoids, are likely to bioaccumulate in organisms or concentrate in sediments whereas the rest, much more polar compounds, will tend to stay in aqueous environmental matrices. However, continuous exposure of aquatic organisms to low aquatic concentrations of these substances, some of them still biologically active (e.g., cocaine (CO), morphine (MOR) and MDMA) may cause undesirable effects on the biota. 

Gossett RW, Brown DA, Young DR. 1983. Predicting the bioaccumulation of organic compounds in marine organisms using octanol/water partition coefficients. Mar Pollut Bull 14 387-392. 

Based on the relatively low value of the octanol/water partition coefficient (K° ) for acrylonitrile (log K OW = -0. 92) (Verschueren 1983), it would notbe expected tnat acrylonitrile will strongly bioaccumulate... 

Tulp, M. T. M., Hutzinger, O. (1978) Some thoughts on the aqueous solubilities and partition coefficients of PCB, and the mathematical correlation between bioaccumulation and physico-chemical properties. Chemosphere 7, 849-860. 

Chiou, C., Freed, D., Schmedding, D., Kohnert, R. (1977) Partition coefficient and bioaccumulation of selected organic chemicals. Environ. Sci. Technol. 11(5),475 -78. 

Geyer, H.J., Politzki, G., Freitag, D. (1984) Prediction of ecotoxicological behaviour of chemicals relationship between n-octanol/water partition coefficient and bioaccumulation of organic chemicals by alga chlorella. Chemosphere 13(2), 269-284. 

Hawker, D.W., Connell, D.W. (1985) Relationships between partition coefficient, uptake rate constant, clearance rate constant and time to equilibration for bioaccumulation. Chemosphere 14, 1205-1219. 

Previous studies showed that PBDE levels increased with the age of the fish, indicating bioaccumulation [39], Fish length is directly related to fish age. Figure 2 shows the measured concentrations of HBCD as a function of fish length at sites C3 and C5. The correlation coefficients indicate acceptable correlations (R2 = 0.71). 

Fisk, A.T., R.J. Norstrom, C.D. Cymbalisty, and D.C.G. Muir. 1998. Dietary accumulation and depuration of hydrophobic organochlorines bioaccumulation parameters and their relationship with the octanol/water partition coefficient. Environ. Toxicol. Chem. 17 951-961. 

Laskowski [1] has thoroughly reviewed the physico-chemical properties of the SPs, and these are summarized briefly below. SPs are typically of low water solubility (in the low microgram per liter range) and are highly nonpolar (logarithmic octanol water partition coefficients of around 6-7), indicating potential for bioaccumulation. Fish bioconcentration factors (BCF) of several hundred to several thousand are reported however metabolism limits the amount of bioaccumulation,... 

The octanol-water partition coefficient, Kow, is the most widely used descriptor of hydrophobicity in quantitative structure activity relationships (QSAR), which are used to describe sorption to organic matter, soil, and sediments [15], bioaccumulation [104], and toxicity [105 107J. Octanol is an amphiphilic bulk solvent with a molar volume of 0.12 dm3 mol when saturated with water. In the octanol-water system, octanol contains 2.3 mol dm 3 of water (one molecule of water per four molecules of octanol) and water is saturated with 4.5 x 10-3 mol dm 3 octanol. Octanol is more suitable than any other solvent system (for) mimicking biological membranes and organic matter properties, because it contains an aliphatic alkyl chain for pure van der Waals interactions plus the alcohol group, which can act as a hydrogen donor and acceptor. 

The major route for bioaccumulation of hydrophobic organic compounds in aquatic animals is passive diffusion over cell membranes. In fish, the gill epithelia are the predominant port of entry, with less than 40% of uptake across the skin [181]. Since permeability of the membrane is a direct function of the membrane-water partition coefficient and the diffusion coefficient across the membrane interior [182], the bioconcentration factor (logBCF) can be directly correlated with log K0Vl. or log Km%v for compounds with intermediate hydro-phobicity [183,184],... 

The dominant transport process from water is volatilization. Based on mathematical models developed by the EPA, the half-life for M-hexane in bodies of water with any degree of turbulent mixing (e.g., rivers) would be less than 3 hours. For standing bodies of water (e.g., small ponds), a half-life no longer than one week (6.8 days) is estimated (ASTER 1995 EPA 1987a). Based on the log octanol/water partition coefficient (i.e., log[Kow]) and the estimated log sorption coefficient (i.e., log[Koc]) (see Table 3-2), ii-hexane is not expected to become concentrated in biota (Swann et al. 1983). A calculated bioconcentration factor (BCF) of 453 for a fathead minnow (ASTER 1995) further suggests a low potential for -hcxanc to bioconcentrate or bioaccumulate in trophic food chains. 

Absorption - desorption - N-octanol/water coefficient - Henry constant - Biodegradation and/or abiotic degr. disappearance coef. - Bioaccumulation - Aquatic Ecotox Fish 24 to 96 hours Daphnia 24 to 48 hours - Air/soil/sediment Ecotox ... 

Legal limitations placed upon the use of all newly launched nonbiodegradable chemicals in Japan require testing each product for accumulation in fish before it can be marketed. These regulations have stimulated corresponding studies about the bioaccumulation of pigments [16]. The distribution coefficient Pow between n-octanol and water may be used to indicate the tendency of a chemical to accumulate in biological systems [17]. 

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