Application of a food web bioaccumulation model for the prediction of polychlorinated biphenyl, dioxin, and furan congener concentrations in Lake Ontario aquatic biota

1999 ◽  
Vol 56 (8) ◽  
pp. 1389-1400 ◽  
Author(s):  
Heather A Morrison ◽  
D Michael Whittle ◽  
Chris D Metcalfe ◽  
Arthur J Niimi

A previously developed benthic/pelagic food web bioaccumulation model was parameterized to predict concentrations of nine nonmetabolized polychlorinated biphenyl (PCB) congeners in invertebrates and fish from Lake Ontario. Predicted concentrations were compared with field-measured concentrations to verify the predictability of the model. Overall, 86% of model predictions were within a factor of 2 and 100% of predictions were within a factor of 10 of field-measured concentrations. The parameterized model was used to estimate chemical metabolic rates for 15 PCB, polychlorinated dibenzo-p-dioxin (PCDD), and polychlorinated dibenzo-p-furan (PCDF) congeners that are potentially metabolized. Estimated chemical metabolic rates ranged from 7.5 × 10-3 to 1.0 × 10-7·day-1 and were in general agreement with qualitative studies describing rates of metabolism of these chemicals by aquatic biota. The calibrated model was used to predict concentrations of all 24 PCB, PCDD, and PCDF congeners in invertebrates and fish commonly found in Lake Ontario but for which no field-measured data exist. These concentrations were expressed as the logarithm of the bioaccumulation factor (log BAF). The log BAF's in benthic invertebrates and salmonids ranged from 4.2 to 10.2 and from 5.1 to 11.6, respectively, and were consistent with field-measured BAF's.

Author(s):  
D.N. Collins ◽  
J.N. Turner ◽  
K.O. Brosch ◽  
R.F. Seegal

Polychlorinated biphenyls (PCBs) are a ubiquitous class of environmental pollutants with toxic and hepatocellular effects, including accumulation of fat, proliferated smooth endoplasmic recticulum (SER), and concentric membrane arrays (CMAs) (1-3). The CMAs appear to be a membrane storage and degeneration organelle composed of a large number of concentric membrane layers usually surrounding one or more lipid droplets often with internalized membrane fragments (3). The present study documents liver alteration after a short term single dose exposure to PCBs with high chlorine content, and correlates them with reported animal weights and central nervous system (CNS) measures. In the brain PCB congeners were concentrated in particular regions (4) while catecholamine concentrations were decreased (4-6). Urinary levels of homovanillic acid a dopamine metabolite were evaluated (7).Wistar rats were gavaged with corn oil (6 controls), or with a 1:1 mixture of Aroclor 1254 and 1260 in corn oil at 500 or 1000 mg total PCB/kg (6 at each level).


2004 ◽  
Vol 38 (8) ◽  
pp. 2298-2303 ◽  
Author(s):  
Gregg T. Tomy ◽  
Wes Budakowski ◽  
Thor Halldorson ◽  
D. Michael Whittle ◽  
Micahel J. Keir ◽  
...  
Keyword(s):  
Food Web ◽  

Author(s):  
Mark D. Sensmeier ◽  
Kurt L. Nichol

Correlation between dynamic strain gage measurements and modal analysis results can be adversely affected by gage misplacement and gage misorientation. An optimization algorithm has been developed which allows the modeled strain gage locations and orientations to be varied within specified tolerances. An objective function is defined based on the least squares sum of the differences between experimental and model results. The Kuhn-Tucker conditions are then applied to find the gage locations and orientations which minimize this objective function. The procedure is applied on a one-time basis considering all measured modes of vibration simultaneously. This procedure minimizes instrumentation error which then allows the analyst to modify the model to more accurately represent other factors, including boundary conditions. Flat plate vibratory data was used to demonstrate a significant improvement in correlation between measured data and model predictions.


2004 ◽  
Vol 67 (10) ◽  
pp. 2326-2331 ◽  
Author(s):  
MOJCA JEVŠNIK ◽  
VESNA CERKVENIK FLAJS ◽  
DARINKA ZDENKA DOGANOC

The contamination of poultry tissues by total organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs) in Slovenia was examined from a public health perspective. As part of systematic veterinary and sanitary monitoring of foods of animal origin from 1997 to 1999, 87 samples of fat tissue were examined for the presence of α-HCH, lindane, heptachlor, and total DDT (plus DDE and DDD) and 88 samples of fat tissue were examined for the presence of total PCBs (sum of PCB congeners). The levels of poultry tissue contamination in six regions of Slovenia were determined. Levels of OC pesticides were below detection limits in 86.2% of analyses performed. Total PCB levels for most samples (59.1%) of poultry fat tissue were in the 0.002- to 0.02-mg/kg range. The level of contamination with OC pesticides and total PCBs in poultry fat tissue was not influenced by the type of poultry and was the highest in samples from industrial areas, which have been ecologically disturbed. All samples met Slovenian and European Union tolerances.


2013 ◽  
Vol 32 (6) ◽  
pp. 1376-1381 ◽  
Author(s):  
Gregg T. Tomy ◽  
Ed Sverko ◽  
Vince Palace ◽  
Bruno Rosenberg ◽  
Robert McCrindle ◽  
...  

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