Dieldrin uptake

Dieldrin uptake in sheep Uptake may also be described by two-compartment models C = C ax A B X e"" . Figure 8.4 shows that this is the case for sheep and dieldrin. 

Gakstatter, J.H. The uptake from water by several species of freshwater fish to p,p -DDT, dieldrin, and lindane their tissue distribution and elimination rate. PhD Dissertation, Univ. of North Carolina, Chapel Hill (1966)... 

Experiments in this study, done exclusively with midge larvae, include 1) 24-hr toxicity data for representative insecticides, with and without synergists 2) in vivo absorptive uptake and metabolic studies of aldrin and dieldrin, with and without piperonyl butoxide (PBO) 3) body depuration rate (loss to water) for dieldrin 4) determination of optimal in vitro... 

Voennan, S., Besemer, A.F.H. (1975) Persistence of dieldrin, lindane, and DDT in a light sandy soil and their uptake by grass. Bull. Environ. Contam. Toxicol. 13, 501-505. 

There is evidence from both mammalian and fish studies demonstrating that exposure to organochlorines alters the uptake and tissue disposition of lipophilic toxicants. Dietary pre-treatment with 14C-dieldrin modified the tissue distribution of subsequent doses of dieldrin or PAHs in rainbow trout26,38,39. This redistribution of... 

Gilroy, D.J., C.L. Miranda, L.K. Siddens, Q. Zhang, D.R. Buhler and L.R. Curtis. Dieldrin pretreatment alters [C-14]dieldrin and [H-3]7,12-dimethylbenz[a]anthracene uptake in rainbow trout liver slices. Fundam. Appl. Toxicol. 30 187-193, 1996. 

Dieldrin (1), y-BHC (2) and picrotoxinin (3,A) have been shown to influence the presynaptic events on the American cockroach (Periplaneta americana) central nervous system (CNS) and thereby to stimulate excitatory neurotransmitter release. As to the cause for such stimulation, we have proposed that these agents specifically interact with the putative picrotoxinin receptor closely associated with the chloride ionophore in the y-aminobutyric acid-chloride iono-phore complex (designated as the GABA receptor system in this paper) at the presynaptic region, and that such interaction causes inhibition of chloride ion uptake. This uptake is regulated by GABA to modulate the presynaptic membrane potential (4-8). 

Soil Organic Matter Organic compounds may exist in soil either in solution or the vapor phase and can be absorbed through the roots in either state, absorption from solution would be the most likely process. From the discussion of the sorption process in soil (see Sorption, Chapter 3) the concentration of the compound in aqueous solution, Caq, would be a function of the concentration in the soil (Csoii). and the soil distribution ratio, K, which in turn is dependent primarily on SOM content. One would predict that uptake would be inversely related to the level of SOM. Observations of the uptake of diel-drin by carrots raised in different soils provide an opportunity to evaluate this relation and demonstrate the dependence on the concentration of the compound in soil solution. If the uptake efficiency is defined by the ratio of the concentration of dieldrin in carrots to that in the soil it is clear that higher levels of soil organic matter reduce uptake by carrots (Table 5.6). The ATom for dieldrin is 6980 mL g from which values were calculated for dieldrin in each soil. Since = Cjoii/Caq the concentration of dieldrin in soil solution can be determined. If uptake is defined as Ccarrot/Caq consistent value... 

TABLE 5.6 Uptake of Dieldrin by Carrots Grown in Different Soils... 

Grzenda, A. R., W. J. Taylor, and D. F. Paris. 1971. The uptake and distribution of chlorinated residues by goldfish (Carassius auratus) fed a -dieldrin contaminated diet. Trans. Am. Fish. Soc. 100(2) 215-221. 

Chlorinated pesticides differ substantially in their toxicity to aquatic plants. Endrin is among the most toxic, inhibiting growth and carbon uptake at concentrations as low as 0.1-1.0 [xg (Menzel etal., 1970). Equally low levels of dieldrin and aldrin may reduce growth, whereas DDT and DDE generally have little inhibitory effect below 1.0 /xg (Luard, 1973 Powers etal, 1975). Development of tolerance to DDT and its derivatives is frequent, and there are several species that are apparently unaffected by DDT levels > 1000 jug L (Luard, 1973). Chlordane generally elicits toxic responses at concentrations < 50 ju.g L and is therefore more toxic than either heptachlor or toxaphene. However, this order is subject to considerable variability, due to the development of resistance, effects of other species-related variables, and differences in environmental conditions. Lindane and its isomers are generally the least toxic of the pesticides and probably pose little threat to aquatic plants in natural waters the majority of species tolerate concentrations > 1000 /xg L (Luard, 1973). 

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