Polychlorinated biphenyls: evidence of transplacental passage in the Sherman rat

Effects of PCBs (Aroclor 1254) on reproduction and growth rate in Mongolian gerbils (Meriones unguiculatus)

Groups of female Mongolian gerbils were subcutaneously administered 2mg or 4mg PCBs (Aroclor 1254) in 0.1ml oil or vehicle only after pairing for two days with untreated males. No effects were found on the number of pairs breeding, birth intervals, number of pups per litter or percentage of male offspring. The preweaning growth rates of the PCBs exposed first litter offspring was retarded, but second litters showed no differences compared to controls. No other differences in growth were observed.

Characteristics of 2,4,5,2',4',5'-hexachlorobiphenyl distribution among lipoproteins in vitro

The uptake, distribution, and transfer of 2,4,5,2',4',5'-hexachlorobiphenyl (6-CB) were examined in vitro with human and rat whole blood, plasma, and lipoprotein fractions. 6-CB distribution between plasma and erythrocytes as well as among lipoproteins was determined following sedimentation of erythrocytes and ultracentrifugal fractionation of plasma. In both rat and human whole blood, 70 to 75% of 6-CB partitioned into plasma and 25 to 30% into erythrocytes. The uptake of 6-CB into plasma was extremely rapid and the rate of uptake was found to be dependent upon temperature. The distribution of 6-CB among lipoproteins was relatively homogeneous with 20 to 30% being distributed in very low-density lipoproteins (VLDL, d = 0.95-1.006 g/ml), 15 to 20% in low-density lipoproteins (LDL, d = 1.006-1.063 g/ml), and 15 to 25% in high-density lipoproteins (HDL, d = 1.063-1.21 g/ml). Over 25% of 6-CB was found in the remaining bottom fraction. In addition, each isolated fraction when incubated alone with 6-CB was shown capable of uptake. The relative proportion of 6-CB among the lipoproteins was independent of the level taken up by plasma. 6-CB was also found to transfer among lipoproteins. This exchange of 6-CB proved to be dependent upon the concentrations of both protein and triacylglycerol in the incubations. Two proteins in the bottom fraction (Bf), albumin and a steroid binding globulin, were capable of competing with the lipoproteins for 6-CB uptake.

World PCBs map: storage and effects in man and his biologic environment in the 1970s

PCB residues are found in biota all over the world. A biologic magnification of PCBs has been demonstrated in the food chain: plankton-fish-fish eating birds. A world map of the PCBs residues in biota and some of their biologic effects are given in this study. The biologic effects of PCBs are varied and may generally be explained by the induction or inhibition of the activity of a large number of enzymes, which upsets quantitatively, normal biochemical processes. Harm to reproduction, growth, development, defense systems, tissues, and organs appeared in susceptible organisms as a result of such changes or as a chain reaction to heterostases. The adverse health effects, observed in persons occupationally exposed and in those accidentally poisoned, point to the risk for the general population of an ever-increasing environmental pollution by PCBs. There is need for an integrated approach, consisting of epidemiologic studies on high risk groups in the general population and in persons occupationally exposed, as well as periodic assessment of PCB residues in man, his food, and feed supplies.