Plasma Polychlorinated Biphenyls Research Articles

Low Reproductive Rates of Lake Superior Bald Eagles: Low Food Delivery Rates or Environmental Contaminants?

Reproductive rate (productivity) of bald eagles ( Haliaeetus leucocephalus) nesting on the shores of Lake Superior was significantly less than that of neighboring eagles nesting in inland Wisconsin (1.0 vs. 1.3 young per breeding attempt, 1989–1993), and at other inland lake/riverine habitats in the Great Lakes Basin. It is possible that the current causes of low productivity on Lake Superior might include exposure to organochlorine contaminants and/or low food availability. Levels of dichloro-diphenyl-dichloroethylene (DDE) and total polychlorinated biphenyls (PCBs) in addled eggs and eaglet blood from Lake Superior and inland Wisconsin reference sites were measured. Food delivery rates by parent eagles to nestlings, a possible index to food availability, were quantified at both locations. Concentrations of both DDE and total PCBs in addled eggs declined significantly from 1969 to 1993 (p < 0.001, p = 0.006 respectively), and current concentrations of DDE are at or below the no observable adverse effect level (NOAEL) for reproductive impairment. Concentrations of DDE and total PCBs in plasma were greater in individual nestlings from the shores of Lake Superior than in nestlings at inland locations (18.9 μg/kg vs. 3.0 μg/kg DDE, p < 0.001, and 109.1 μg/kg vs. 42.6 μg/kg, p = 0.002), but were not correlated to the 5-year average history of productivity for the territory (p > 0.05). Food delivery rates by parent eagles to nestlings at Lake Superior were 56% lower than those to inland nestlings (2.16 vs. 4.87 prey items per day, p = 0.002). Food delivery rates were significantly correlated to average 5-year productivity for inland Wisconsin reference sites (p < 0.001, r 2 = 0.90), although not for Lake Superior sites (p = 0.593). It is concluded that it is likely that the current low productivity of Lake Superior eagles is at least partly attributable to low food availability, but some other factor, possibly PCBs, may also contribute to low productivity.

PCB Levels in Plasma of Dutch Preschool Children 185

Background: Polychlorinated biphenyls (PCBs) are persistent and toxic environmental pollutants. Humans are exposed to PCBs mainly through the food chain and they are stored in adipose tissue. During lactation high concentrations of PCBs are transferred to breast-fed infants. To study the adverse effects of PCBs on growth and development in children, plasma PCB levels were measured in Dutch preschool children in relation to their perinatal and current exposure to PCBs.

PCB and dioxin levels in plasma and human milk of 418 dutch women and their infants. Predictive value of PCB congener levels in maternal plasma for fetal and infant's exposure to PCBs and dioxins

Polychlorinated biphenyls (PCBs) as well as dioxins (polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs)) are potentially hazardous compounds in the environment for human beings. In order to investigate PCB and dioxin exposure of Dutch women and their neonates, levels were examined in 418 mother-infant pairs. Four non-planar PCB congener levels (PCB 118, 138, 153 and 180) were measured in maternal plasma and in umbilical cord plasma. The 209 mothers who breast-fed their infants collected human milk samples for the analysis of seventeen 2,3,7,8-substituted PCDD and PCDF congener levels, three planar PCB and twenty-three non-planar PCB congener levels. The dioxin and planar PCB levels we measured in human milk (mean 30 respectively 16 pg TEQ/g fat), belong to the highest background levels analysed all over the world but they are in the normal range for highly industrialised, densely populated countries in Western Europe. Correlation coefficients between PCB 118, 138, 153 and 180 congener levels in maternal plasma and PCB levels in cord plasma or PCB and dioxin levels in human milk are highly significant. However, the 95% predictive interval is too wide to predict accurately the PCB and dioxin levels to which an individual infant is exposed in utero or postnatally by breast-feeding, from the PCB levels in maternal plasma.

Long-term effects of Aroclor 1254 (PCBs) on plasma lipid and carnitine concentrations in rhesus monkey

Sixty-seven female rhesus monkeys ( Macaca mulatta) were orally dosed daily for 152 weeks with 0, 5, 20, 40, and 80 μg Aroclor 1254 (PCB)/kg body wt. Blood polychlorinated biphenyl (PCB) concentrations were highly positively correlated ( r=0.92, P < 0.001) with doses of PCB administered. A comprehensive analysis of plasma lipids/lipoproteins revealed a PCB-associated increase in plasma triglycerides and decreases in plasma total cholesterol, high-density lipoprotein cholesterol (HDL-chol), very-low plus low-density lipoprotein cholesterol (VLDL + LDL-chol), and total carnitine (which is involved in fatty acid metabolism). All of the lipid/lipoprotein changes were significantly ( P <- 0.05) correlated with blood PCB concentration. These data, obtained after 152 weeks of continuous daily exposure of a primate model to PCB support a causal relationship between plasma lipid changes and PCB intake. Previously, causality has been refuted on the premise that the commonly observed elevation of triglycerides with increasing centration of blood PCB is a reflection, not of PCB dose, but of the partitioning of PCB between tissues (adipose) and blood in proportion to the blood lipid present. The mechanism of the plasma lipid changes was not investigated in this study but the altered lipid/lipoprotein pattern is discussed with respect to known cardiovascular risk profiles.

Changes in plasma lipoprotein metabolism in chicks in response to polychlorinated biphenyls (PCBs)

The results of the present study strongly suggest that the hypertriglyceridaemia in chicks treated with Aroclor 1254 is a result of reduction in VLDL clearance rather than an increase in rate of VLDL secretion. The decrease in post-heparin LPL activity responsible for reduced VLDL clearance may be mediated by cytokines produced by chronic activation of the immune system.

Polychlorinated Biphenyl Uptake and Transport by Lymph and Plasma Components

The uptake and vascular transport of ingested Aroclor 1242, an isomeric mixture of polychlorinated biphenyls (PCB), was investigated in experimental animals. High concentrations of ingested PCB were found in the chylomicron fraction of thoracic duct lymph. When the lymph flow was exteriorized PCB were not subsequently found in the vascular circulation. When lymph was not exteriorized plasma PCB concentrations reached maximal levels 6 hr after ingestion. Less than 1% of total plasma PCB was detected in cellular fractions of blood over a 10-hr period following ingestion. Chylomicrons contained 31% of total plasma PCB 30 min after ingestion, decreasing to less than 6% at 4 hr. A maximum of 10% of plasma PCB at 1 hr, and less than 5% at 6 hr, after ingestion was associated with very low density lipoproteins (VLDL) or low density lipoproteins (LDL). Although PCB enter the vascular circulation with the chylomicron fractions of lymph, delipoproteinated plasma contained 52% of the total PCB in blood collected 30 min after ingestion. This level increased to 78% after 2 hr, and remained constant at about 80% for an additional 8-hr period. High performance liquid chromatographic (HPLC) examinations of delipoproteinated plasma from blood taken 6 hr after PCB ingestion showed elution of greater than 95% of plasma PCB to coincide with the albumin peak. Electrophoretic examinations of delipoproteinated plasma showed the association of PCB with albumin to be noncovalent. The results suggest that apolar PCB are absorbed into intestinal epithelial cells from which they are secreted into the lymphatic drainage sequestered within the apolar core of chylomicrons, that these PCB transit the thoracic duct and enter the vascular circulation within chylomicrons and are metabolized or otherwise released from chylomicrons during hepatic chylomicron clearance, and that resulting PCB or PCB derivatives circulate in association with plasma albumins.

Dermatological findings in capacitor manufacturing workers exposed to dielectric fluids containing polychlorinated biphenyls (PCBs).

Significant occupational exposure to polychlorinated biphenyls (PCBs) may occur in the manufacturing of capacitors and transformers, in which PCBs are used as electrical insulators. Reports of adverse health effects resulting from PCB exposure have come primarily from an incident resulting from the accidental ingestion of contaminated rice oil in Japan in 1968 ("yusho"). Dermatological findings were prominent features and included pigmentation disturbances and chloracne. To evaluate the dermatological effects of long-term occupational exposure to PCBs, a cross-sectional clinical survey was conducted of 326 capacitor manufacturing workers. A high prevalence (37%) of dermatological abnormalities was found, but typical PCB-associated signs, such as chloracne, were less frequent than among patients with "yusho," despite high concentrations of plasma PCB. As association between dermatological signs and plasma levels of higher homologues of PCBs was suggested, but contaminants which have been reported to be present in commercial PCB mixtures (polychlorinated dibenzofurans) should be considered an etiologic factor or co-factor in the development of "PCB-associated" dermatological findings.