Polychlorinated Biphenyls In Eggs Research Articles

Chiral polychlorinated biphenyls (PCBs) in bioaccumulation, maternal transfer, and embryo development of chicken.

Polychlorinated biphenyls (PCBs) and enantiomer fractions (EFs) of PCB enantiomers (PCBs 95, 132, 135, and 149) were investigated in soil and chicken feed, chicken (Gallus domesticus) tissues, eggs on 0, 7, and 14 days after the onset of incubation, and newborn chick tissues. The EF values of PCBs 95, 132, and 149 changed significantly from soil to chicken tissues, and the values in the liver exhibited the highest deviation from the racemic ratio, indicating enantiomer-selective metabolism in hens. Congeners, which are highly resistant to degradation, such as PCBs 138, 153, and 180, exhibited the highest maternal transfer potentials when muscle and liver were used to assess the maternal transfer. However, uniform transfer ratios were observed for most of the PCB congeners when visceral fat was used. The EFs of chiral PCBs in eggs either did not match with muscle or with liver or were similar to those in visceral fat. These results indicate that hens mainly mobilized visceral fat for egg formation and PCBs were deposited in eggs by associating with these lipid materials. Further enantiomeric enrichment of PCBs 95, 132, and 149 occurred in the newborn chick tissues. However, an opposite enantioselectivity for PCB 135 in newborn chicks was observed. These results indicate that the potential toxicity of PCB enantiomers to newborn chicks may be different from that of adults.

Changes in polychlorinated biphenyl (PCB) exposure in tree swallows (Tachycineta bicolor) nesting along the Sheboygan River, WI, USA.

Exposure to polychlorinated biphenyls (PCBs) in tree swallow (Tachycineta bicolor) eggs on the Sheboygan River, Wisconsin in the 1990s was higher at sites downstream (geometric means = 3.33-8.69 μg/g wet wt.) of the putative PCB source in Sheboygan Falls, Wisconsin than it was above the source (1.24 μg/g) with the exposure declining as the distance downstream of the source increased. A similar pattern of declining exposure was present in the 2010s as well. Although exposure to PCBs in eggs along the Sheboygan River at sites downstream of Sheboygan Falls has declined by ~60 % since the mid-1990s (8.69 down to 3.27 μg/g) there still seems to be residual pockets of contamination that are exposing some individuals (~25 %) to PCB contamination, similar to exposure found in the 1990s. The exposure patterns in eggs and nestlings among sites, and the changes between the two decades, are further validated by accumulation rate information.

Levels of PCBs in wild bird eggs: Considering toxicity through enzyme induction potential and molecular structure

Polychlorinated biphenyls (PCBs) were analysed in wild bird eggs from industrialised areas in South Africa. The concentration, congener profile, feeding guild, potential associated risk and biology were investigated. PCBs were detected in all eggs with 30 congeners present in more than 80% of the samples. Σ34PCB concentrations ranged between 0.9 and 296ngg−1wet weight (ww). The metabolic potential of the PCB metabolic groups showed good agreement with the biodegradability of the individual congeners. Phenobarbital-type (PB-type) inducer PCBs were prevalent, indicating the predominance of less toxic PCB congeners. However, non-ortho PCBs which were not included in the current analyses, could affect the toxic potential of the PCBs in the eggs requiring more investigation. Although the current levels of PCBs measured do not indicate a health risk to the birds assessed, the presence of mono-ortho PCBs at appreciable levels motivates for the assessment of dioxin-like chemicals in wild bird eggs.

Adult tree swallow(Tachycineta bicolor)survival on the polychlorinated biphenyl‐contaminated Housatonic River, Massachusetts, USA

Tree swallows (Tachycineta bicolor) were captured and banded at six sites that differed in polychlorinated biphenyl (PCB) contamination levels in the Housatonic River watershed, western Massachusetts, USA, from 2000 through 2004 to test the prediction that apparent survival rates of females in more contaminated areas were lower than those from less contaminated areas. We also tested whether plumage coloration affected over-winter survival and whether concentrations of PCBs in eggs differed between birds that did and that did not return the following year. Apparent survival rates were calculated using mark-recapture methods and compared using Akaike's Information Criterion. Model-adjusted survival rates ranged from 0.365 to 0.467 for PCB-contaminated females and between 0.404 and 0.476 for reference females. Models with either survival or capture probability modeled as functions of treatment (degree of PCB contamination), year, and age received some support. The model-averaged parameter estimate reflecting a treatment effect for high-PCB birds was negative (beta = -0.046, SE(beta) = 0.0939). Fifty-four percent of the total model weights involved models in which survival was a function of PCB treatment. Eggs were collected for contaminant analyses from a random sample of females that did and that did not return the following year. Concentrations of total PCBs were the same or higher in the eggs of females that returned compared to the eggs of those that did not return at both the highly and the moderately contaminated PCB sites. This may have resulted from higher-quality females with higher lipid reserves being more likely than lower-quality females to return the following year. Percentage lipid was positively correlated with total PCBs in eggs. Survival rates were similar among swallows with brown versus blue plumage.

Evaluation of population‐level ecological risks of dioxin‐like polychlorinated biphenyl exposure to fish‐eating birds in Tokyo Bay and its vicinity

Population-level assessments of the ecological risks of dioxin-like polychlorinated biphenyl (PCB) exposure to fish-eating birds in Tokyo Bay and its vicinity were performed to judge the need for risk management measures to protect aquatic wildlife from dioxin-like PCB contamination. Egg mortality risk and changes in the population growth rate (lambda) in relation to the contamination levels of dioxin-like PCBs in eggs of gray heron (Ardea cinerea), great cormorant (Phalacrocorax carbo), osprey (Pandion halieaetus), and kingfisher (Alcedo atthis) were determined by integrating the results of exposure analysis, effect analysis, and a life-history model for each species. The egg mortality risks for the gray heron, great cormorant, osprey, and kingfisher populations were calculated to be 5.8, 6.8, 12, and less than 1%, respectively. The estimated lambda for those populations were calculated to be 1.061, 1.405, 1.024, and 1.131, respectively. The percentage changes in lambda for those populations were estimated to be 1.2, 2.0, 1.6, and less than 1%, respectively. Our results implied that the levels of dioxin-like PCBs observed in the Tokyo Bay area alone would not have significant population-level effects on the fish-eating bird populations. It is concluded that along with the trend toward decreasing dioxin and dioxin-like PCB levels in Tokyo Bay, no urgent need exists for risk-reduction measures to protect fish-eating bird populations against dioxin-like PCBs.

Evaluation of Population-Level Ecological Risks of Dioxin-Like Polychlorinated Biphenyl Exposure to Fish-Eating Birds in Tokyo Bay and Its Vicinity

Population-level assessments of the ecological risks of dioxin-like polychlorinated biphenyl (PCB) exposure to fish-eating birds in Tokyo Bay and its vicinity were performed to judge the need for risk management measures to protect aquatic wildlife from dioxin-like PCB contamination. Egg mortality risk and changes in the population growth rate (λ) in relation to the contamination levels of dioxin-like PCBs in eggs of gray heron (Ardea cinerea), great cormorant (Phalacrocorax carbo), osprey (Pandion halieaetus), and kingfisher (Alcedo atthis) were determined by integrating the results of exposure analysis, effect analysis, and a life-history model for each species. The egg mortality risks for the gray heron, great cormorant, osprey, and kingfisher populations were calculated to be 5.8, 6.8, 12, and less than 1%, respectively. The estimated λ for those populations were calculated to be 1.061, 1.405, 1.024, and 1.131, respectively. The percentage changes in λ for those populations were estimated to be 1.2, 2.0, 1.6, and less than 1%, respectively. Our results implied that the levels of dioxin-like PCBs observed in the Tokyo Bay area alone would not have significant population-level effects on the fish-eating bird populations. It is concluded that along with the trend toward decreasing dioxin and dioxin-like PCB levels in Tokyo Bay, no urgent need exists for risk-reduction measures to protect fish-eating bird populations against dioxin-like PCBs.

RISK ASSESSMENT OF GREAT HORNED OWLS (BUBO VIRGINIANUS) EXPOSED TO POLYCHLORINATED BIPHENYLS AND DDT ALONG THE KALAMAZOO RIVER, MICHIGAN, USA

The great horned owl (GHO; Bubo virginianus) was used in a multiple lines of evidence study of polychlorinated biphenyls (PCBs) and p,p'-dichlorodiphenyltrichloroethane (DDT) exposures at the Kalamazoo River Superfund Site (KRSS), Kalamazoo, Michigan, USA. The study examined risks from total PCBs, including 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQWorld Health Organization [WHO]-Avian Toxicity Equivalency Factor [TEF]), and total DDTs (sum of DDT, dichlorodiphenyldichloroethylene [DDE], and dichlorodiphenyldichloroethane [DDD]; sigmaDDT) by measuring concentrations in eggs and nestling blood plasma in two regions of the KRSS (upper, lower) and an upstream reference area (RA). An ecological risk assessment compared concentrations of the contaminants of concern (COCs) in eggs or plasma to toxicity reference values. Productivity and relative abundance measures for KRSS GHOs were compared with other GHO populations. Egg shell thickness was measured to assess effects of p,p'-DDE. The concentrations of PCBs in eggs were as great as 4.7 x 10(2) and 4.0 x 10(4) ng PCB/g, wet weight at the RA and combined KRSS sites, respectively. Egg TEQ(WHO-Avian) calculated from aryl hydrocarbon receptor-active PCB congeners and WHO TEFs ranged to 8.0 and 1.9 x 10(2) pg TEQ(WHO-Avian)/g, (wet wt) at the RA and combined KRSS, respectively. Egg sigmaDDT concentrations were as great as 4.2 x 10(2) and 5.0 x 10(3) ng sigmaDDT/g (wet wt) at the RA and combined KRSS, respectively. Hazard quotients (HQs) for the upper 95% confidence interval (UCI) (geometric mean) and least observable adverse effect concentration (LOAEC) for COCs in eggs were < or = 1.0 for all sites. Hazard quotient values based on the no observable adverse effect concentration (NOAEC) 95% UCI in eggs were < or = 1.0, except at the LKRSS (PCB HQ = 3.1; TEQ(WHO-Avian) HQ = 1.3). Productivity and relative abundance measures indicated no population level effects in the UKRSS.

Contaminant Exposure of Barn Swallows Nesting on Bayou D'Inde, Calcasieu Estuary, Louisiana, USA

Current and historical point source discharges, storm water runoff, and accidental spills have contaminated the water, sediment, and biota within the Calcasieu Estuary in southwestern Louisiana. In 2003, barn swallow (Hirundo rustica) eggs and nestlings were collected beneath two bridges that cross Bayou d'Inde, the most contaminated waterway within the Calcasieu Estuary. Samples were also collected from a bridge over Bayou Teche, a reference site in south central Louisiana. Polychlorinated biphenyl (PCB) concentrations in barn swallow eggs and nestlings were significantly higher at the downstream site on Bayou d'Inde (2.8 micro g/g PCBs in eggs and 1.5 micro g/g PCBs in nestlings) than at the other two sites (< 0.2 micro g/g PCBs in eggs and nestlings at both sites). Ethoxyresorufin-O-dealkylase activity in nestling livers was significantly higher at the downstream site on Bayou d'Inde (50 pmol/min/mg) compared to the other two locations (24 pmol/min/mg, each), probably because of exposure to PCBs. Polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran concentrations in eggs and polycyclic aromatic hydrocarbons in nestlings were at background concentrations at all sites. Trace element concentrations in barn swallow eggs and nestling livers were at background levels and did not differ among the three sites. A biomarker of DNA damage did not differ among sites.

Accumulation of PCB Congeners in Nestling Tree Swallows (Tachycineta bicolor) on the Hudson River, New York

Tree swallows (Tachycineta bicolor) were used as a sentinel species to monitor the contamination and bioavailability of polychlorinated biphenyls (PCBs) in the Hudson River watershed. Several tree swallow nest box colonies around and downstream from Hudson Falls, NY, were studied. Tree swallow eggs, adults, and 5-, 10-, and 15-day-old nestlings were collected and analyzed for 103 PCB congeners. Emergent insects collected by net (primarily Odonata) or as a food bolus (primarily Diptera) taken from the mouths of adult tree swallows returning to the nest were analyzed in the same manner. Total PCB concentrations (wet weight) in eggs from two contaminated sites ranged from 9000 to 25,000 ng/g and accumulated to 32,000 and 96,000 ng/g in 15-day-old nestling at two contaminated sites. The congener patterns of PCBs in eggs, nestlings, and adults were compared to those found in emergent insects (Odonata and Diptera) using principal components analysis. The PCB patterns of the biota differed from that of Aroclor technical mixtures. PCB patterns in adult tree swallows were similar to those in eggs, while the patterns in dietary insects were similar to nestling tree swallows. Uptake rate constants were determined for tree swallow nestlings and compared between the two contaminated sites. The estimated PCB congener uptake rate constants were 0.008-0.02 d(-1) based on uptake in nestlings until day 15 post-hatch. The rate constants were comparable between the two study areas and may be used to predict nestling contamination at other locations. Our studies confirm the utility of nestling tree swallows to evaluate localized PCB contamination.

Dioxins and congener-specific polychlorinated biphenyls in three avian species from the Wisconsin River, Wisconsin

Sediments from the Wisconsin River, WI, USA are contaminated with 2,3,7,8-tetrachloro- p-dioxin (TCDD) and polychlorinated biphenyls (PCBs). Wet weight concentrations of TCDD and PCBs in eggs were at background levels and highest in the piscivorous hooded merganser ( Lophodytes cucullatus; geometric mean=7 pg/g TCDD and 0.92 μg/g PCBs) and lowest in the omnivorous wood duck ( Aix sponsa) (<1 pg/g and 0.07 μg/g); concentrations in eggs of the insectivorous tree swallow ( Tachycineta bicolor) were intermediate (<1 pg/g and 0.33 μg/g). Positive accumulation rates of TCDD (8–19 pg/day) and PCBs (0.4–0.7 μg/day) in tree swallow nestlings suggest that the Wisconsin River is the source of these contaminants for tree swallow nestlings. The lower representation of trichlorobiphenyls and tetrachorobiphenyls in hooded merganser eggs compared to wood duck or tree swallow eggs suggests that the hooded merganser or its diet has a greater ability to metabolize lower-numbered PCB congeners than wood ducks or tree swallows.

PCB uptake and accumulation by oysters ( Crassostrea virginica) exposed via a contaminated algal diet

Reproductively active oysters were fed daily with 0.2 g algal paste containing 0, 0.1, and 1.0 μg polychlorinated biphenyls (PCBs) (1:1:1 mixture of Aroclor 1242, 1254 and 1260) for either 15 or 30 days, and accumulation of PCBs in different organ tissues and eggs assessed. The effects of PCB exposure on lipid content, lipid class and fatty acid composition were also evaluated. PCBs were accumulated by the oysters and transferred to the eggs. PCB accumulation in oysters was dose, time and tissue dependent. Mean PCB contents were 3150, 1970, and 250 ng/g dry wt., respectively, in the visceral mass, gills+mantle and muscle of oysters fed algal paste containing 1.0 μg PCBs for 30 days. The PCBs in the eggs from the same oysters reached 671 ng PCBs/g dry wt. Feeding oysters with PCB-sorbed algal paste for 30 days significantly increased phospholipid and free fatty acid contents in gills+mantle tissues compared to the same tissues in the undosed control.

Reproduction and environmental contamination in tree swallows nesting in the Fox River Drainage and Green Bay, Wisconsin, USA

AbstractConcentration, accumulation, and effects of polychlorinated biphenyls (PCBs) o nreproduction in tree swallows (Tachycineta bicolor) were studied at four sites in the Fox River drainage and in Green Bay, Lake Michigan, Wisconsin, USA, in 1994 and 1995. Total PCBs in eggs and newly hatched young (mean = 3.01 μg/g wet weight, years and sites combined) and 12‐d‐old nestlings (mean = 2.34 μg/g wet weight) at two contaminated sites (Kidney Island and Arrowhead) were higher than concentrations at two reference sites (Lake Poygan and High Cliff State Park, years and sites combined, pippers mean = 0.26 μg/g, nestlings mean = 0.01 μg/g). Concentrations of 11 PCB congeners were also higher at contaminated compared to reference sites. Polychlorinated biphenyls (PCBs) accumulated in nestlings at a higher rate (1.34–6.69 μg/d) at contaminated sites compared to reference locations (0.06–0.42 μg/d). Dichlorodiphenyldichloroethylene (DDE) was the only other organochlorine found in all samples; concentrations for all samples averaged ≤0.20 μg/g wet weight. Total PCBs and p,p′‐DDE concentrations did not differ among clutches where all eggs hatched, some eggs hatched, and no eggs hatched.

Congener-specific polychlorinated biphenyl patterns in eggs of aquatic birds from the lower laguna madre, texas

Eggs from four aquatic bird species nesting in the Lower Laguna Madre, Texas, were collected to determine differences and similarities in the accumulation of congener-specific polychlorinated biphenyls (PCBs) and to evaluate PCB impacts on reproduction. Because of the different toxicities of PCB congeners, it is important to know which congeners contribute most to total PCBs. The predominant PCB congeners were 153, 138, 180, 110, 118, 187, and 92. Collectively, congeners 153, 138, and 180 accounted for 26 to 42% of total PCBs. Congener 153 was the most abundant in Caspian terns (Sterna caspia) and great blue herons (Ardea herodias) and congener 138 was the most abundant in snowy egrets (Egretta thula) and tricolored herons (Egretta tricolor). Principal component analysis indicated a predominance of higher chlorinated biphenyls in Caspian terns and great blue herons and lower chlorinated biphenyls in tricolored herons. Snowy egrets had a predominance of pentachlorobiphenyls. These results suggest that there are differences in PCB congener patterns in closely related species and that these differences are more likely associated with the species' diet rather than metabolism. Total PCBs were significantly greater (p < 0.05) in Caspian terns than in the other species. Overall, PCBs in eggs of birds from the Lower Laguna Madre were below concentrations known to affect bird reproduction.

Concentrations and metabolism of PCBs in eggs of waterbirds on the German North Sea coast.

Among environmental chemicals found in top predators the polychlorinated biphenyls (PCB) often occur at high concentrations and are of toxicological relevance. Not only concentrations but also the composition of the PCB mixtures, which consist of many congeners of different degrees of chlorination, vary among species and sites. In this paper we show the interspecific variation in PCB concentrations and in the degree of metabolism of the PCB mixtures in eggs of 11 waterbird species breeding on the highly polluted German Wadden Sea coast, where the PCB contamination of birds has been increasing during the last decade. 14 refs., 2 tabs.

Bioassay-Derived 2,3,7,8-Tetrachlorodibenzo-p-dioxin Equivalents in PCB-Containing Extracts from the Flesh and Eggs of Lake Michigan Chinook Salmon (Oncorhynchus tshawytscha) and Possible Implications for Reproduction

Concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQ), derived via the H4IIE rat hepatoma cell bioassay, were measured in polychlorinated biphenyl (PCB) containing extracts of flesh (dorsal muscle) and egg samples from 10 spawning chinook salmon (Oncorhynchus tshawytscha) from Lake Michigan. There was a marked maternal transfer of both TCDD-EQ and PCBs, and potency of the PCB mixture (expressed as picograms of TCDD-EQ per microgram of PCB) in eggs was 2.5 times greater than potency of the PCB mixture in dorsal muscle of the fish. There was a statistically significant, inverse relationship between the total concentration of PCBs in eggs and hatching success of the fish, with an effect concentration that corresponded to approximately 100 pg TCDD-EQ/g egg. Our results, based on a relatively small sample size, suggest that PCBs, in particular those with TCDD-type activity, may have influenced reproductive success of the fish.

Levels of chlorinated insecticides, total PCBs and PCB congeners in Spanish Gull eggs

Eggs from Herring Gulls, Audouin Gulls and Gull Billed Terns were collected at three different locations in Spain during the breeding season of 1988. Organochlorine pesticides, total polychlorinated biphenyls (PCBs) and seven selected individual chlorobiphenyl congeners were determined in each of the thirty infertile eggs. The levels of DDE and total PCBs in eggs from the Delta Ebro River are greater than those gathered at Chafarinas Island and Cuenca. Among the species investigated, the Gull Billed Tern eggs showed the lowest level followed by the Herring Gull and the Audouin Gull eggs. The levels of the seven congeners of PCBs showed that 138 was the most prominent, followed by, in decreasing order, 153, 180, 170, 101, 151, and 194. Congener 138 constituted 10.5% ± 2.7 (S.D) of the total PCBs concentration, the 153 8.7% ± 4.2, the 180 7.5% ± 1.9, the 170 3.2% ±1.0, the 101 1.9% ± 3.06, the 151 1.1% ± 1.5 and the 194 0.9% ± 0.5. Polychlorinated biphenyl (PCB) residues (48 congeners) from gull eggs gathered at Ebro Delta and Chafarinas Islands were analyzed with SIMCA (Soft Independent Modeling of Class Analogy), a principal components analysis technique. A series of technical Aroclors® were also analyzed to provide a reference data set for pattern recognition. Environmental PCB residue profiles differed according to the sample's origin. This analysis discriminated between the two regions sampled.

A Feeding Test of Polychlorinated Biphenyl (PCB): Its Accumulation and Disappearance in Hen's Eggs and Fat, and Its Effect on Egg Produetion

Experiment 1 was designed to elucidated PCB accumulation and disappeance in egg. Seventy-five laying hens were divided into 5 groups of 15 hens each. Each of 4 groups was fed one of 4 diets containing 0, 10, 20, or 40ppm of PCB for 6 weeks and thereafter fed PCB-free diet for 20 weeks. To the rest, one group was fed diet containing 20ppm of PCB for 20 weeks to find the PCB effect on the egg production.Experiment 2 was designed to exmine the PCB accumulation in hen's fat by feeding PCB. Ninety-six hens were divided into 2 groups of eighteen and seventy-eight hens each. Each of 2 groups was fed one of 2 diets containing either 0 or 20ppm of PCB for 6 weeks, and then fed PCB-free diet for 20 weeks.1. Change in PCB composion: PCB used in this experiment was KC-500 of Kanegafuchi Chemical Company which is known as a mixture of PCB isomers. The gas chromatographic analysis differentiated 14 to 18 peaks in KC-500 by chlorine number and their position in PCB molecule. The method of gas chromatography was used to estimate PCB contents and to analyze PCB peaks in eggs and fat. PCB peaks with fewer chlorines have been detected in early period, then they decreased rapidly, while PCB peaks with more chlorines remained longer. The trend of change in PCB composition in eggs and fat was similar.2. PCB accumulation in eggs and fat during PCB feeding: The change in content of PCB in eggs of hens fed 10, 20, or 40ppm of PCB for 6 weeks and those fed 20ppm of PCB for 20 weeks could be explained by Equation 10. The change in PCB content in adipose tissue could be explained by Equation 5.y=x(0.231+0.291lnt)……(10)where, t(6_??_t_??_1) is length of PCB feeding (weeks) and y is PCB content (ppm) in eggs.y=8.822+45.607lnt……(5)where, t(6_??_t_??_1) is length of PCB feeding (weeks) and y is PCB content (ppm) in adipose tissue.3. Disappearance of PCB from eggs and fat after the withdrawal of PCB feeding. Two separable periods are noticed on PCB disappearance. The first period is the first week after the withdrawal of PCB feeding. In this period, PCB disappeared rapidly, and one thirds of the PCB accumulated in eggs was excreted. In the second period, remaining two thirds of PCB were excreted slowly. PCB disappearance from eggs in the first and second period could be explained as exponential, respectively. Pattern of PCB disappearance from eggs of hens fed 10, 20, and 40ppm of PCB for 6 weeks could be explained by Equation 6, 7, and 8, respectively as the following.y=3.266e-2.418•t+5.398e-0.0855•t……(6)y=5.043e-1.671•t+10.319e-0.0628•t……(7)y=14.112e-2.525•t+23.127e-0.0785•t……(8)where, t(20_??_t_??_1/7) is length after PCB withdrawal (weeks) and y is as in Equation 10. Pattern of PCB disappearance from adipose tissue of hens fed 20ppm of PCB for 6 weeks could be described by Equation 9, y=88.677e-0.0424•t……(9)where, t and y are as in Equation 6.4. No significant effect was observed by feeding PCB at 10, 20, and 40ppm on performance of laying hens. No significant effect was observed on average egg weight, egg production per hen per day, feed intake, body weight, and viability among the hens fed various levels of PCB.