Use of a vial equilibration technique to measure the change in fugacity capacity of avian food and feces samples for 1,2,3,4-tetrachlorobenzene.

A vial equilibration technique was used to estimate the fugacity capacities of food and feces samples for 1,2,3,4-tetrachlorobenzene (TCB). The method was calibrated using different volumes of n-octanol and by comparing the measured and predicted fugacity capacity (Zoct) of n-octanol for TCB. The vial equilibration technique showed linearity with increasing amounts of n-octanol added to the vial.

Tissue distribution kinetics of 2,2',4,4',5,5'-hexachlorobiphenyl in ringdoves after oral dosing.

Ring doves were provided contaminated food spiked with [(13)C]-2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153) over a period of 63 days. Animals were sacrificed after 0.33, 0.

Persistence of organochlorine chemical residues in fish from the Tombigbee River (Alabama, USA): Continuing risk to wildlife from a former DDT manufacturing facility.

Organochlorine pesticide and total polychlorinated biphenyl (PCB) concentrations were measured in largemouth bass from the Tombigbee River near a former DDT manufacturing facility at McIntosh, Alabama. Evaluation of mean p,p'- and o,p'-DDT isomer concentrations and o,p'- versus p,p'-isomer proportions in McIntosh bass indicated that DDT is moving off site from the facility and into the Tombigbee River. Concentrations of p,p'-DDT isomers in McIntosh bass remained unchanged from 1974 to 2004 and were four times greater than contemporary concentrations from a national program.

Geographic distribution of selected elements in the livers of polar bears from Greenland, Canada and the United States.

To assess geographic distributions of elements in the Arctic we compared essential and non-essential elements in the livers of polar bears (Ursus maritimus) collected from five regions within Canada in 2002, in Alaska between 1994 and 1999 and from the northwest and east coasts of Greenland between 1988 and 2000. As, Hg, Pb and Se varied with age, and Co and Zn with gender, which limited spatial comparisons across all populations to Cd, which was highest in Greenland bears. Collectively, geographic relationships appeared similar to past studies with little change in concentration over time in Canada and Greenland for most elements; Hg and Se were higher in some Canadian populations in 2002 as compared to 1982 and 1984.

ABAM, a model for bioaccumulation of POPs in birds: validation for adult herring gulls and their eggs in Lake Ontario.

An Avian BioAccumulation Model (ABAM) of persistent organic pollutant (POP) uptake and elimination in adult life-stage of birds was validated by simulation of concentrations of DDE, dieldrin, mirex, and HCB in herring gull eggs in Lake Ontario for the years 1985, 1990, and 1992. These chemicals represented a range of whole-body half-lives of 82-265 days in the gull. Dietary intake of POPs by a female gull was simulated by a dynamic bioenergetics model which included dependence on temperature, photoperiod, egg production, and feeding chicks.

Regional and species specific bioaccumulation of major and trace elements in Arctic seabirds.

Twenty-five essential and nonessential elements were analyzed in Arctic seabirds to study the influence of phylogeny, tissue, Arctic region, and diet on avian element accumulation and to identify co-occurrence among metals. Muscle and liver concentrations were positively correlated, generally being higher in liver than in muscle, and generally did not differ by sex. Zinc showed the highest absolute concentrations in all samples (mean, 11.

Composition of chlorinated hydrocarbon contaminants among major adipose tissue depots of polar bears (Ursus maritimus) from the Canadian high Arctic.

Monitoring of environmental contaminants in Canadian Arctic polar bears (Ursus maritimus) typically has used superficial adipose tissue samples collected as part of controlled native subsistence hunts. However, little attention has been paid to the compositional difference in contaminants that may exist among the major adipose depots that are routinely collected. To address this knowledge gap, we investigated the profiles and concentrations of chlorinated hydrocarbon contaminants (CHCs), including major polychlorinated biphenyl (PCB) congeners and organochlorine (OC) pesticides and metabolites, in six major adipose depots (i.

Comprehensive re-analysis of archived herring gull eggs reconstructs historical temporal trends in chlorinated hydrocarbon contamination in Lake Ontario and Green Bay, Lake Michigan, 1971-1982.

Herring gull egg homogenates collected between 1971 and 1982 from a colony in central Lake Ontario (Scotch Bonnet Island) and from a colony in central Green Bay, Lake Michigan (Big Sister Island) were archived in the Canadian Wildlife Service Specimen Bank. Pooled samples (N = 10) were exhaustively analyzed in 1993 for a wide range of individual chlorinated hydrocarbon contaminant (CHC) compounds: DDT, mirex and chlordane compounds and metabolites, chlorobenzenes (CBzs), dieldrin, chlorostyrenes (CSs), hexachlorocyclohexanes (HCHs), polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), and 87 PCB congeners, including the TCDD-like non-ortho and mono-ortho congeners. PCBs and DDTs were the dominant residues in eggs from both Lake Ontario (31-242 mg kg(-1) and 9-64 mg kg(-1)) and Green Bay (34-133 mg kg(-1) and 14-91 mg kg(-1)).

Temporal trends of perfluoroalkyl contaminants in polar bears (Ursus maritimus) from two locations in the North American Arctic, 1972-2002.

Perfluoroalkyl substances are globally distributed anthropogenic contaminants. Their production and use have increased dramatically from the early 1980s. While many recent publications have reported concentrations of perfluorooctane sulfonate (PFOS) and other perfluoroalkyl acids (PFAs) in biotic and abiotic samples, only limited work has addressed temporal trends.

Brominated flame retardants in polar bears (Ursus maritimus) from Alaska, the Canadian Arctic, East Greenland, and Svalbard.

Polybrominated diphenyl ethers (PBDEs) were determined in adipose tissue of adult and subadult female polar bears sampled between 1999 and 2002 from sub-populations in Arctic Canada, eastern Greenland, and Svalbard, and in males and females collected from 1994 to 2002 in northwestern Alaska. Only 4 congeners (BDE47, 99, 100, and 153) were consistently identified in all samples. BDE47 was the major PBDE congener representing from 65% to 82% of the sum (sigma) PBDEs.

Enantiomeric fractions of chiral polychlorinated biphenyls provide insights on biotransformation capacity of arctic biota.

Chiral polychlorinated biphenyls (PCBs) were measured in an arctic marine food web from the Northwater Polynya (NOW) in the Canadian Arctic to examine potential biotransformation of chiral PCB atropisomers. Organisms under investigation included pelagic zooplankton, Arctic cod (Boreogadus saida), seabirds, and ringed seals (Phoca hispida). Previous studies using achiral methods (e.

Enantioselective and gender-dependent depletion of chlordane compounds from rat tissues.

Isomers and metabolites of the organochlorine pesticide chlordane persist in the environment and bioaccumulate in Arctic marine food webs. Rodent studies indicate that there are gender-related differences in trans-nonachlor and oxychlordane metabolism. Thus, comparative tissue depletion studies were undertaken in male and female rats exposed to trans-nonachlor, oxychlordane, or trans-chlordane at 2.

An assessment of the toxicological significance of anthropogenic contaminants in Canadian arctic wildlife.

Anthropogenic contaminants have been a concern in the Canadian arctic for over 30 years due to relatively high concentrations of bioaccumulating and biomagnifying organochlorine contaminants (OCs) and toxic metals found in some arctic biota and humans. However, few studies have addressed the potential effects of these contaminants in Canadian arctic wildlife. Prior to 1997, biological effects data were minimal and insufficient at any level of biological organization.

Chlorinated hydrocarbon contaminants and metabolites in polar bears (Ursus maritimus) from Alaska, Canada, East Greenland, and Svalbard: 1996-2002.

A suite of chlorinated hydrocarbon contaminants (CHCs) including organochlorine pesticides (OCPs) and by-products, polychlorinated biphenyls (PCBs), and methyl sulfone (MeSO2) PCB and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) metabolites were determined in adipose tissue of 107 adult and sub-adult polar bears, almost exclusively females, sampled between 1996 and 2002 from populations spanning Arctic and Subarctic regions of Alaska, Canada, East Greenland, and Svalbard. The East Greenland and Svalbard populations of polar bears were distinguished by higher proportions of dichlorodiphenyldichloroethane (DDT)-related compounds, nonachlors, oxychlordane, and higher-chlorinated and persistent PCB congeners (hepta- to nona-chlorinated). Conversely, Alaska, the westernmost population of the North American Arctic, was characterized by higher proportions of relatively volatile compounds such as hexachlorocyclohexanes (HCHs) and pentachlorobenzene (PnCBz), lower-chlorinated PCB congeners (tri- to penta-chlorinated), and lower proportions of oxychlordane.

Persistent organic pollutants and mercury in marine biota of the Canadian Arctic: an overview of spatial and temporal trends.

This review summarizes and synthesizes the significant amount of data which was generated on mercury (Hg) and persistent organic pollutants (POPs) in Canadian Arctic marine biota since the first Canadian Arctic Contaminants Assessment Report (CACAR) was published in 1997. This recent body of work has led to a better understanding of the current levels and spatial and temporal trends of contaminants in biota, including the marine food species that northern peoples traditionally consume. Compared to other circumpolar countries, concentrations of many organochlorines (OCs) in Canadian Arctic marine biota are generally lower than in the European Arctic and eastern Greenland but are higher than in Alaska, whereas Hg concentrations are substantially higher in Canada than elsewhere.

Mercury and other trace elements in a pelagic Arctic marine food web (Northwater Polynya, Baffin Bay).

Total mercury (THg), methylmercury (MeHg) and 22 other trace elements were measured in ice algae, three species of zooplankton, mixed zooplankton samples, Arctic cod (Boreogadus saida), ringed seals (Phoca hispida) and eight species of seabirds to examine the trophodynamics of these metals in an Arctic marine food web. All samples were collected in 1998 in the Northwater Polynya (NOW) located between Ellesmere Island and Greenland in Baffin Bay. THg and MeHg were found to biomagnify through the NOW food web, based on significant positive relationships between log THg and log MeHg concentrations vs.

Why do organochlorine differences between arctic regions vary among trophic levels?

Statistical analysis of organochlorine contaminants (OCs) in marine mammals has shown that, for most OCs, the European Arctic is more contaminated than the Canadian and U.S. Arctic.

Does high organochlorine (OC) exposure impair the resistance to infection in polar bears (Ursus maritimus)? Part II: Possible effect of OCs on mitogen- and antigen-induced lymphocyte proliferation.

Previous studies have reported alarmingly high levels of organochlorines (OCs), particularly polychlorinated biphenyls (PCBs), in free-ranging polar bears (Ursus maritimus). In this study plasma concentration of PCBs ranged from 14.8 to 200 ng/g wet weight.

Vapour pressures, aqueous solubilities, Henry's Law constants, and octanol/water partition coefficients of a series of mixed halogenated dimethyl bipyrroles.

Basic physical-chemical properties of five bromine and chlorine containing mixed halogenated dimethyl bipyrroles (HDBPs) were determined using established methods. Subcooled liquid vapour pressures (P(o)(L,25)), aqueous solubilities (S(w,25)), and octanol/water partition coefficients (K(ow)) were determined using the gas chromatography-retention time, generator column, and slow-stirring methods, respectively. Henry's Law constants (H25) were estimated using experimentally-derived P(o)(L) and S(w,25) data.

Does high organochlorine (OC) exposure impair the resistance to infection in polar bears (Ursus maritimus)? Part I: Effect of OCs on the humoral immunity.

This study was undertaken to assess if high levels of organochlorines (OCs) are associated with decreased ability to produce antibodies in free-ranging polar bears (Ursus maritimus) and thus affect the humoral immunity. In 1998 and 1999, 26 and 30 polar bears from Svalbard, Norway, and Churchill, Canada, respectively, were recaptured 32-40 d following immunization with inactivated influenza virus, reovirus, and herpes virus and tetanus toxoid. Blood was sampled at immunization and at recapture for determination of plasma levels of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs), serum immunoglobulin G (IgG) concentrations, and specific antibodies against influenza virus, reovirus, and herpes virus, tetanus toxoid, and Mannheimia haemolytica.

Radiocarbon evidence for a naturally produced, bioaccumulating halogenated organic compound.

Halogenated organic compounds (HOCs) such as 1,1'-dimethyl-3,3',4,4'-tetrabromo-5,5'-dichloro-2,2'-bipyrrole (DBP-Br4Cl2) and heptachloro-1'-methyl-1,2'-bipyrrole (Q1) have been detected worldwide, sometimes at high levels in Antarctic air, seabird eggs, the blubber of marine mammals, and, most notably, even human milk. To date, it has been difficult to determine whether these compounds are natural products or derived from industrial synthesis. Molecular-level 14C analysis of these compounds is particularly appealing because most industrial compounds are manufactured from petrochemicals (14C-free) and natural compounds should have "modern" or "contemporary" 14C levels.

Environmental contamination and developmental abnormalities in eggs and hatchlings of the common snapping turtle (Chelydra serpentina serpentina) from the Great Lakes-St Lawrence River basin (1989-1991).

During 1989-1991, we assessed developmental abnormalities in embryos and hatchlings from eggs of the common snapping turtle (Chelydra serpentina serpentina). Eggs were collected and artificially incubated from eight sites in Ontario, Canada and Akwesasne/New York, USA. In eggs from the same clutches we measured 20 organochlorine pesticides, 48 polychlorinated biphenyl (PCBs) congeners including 6 non-ortho PCBs, 8 polychlorinated dibenzodioxins (PCDDs), 14 polychlorinated dibenzofurans (PCDFs) and total mercury.

Organochlorine contaminants in seven species of Arctic seabirds from northern Baffin Bay.

Organochlorine contaminants (OCs) were determined in liver and fat of seven species of seabirds (Alle alle, Uria lomvia, Cepphus grylle, Rissa tridactyla, Pagophila eburnea, Larus hyperboreus, and Fulmaris glacialis) collected in May/June 1998 from the Northwater Polynya in northern Baffin Bay. OC concentrations ranged over an order of magnitude between seabird species and OC groups, with PCBs having the highest concentrations followed by DDT, chlordane, HCH and ClBz. Positive relationships between delta15N (estimator of trophic level) and OC concentrations (lipid basis) were found for all OC groups, showing that trophic position and biomagnification significantly influence OC concentrations in Arctic seabirds.

Naturally produced halogenated dimethyl bipyrroles bind to the aryl hydrocarbon receptor and induce cytochrome P4501A and porphyrin accumulation in chicken embryo hepatocytes.

Halogenated dimethyl bipyrroles (HDBPs) recently have been identified as a group of environmentally persistent naturally produced bioaccumulative organohalogens. The ability of these compounds to activate the aryl hydrocarbon receptor (AhR) signaling pathway in vitro was examined. Induction of cytochrome P4501A (CYP1A), measured as ethoxyresorufin-O-deethylase (EROD) activity, and porphyrin accumulation were monitored after exposure of chick embryo hepatocytes to three individual HDBP congeners and two HDBP mixtures.

Reproductive and morphological effects of halogenated dimethyl bipyrroles on captive American kestrels (Falco sparverius).

Sixty-four adult captive American kestrels (Falco sparverius) were exposed to a dietary source of halogenated dimethyl bipyrroles (HDBPs), a group of organohalogens proposed to have a natural origin. Adult kestrels were assigned to four treatment groups that were administered a different dose of HDBPs [high, 140 microg/(bird x d); medium, 4.3 microg/(bird x d); low, 0.