Accumulation and maternal transfer of polychlorinated biphenyls in Steller Sea Lions (Eumetopias jubatus) from Prince William Sound and the Bering Sea, Alaska

Fasting durations of Steller sea lion pups vary among subpopulations-evidence from two plasma metabolites

Geographic differences in population growth trends are well-documented in Steller sea lions (Eumetopias jubatus), a species of North Pacific pinniped listed under the U.S. Endangered Species Act in 1990 following a marked decline in population abundance that began during the 1970s. As population growth is intrinsically linked to pup production and survival, examining factors related to pup physiological condition provides useful information to management authorities regarding potential drivers of regional differences. During dam foraging trips, pups predictably transition among three fasting phases, distinguished by the changes in the predominant metabolic byproduct. We used standardized ranges of two plasma metabolites (blood urea nitrogen and β-hydroxybutyrate) to assign pups to fasting categories (n = 1528, 1990-2016, 12 subpopulations): Recently Fed-Phase I (digestion/assimilation-expected hepatic/muscle glycogen usage), Phase II (expected lipid utilization), transitioning between Phases II-III (expected lipid utilization with increased protein reliance), or Phase III (expected protein catabolism). As anticipated, the majority of pups were classified as Recently Fed-Phase I (overall mean proportion = 0.72) and few pups as Phase III (overall mean proportion = 0.04). By further comparing pups in Short (Recently Fed-Phase II) and Long (all other pups) duration fasts, we identified three subpopulations with significantly (P < 0.03) greater proportions of pups dependent upon endogenous sources of energy for extended periods, during a life stage of somatic growth and development: the 1) central (0.27 ± 0.09) and 2) western (0.36 ± 0.13) Aleutian Island (declining population trend) and 3) southern Southeast Alaska (0.32 ± 0.06; increasing population trend) subpopulations had greater Long fast proportions than the eastern Aleutian Islands (0.10 ± 0.05; stabilized population). Due to contrasting population growth trends among these highlighted subpopulations over the past 50+ years, both density-independent and density-dependent factors likely influence the dam foraging trip duration, contributing to longer fasting durations for pups at some rookeries.

Immunohistochemical Analysis Using Monoclonal Antibody PMab-269 Against Steller Sea Lion Podoplanin

Monoclonal antibodies (mAbs) that specifically target podoplanin (PDPN), a marker for type I alveolar cells, are required for immunohistochemical analyses. Anti-PDPN mAbs are available for many species, including human, mouse, rat, rabbit, dog, cat, bovine, pig, Tasmanian devil, alpaca, tiger, whale, goat, horse, bear, sheep, and California sea lion PDPNs. However, no anti-Steller sea lion PDPN (stePDPN) antibody has been developed. Immunohistochemical analysis showed that an anti-California sea lion PDPN mAb (PMab-269) reacted with type I alveolar cells from the Steller sea lion lung, renal glomeruli and Bowman's capsules from kidney, and lymphatic endothelial cells from the colon, indicating that PMab-269 is useful for detecting stePDPN.

Persistent organic pollutants in killer whales (Orcinus orca) of the Russian Far East

Exposure to persistent organic pollutants (POPs) is a key factor in predicting the collapse of global killer whale (Orcinus orca) populations due to reproductive and immune impacts. Blubber biopsies from killer whales (n = 25) were collected in the Russian Far East in 2002-2004. Biopsies were analyzed for ΣDDT, ΣPCB, and HCB concentrations. A subset of biopsies was further examined for additional contaminants, ΣPBDE, ΣHCH, ΣCHLD, mirex, and dieldrin. Mean concentrations were compared across resident (fish-eating) and transient (mammal-eating) ecotypes and between sexes. ΣPCB analytes (resident males 18,000, resident females 1200, and transient males 420,000 ng g^-1 lw) and HCB (resident males 750, resident females 81, and transient males 6200 ng g^-1 lw) differed significantly (p < 0.001). No significant difference was observed between sexes. Notable disparities in contaminant levels between ecotypes support the major toxicological theories of contaminant bioaccumulation and dietary impacts on individual contaminant load.

Polychlorinated Biphenyls in Surface Soil from North-East India: Implication for Sources Apportionment and Health-Risk Assessment

Although India never manufactured polychlorinated biphenyls (PCBs), evidence suggests the prevalence of PCBs in multi-environmental matrices. Despite the high level of PCBs that has been detailed in the major urban areas of India, little is known about the fate and sources of PCBs in Northeast India (NEI). This motivated us to investigate the contamination level and sources of PCBs in the surface soil. In this study, the environmental concentration and sources of 25 PCBs were investigated in surface soil (n = 60) from three states of NEI (lower Assam, Manipur, and Tripura). Additionally, the relationship between soil organic carbon (SOC) and PCBs was studied to investigate the role of SOC in the distribution of PCBs. Overall, the concentration of ∑₂₅PCBs ranged from 2950 to 16,700 pg/g dw (median 7080 pg/g dw), 3580-21,100 pg/g dw (median 11,500 pg/g dw), and 2040-11,000 pg/g dw (median 4270 pg/g dw) in Assam, Manipur, and Tripura, respectively. Low-chlorinated PCBs were more prevalent than highly chlorinated PCBs. PCB-49 was identified as the most abundant in soil, followed by PCB-52, and accounted for 13% and 12.9% of ∑₂₅PCBs, respectively. With respect to land use categories, high ∑₂₅PCBs were related to grassland areas and proximity to the roadside soil. The principal component analysis indicated emissions from technical PCB mixtures, combustion of municipal wastes/residential wood, incineration of hospital wastes, and e-waste recycling/disposal sites are the real sources of PCBs. Marginally, a moderate-to-weak correlation of SOC with ∑₂₅PCBs (R² = 0.144, p < 0.05) and their homologs (R² = 0.280-0.365, p < 0.05) indicated the little role of SOC in the dispersion of PCBs. The estimated toxic equivalency of dioxin-like PCBs suggested that PCB-126 is the most toxic contaminant to endanger the human population.

The Risk of Polychlorinated Biphenyls Facilitating Tumors in Hawaiian Green Sea Turtles (Chelonia mydas)

The Hawaiian green turtle (Chelonia mydas) is on the list of threatened species protected under the U.S. Endangered Species Act in 1978 in large part due to a severe tumor-forming disease named fibropapillomatosis. Chemical pollution is a prime suspect threatening the survival of C. mydas. In this study, PCBs concentrations were determined in 43 C. mydas plasma samples archived on Tern Island. The total PCBs concentration in male C. mydas (mean 1.10 ng/mL) was two times more than that of females (mean 0.43 ng/mL). The relationship between straight carapace length and PCBs concentration in females has also been studied, which was negatively related. To figure out the possible existence of correlations between PCBs and tumor status, we measured the PCBs concentration in turtles with no tumor, moderate or severe tumor affliction. PCBs concentration of two afflicted groups was much higher than the healthy group, suggesting that PCBs may play a role in fibropapillomatosis in Hawaiian green turtle.

Polychlorinated biphenyls in Nepalese surface soils: Spatial distribution, air-soil exchange, and soil-air partitioning

Regardless of the ban on the polychlorinated biphenyls (PCBs) decade ago, significant measures of PCBs are still transmitted from essential sources in cities and are all inclusive ecological contaminants around the world. In this study, the concentrations of PCBs in soil, the air-soil exchange of PCBs, and the soil-air partitioning coefficient (K_SA) of PCBs were investigated in four noteworthy urban areas in Nepal. Overall, the concentrations of ∑₃₀PCBs ranged from 10 to 59.4ng/g dry weight; dw (mean 12.2ng/g ±11.2ng/g dw). The hexa-CBs (22-31%) was most dominant among several PCB-homologues, followed by tetra-CBs (20-29%), hepta-CBs (12-21%), penta-CBs (15-17%) and tri-CBs (9-19%). The sources of elevated level of PCBs discharge in Nepalese soil was identified as emission from transformer oil, lubricants, breaker oil, cutting oil and paints, and cable insulation. Slightly strong correlation of PCBs with TOC than BC demonstrated that amorphous organic matter (AOM) assumes a more critical part in holding of PCBs than BC in Nepalese soil. The fugacity fraction (ff) results indicated the soil being the source of PCB in air through volatilization and net transport from soil to air. The soil-air partitioning coefficient study suggests the absorption by soil organic matter control soil-air partitioning of PCBs. Slightly weak but positive correlation of measured Log K_SA with Log K_OA (R² = 0.483) and Log K_BC-A (R² = 0.438) suggests that both Log K_OA and Log K_BC-A can predict soil-air partitioning to lesser extent for PCBs.

Assessing the variables affecting on the rate of solid waste generation and recycling: An empirical analysis in Prespa Park

Economic development, urbanization, and improved living standards increase the quantity and complexity of generated solid waste. Comprehensive study of the variables influencing household solid waste production and recycling rate is crucial and fundamental for exploring the generation mechanism and forecasting future dynamics of household solid waste. The present study is employed in the case study of Prespa Park. A model, based on the interrelationships of economic, demographic, housing structure and waste management policy variables influencing the rate of solid waste generation and recycling is developed and employed. The empirical analysis is based on the information derived from a field questionnaire survey conducted in Prespa Park villages for the year 2014. Another feature of this study is to test whether a household's waste generation can be decoupled from its population growth. Descriptive statistics, bivariate correlation analysis and F-tests are used to know the relationship between variables. One-way and two-way fixed effects models data analysis techniques are used to identify variables that determine the effectiveness of waste generation and recycling at household level in the study area. The results reveal that households with heterogeneous characteristics, such as education level, mean building age and income, present different challenges of waste reduction goals. Numerically, an increase of 1% in education level of population corresponds to a waste reduction of 3kg on the annual per capita basis. A village with older buildings, in the case of one year older of the median building age, corresponds to a waste generation increase of 12kg. Other economic and policy incentives such as the mean household income, pay-as-you-throw, percentage of population with access to curbside recycling, the number of drop-off recycling facilities available per 1000 persons and cumulative expenditures on recycling education per capita are also found to be effective measures in waste reduction. The mean expenditure for recycling education spent on a person for years 2010 and 2014 is 12 and 14 cents, respectively and it vary from 0 to €1. For years 2010 and 2014, the mean percentage of population with access to curbside recycling services is 38.6% and 40.3%, and the mean number of drop-off recycling centers per 1000 persons in the population is 0.29 and 0.32, respectively. Empirical evidence suggests that population growth did not necessarily result in increases in waste generation. The results provided are useful when planning, changing or implementing sustainable municipal solid waste management.

Concentrations, distribution, sources and risk assessment of organohalogenated contaminants in soils from Kenya, Eastern Africa

The organohalogenated contaminants (OCs) including 12 organochlorine pesticides (OCPs), 7 indicator polychlorinated biphenyls (PCBs) and 7 polybrominated diphenyl ethers (PBDEs) were determined in soils collected from Kenya, Eastern Africa. The total OCPs fell in the range of n.d-49.74 μg kg(-1) dry weight (dw), which was dominated by DDTs and endosulfan. Identification of pollution sources indicated new input of DDTs for malaria control in Kenya. The total PCBs ranged from n.d. to 55.49 μg kg(-1) dw, dominated by penta- and hexa-PCBs, probably associated with the leakage of obsolete transformer oil. The soils were less contaminated by PBDEs, ranging from 0.19 to 35.64 μg kg(-1) dw. The predominant PBDE congeners were penta-, tri- or tetra-BDEs, varying among different sampling sites. Risk assessment indicated potential human health risks posed by OCs in soils from Kenya, with PCBs as the most contributing pollutants. The local authorities are recommended to make best efforts on management of OC pollution, particularly from DDTs and PCBs to meet the requirement of Stockholm Convention.

Deep-ocean foraging northern elephant seals bioaccumulate persistent organic pollutants

As top predators in the northeast Pacific Ocean, northern elephant seals (Mirounga angustirostris) are vulnerable to bioaccumulation of persistent organic pollutants (POPs). Our study examined a suite of POPs in blubber (inner and outer) and blood (serum) of free-ranging northern elephant seals. For adult females (N=24), we satellite tracked and sampled the same seals before and after their approximately seven month long foraging trip. For males, we sampled different adults and sub-adults before (N=14) and after (N=15) the same foraging trip. For females, we calculated blubber burdens for all compounds. The highest POP concentrations in males and females were found for ∑DDTs and ∑PCBs. In blubber and serum, males had significantly greater concentrations than females for almost all compounds. For males and females, ∑DDT and ∑PBDEs were highly correlated in blubber and serum. While ∑PCBs were highly correlated with ∑DDTs and ∑PBDEs in blubber and serum for males, ∑PCBs showed weaker correlations with both compounds in females. As females gained mass while foraging, concentrations of nearly all POPs in inner and outer blubber significantly decreased; however, the absolute burden in blubber significantly increased, indicating ingestion of contaminants while foraging. Additionally, we identified three clusters of seal foraging behavior, based on geography, diving behavior, and stable carbon and nitrogen isotopes, which corresponded with differences in ∑DDTs, ∑PBDEs, MeO-BDE 47, as well as the ratio of ∑DDTs to ∑PCBs, indicating the potential for behavior to heighten or mitigate contaminant exposure. The greatest concentrations of ∑DDTs and ∑PBDEs were observed in the cluster that foraged closer to the coast and had blood samples more enriched in (13)C. Bioaccumulation of POPs by elephant seals supports mesopelagic food webs as a sink for POPs and highlights elephant seals as a potential sentinel of contamination in deep ocean food webs.

The effect of organohalogen contaminants on western Steller sea lion survival and movement in the Russian Far East

The western stock of Steller sea lions (Eumetopias jubatus) have experienced dramatic declines since the 1960s, particularly in the western Alaskan and Asian portions, which have continued to decline or stabilized at low levels. Multiple causes for this decline have been proposed and may include anthropogenic contamination from organohalogen contaminants (OCs). These include polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT), which have not been ruled out as a potential cause for the lack of recovery. The objective of this study was to determine the effects of OCs on survival and movement probabilities estimated in program MARK using resighting data collected from 2003 to 2009. PCBs and DDTs were measured in whole blood from 136 (74 males and 62 females) individually marked, free-ranging pups from four Russian Far East rookeries. The mean concentration of ∑PCB and ∑DDT was 4.25±5.12 and 3.22±4.28 ng g(-1) ww (n=136), respectively, and the average ∑PCB and ∑DDT concentration for those above the aggregate mean (n=44) was 9.25±6.55 and 7.65±5.21 ng g(-1) ww, and those below the aggregate mean (n=92) the concentration was 1.86±0.89 and 1.11±0.65 ng g(-1) ww, respectively. The lowest estimated probabilities of survival occurred in the first year, ranging from 38% to 74%, but increased for ages 1-9, ranging from 82% to 94%. The greatest movement occurred from Medny Island west toward the Kamchatka Peninsula (33%) and to Bering Island (18%), and low movement estimates for other natal rookeries was largely due to minimal resighting effort. The estimated probabilities of resighting varied by location (48%-87%), but had greater precision than survival or movement parameters. Survival and movement were most affected by age and location rather than OCs.

Maternal-to-fetal transfer and concentration profiles of PCB congeners for Steller sea lions (Eumetopias jubatus) from Hokkaido, Japan

The concentrations of PCB congeners in the blubber and liver of mother Steller sea lions (Eumetopias jubatus; SSLs) and their fetuses from the coast of Hokkaido, Japan in 2008, 2010 and 2012 were analyzed by HRGC-HRMS, in order to elucidate PCB congener profiles and maternal-to-fetal transfer of PCBs in SSLs. ΣPCBs in the fetuses were 1400 ± 660 (the mean ± SD) ng/g-fat in the blubber and 570 ± 320 ng/g-fat in the liver, respectively. There was a concern that SSLs had been contaminated by PCBs during the fetal period. The concentrations of the major congeners in the blubber and liver were a correlation between the fetus and mother (blubber: r=0.9934, liver: r=0.9160; P ≦ 0.05). The results indicated that PCBs in the fetuses came from the mothers. #177 and #199 showed no correlations between the fetus and the mother in the blubber and liver. This indicated a selective capture by some natural protector such as the placenta.

PBDE flame retardants and PCBs in migrating Steller sea lions (Eumetopias jubatus) in the Strait of Georgia, British Columbia, Canada

Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) were measured in blubber biopsy samples from 22 live-captured Steller sea lions (Eumetopias jubatus) that had just entered the Strait of Georgia, British Columbia, Canada, for their overwintering feeding season. ∑PBDE ranged from 50μgkg(-1) (lipid weight) in adult females to 3780μgkg(-1) in subadult individuals. ∑PCBs ranged from 272μgkg(-1) in adult females to 14280μgkg(-1) in subadult individuals. While most PBDE and PCB congeners were transferred through milk to pups, PCBs with logK(OW)>7.0 (PCBs 206, 207, 208 and 209) appeared constrained, resulting in a lighter mixture in pups compared to adult females. The ratio of individual PCB congeners by metabolic group (Groups I, II, III, IV and V) to PCB-153 regressed against length of males suggested poor biotransformation of these compounds (slopes did not differ from zero, p>0.05). PBDE congeners 49, 99, 153 and 183 appeared bioaccumulative (slopes of ratio BDE/PCB 153 versus length were higher than zero, p<0.05), but the dominance of the single congener, BDE-47 (64% of total PBDEs), likely due in part to debromination pathways, reduced our ability to explore congener-specific dynamics of PBDEs in these pinnipeds. With 80% of our Steller sea lions exceeding a recent toxicity reference value for PCBs, the fasting-associated mobilization of these contaminants raises concerns about a heightened vulnerability to adverse effects during annual migrations.

Lactational transfer of mercury and polychlorinated biphenyls in polar bears

We examined concentrations of total mercury (tHg, inorganic and methylated forms) and polychlorinated biphenyls (PCBs) in blood and milk from free-ranging Southern Beaufort-Chukchi Sea polar bears (Ursus maritimus) to assess maternal transfer of contaminants during lactation and the potential health risk to nursing young. Concentrations of contaminants in the blood of dependent and juvenile animals (ages 1-5 years) ranged from 35.9 to 52.2 μg kg(-1) ww for tHg and 13.9 to 52.2 μg kg(-1) ww (3255.81-11067.79 μg kg(-1) lw) for ΣPCB(7)s, similar to those of adult females, but greater than adult males. Contaminant concentrations in milk ranged from 5.7 to 71.8 μg tHg kg(-1)ww and 160 to 690 μg ΣPCB(11)s kg(-1) ww (547-5190 μg kg(-1) lw). The daily intake levels for tHg by milk consumption estimated for dependent young were below the tolerable daily intake level (TDIL) of tHg established for adult humans. Although the daily intake levels of PCBs through milk consumption for cubs of the year exceeded the TDIL thresholds, calculated dioxin equivalents for PCBs in milk were below adverse physiological thresholds for aquatic mammals. Relatively high concentrations of non-dioxin like PCBs in polar bear milk and blood could impact endocrine function of Southern Beaufort-Chukchi Sea polar bears, but this is uncertain. Transfer of contaminants during mid to late lactation likely limits bioaccumulation of dietary contaminants in female polar bears during spring. As polar bears respond to changes in their arctic sea ice habitat, the adverse health impacts associated with nutritional stress may be exacerbated by tHg and PCBs exposure, especially in ecologically and toxicologically sensitive polar bear cohorts such as reproductive females and young.