bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dietary exposure of mink (Mustela vison) to fish from the Housatonic River, Berkshire County, Massachusetts, USA: Effects on reproduction, kit growth, and survival
Authors: Bursian Steven J. , Sharma Chanda , Aulerich Richard J. , Yamini Behzad , Mitchell Rachel R. , Orazio Carl E. , Moore Dwayne R. J. , Svirsky Susan , Tillitt Donald E. 
Published: May 2006

AbstractWe evaluated the effects of feeding farm-raised mink (Mustela vison) diets containing polychlorinated biphenyl (PCB)-contaminated fish from the Housatonic River (HR; Berkshire County, MA, USA) on adult reproductive performance and kit growth and survival. Diets contained 0.22–3.54% HR fish, providing 0.34–3.7 μg total PCBs (TPCB)/g feed wet wt (3.5–68.5 pg toxic equivalence [TEQ]/g). Female mink were fed diets before breeding through weaning of kits. Twelve kits from each treatment were maintained on their respective diets for an additional 180 d. Dietary PCBs had no effect on the number of offspring produced, gestation period, or other measures of adult reproductive performance. Mink kits exposed to 3.7 μg TPCB/g feed (68.5 pg TEQ/g) in utero and during lactation had reduced survivability between three and six weeks of age. The lethal concentrations to 10 and 20% of the population (LC10 and LC20, respectively) were estimated to be 0.231 and 0.984 μg TPCB/g feed, respectively. Because inclusion of PCB-contaminated fish that composed approximately 1% of the diet would reduce mink kit survival by 20% or more, it is likely that consumption of up to 30-fold that quantity of HR fish, as could be expected for wild mink, would have an adverse effect on wild mink populations.
Dietary exposure of mink (Mustela vison) to fish from the Housatonic River, Berkshire County, Massachusetts, USA: Effects on organ weights and histology and hepatic concentrations of polychlorinated biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalence
Authors: Bursian Steven J. , Sharma Chanda , Aulerich Richard J. , Yamini Behzad , Mitchell Rachel R. , Beckett Kerrie J. , Orazio Carl E. , Moore Dwayne , Svirsky Susan , Tillitt Donald E. 
Published: May 2006

AbstractThe effects of feeding ranch mink (Mustela vison) diets containing polychlorinated biphenyl (PCB)-contaminated fish (88 gold fish [Carassius auratus] weighing a total of 70.3 kg and 16 carp [Cyprinus carpio] weighing a total of 77.3 kg) collected from the Housatonic River (HR; Berkshire County, MA, USA) in October 1999 on organ weights and histology and hepatic concentrations of total PCBs (ΣPCBs) and 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalence (TEQ) were evaluated. Diets contained 0.22 to 3.54% HR fish, which provided 0.34 to 3.7 μg ΣPCBs/g feed (3.5-69 pg TEQ/g feed). Female mink were fed the diets eight weeks before breeding through weaning of kits at six weeks of age. Offspring were maintained on their respective diets for an additional 180 d. The dietary concentration of PCBs that caused a decrease in kit survival (3.7 μg ΣPCBs/g feed [69 pg TEQ/g]) resulted in a maternal hepatic concentration of 3.1 μg ΣPCBs/g wet weight (218 pg TEQ/g). Organ weights were not consistently affected. Mandibular and maxillary squamous cell proliferation was apparent in 31-week-old juveniles exposed to as low as 0.96 (xg ΣPCBs/g feed (9.2 pg TEQ/g). Juveniles in this treatment group had a liver concentration of 1.7 μg ΣPCBs/g wet weight (40 pg TEQ/g). Because inclusion of PCB-contaminated fish, which comprised approximately 1% of the diet, resulted in mandibular and maxillary squamous cell proliferation, it is possible that consumption of up to 30-fold that quantity of HR fish, as could be expected for wild mink, would result in more severe lesions characterized by loss of teeth, thus impacting survivability.
Natural attenuation of pharmaceuticals and alkylphenol polyethoxylate metabolites during river transport: Photochemical and biological transformation
Authors: Lin Angela Yu-Chen , Plumlee Megan H. , Reinhard Martin 
Published: May 2006

Abstract
The capacity of rivers to naturally attenuate trace organic compounds is an important but poorly understood process because the many factors that control attenuation are interrelated and difficult to study in isolation. To better understand the relative importance of chemical (photolysis and sorption) and biological attenuation processes, contaminant removal along a 12-km stretch of the Santa Ana River (SAR) was determined as a function of travel time, distance, and irradiance. Target contaminants included three pharmaceuticals (gemfibrozil, ibuprofen, and naproxen) and their metabolites, and the metabolites of alkylphenol polyethoxylates (APEMs). The APEMs included alkylphenols (APs), short-chain alkylphenol polyethoxylates (APEOs), alkylphenol polyethoxycarboxylates (APECs), and carboxyalkylphenol polyethoxycarboxylates (CAPECs). Overall removals ranged from 50% for APs to 100% for naproxen and increased with distance and time, in many cases following first-order kinetics. For naproxen, which is photolabile, average removals were 20 to 30% more during the day than at night; the nighttime and daytime half-lives were 3 h and 1.7 to 1.9 h, respectively. Comparison of field and laboratory data suggests that approximately 40% of the daytime naproxen removal can be attributed to photolysis with the remainder due to other processes, most likely sorption. For ibuprofen and gemfibrozil, half-lives were 5.4 and 2.7 h, respectively, and laboratory data suggest that biotransformation is the principal attenuating process. The APEM attenuation might be due to sorption and biotransformation; phototransformation may also play a minor role. These data demonstrate that travel times on the order of hours can significantly mitigate the impact of effluent discharge on the water quality of shallow rivers.
Chronic toxicity of 2,4,2′,4′-tetrabromodiphenyl ether on the marine algaSkeletonema costatumand the crustaceanDaphnia magna
Authors: Källqvist Torsten , Grung Merete , Tollefsen Knut-E. 
Published: May 2006

AbstractPolybrominated diphenyl ethers form a groupof highly hydrophobic and persistent chemicals that are detected in various environmental matrices, such as soil, water, sediments, and biota. Although a variety of biological effects have been documented in vertebrates, the effects in invertebrates seem to be largely unknown. The objective of the present study was to determine the toxic effects of 2,4,2′,4′-tetrabromodiphenyl ether (BDE 47) on the growth of the marine diatom Skeletonema costatum and on the parthogenetic reproduction and filtering activity of the freshwater crustacean Daphnia magna. The results showed that BDE 47 caused growth inhibition in S. costatum (no-observed-effect concentration [NOEC], 6.6 μg/L; median effect concentration, 70 μg/L; 95% confidence interval, 64–77 μg/L) and depressed the reproductive output of D. magna (NOEC, 14 μg/L). No effects were seen on the filtering rate of D. magna at any of the concentrations tested. Although sublethal toxicity was observed at low-μg/L levels, documented environmental water concentrations are many orders of magnitude lower, thus suggesting that BDE 47 is of minor risk to these organisms through direct water exposure.
Pyrolusite (β-MnO2)-mediated, near dry-phase oxidation of 2,4,6-trichlorophenol
Authors: Smith Brant A. , Siems William F. , Teel Amy L. , Watts Richard J. 
Published: May 2006

Abstract
The pyrolusite (β-MnO2)-mediated oxidation of 2,4,6-trichlorophenol (TCP) under nonaqueous conditions was investigated to assess the potential for abiotic transformations of chlorophenols and their transformation pathways when they are released to soils and the vadose zone. Lower rates of TCP oxidation were found at lower relative humidities, but the rates were still relatively high under near-dry conditions, with 86% of the TCP transformed within 24 h at less than 2% relative humidity. The rates of TCP transformation and soluble manganese formation at less than 2% relative humidity were not affected by atmospheric oxygen content. The manganese oxide-mediated oxidation of TCP resulted in the formation of 2,6-dichloro-1,4-benzoquinone and dimers, including polychlorinated phenoxyphenols and at least one tetrachlorodibenzo-p-dioxin. The products are consistent with the proposed mechanism in which some of the TCP is transformed into trichlorophenoxy radicals that attack TCP and its transformation products. The present results demonstrate that naturally occurring manganese oxides have the potential to oxidize industrial compounds such as TCP; however, the transformation products may be more toxic and persistent than the parent compound.
Effects of the antibiotic ciprofloxacin on stream microbial communities and detritivorous macroinvertebrates
Authors: Maul Jonathan D. , Schuler Lance J. , Belden Jason B. , Whiles Matt R. , Lydy Michael J. 
Published: May 2006

Abstract
Microbial communities play an important role in stream ecosystem processes, such as breakdown of senescent leaf litter, and as a primary nutritional source for detritivorous macroinvertebrates. Antibiotics may affect stream microbial communities and associated ecosystem processes, especially because recent stream and river monitoring programs have indicated the presence of antibiotics downstream of wastewater treatment plants. In the current study, effects of chronic exposure to the fluoroquinolone antibiotic ciprofloxacin (Cipro) were examined on stream microbial community-level physiological profiles and growth indices of detritivorous amphipods (Gammarus spp.) and caddisflies (Lepidostoma liba). Microcosm experiments were conducted using stream sediments and water, senesced leaf material (Acer saccharum), and macroinvertebrates. A shift in function of leaf-associated microbial communities (based on carbon source utilization) was observed for samples exposed to 100 μg/L of Cipro for 12 d compared to control and treatments exposed to 1 and 10 μg/L of Cipro. This was attributable to carbohydrate substrates, which had 2.7- to 3.5-fold lower microbial respiration than the lower concentrations and control (p &lt; 0.001). For detritivores, Gammarus spp. condition index did not differ among control, 0.1, and 1.0 μg/L treatments after 30-d exposures (p &gt; 0.05). Similarly, L. liba growth rate did not vary among control, 10, and 100 μg/L treatments after 45-d exposures (p &gt; 0.05). These results suggest that Cipro may affect leaf-associated microbial communities, but at concentrations four orders of magnitude above those detected in streams. However, effects of the antibiotic on growth and condition of detritivores were not observed. Future work should focus on identifying specific changes in stream microbial communities as a result of Cipro exposure and impacts on other aquatic species.
Passive sampler-derived air concentrations for polybrominated diphenyl ethers and polycyclic aromatic hydrocarbons in Kuwait
Authors: Gevao Bondi , Al-Omair Ali , Sweetman Andy , Al-Ali Lulwa , Al-Bahloul Majed , Helaleh Murad , Zafar Jamal 
Published: May 2006

Abstract
The present study presents, to our knowledge, the first ambient air data for a range of polybrominated diphenyl ethers (PBDEs) and polycyclic aromatic hydrocarbons (PAHs) in Kuwait. This was achieved by concurrently deploying polyurethane foam-disk passive samplers at 14 sites over a six-week period. Calculated mean Σ5PBDE concentrations (sum of brominated diphenyl ethers [BDEs] 47, 99, 100, 153, and 154) ranged from 2.5 to 32 pg/m3 of air, with BDE 47 contributing between 39 and 65% of the ΣPBDEs detected. Differences in relative concentrations were observed between sites, with higher concentrations measured close to suspected sources. Calculated ΣPAH concentrations ranged from 5 to 13 ng/m3 (mean, 8.3 ng/m3). The compound distribution was dominated by three- and four-ring compounds, which constituted approximately 90% of the ΣPAHs, with phenanthrene contributing approximately 35%. However, the proportion of five- and six-ring PAHs increased around the “oil lakes,” which were formed by the torching of oil wells during the 1991 Gulf War. The oil lakes are a reservoir of PAHs that will continue feeding the atmosphere as long as they remain untreated.
Biomarkers of exposure and effects of environmental contaminants on swallows nesting along the Rio Grande, Texas, USA
Authors: Mora Miguel A. , Musquiz Daniel , Bickham John W. , Mackenzie Duncan S. , Hooper Michael J. , Szabo Judit K. , Matson Cole W. 
Published: May 2006

AbstractWe collected adult cave swallows (Petrochelidon fulva) and cliff swallows (P. pyrrhonota) during the breeding seasons in 1999 and 2000 from eight locations along the Rio Grande from Brownsville to El Paso (unless otherwise specified, all locations are Texas, USA) and an out-of-basin reference location. Body mass, spleen mass, hepatosomatic index (HSI), gonadosomatic index (GSI), thyroxine (T4) in plasma, DNA damage measured as the half-peak coefficient of variation of DNA content (HPCV) in blood cells, as well as acetylcholinesterase and butyrylcholinesterase in brain were compared with concentrations of organochlorines, metals, and metalloids in carcasses to determine potential effects of contaminants on swallows during the breeding season. Concentrations of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p′-DDE) were significantly greater in swallows from El Paso than in those from most locations, except for Pharr and Llano Grande. All swallows from these three locations had p,p′-DDE concentrations of 3 μg/g wet weight or greater. Swallows from El Paso either had or shared the highest concentrations of p,p′-DDE, polychlorinated biphenyls, and 13 inorganic elements. Swallows from El Paso exhibited greater spleen mass and HPCV values as well as lower T4 values compared with those from other locations. Thyroxine was a potential biomarker of contaminant exposure in swallows of the Rio Grande, because it was negatively correlated with p,p′-DDE and Se. Spleen mass was positively correlated with selenium and HSI and negatively correlated with body mass, GSI, Mn, and Ni. Overall, the present study suggests that insectivorous birds living in areas of high agricultural and industrial activity along the Rio Grande bioaccumulate environmental contaminants. These contaminants, particularly p,p′-DDE, may be among multiple factors that impact endocrine and hematopoietic function in Rio Grande swallows.
Effect of suspended solids on bioavailability of pyrethroid insecticides
Authors: Yang Weichun , Gan Jianying , Hunter Wesley , Spurlock Frank 
Published: May 2006

AbstractRunoff and surface-water effluents commonly contain suspended solids. Adsorption to suspended particles and the associated dissolved organic matter (DOM) may significantly decrease the freely dissolved concentration of a hydrophobic compound and, hence, its availability to aquatic organisms. In the present study, we evaluated phase distribution and bioaccumulation of two synthetic pyrethroids, bifenthrin and permethrin, in water samples containing suspended solids from different source sediments. Uptake of [14C]bifenthrin or [14C] permethrin by Daphnia magna after 24 h consistently decreased with increasing levels of suspended solids in the range of 0 to 200 mg/L. The trend of decrease was closely mimicked by pesticide accumulation on polydimethylsiloxane (PDMS) fibers exposed under the same conditions, and the ratio of body residues in D. magna to the concentration detected in the PDMS fiber was consistently around 2.4. Regression analysis showed that the pesticide adsorbed on particles or DOM was completely unavailable to D. magna for uptake during the 24-h exposure. The relative contribution of particles and DOM to the reduced bioavailability depended on the organic matter content and the texture of the source sediment. The influence from particles was predominant for sandy sediments, but contribution from DOM became comparable to or even greater than particles when the organic matter content of the source sediment was 1% or greater. The inhibitory effects of suspended solids on bioavailability should be considered when monitoring runoff and surface-water effluents for synthetic pyrethroids. The proposed PDMS method is simple and inexpensive, and it may serve as an effective option for obtaining ecotoxicologically relevant concentrations.
Influence of soil properties and aging on arsenic phytotoxicity
Authors: Song Jing , Zhao Fang-Jie , McGrath Steve P. , Luo Yong-Ming 
Published: May 2006

Abstract
Bioavailability of As varies among soils, and this needs to be taken into account during environmental risk assessment. Using a standardized barley root elongation assay, we investigated the phytotoxicity of arsenate added to 16 European soils that varied widely in their physicochemical properties. The effective concentrations of As causing 10% (EC10) and 50% (EC50) inhibition were estimated based on the concentrations of total added As or As extracted with 0.05 M (NH4)2SO4 or 0.05 M NH4H2PO4. In addition, four soils were used to evaluate changes in arsenate phytotoxicity over a three-month period. The EC10s and EC50s of added As varied from 4.2 to 206.7 mg/kg and from 26.6 to 458.2 mg/kg, respectively. Multiple-regression analysis showed that the variability in the EC10 and EC50 was largely (&gt;89%) explained by the contents of amorphous Mn oxide and clay and, to a lesser extent, Fe oxide, indicating that arsenate adsorption was a key factor controlling its bioavailability. Neither (NH4)2SO4 nor NH4H2PO4 extraction could explain arsenate phytotoxicity independently of soil properties. Furthermore, arsenate phytotoxicity decreased significantly after aging for three months, although the extent of aging differed among soils. This aging effect should be taken into account during the risk assessment.
Are organohalogen contaminants a cofactor in the development of renal lesions in East Greenland polar bears (Ursus maritimus)?
Authors: Sonne Christian , Dietz Rune , Leifsson Pall S. , Born Erik W. , Kirkegaard Maja , Letcher Robert J. , Muir Derek C. G. , Riget Frank F. , Hyldstrup Lars 
Published: May 2006

Abstract
Tissues of polar bears (Ursus maritimus) from East Greenland contain the highest concentrations of organohalogen contaminants (OHCs) among subpopulations of any mammalian species in the Arctic. Negative associations also have been found between OHC concentrations and bone mineral density and liver histology parameters for this subpopulation of polar bears. The present study examined the OHC concentrations and adverse effects on renal tissue for 75 polar bears collected during 1999 to 2002. Specific lesions were diffuse glomerular capillary wall thickening, mesangial glomerular deposits, tubular epithelial cell hyperplasia, hyalinization of the tubular basement membrane, tubular dilatation, atrophy and necrosis, tubular medullary hyalin casts, interstitial fibrosis, and mononuclear cell infiltration. With the exception of mononuclear cell infiltrations, all these parameters were correlated with age, whereas none was associated with the sex of the animals. In an age-controlled statistical analysis of covariance, increases in glomerular mesangial deposits and interstitial fibrosis were significantly (p &lt; 0.05) correlated with polybrominated diphenyl ether (ΣPBDE) concentrations in subadults. In adult males, statistically significant (p &lt; 0.05) positive correlations were found for tubular epithelial cell hyperplasia and dieldrin concentration; diffuse glomerular capillary wall thickening and chlordane (ΣCHL) concentrations, and tubular medullary hyalin casts and ΣCHL, ΣPBDE, polychlorinated biphenyl, and hexachlorocyclohexane concentrations. The lesions were consistent with those reported previously in highly OHC-contaminated Baltic seal populations and exposed laboratory animals. The renal lesions were a result of aging. However, based on the above statistical findings as well as the nature of the findings, we suggest that long-term exposure to OHCs may be a cofactor in renal lesion occurrence, although other cofactors, such as exposure to heavy metals and recurrent infections from microorganisms, cannot be ruled out. This is new and important knowledge in the assessment of health status among wildlife populations and humans relying on food resources that are contaminated with OHCs.
Solid-phase sediment toxicity identification evaluation in an agricultural stream
Authors: Phillips Bryn M. , Anderson Brian S. , Hunt John W. , Huntley Sarah A. , Tjeerdema Ron S. , Kapellas Nancy , Worcester Karen 
Published: May 2006

AbstractThe lower Santa Maria River watershed provides important aquatic habitat on the central California coast and is influenced heavily by agricultural runoff. As part of a recently completed water quality assessment, we conducted a series of water column and sediment toxicity tests throughout this watershed. Sediment from Orcutt Creek, a tributary that drains agricultural land, consistently was toxic to the amphipod Hyalella azteca, which is a resident genus in this river. Toxicity identification evaluations (TIEs) were conducted to determine cause(s) of toxicity. We observed no toxicity in sediment interstitial water even though concentrations of chlorpyrifos exceeded published aqueous toxicity thresholds for H. azteca. In contrast to interstitial water, bulk sediment was toxic to H. azteca. In bulk-phase sediment TIEs, the addition of 20% (by volume) coconut charcoal increased survival by 41%, implicating organic chemical(s). Addition of 5% (by volume) of the carbonaceous resin Ambersorb 563® increased survival by 88%, again suggesting toxicity due to organic chemicals. Toxicity was confirmed by isolating Ambersorb from the sediment, eluting the resin with methanol, and observing significant toxicity in control water spiked with the methanol eluate. A carboxylesterase enzyme that hydrolyzes synthetic pyrethroids was added to overlying water, and this significantly reduced toxicity to amphipods. Although the pesticides chlorpyrifos, DDT, permethrin, esfenvalerate, and fenvalerate were detected in this sediment, and their concentrations were below published toxicity thresholds for H. azteca, additivity or synergism may have occurred. The weight-of-evidence suggests toxicity of this sediment was caused by an organic contaminant, most likely a synthetic pyrethroid.
Exposure to 3,3′,4,4′,5-pentachlorobiphenyl during embryonic development has a minimal effect on the cytochrome P4501A response to 2,3,7,8-tetrachlorodibenzo-P-dioxin in cultured chicken embryo hepatocytes
Authors: Head Jessica A. , O'Brien Jason , Kennedy Sean W. 
Published: May 2006

AbstractConcentrations of dioxin-like compounds in avian eggs can vary substantially between individuals, species, and collection sites. Although the inducibility of cytochrome P4501A (CYP1A) in hepatocyte cultures is commonly used to predict species sensitivity to environmental contaminants, it is not known how exposure to dioxin-like compounds during embryonic development might alter this biomarker response. To investigate this question, we injected vehicle or 0.4, 0.8, or 1.6 μg/kg of 3,3ǐ,4,4ǐ,5-pentachlorobiphenyl (PCB 126) into the air cell of fertilized chicken eggs before incubation, and we measured CYP1A endpoints in cultured hepatocytes of day-19 embryos from each treatment group. The CYP1A response to PCB 126 also was assessed in whole liver tissue. Embryonic exposure to the most environmentally relevant treatment, 0.4 μg/kg of PCB 126, increased CYP1A4 mRNA expression 29-fold compared to control values in whole liver tissue but only twofold compared to control values in cultured hepatocytes. The CYP1A response to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was not altered in hepatocytes cultured from embryos treated with 0.4 μg/kg of PCB 126, but at 0.8 and 1.6 μg/kg of PCB 126, several concentration-dependent effects were observed. For example, embryos exposed to higher concentrations of PCB 126 in ovo were more responsive to CYP1A mRNA induction by TCDD in vitro. These findings suggest that exposure to environmental levels of dioxin-like compounds during incubation is not likely to alter species-sensitivity estimates derived from in vitro CYP1A data.