bluuebunny/crossref_metadata_2025_split huggingface dataset:
Toxicity of triphenyltin and tributyltin to the freshwater mud snailPotamopyrgus antipodarumin a new sediment biotest
Authors: Duft Martina , Schulte-Oehlmann Ulrike , Tillmann Michaela , Markert Bernd , Oehlmann Jörg 
Published: March 2010

AbstractThe effects of two suspected endocrine-disrupting chemicals, the xeno-androgens triphenyltin (TPT) and tributyltin (TBT), were investigated in a new whole-sediment biotest with the freshwater mudsnail Potamopyrgus antipodarum (Gastropoda, Prosobranchia). Artificial sediments were spiked with seven concentrations, ranging from 10 to 500 μg nominal TPT-Sn/kg dry weight and TBT-Sn/kg dry weight, respectively. We analyzed the responses of the test species after two, four, and eight weeks exposure. For both compounds, P. antipodarum exhibited a sharp decline in the number of embryos sheltered in its brood pouch in a time- and concentration-dependent manner in comparison to the control sediment. The number of new, still unshelled embryos turned out to be the most sensitive parameter. The lowest-observed-effect concentration (LOEC) was equivalent to the lowest administered concentration (10 μg/kg of each test compound) for most parameters and thus no no-observed-effect concentration (NOEC) could be established. The calculation of effect concentrations (EC10) resulted in even lower values for both substances (EC10 after eight weeks for unshelled embryos: 0.03 μg TPT-Sn/kg, EC10 after four weeks for unshelled embryos: 0.98 μg TBT-Sn/kg). Our results indicate that P. antipodarum is highly sensitive to both endocrine disruptors TPT and TBT at environmentally relevant concentrations.
Developing transgenic arabidopsis plants to be metal-specific bioindicators
Authors: Krizek Beth A. , Prost Valerie , Joshi Ratan Mani , Stoming Terry , Glenn Travis C. 
Published: March 2010

AbstractDeoxyribonucleic acid (DNA) microarrays provide a means to assess genome-wide expression patterns after exposure of an organism to different xenobiotics. Potential uses for this technology include identification of unknown toxicants, assessment of toxicity of new compounds, and characterization of the cellular mechanisms of toxicant action. Here we describe another use of DNA microarrays in toxicant-specific gene discovery. Combining results from two DNA microarray experiments, we have identified genes from the model plant Arabidopsis thaliana that are induced in response to one but not other heavy metals. The promoters of these genes should be useful in developing metal-specific transgenic biomonitors. To test this idea, we have fused the promoter of one of the newly identified Ni-inducible genes (AHB1) to the β-glucuronidase (GUS) reporter gene. Arabidopsis plants containing the AHB1::GUS transgene show reporter gene activity when they are grown on media containing Ni but not when grown on media containing Cd, Cu, Zn, or without added metals. Thus, this approach has resulted in the creation of a transgenic strain of Arabidopsis that can report on the presence and concentration of Ni in plant growth media. Such transgenic models can serve as cheap and efficient biomonitors of bioavailable heavy metal contamination in soils and sediments.
Impact of atrazine on aneuploidy in pacific oysters, Crassostrea gigas
Authors: Bouilly Karine , Leitão Alexandra , McCombie Helen , Lapègue Sylvie 
Published: March 2010

Abstract
Aneuploidy has previously been described and studied in the Pacific oyster, Crassostrea gigas, and has been shown to be negatively correlated with growth. The present study investigated the effect of atrazine on the level of aneuploidy in this species. Crassostrea gigas adults and juveniles were subjected to different concentrations of atrazine representing a peak value found in a polluted environment (46.5 nM) and a value 10 times higher (465 nM). Although atrazine did not show any effect on the oyster mortality, significant differences in aneuploidy level were observed between the different treatments (9% for the control, 16% for 46.5 nM and 20% for 465 nM atrazine). Moreover, the same levels of aneuploidy were observed at adult and juvenile stages. This is the first reported evidence for an environmental effect on aneuploidy in C. gigas. These results will be useful for the oyster aquaculture industry and management of resources. The lowest atrazine level in the current study represents realistic potential exposure, and the results suggest that studies should be made on other aquatic species at risk of exposure to atrazine in the wild. This widely used compound may be an important factor causing damage to genetic material.
The presence of morphologically intermediate papilla syndrome in United Kingdom populations of sand goby (Pomatoschistus spp.): Endocrine disruption?
Authors: Kirby Mark F. , Bignell John , Brown Elaine , Craft John A. , Davies Ian , Dyer Robert A. , Feist Steven W. , Jones Gary , Matthiessen Peter , Megginson Colin , Robertson Fiona E. , Robinson Craig 
Published: March 2010

Abstract
The sand goby (Pomatoschistus spp.) is a small estuarine fish. Its abundance, life history, and sedentary nature lead to its adoption as a key species in the U.K. Endocrine Disruption in the Marine Environment (EDMAR) Program. This study investigated the presence of classic markers of estrogenic exposure by determining vitellogenin (VTG) and zona radiata protein (ZRP) mRNA levels and ovotestis in estuarine-caught male gobies and investigated morphological changes in the urogenital papilla (UGP). Laboratory exposures to estrogens were also conducted to ascertain the responses of these markers. Wild-caught male fish showed no evidence of ovotestis, VTG, or ZRP mRNA induction. Laboratory exposures suggested that sensitivity of the goby to VTG/ZRP mRNA induction was similar to flounder. The UGP inspection of wild-caught specimens revealed evidence of feminization of male papillae, a condition denoted as morphologically intermediate papilla syndrome (MIPS). Morphologically intermediate papilla syndrome was more prevalent at estrogenically contaminated sites. Juvenile goby experimentally exposed to 17β-estradiol for 11 to 32 weeks exhibited signs of the MIPS condition, showing that it was inducible by estrogenic exposure and could therefore be a form of estrogenic endocrine disruption. The estuaries where the MIPS condition was most prevalent (&gt;50% at certain sites) were the Tees, Mersey, and Clyde. The potential of the MIPS condition to significantly interfere with reproductive performance is discussed as well as its use as a monitoring tool for endocrine disruption in the estuarine environment.
Adsorption of metals to membrane filters in view of their speciation in nutrient solution
Authors: Weltje Lennart , den Hollander Wim , Wolterbeek Hubert Th. 
Published: March 2010

Abstract
Filtration of a solution may lower metal concentrations through adsorption of metal species to the filter. Processes such as filter-sterilizing nutrient solution and filtration of field water are sensitive to these sorption artifacts, yet basic data on the affinity of different filters for metals are lacking. This article describes the adsorption of five metals to eight types of 0.2-μm membrane filters used for sterilizing a plant (Lemna minor L.) culture medium. Filters of cellulose acetate, cellulose nitrate, mixed cellulose ester, nylon, polyamide, polycarbonate, polyester, and polyvinylidene fluoride were tested for their affinity toward mono- (K), di-(Mn, Cu, Zn), and trivalent (lanthanum [La]) metals. Metal concentrations were quantified using radioisotopes and speciation was calculated. Results showed that metals had the lowest affinity for polycarbonate and nylon filters and the highest affinity for cellulose- and polyester-type filters. Furthermore, it was shown that the metal load on cellulose filters correlated best with free ion concentrations (indicating electrostatic attraction), while loads on other filters correlated better with total metal concentrations. Filtering a 5-ml solution of pH 5 did not affect its metal concentrations, ranging from 10 nM (La) to 49 μM (K). To minimize filtration artifacts, we propose using polycarbonate or nylon filters, especially when dealing with low volumes of high pH and low metal species concentrations.
Assessing the toxicity of dodecylbenzene sulfonate to the midgeChironomus ripariususing body residues as the dose metric
Authors: Hwang Haejo , Fisher Susan W. , Kim Kyeok , Landrum Peter F. , Larson Robert J. , Versteeg Donald J. 
Published: March 2010

AbstractDodecylbenzene sulfonate (DBS) is a component of linear alkylbenzene sulfonate (LAS), an anionic surfactant, mainly used in household detergents. Due to the large quantity of DBS in use, there is concern over adverse environmental effects. This work examined the toxicokinetics and toxicity of the 2-phenyl isomer of dodecylbenzene sulfonate in 4-d, 10-d, and partial life-cycle tests on the midge, Chironomus riparius, exposed to aqueous solutions. Toxicokinetics were determined in 10-d uptake and 5-d elimination tests. The toxicokinetics were based on parent compound concentration in water and yielded an uptake coefficient (ku) of 17.5 (14.87–20.20) ml/g/h, an elimination rate constant (ke) of 0.073 (0.062–0.085) per h, a bioconcentration factor (BCF) of 56 to 240, and a half-life (t1/2) of 9.5 (8.0–11.0) h. Biotransformation measurements did not reveal evidence for DBS metabolism. Thus, body residues, determined in the toxicity study, represent parent compound. In toxicity tests, 4- and 10-d LR50s (the body residue required to cause 50% mortality) in live midges were 0.72 (0.65–0.79) and 0.18 (0.08–0.42) mmol/kg, respectively. Thirty-day LR50s were 0.18 (0.09–1.64) and 0.21 (0.15–0.39) mmol/kg in duplicate studies. Of the sublethal endpoints, only developmental time increase was significant, with the lowest-observed-effect residues of 0.085 (0.067–0.105) and 0.100 (0.087–0.114) mmol/kg for male and female midges, respectively. Deformities in surviving larvae were also observed as chronic responses for body residues exceeding the 30-d LR50. The body residues required for mortality suggest that DBS acts like a polar narcotic in the midge.
Exposure to the polychlorinated biphenyl mixture Aroclor® 1254 alters melanocyte and tail muscle morphology in developingXenopus laevistadpoles
Authors: Fisher Marla A. , Jelaso Anna M. , Predenkiewicz Amy , Schuster Lindsey , Means Jay , Ide Charles F. 
Published: March 2010

AbstractPolychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants that have damaging effects on both ecosystem and human health. Numerous studies have shown that exposure to PCBs can alter growth and development of aquatic organisms, including frogs. In this report, developing Xenopus laevis tadpoles were exposed to the PCB mixture Aroclor® 1254. Tadpoles were exposed from 5 through 9 d postfertilization to either 0, 1, 10, 50, or 100 ppm Aroclor 1254. Exposure to an acute, high concentration of Aroclor 1254 (10, 50, and 100 ppm) caused statistically significant reductions in survival and body size. In addition, tadpoles exposed to these higher concentrations showed histological abnormalities, including aberrant tail tip, myotomal, and melanocyte morphologies. Described adverse health effects associated with PCB exposure of developing frogs will serve as useful health endpoints in ongoing and future molecular-based studies that correlate health effects with changes in gene expression.
In vitro and in vivo estrogenicity and toxicity of o-, m-, and p-dichlorobenzene
Authors: Versonnen Bram J. , Arijs Katrien , Verslycke Tim , Lema Wouter , Janssen Colin R. 
Published: March 2010

Abstract
The estrogenicity of o-, m-, and p-dichlorobenzene (DCB) was evaluated with a yeast estrogen screen (YES) and zebrafish (Danio rerio) vitellogenin (VTG) assays. With the YES, p-DCB and m-DCB were found to be estrogenic in a concentration-responsive manner. The relative potency measured with the YES (relative to 17β-estradiol) was 2.2 × 10−7 for p-DCB and 1.04 × 10−8 for m-DCB. Following acute toxicity tests with the zebrafish, plasma VTG production was measured to examine the in vivo estrogenic activity of the three compounds after a 14-d exposure. Adult zebrafish were exposed to different concentrations of o-, m- and p-DCB, ranging from 0.1 to 32 mg/L; ethynylestradiol ([EE2]; 5 ng/L, 10 ng/L, 50 ng/L, and 100 ng/L) was used as a positive control. After exposure, blood samples were taken and protein electrophoresis was performed to determine the relative VTG content. Gonadosomatic indices (GSI) and condition factors (CF) were also calculated. Elevated VTG levels and decreased female GSIs were found in fish exposed to ≥5 ng EE2/L and in fish exposed to ≥10 mg p-DCB/L. Low GSIs coincided with high levels of VTG in the blood of female zebrafish. This relation was not only found in fish exposed to EE2 but also in controls and fish exposed to DCB. Therefore, a direct or indirect effect of VTG on the GSI is suggested rather than a direct toxic effect of the tested compounds on the gonads.
Laboratory and field validation of multiple molecular biomarkers of contaminant exposure in rainbow trout (Oncorhynchus mykiss)
Authors: McClain J. Scott , Oris James T. , Burton G. Allen , Lattier David 
Published: March 2010

AbstractNovel primers for three different genes (CYP1A1, vitellogenin, and metallothionein) for use in reverse transcriptionpolymerase chain reaction (RT-PCR) were developed and tested in laboratory flow-through experiments using model compounds benzo[a]pyrene, estradiol, and cadmium. Field validations of the molecular biomarkers were performed using 8-d or 48-h in situ, caged exposure of juvenile rainbow trout (Oncorhynchus mykiss). Expression levels of gene transcription (messenger RNA [mRNA]) were monitored in gill and liver tissue after exposure at sites downstream of a known source of creosote contamination in the Little Scioto River (Marion, OH, USA) and metals and hydrocarbon contamination in Dick's Creek (Middletown, OH, USA). Significant increases of liver cytochrome P4501A1 gene (CYP1A1) and vitellogenin were measured in both streams at sites downstream of contaminant sources. Significant increases of gill CYP1A1 were also observed. Significant increases of gill and liver metallothionein occurred in Dick's Creek. A sample of gill tissue taken from each fish prior to placement in the Little Scioto River provided a preexposure control measurement for each individual. Expression of CYP1A1 and vitellogenin in trout at both streams indicated that exposure to bioavailable hydrocarbons and endocrine-disrupting compounds had taken place. Previous to this study, estrogenic compounds had not been detected in the Little Scioto River. Metallothionein expression confirmed the presence of metals in Dick's Creek. These results suggest a mixed contaminant environment that poses physiological hazard to existing teleost populations. Multiple molecular biomarkers provided a sensitive, physiologically based method of determining contaminant presence and bioavailability to aquatic organisms.
Associations between regional differences in polychlorinated biphenyls and dichlorodiphenyldichloroethylene in blood of nestling bald eagles and reproductive productivity
Authors: Bowerman William W. , Best David A. , Giesy John P. , Shieldcastle Mark C. , Meyer Michael W. , Postupalsky Sergej , Sikarskie James G. 
Published: March 2010

Abstract
The relationship between regional reproduction rates of bald eagles (Haliaeetus leucocephalus) and concentrations of p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE) and total polychlorinated biphenyls (PCBs) in blood plasma from nestling bald eagles was assessed. Blood was analyzed from 309 nestlings from 10 subpopulations of eagles across the Great Lakes region. Geometric mean concentrations of p,p′-DDE and total PCBs were inversely correlated to the productivity and success rates of nesting bald eagles within nine subpopulations. Nestlings eight weeks of age and older had significantly greater geometric mean concentrations of total PCBs and p,p′-DDE than nestlings less than eight weeks of age. The ability to use measurements of p,p′-DDE and total PCBs in nestling blood to determine the potential impact of these contaminants on adult nesting on a regional scale was demonstrated.
Environmental polychlorinated biphenyl exposure and cytochromes P450 in raccoons (Procyon lotor)
Authors: Smith Philip N. , Bandiera Stelvio M. , Skipper Sherry L. , Johnson Kevin A. , McMurry Scott T. 
Published: March 2010

AbstractAn investigation involving raccoons as a sentinel species at the Paducah Gaseous Diffusion Plant (PGDP) and Ballard Wildlife Management Area in western Kentucky (USA) delineated the extent of exposure to polychlorinated biphenyls (PCBs). Three separate measures of hepatic cytochrome P450 (CYP) induction were used to evaluate raccoon physiological responses to PCB exposure. Hepatic CYP induction was estimated via determination of total CYP, dealkylase activities, and immunoreactive proteins. There were no differences in raccoon biomarker responses between study sites. Significant relationships between and among PCB residues and biomarkers indicated that hepatic CYP induction had occurred in response to PCB exposure. Pentoxy-resorufin O-deethylase (PROD) activity, CYP1A1, and CYP1A2 were biomarkers most closely associated with PCB exposure. The rank order of responses was CYP1A1 &gt; CYP1A2 &gt; PROD &gt; ethoxyresorufin O-deethylase (EROD) as related to raccoon liver PCB concentrations, whereas the order was CYP1A1 &gt; PROD &gt; EROD &gt; CYP1A2 when regressed with total PCB concentrations in abdominal fat.
Toxicokinetics of sediment-sorbed benzo[a]pyrene and hexachlorobiphenyl using the freshwater invertebratesHyalella azteca, Chironomus tentans, andLumbriculus variegatus
Authors: Schuler Lance J. , Wheeler Matthew , Bailer A. John , Lydy Michael J. 
Published: March 2010

AbstractThis study investigated the effect of long-term sediment aging on the toxicokinetics of benzo[a]pyrene (BaP) and hexachlorobiphenyl (HCBP) using three freshwater benthic invertebrates. Hyalella azteca, Chironomus tentans, and Lumbriculus variegatus were exposed to BaP- and HCBP-spiked sediments that were aged for 7 d or 1.5 years. The toxicokinetics of the two compounds were determined for each test organism using a two-compartment model. The modeling of BaP was more complex because biotransformation was included within the model. The results of this study showed that the HCBP uptake clearance rates (ks) for each species were generally an order of magnitude greater than those determined for BaP and this difference was most likely due to preferential and rapid binding of BaP to sediment particles. Overall, the bioavailability of HCBP in spiked sediments tended to decrease with duration of aging, based on ks values and bioaccumulation factors (BAFs). However, the decreases in bioavailability appear to be species specific. Benzo[a]pyrene did not decline in bioavailability for the species tested because it may resist movement into the micropores of the sediment due to its large size. In addition to the bioassays, this article outlines a method for toxicokinetic modeling of biotransformed compounds and methods for statistical comparisons of kinetic parameters (i.e., ks, kd …) and BAF values.
Contamination of fish in streams of the Mid-Atlantic Region: An approach to regional indicator selection and wildlife assessment
Authors: Lazorchak James M. , McCormick Frank H. , Henry Tala R. , Herlihy Alan T. 
Published: March 2010

Abstract
The extent of contamination of fish in the Mid-Atlantic Region was evaluated as part of the U.S. Environmental Protection Agency's Monitoring and Assessment Program's regional assessment in 1993 through 1994. Fish assemblages from wadeable streams were dominated by small, short-lived fishes (e.g., minnows, darters, and sculpins) that were more widely distributed and abundant than large fishes typically chosen for tissue contaminant studies (e.g., trout, black bass, sunfish, common carp). Chemical concentrations in whole-fish homogenates exceeded detection limits for mercury, DDT, and polychlorinated biphenyls (PCBs) in 75 to 100% of the stream length assessed using small fishes and 84 to 100% of the stream length assessed using large fishes. Wildlife values (WVs) representing a threshold for toxic effect were developed to allow examination of the spatial extent of potential risk to piscivorous wildlife. For mercury, DDT, dieldrin, and chlordane, estimates of the regional extent of streams where fish contaminant concentrations exceeded the WVs were greater when based on small fishes than on large fishes. However, within the distribution of stream lengths assessed using small and large fishes, the percentage of stream kilometers exceeding the WVs were quite similar. Our data demonstrate that the greater abundance and distribution of small, short-lived fishes provide greater estimates of regional extent of contamination for first- through third-order streams and can be used for regional assessments of potential exposure and effects in wildlife.
Developmental toxicity of in ovo exposure to polychlorinated biphenyls: I. Immediate and subsequent effects on first-generation nestling American kestrels (Falco sparverius)
Authors: Fernie Kim , Smits Judit , Bortolotti Gary 
Published: March 2010

AbstractWe determined that in ovo exposure to polychlorinated biphenyls (PCBs) alters growth off first-generation nestlings during and one year after parental exposure. Captive American kestrels (Falco sparverius) laid eggs with environmentally relevant total PCB levels (34.1 μg/g whole-egg wet wt) when fed PCB-spiked (Aroclor® 1248, 1254, and 1260) food (7 mg/kg body wt/d) for 100 d in 1998. In 1999, the same adults laid eggs with estimated total PCBs of 29.0 μg/g. Nonsurviving PCB-exposed chicks were small (mass, bones) in 1998. Survivors showed a strong sex-specific growth response (mass, bones) compared to respective sex controls: Only female hatchlings were larger, and only male nestlings had longer feathers (1998); maximal growth and bone growth rates also differed (males were advanced, faster; females delayed, slower) (1999); and male nestlings fledged earlier and were smaller, while females were larger (1998, 1999). However, regardless of sex, PCB-exposed nestlings generally grew at faster rates in both years. In 1998, greater contaminant burdens and toxic equivalent concentrations in sibling eggs were associated with nestlings being lighter, having longer bones and feathers, and growing at faster rates (mass, bone) for females but slower rates (mass) for males. Both physiological-biochemical and behavioral changes are likely mechanisms. This study supports and expands on the Great Lakes embryo mortality, edema, and deformities syndrome: While PCB exposure alters nestling size, maximal growth and growth rates also change immediately, are sustained, and are sex specific.