bluuebunny/crossref_metadata_2025 huggingface dataset:
Dose–response and time course relationships for vitellogenin induction in male western fence lizards (Sceloporus occidentalis) exposed to ethinylestradiol
Authors: Brasfield Sandra M. , Weber Lynn P. , Talent Larry G. , Janz David M.
Published: March 2010

The long-term goal of this research is to develop and validate an in vivo reptile model for endocrine-mediated toxicity using fence lizards (Sceloporus spp.). One of the best defined estrogenic responses in oviparous vertebrates is induction of the yolk precursor protein, vitellogenin (Vtg). In this study, dose–response and time course relationships for Vtg induction were determined in male western fence lizards (Sceloporus occidentalis) given intraperitoneal injections of 17α-ethinylestradiol (EE2). Plasma Vtg was quantified directly with an antibody-capture enzyme-linked immunosorbent assay (ELISA) and indirectly using plasma alkalinelabile phosphate (ALP) in order to compare these two methods. Both ELISA and ALP predicted similar median effective dose (ED50 [dose causing a 50% maximal response]) values for plasma Vtg induction (0.167 mg/kg for ELISA and 0.095 mg/kg for ALP). In addition, both ELISA and ALP detected significant Vtg induction at a dose of 0.0003 mg/kg of EE2, which was the lowest dose used in our study. A decrease in body weight at the highest dose (10 mg/kg) and an increase in hepatosomatic index at the four highest doses were observed. Serial dilutions of plasma from an EE2-exposed male revealed a high correlation between plasma Vtg and ALP determinations in this species. In conclusion, our data show that plasma ALP may be a suitable alternative for measuring plasma Vtg compared with developing a Vtg ELISA in fence lizards exposed to estrogenic compounds.
Accumulation of tributyltin in the blood of fish: Its application for monitoring in the marine environment
Authors: Shim Won Joon , Jeon Joong Kyun , Oh Jae Ryoung , Kim Nam Sook , Lee Soo Hyung
Published: March 2010

Accumulation of tributyltin (TBT) in serum, liver, muscle, and gill of olive flounder (Paralichthys olivaceus) was examined in a 30-d static-renewal exposure. Tributyltin accumulated rapidly in the serum of the olive flounder and to a greater extent than in the other tissues. The accumulated TBT concentrations in tissues were in the order of serum > gill > liver > muscle on a dry-weight basis. Tributyltin also was detected in the serum of feral fine-spotted flounder, Pleuronichthys cornutus, collected from the coastal area. The mean TBT concentration in serum (2,470 ng Sn/g) of the fine-spotted flounder was about 40 times higher than that in the liver (60 ng Sn/g) and 200 times higher than that in the muscle (27 ng Sn/g) on a dry-weight basis. The TBT concentrations in serum and sediment demonstrated a positive correlation. The percent TBT composition to total butyltin was much higher in the serum (71%) than in the other tissues and sediment (<47%). These results suggest that the analysis of fish blood serum could be a useful tool for monitoring exposure to TBT in the marine environment.
Acute toxicity and cholinesterase inhibition in larval and early juvenile walleye exposed to chlorpyrifos
Authors: Phillips Todd A. , Wu Jigang , Summerfelt Robert C. , Atchison Gary J.
Published: March 2010

Application of organophosphorus (OP) insecticides to agricultural fields during the spring often overlaps the period of spawning, egg incubation, and larval stages of fish species such as walleye (Stizostedion vitreum). Because life stage can affect uptake, distribution, and effects of contaminants, our objective was to identify the most sensitive life stage of walleye to chlorpyrifos, a broad-spectrum OP insecticide. Prolarvae (yolk sac, endogenous feeding stage) were least sensitive to chlorpyrifos (median lethal concentration [LC50] = 225–316 μg/L), and postlarvae I (oil globule, exogenous feeding stage) were less sensitive (LC50 = 24–29 μg/L) than postlarvae II (oil globule absent; LC50 = 12–13 μg/L). The differences in sensitivity of the larval stages coincide with stages of gill development. Gill filaments were absent until the end of the prolarval stage, and development of secondary lamellae did not occur until the end of the postlarval I stage. Juvenile fish were less sensitive than postlarval stages, but did not differ significantly among the juvenile ages tested. The LC50s ranged from 37 to 45 μg/L for 30- and 90-d-old juvenile walleye, respectively. Larval walleye survived when cholinesterase (ChE) activity was inhibited by as much as 90%; however, 60- and 90-d-old juvenile walleye did not survive when ChE activity was inhibited more than 71%.
Ecological impact and environmental fate of perfluorooctane sulfonate on the zooplankton community in indoor microcosms
Authors: Sanderson Hans , Boudreau Timothy M. , Mabury Scott A. , Cheong Woo-Jay , Solomon Keith R.
Published: March 2010

There is presently a substantial amount of information being gathered concerning the environmental risk associated with the perfluorooctane sulfonate (PFOS) compound. The U.S. Environmental Protection Agency (U.S. EPA) is requiring that more research be completed before making definitive decisions concerning the regulatory issues covered in the significant new use rule (18/10–2000) under the Toxic Substance Control Act. However, there are no risk assessment requirements under seminatural conditions in microcosms. The PFOS can enter, and has been found in, the aquatic environment through different pathways, including spills associated with use of fire-fighting foams containing PFOS, leaching from washing Scotchgard™-treated clothes with the wastewater, leaching from various coatings, discharges as residual waste from fluorochemical production, or volatilization and transportation atmospherically. The biota is the sink of PFOS rather than the sediment or soil. The aim of this article is to determine a 35-d community no-observable-effect concentration (NOECcommunity) for freshwater zooplankton and the fate of PFOS during the course of study. The PFOS persisted in the water phase with only slight reductions over the study; only the decrease from 33.9 mg/L at day 1 to 29.8 mg/L at day 35 was significant. A 90 to 100% reduction (p < 0.01) of the total zooplankton population was found after one week of exposure to 30 mg PFOS/L and a similar reduction after two weeks at 10 mg PFOS/L. The Daphnia magna 21-d NOECsurvival of 12 mg/L has previously been found in a standard laboratory bioassay by 3M. The rank order of susceptibility for the test community was Copepoda > Cladocera > Rotifera, assuming all adverse direct effects.
Estimating the probability of bird mortality from pesticide sprays on the basis of the field study record
Authors: Mineau Pierre
Published: March 2010

The outcome of avian field studies was examined to model the likelihood of mortality. The data were divided into clusters reflecting the type of pesticide application and bird guilds present on site. Logistic regression was used to model the probability of a bird kill. Four independent variables were tested for their explanatory power: a variable reflecting acute oral toxicity and application rate; a variable reflecting the relative oral to dermal toxicity of the pesticides; Henry's law constant; and a variable reflecting possible avoidance of contaminated food items, the hazard factor (HF). All variables except for HF significantly improved model prediction. The relative dermal to oral toxicity, especially, was shown to have a major influence on field outcome and clearly must be incorporated into future avian risk assessments. The probability of avian mortality could be calculated from a number of current pesticide applications and the conclusion was made that avian mortality occurs regularly and frequently in agricultural fields.
Predicting the occurrence of genetic adaptation to dioxinlike compounds in populations of the estuarine fishFundulus heteroclitus
Authors: Nacci Diane E. , Champlin Denise , Coiro Laura , McKinney Rick , Jayaraman Saro
Published: March 2010

A population of the nonmigratory estuarine fish species Fundulus heteroclitus (mummichog) indigenous to a polychlorinated biphenyl (PCB)-contaminated Superfund site (New Bedford Harbor, MA, USA) demonstrated an inherited tolerance to local, dioxinlike contaminants (DLCs). These findings suggest that DLCs have acted as selective agents, allowing the survival of only the most tolerant individuals, forming DLC-adapted populations. We hypothesized that DLC-tolerant mummichog populations would reside where local conditions are toxic to sensitive individuals, and that toxic environmental conditions could be predicted based on responses of sensitive early life stages to laboratory exposures of DLCs. As a measure of DLC tolerance, progeny of field-collected fish were tested in the laboratory with a dioxinlike PCB congener, 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126). Mummichog populations were collected from sites with sediment PCB concentrations predicted to range from nontoxic to toxic. Consistent with predictions, tolerant populations were indigenous to sites with elevated sediment PCB concentrations. Also, as predicted, DLC-tolerant populations were resident to sites far less contaminated than the Superfund site. These results suggest that exposures to persistent, bioaccumulative, and toxic contaminants may produce evolutionary effects on a geographic scale larger than previously envisioned. This study presents an approach and describes a model system that may improve understanding of the scale of occurrence for these potentially irreversible ecological effects.
Comparison of pesticide root zone model 3.12: Runoff predictions with field data
Authors: Singh Piyush , Jones Russell L.
Published: March 2010

As part of a process to improve confidence in the results of regulatory modeling, predictions of pesticide root zone model (PRZM) 3.12 were compared with measured data collected in nine different runoff field studies. This comparison shows that PRZM 3.12 provides a reasonable estimate of chemical runoff at the edge of a field. Simulations based on the best choices for input parameters (no conservatism built into input parameters) are generally within an order of magnitude of measured data, with better agreement observed both for larger events and for cumulative values over the study period. When the model input parameters are calibrated to improve the hydrology, the fit between predicted and observed data improves (results are usually within a factor of three). When conservatism is deliberately introduced into the input pesticide parameters, substantial overprediction of runoff losses occur. Recommendations for future work to improve regulatory models include implementation of more sophisticated evapotranspiration routines, allowing for seasonal variation of various model parameters (such as curve numbers, crop cover, and Manning's surface roughness coefficients), better procedures for estimating site-specific degradation rates in surface and subsoils, and improved sorption routines.
Sensitivity analysis for validating expert opinion as to ideal data set criteria for transport modeling
Authors: Wolt Jeff , Singh Piyush , Cryer Steven , Lin Jim
Published: March 2010

Environmental fate modeling results are often used in risk assessment without adequately considering uncertainty in exposure predictions. Sensitivity analysis is fundamental to model validation and error prediction since sensitive model input parameters account for the largest variance in model prediction. Once identified, sensitive model input parameters can be used to propagate parametric uncertainty in numerical predictions. Output sensitivity to variation in input code sequences was investigated for the pesticide root zone model (PRZM 3) using Plackett-Burman analysis for six runoff and leaching data sets. The analysis utilized an incomplete block factorial design with even parameter weighting and uniform proportional input perturbation. Timing and duration of key period rainfall were assumed a priori to be dominant sensitive inputs. Thus, meteorological data were fixed, allowing identification of additional input components contributing to model sensitivity. Results validated expert modeler assumptions concerning parameters most critical for model validation. For leaching data sets, the application rate, soil bulk density (an indicator of available water-holding capacity), chemical partition coefficient, and pesticide degradation rates were commonly the most sensitive inputs. For runoff data sets, the in-crop runoff curve number was the most significant input governing pesticide loss in runoff and erosion flux. The chemical partition coefficient, soil and foliar decay rates, and soil bulk density were also common sensitive components for runoff predictions. These commonly observed sensitive components for runoff and leaching prediction need to be carefully considered in the design and conduct of relevant field studies, modeling assessment of such studies, and future improvements in algorithms for environmental transport modeling.
Using Monte Carlo techniques to judge model prediction accuracy: Validation of the pesticide root zone model 3.12
Authors: Warren-Hicks William , Carbone John P. , Havens Patrick L.
Published: March 2010

Individuals from the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Environmental Model Validation Task Force (FEMVTF) Statistics Committee periodically met to discuss the mechanism for conducting an uncertainty analysis of Version 3.12 of the pesticide root zone model (PRZM 3.12) and to identify those model input parameters that most contribute to model prediction error. This activity was part of a larger project evaluating PRZM 3.12. The goal of the uncertainty analysis was to compare site-specific model predictions and field measurements using the variability in each as a basis of comparison. Monte Carlo analysis was used as an integral tool for judging the model's ability to predict accurately. The model was judged on how well it predicts measured values, taking into account the uncertainty in the model predictions. Monte Carlo analysis provides the tool for inferring model prediction uncertainty. We argue that this is a fairer test of the model than a simple one-to-one comparison between predictions and measurements. Because models are known to be imperfect predictors prior to running the model, the inaccuracy in model predictions should be considered when models are judged for their predictive ability. Otherwise, complex models can easily fail a validation test. Few complex models, such as PRZM 3.12, would pass a typical model validation exercise. This paper describes the approaches to the validation of PRZM 3.12 used by the committee and discusses issues in sampling distribution selection and appropriate statistics for interpreting the model validation results.
Distribution of polycyclic aromatic hydrocarbons in soils and terrestrial biota after a spill of crude oil in Trecate, Italy
Authors: Brandt Charles A. , Becker James M. , Porta Augusto
Published: March 2010

Ecological and human health exposures from soil-based petroleum-derived contaminants commonly are estimated by using soil-to-biota transfer factors that usually are based on octanol-water partitioning. Few studies of biota have been conducted in relation to spills of crude oils in terrestrial environments. After a large blowout of crude oil in northern Italy in 1994, the distribution of polycyclic aromatic hydrocarbons (PAHs) was examined over time and space in soils, uncultivated wild vegetation, insects, mice, and frogs in the area. Within two years of the blowout, PAH concentrations declined to background levels over much of the area where initial concentrations were within an order of magnitude above background, but had not declined to background in areas where starting concentrations exceeded background by two orders of magnitude. Octanol-water partitioning and extent of alkylation explained much of the variance in uptake of PAHs by plants and animals. The PAHs with lower octanol-water partition coefficients (KOWs) and higher-alkylated PAHs had higher biota-soil accumulation factors (BSAFs) than did high-KOW and unalkylated forms. The BSAFs for PAHs with higher KOWs were very low for plants, but much higher for animals, with frogs accumulating more of these compounds than other species.
Soil microbial toxicity of eight polycyclic aromatic compounds: Effects on nitrification, the genetic diversity of bacteria, and the total number of protozoans
Authors: Sverdrup Line Emilie , Ekelund Flemming , Krogh Paul Henning , Nielsen Torben , Johnsen Kaare
Published: March 2010

Eight polycyclic aromatic compounds (PACs) were tested for their toxic effect on the soil nitrification process, bacterial genetic diversity, and the total number of protozoans (naked amoebae and heterotrophic flagellates). After four weeks of exposure in a well-characterized agricultural soil, toxic effects were evaluated by comparison to uncontaminated control soils. All PACs affected the nitrification process, and the calculated no-observed-effect concentrations (NOECs) for nitrification were 79 mg/kg for pyrene, 24 mg/kg for fluoranthene, 26 mg/kg for phenanthrene, 72 mg/kg for fluorene, 23 mg/kg for carbazole, 22 mg/kg for dibenzothiophene, 75 mg/kg for dibenzofuran, and 1,100 mg/kg for acridine. For all substances but acridine, nitrification was the most sensitive of the three toxicity indicators evaluated. No effect of the tested substances on bacterial diversity was found, as measured by denaturant gradient gel electrophoresis. In general, only weak effects at very high concentrations were found for the protozoans. However, for acridine, protozoan numbers were reduced at lower concentrations than those that affected the nitrification process, that is, with a 5% reduction at 380 mg/kg. For effects on nitrification, toxicity (NOEC values) expressed as soil pore-water concentrations (log10(μmol/L)) showed a significant inverse relationship with lipophilicity (log octanol-water partition coefficient) of the substances (r2 = 0.69, p = 0.011, n = 8). This finding could indicate that the toxicity of substances similar to those tested might be predicted by a quantitative structure-activity relationship with lipophilicity as the predictor variable.
Effects of earthworm (Eisenia fetida) and wheat (Triticum aestivum) straw additions on selected properties of petroleum-contaminated soils
Authors: Callaham Mac A. , Stewart Arthur J. , Alarcón Clara , McMillen Sara J.
Published: March 2010

Current bioremediation techniques for petroleum-contaminated soils are designed to remove contaminants as quickly and efficiently as possible, but not necessarily with postremediation soil biological quality as a primary objective. To test a simple postbioremediation technique, we added earthworms (Eisenia fetida) or wheat (Triticum aestivum) straw to petroleum land-farm soil and measured biological quality of the soil as responses in plant growth, soil respiration, and oil and grease (O&G) and total petroleum hydrocarbon (TPH) concentrations. Results indicated that plant growth was greater in earthworm-treated land-farm soil. Furthermore, addition of wheat straw resulted in greater total respiration in all soils tested (land-farm soil, noncontaminated reference soil, and a 1:1 mixture of land-farm and reference soils). We observed a 30% increase in soil respiration in straw-amended oily soil, whereas respiration increased by 246% in straw-amended reference soil. Much of the difference between oily and reference soils was attributable to higher basal respiration rates of nonamended oily soil compared to nonamended reference soil. Addition of earthworms resulted in greater total respiration of all soil and straw treatments except two (the land-farm and the 1:1 mixture soil treatments without straw). Straw and earthworm treatments did not affect O&G or TPH concentrations. Nevertheless, our findings that earthworm additions improved plant growth and that straw additions enhanced microbial activity in land-farm soil suggest that these treatments may be compatible with plant-based remediation techniques currently under evaluation in field trials, and could reduce the time required to restore soil ecosystem function.
Toxicity of methyl tert-butyl ether to plants (Avena sativa, Zea mays, Triticum aestivum, and Lactuca sativa)
Authors: An Youn-Joo , Kampbell Donald H. , McGill Mary E.
Published: March 2010

Influence of methyl tert-butyl ether (MTBE) on the germination of seeds and growth of seedling plants were studied in laboratory experiments. Test plants were wild oats (Avena sativa), sweet corn (Zea mays), wheat (Triticum aestivum), and lettuce (Lactuca sativa). Seed germination, shoot growth, and root growth of plants exposed to different concentrations of MTBE in a moist soil were examined. Seed germination and seedling growth in MTBE-contaminated soil were markedly reduced in all test plants. The median lethal concentration values for seed germination tests and the median effective concentration values for shoot or root growth were calculated. The values for lettuce, wild oats, wheat, and sweet corn were in the range of 18 to 91, 362 to 459, 432 to 751, and 672 to 964 mg MTBE/kg soil as dry weight, respectively. Lettuce was most sensitive to MTBE, followed (in order of decreasing sensitivity) by wild oats, wheat, and sweet corn. Because MTBE can be readily absorbed by plants due to its high solubility in water, plant growth was a more sensitive endpoint than seed germination. Shoot length was more reduced in MTBE-contaminated soil than was the root length, which indicated that MTBE might be transported within the plant from the roots to the shoots.
The further development of ionoregulatory measures as biomarkers of sensitivity and effect in fish species
Authors: Croke S. J. , McDonald D. G.
Published: March 2010

Extensive season-by-season sampling was used to establish the normal range of whole-body Na+ and Cl− and Na+ uptake in healthy populations of two fish species, rainbow trout, Oncorhynchus mykiss, and fathead minnow, Pimephales promelas, of known differences in sensitivity to ionoregulatory toxicants (low pH, trace metals). These data together with responses of both species to six different ionoregulatory challenge tests of increasing severity (mild handling, exposure to low Ca2+ water, epinephrine injection, net-confinement stress, exposure to copper, and osmotic shock) were evaluated for their potential as biomarkers of sensitivity and of effect of ionoregulatory toxicants. There were no obvious biomarkers of sensitivity in the ion measures themselves, but four of the six challenges (exposure to low Ca2+ water, epinephrine injection, exposure to copper, and osmotic shock) produced a significantly greater effect in the more sensitive of the two species, fathead minnow. Based on the responses of both species, this article makes a number of recommendations for the application of ion measures alone and in combination with challenge tests to the assessment of chronic effects in populations experiencing sublethal ionoregulatory stress.
Effect of ethinylestradiol on the reproduction and induction of vitellogenin and testis-ova in medaka (Oryzias latipes)
Authors: Seki Masanori , Yokota Hirofumi , Matsubara Haruki , Tsuruda Yukinari , Maeda Masanobu , Tadokoro Hiroshi , Kobayashi Kunio
Published: March 2010

Mature medaka (Oryzias latipes) were exposed to ethinylestradiol (EE2) at measured concentrations of 32.6, 63.9, 116, 261, and 488 ng/L for 21 d under flow-through conditions. Effects on reproductive success of the fish as well as on gonadal condition and vitellogenin (VTG) induction were assessed. A significant decrease in fecundity was observed only at the highest EE2 concentration, whereas hepatic VTG concentration in males was increased at concentrations of 63.9 ng/L and greater. In addition, an intersex condition (testis-ova) of the gonad was observed in male medaka exposed to EE2 concentrations of ≥63.9 ng/L. Overall, these results indicate that the lowest-observed-effect concentrations of EE2 based on reproduction versus induction of both VTG and testis-ova in the medaka were 488 and 63.9 ng/L, respectively. Thus, the physiological and histological measurements were approximately eightfold more responsive to the EE2 exposure than were overt reproductive effects. This suggests that the elevated VTG levels and testis-ova may not be definitely responsible for reproductive impairment of the fish.
Sequence analysis of choriogenin H gene of medaka (Oryzias latipes) and mRNA expression
Authors: Lee Chulwoo , Jeon Seong Hwan , Na Jin Gyun , Park Kwangsik
Published: March 2010

Zona radiata proteins of medaka (Oryzias latipes) consist of two major subunit groups, ZI-1,2 and ZI-3. The precursor of ZI-1,2, which is a glycoprotein with a molecular weight of 74,000 to 76,000 Da, is called choriogenin H, and the precursor of ZI-3, with a molecular weight of 49,000 Da, is called choriogenin L. The precursor proteins are synthesized in the liver in response to estrogen in sexually mature female medaka. However, they are also induced in the male medaka when fish are exposed to estrogenic chemicals. Therefore, choriogenin is known as a possible sensitive biomarker for endocrine disruption in fish. In this study, the choriogenin H cDNA sequence was reanalyzed and the genomic DNA sequence was newly analyzed. This was done for the selection of proper reverse transcription-polymerase chain reaction (RT-PCR) primers to measure the choriogenin mRNA induction by estrogenic chemicals. In the results, the full cDNA sequence was found to be 2,109 bp long and the size of the open reading frame (ORF) was found to be a total of 1,998 bp encoding 666 predicted amino acids, which was found to be different from previously reported cDNA sequence of medaka choriogenin. In the choriogenin H cDNA, a repetitive domain and a nonrepetitive domain were shown. Regarding the repetitive domain, seven complete repeats of the 45 bp of 5′-ccc cag tac cca tca aag cct cag ccc cct cag aat cct cag gtc-3′ encoding PQYPSKPQPPQNPQV were found. Medaka choriogenin H gene was found to possess seven exons and six introns, and the total length was 2,643 bp long. The seven repetitive nucleotide residues described above existed in exon 1, which was found to be 1,033 bp long. Based on the full sequence information, proper primers were synthesized for RT-PCR to detect choriogenin H mRNA induction in male and juvenile medaka by 17α-ethinylestradiol, and this type of measurement system was found to be effective as a simple tool for the screening of endocrine-disrupting chemicals.
Polychlorinated biphenyl toxicokinetics and P4501A responses in anadromous Arctic charr during winter emaciation
Authors: Jørgensen Even H. , Foshaug Hanne , Andersson Patrik , Burkow Ivan C , Jobling Malcolm
Published: March 2010

Polychlorinated biphenyl (PCB) toxicokinetics andhepaticP450 (CYP) 1A activities werestudied in wild anadromous Arctic charr (Salvelinus alpinus) during winter emaciation. The fish were captured as they returned from summer feeding in seawater and were held without food over winter. In September the fish were given a single, oral dose of either 0 (control), 0.1, 1, or 50 μg PCB/g fish. During winter a net loss of PCB occurred from the carcass (including gut), whereas net inputs and increases in concentrations of PCB in the liver and brain occurred with increases in brain PCB concentrations being up to 10-fold. Hepatic CYP1A activities were positively correlated with the PCB dose in October. In the fish given 1 mg PCB/kg fish in September, however, a 12-fold increase in CYP1A activity occurred from October to May. This increase in CYP1A activity was observed during a period in which the body burden of PCB decreased by 20%. These results demonstrate that interpretations of the CYP1A biomarker response must be made with caution. Overall, the findings point to potentiated risks of biological effects of PCB during periods of emaciation.
Aerobic biodegradation of aliphatic polyethoxylates: An 1H-nuclear magnetic resonance spectroscopy investigation
Authors: De Lazzari Alessandra , Pojana Giulio , Giacometti Andrea , Lucchini Vittorio , Marcomini Antonio
Published: March 2010

Aerobic biodegradation tests of three blends representative of the most commonly marketed aliphatic alcohol polyethoxylates (AE) and a commercial polyethylene glycols (PEG) mixture were run under standard test conditions (Organization for Economic Cooperation and Development, Paris, France [OECD] 301 E protocol). The test liquors were investigated using a 400-MHz proton-nuclear magnetic resonance (1H-NMR) spectrometer in order to elucidate the biodegradation mechanism. Diagnostic signals for both linear and branched AE homologs were identified by bidimensional homocorrelated spectroscopy (COSY) and by double quantum filter correlated spectroscopy (DQFCOSY). The 1H-NMR allowed individually monitoring the fate of the alkyl and polyethoxyl fragments of the parent compounds and distinguishing between oxidative and nonoxidative polyethoxyl depoly-merization, which could not be performed by other reported techniques such as high-peformance liquid chromatography (HPLC) or mass spectrometry (MS) or FAB spectroscopy. The AE biodegradation time profiles showed that under the test conditions, both alkyl and polyethoxyl chains of the linear and oxo-AE were biodegraded quite readily. The removal of the multibranched AE was slower when compared to that of linear and oxo-AE, while PEG exhibited a time profile characterized by a biodegradation rate significantly slower than that of PEG released by the microbial attack of linear and oxo-AE. In the case of linear AE, the alkyl chain was biodegraded much faster than the polyethoxyl chain, while in the case of oxo- and multibranched AE, both the alkyl and the polyethoxyl chains were biodegraded at similar rates.
Use of anodic stripping voltammetry in predicting toxicity of copper in river water
Authors: Wang Zijian , Huang Shengbiao , Liu Qing
Published: March 2010

The labile concentration and toxicity of Cu as influenced by alkalinity and different concentrations of ethylenediaminetetraacetic acid (EDTA) and naturally derived fulvic acid (FA) were determined by bioassays carried out in the culture media for Daphnia magna (D. magna). The labile concentration of Cu was obtained by differential pulse anodic stripping voltammetry with a double-acidification method (DAM-DPASV). Changes in water alkalinity did not affect the labile concentration of Cu, but increase in alkalinity did reduce the mortality of D. magna. In the presence of EDTA and FA, both labile concentration of Cu and mortality were reduced. By excluding Cu-carbonate complexes from the labile concentration, a bioavailable concentration of Cu ([Cu*]) was obtained and was used to predict the acute toxicity of Cu on D. magna. For natural waters, the labile concentration of Cu was measured by DAM-DPASV, and [Cu*] was calculated using MINTEQ A2 software (developed by the U.S. Environmental Protection Agency) based on the anion composition of waters. This procedure was tested for waters and sediment elutriates sampled from the Le An River (Jiangxi Province, China) that were severely polluted by the discharges from a copper mine. The results showed that [Cu*] was a good indicator for Cu toxicity and could be used under field conditions.
Vapor pressures, aqueous solubilities, and Henry's law constants of some brominated flame retardants
Authors: Tittlemier Sheryl A. , Halldorson Thor , Stern Gary A. , Tomy Gregg T.
Published: March 2010

The subcooled liquid vapor pressures (P°L,25s) and aqueous solubilities (Sw,25s) were determined and Henry's law constants (H25s) were estimated for a number of brominated flame retardants (BFRs) at 25°C. The established methods of the gas chromatography-retention time and generator column techniques were used to experimentally determine P 0L,25 and Sw,25 for hexabromobenzene and a series of brominated diphenyl ether (BDE) congeners. The H25 was estimated as the ratio of P 0L,25 to the subcooled liquid aqueous solubility. Values of P 0L,25 obtained ranged from 0.000000282 Pa (BDE-190) to 0.259 Pa (BDE-3); Sw,25 ranged from 0.00000087 g/L (BDE-153 and BDE-154) to 0.00013 g/L (BDE-15); and H25 ranged from 0.0074 Pa m3/mol (BDE-183) to 21 Pa m3/mol (BDE-15). An increase in the bromine content of polybrominated diphenyl ether congeners resulted in significant decreases of P 0L,25, Sw,25, and H25. A simple four-compartment equilibrium distribution model suggested that the majority of BFRs being released into the environment would reside in soil and sediment and have localized distributions. The model also suggested that lower brominated congeners tend to be somewhat more mobile. Degradative debromination reactions that yield these congeners would mobilize them environmentally, and ultimately affect the fate and distribution of BFRs.
Environmental cadmium induces histopathological changes in kidneys of roe deer
Authors: Beiglböck Christoph , Steineck Theodora , Tataruch Frieda , Ruf Thomas
Published: March 2010

Kidney samples of 224 roe deer (113 males, 111 females) aged three months to approximately nine years were collected in eastern Austria. Cadmium contents were examined and histological examinations were performed considering 11 different pathomorphological parameters. Cadmium burden was relatively high (range: 0.010-22.076 ppm) and increased with age. Females aged one to two years had higher contents than males of the same age. The culling site had no influence on cadmium load. The relation between the occurrence of histopathological changes and age, sex, origin, and cadmium concentration in 208 roe deer was tested. The frequency of vacuolic degeneration, pycnotic nuclei, caryolysis, and necrosis was related to increased cadmium levels. Increasing age correlated with lymphohistiocytic infiltration, interstitial fibrosis, and swelling of glomeruli. Pigment deposits and thickening of Bowman's capsule could be related to both cadmium and age. Furthermore, roe deer from an industrialized region showed alterations more frequently than animals from rural areas. We found no relation between morphological changes and sex. Though it remains to be established whether environmental cadmium exposure is the sole cause for the histopathological alterations observed, the results of this study indicate that chronic cadmium poisoning may be an important cofactor in the pathogenic mechanisms of renal damage in roe deer and that cadmium intoxication may be more widespread among wildlife than previously known.
Uptake and loss of chlorpyrifos and atrazine byJuncus effususL. in a mesocosm study with a mixture of pesticides
Authors: Lytle Julia S. , Lytle Thomas F.
Published: March 2010

Aquatic organisms in agricultural regions typically are exposed to mixtures of agrochemicals, and effects are not adequately predicted from results of single pesticide exposure studies. Thus, a mesocosm study was designed to examine the fate and effects of varying mixtures of three pesticides (chlorpyrifos, atrazine, and monosodium methanearsonate) and mercury-contaminated sediment to the common freshwater macrophyte Juncus effusus L. Exposure doses of pesticides added to mesocosms represented those that might be encountered in a typical runoff or direct spray application. This study reports the uptake and loss of chlorpyrifos and atrazine in the leaves of J. effusus after a single and a repeated dose of the chemical mixture over 94 d. The measured chlorpyrifos levels in leaves were highest on day 1, but levels in both leaves and water dropped rapidly and were at background levels by day 32. Atrazine remained near nominal concentrations in the water through day 16 and reached maximum accumulation in the leaves on day 16. The chemical mixture affected uptake of chlorpyrifos more strongly than atrazine as measured by differences in uptake variability. After the second dose, J. effusus showed a similar uptake pattern for both compounds, although somewhat faster, to that observed after the first dose, with no diminished capacity for uptake of either compound. The greater volatility of chlorpyrifos, the higher solubility of atrazine, and the more efficient transport of atrazine to the root zone are characteristics that are consistent with the differences observed in their uptake and loss behavior.
Biochemical effects of chlorpyrifos on two developmental stages ofXenopus laevis
Authors: Richards Sean M. , Kendall Ron J.
Published: March 2010

The effects of a 96-h static exposure to chlorpyrifos were examined in two developmental stages of larval Xenopus laevis (premetamorph and metamorph). Measures of effect included mortality, deformity, cholinesterase (ChE) activity, and DNA and protein concentration. All parameters indicated that metamorphs were more sensitive than were premetamorphs. For larvae exposed as premetamorphs, the median lethal concentration and median effective concentration were 14.6 mg/L and 1.71 mg/L; for those exposed as metamorphs, values were 0.56 mg/L and 0.24 mg/L, respectively. Cholinesterase activity was the most sensitive biochemical parameter. Exposure to chlorpyrifos at 0.01 mg/L caused significant decreases in the ChE activity of metamorphs; 0.1 mg/L significantly decreased premetamorph ChE activity. Metamorph DNA was significantly decreased at 0.1 mg/L; premetamorph DNA was not reduced until exposure to 1.0 mg/L. Whole-body protein was the least sensitive biochemical measure of effect. Premetamorphs did not experience a reduction in protein concentrations. Metamorph protein concentration was significantly decreased at 1.0 mg/L. Based on current surface water data, the most sensitive effect would not have a high probability (≤4.2%) of occurring in the environment.
Cadmium-induced production of a metallothioneinlike protein inTubifex tubifex(Oligochaeta) andChironomus riparius(Diptera): Correlation with reproduction and growth
Authors: Gillis Patricia L. , Diener Lara C , Reynoldson Trefor B. , Dixon D. George
Published: March 2010

Laboratory-cultured Chironomus riparius and Tubifex tubifex were exposed to sediments artificially enriched with a range of cadmium (Cd) concentrations. Both species accumulated Cd in a concentration-dependent manner. The concentration of a metallothioneinlike protein (MTLP), as measured by a mercury saturation assay, increased with increasing Cd exposure. After reaching a threshold of Cd exposure, the whole-body endpoints of reproductive output in T. tubifex and growth in C. riparius declined significantly. The threshold effect concentrations for T. tubifex and C. riparius were 2.68 and 0.134 μmol Cd/g dry sediment, respectively. Metallothioneinlike protein and Cd tissue concentrations were more sensitive indicators of exposure than the whole-body endpoints. For T. tubifex, the concentrations of MTLP and tissue Cd were significantly elevated above control levels after exposure to the 0.67 μmol Cd/g dry sediment treatment. In C. riparius, MTLP concentration and tissue Cd concentration were both significantly elevated above control levels after exposure to the 3.8 × 10−3 μmol Cd/g dry sediment treatment. Analysis of these data suggests that MTLP and tissue Cd concentrations are sensitive subcellular endpoints, which can be used to predict exposure to and the effects of metals at the individual or population level.
Transplanted zebra mussels (Dreissena polymorpha) as active biomonitors in an effluent-dominated river
Authors: Smolders Roel , Bervoets Lieven , Blust Ronny
Published: March 2010

For over 20 years, mussels have been recommended as one of the most suitable biomonitoring organisms for aquatic ecosystems. Though the common mussel (Mytilus edulis) is frequently used for biomonitoring estuarine and marine ecosystems, no freshwater species is promoted for similar monitoring networks. Recently, however, the zebra mussel (Dreissena polymorpha) has been proposed as a suitable monitoring organism in freshwater ecosystems. The aim of this study was to explore the usefulness of transplanted zebra mussels as active biomonitors in an effluent-dominated stream. Results showed that for these purposes, an exposure period of at least a few weeks is required to detect any significant changes in condition status or scope for growth. Wet-tissue-weight:dry-tissue-weight ratio was the most sensitive measure to quantify effects of field exposure on physiological fitness. In case of scope for growth (SfG), energy intake was the factor determining the overall energy budget of the mussels. Based on the dilution rates of the two different effluents present, effluent 2 had the most important effect on the condition status of the exposed organisms. Overall, we conclude that the use of transplanted mussels is a sensitive and easily applicable active biomonitor that can be used to assess water quality, pollution, and subsequent recovery through self-purification in field situations.
Fish (Fundulus heteroclitus) populations with different exposure histories differ in tolerance of creosote-contaminated sediments
Authors: Ownby David R. , Newman Michael C. , Mulvey Margaret , Vogelbein Wolfgang K. , Unger Michael A. , Arzayus L. Felipe
Published: March 2010

Prior studies suggest that field-collected fish (Fundulus heteroclitus) from a creosote-contaminated Superfund site (Atlantic Wood Industries site, Elizabeth River, VA, USA) have enhanced tolerance to local, contaminated sediments. This study was designed to test whether other populations in the Elizabeth River at less contaminated sites also show similar tolerance and whether this tolerance is heritable. To test this, F. heteroclitus populations were sampled from four sites within the Elizabeth River with varying sediment polycyclic aromatic hydrocarbon (PAH) concentrations (3.9–264 ng PAH/g dry wt·103) and one reference site in a nearby, uncontaminated estuary (York River, VA, USA; 0.27 ng PAH/g dry wt·103). Embryo assays were performed to quantify population differences in teratogenic effects during contaminated sediment exposure. Atlantic Wood sediment was mixed with reference sediment to achieve a range of sediment concentrations. Minimal differences were observed in teratogenic effects among fish taken from sites within the Elizabeth River; however, embryos of fish collected from a nearby, uncontaminated York River site and exposed to contaminated sediments had a significantly higher proportion of embryos with cardiac abnormalities than those from the Elizabeth River sites. Embryos from wild-caught and laboratory-reared Elizabeth River F. heteroclitus were simultaneously exposed to contaminated sediments, and no significant tolerance differences were found between embryos from fish taken directly from the field and those reared for a generation in the lab. Differences between fish populations from the two estuaries were larger than differences within the Elizabeth River, and these differences in tolerance were heritable.
Acute and chronic toxicity of zinc to the mottled sculpin Cottus bairdi
Authors: Woodling John , Brinkman Stephen , Albeke Shannon
Published: March 2010

The acute and chronic toxicity of zinc to wild mottled sculpin (Cottus bairdi) was measured with 13-d and 30-d flow-through toxicity tests, respectively. Exposure water hardness was 48.6 mg/L as CaCO3 and 46.3 mg/L as CaCO3 in the acute and chronic tests, respectively; pH was slightly above neutral; and temperature near 12°C. The median lethal concentration (LC50) after 96 h was 156 μg Zn/L, but decreased with exposure duration to a median incipient lethal level (ILL50) of 38 μg Zn/L after 9 d, the lowest zinc LC50 reported for any fish species. The 30-d chronic no-effect and lowest-effect concentrations were 16 μg Zn/L (no mortality) and 27 μg Zn/L (32% mortality), respectively. The ILL50 was 32 μg Zn/L. No sublethal growth differences were observed during the chronic test. Analysis of the results from these tests suggested that mottled sculpin may experience acute and chronic toxicity at zinc concentrations lower than any other fish species tested to date. Protection of aquatic communities in stream reaches contaminated by metals seem to require determination of zinc toxicity to lotic species other than trout and other species amenable to aquaculture.
Relative sensitivity of three terrestrial invertebrate tests to polycyclic aromatic compounds
Authors: Sverdrup Line E. , Krogh Paul Henning , Nielsen Torben , Stenersen Jørgen
Published: March 2010

In a project investigating the ecotoxicity of polycyclic aromatic compounds (PACs), we have previously reported on the sublethal toxicity of eight PACs to springtails (Folsomia fimetaria) and enchytraeids (Enchytraeus crypticus). The model substances included four polycyclic aromatic hydrocarbons (PAHs) and four N-S-O-heterocyclics. Here, new data are presented on the effects of PACs on the survival and growth of the earthworm Eisenia veneta, showing that, in general, earthworm growth was reduced at PAC concentrations above 25 mg/kg soil dry weight. The E. veneta tests were performed using the same soil type and very similar test conditions as for the F. fimetaria and E. crypticus tests, thus providing a good opportunity to compare the sensitivity of these three organisms. Species sensitivity was examined using the 50% reduction in survival (LC50 values) and no-observable-effect concentrations (NOEC values) for growth or reproduction as endpoints. The difference between the least and most sensitive species was generally much larger for LC50 values as compared to the NOEC values, suggesting a higher degree of uncertainty when extrapolating from one species to another for the LC50 data. For the NOEC data, relatively small differences in sensitivity was observed, but as a rather consistent pattern, F. fimetaria was the most sensitive and E. crypticus the least sensitive species. However, one substance (acridine) showed specific toxicity toward E. veneta, which was more sensitive than the two other species by more than one order of magnitude.
Evaluation of androstenedione as an androgenic component of river water downstream of a pulp and paper mill effluent
Authors: Durhan Elizabeth J. , Lambright Christy , Wilson Vickie , Butterworth Brian C. , Kuehl Douglas W , Orlando Edward F. , Guillette Louis J. , Gray L. Earl , Ankley Gerald T.
Published: March 2010

This study evaluates a recent report indicating that androstenedione (4-androsten-3, 17-dione) contributes to the andro-genicity of water downstream of a pulp and paper mill discharge on the Fenholloway River (FL, USA). Extraction and concentration of Fenholloway water with C18 solid-phase extraction columns followed by reverse-phase high-pressure liquid chromatography resulted in clearly defined fractions with in vitro androgenic activity in CV-1 cells that had been transiently cotransfected with human androgen receptor and reporter gene constructs. However, we were unable to detect androstenedione in the active fractions by gas chromatography/mass spectrometry. Mass spectrometry analyses of deionized and Fenholloway River water samples that had been spiked with androstenedione, then extracted and fractionated, revealed that the androgen was found only in inactive fractions. We conclude that, although androstenedione was present at easily detectable concentrations in the river water (>100 ng/L), this compound is not associated with androgenic activity of water from the site.