bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exposure and effects of persistent organic pollutants in european shag (Phalacrocorax aristotelis) hatchlings from the coast of Norway
Authors: Murvoll Kari Mette , Skaare Janneche Utne , Anderssen Endre , Jenssen Bjorn Munro 
Published: January 2006

AbstractAlthough the coast of Norway is relatively clean regarding contaminants compared to areas of Europe with higher density of both people and industry, levels of persistent organic pollutants (POPs) exist in the marine ecosystem that may cause chronic exposure effects in wildlife. In this study, polychlorinated biphenyls (PCBs), some organochlorinated pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), and hexabromocyclododecane (HBCD) were analyzed in yolk sac of European shag (Phalacrocorax aristotelis) hatchlings from an island situated on the coast of Mid-Norway. In addition, levels of retinol (vitamin A), retinyl palmitate, and α-tocopherol (vitamin E) were measured in plasma and liver. The shag hatchlings seemed to be relatively highly contaminated by PBDEs and HBCD on a European scale. A negative relationship between PBDE-28 and liver tocopherol levels was revealed, and plasma retinol levels correlated negatively to levels of several PCB congeners, the summed PCB concentrations (ΣPCBs), and some OCPs. More studies should be done to reveal the effects of POPs, and especially PBDEs, on vitamin status in wild birds.
Toxicity, accumulation, and retention of zinc by carp under normoxic and hypoxic conditions
Authors: Hattink Jasper , De Boeck Gudrun , Blust Ronny 
Published: January 2006

AbstractZinc is an essential micronutrient that becomes toxic at elevated concentrations. Under hypoxic events, i.e., temporal depletion of oxygen, the toxicity of Zn increases for fish, apart from the direct effects of the reduced oxygen levels. This enhanced toxicity currently is explained by the increased ventilation rates under hypoxia, causing a higher water flow over the gills. However, the few experimental studies available on the uptake of heavy metals under hypoxia draw contradictory conclusions. The present study verifies the enhanced zinc toxicity under hypoxia and tests whether accumulation of zinc is increased in common carp, Cyprinus carpio (L.). Second, the effect of acclimatization to three oxygen levels (100, 50, and 25% saturation) on the zinc uptake and elimination was studied in a standard radiotracer uptake-and-elimination study for 63 d at 100 nmol/L Zn and 25°C. The sensitivity of carp for Zn was threefold higher under hypoxia than at normoxic conditions. The lethal concentration for 50% of the population after 96 h (96-h LC50) for normoxia and hypoxia (25%) were 149 (91–317) and 55 (30–100) μmol/L Zn, respectively. However, the kinetic data indicate that zinc uptake and elimination are not altered under hypoxia for common carp. Moreover, observed uptake rates are considerably lower than predicted from a ventilation-and-diffusion–regulated uptake mechanism. Setting these results in the framework of similar experiments of other investigators, we conclude that, in general, metal uptake in fish is not related to its ventilation rate within a normal physiological range.
Effect of copper on the photochemical efficiency, growth, and chlorophyllAbiomass of natural phytoplankton assemblages
Authors: Pérez Patricia , Estévez-Blanco Patricia , Beiras Ricardo , Fernández Emilio 
Published: January 2006

AbstractIn this investigation, we have tested the potential usefulness of variable fluorescence, i.e., the potential photochemical efficiency of photosystem II (Fv/Fm), determined with a fast repetition rate fluorometer (FRRF), as an indicator of the effect of metal pollution on natural phytoplankton assemblages. Phytoplankton populations were collected from an eutrophic embayment and exposed to different copper concentrations within the ppb range for 4 d. Enhanced photosynthesis was found for Cu concentrations of 10 and 20 μg/L, at very short exposure times (1 and 5 h). However, after 72 h even at 10 μg/L of Cu, Fv/Fm-values were significantly lower than those measured in the control. The highest Cu concentration tested (80 μg/L) caused a statistically significant decrease of Fv/Fm after 5 h. This response was contrasted with parallel determinations of chlorophyll a concentration, measurements of photosynthetic O2 production rates, and changes in the taxonomic composition and size structure of the microplankton communities. A reduction in overall particle size was found at Cu concentrations of 80 and 40 μg/L. Enhanced abundance of flagellates and the diatom Pseudonitzschia pungens was observed at 20 μg/L of copper. This study demonstrates the utility of this methodological approach as a rapid, nondestructive way for detecting trace-metal toxicity on natural phytoplankton.
Effects of air cell injection of perfluorooctane sulfonate before incubation on development of the white leghorn chicken (Gallus domesticus) embryo
Authors: Molina Elizabeth D. , Balander Richard , Fitzgerald Scott D. , Giesy John P. , Kannan Kurunthachalam , Mitchell Rachel , Bursian Steven J. 
Published: January 2006

Abstract
Fifty white leghorn chicken (Gallus domesticus) eggs per group were injected with 0.1, 1.0, 10.0, or 20.0 μg perfluorooctane sulfonate (PFOS)/g egg before incubation to investigate the effects of PFOS on the developing embryo. Hatchlings were weighed, examined for gross developmental abnormalities, and transferred to a battery brooder, where they were raised for 7 d. Chicks were then weighed, and 20 birds per treatment were randomly chosen for necropsy. The brain, heart, kidneys, and liver were removed and weighed. Livers were processed further for determination of PFOS concentrations and histological assessment. Hatchability was reduced significantly in all treatment groups in a dose-dependent manner. The calculated median lethal dose was 4.9 μg PFOS/g egg. Perfluorooctane sulfonate did not affect posthatch body or organ weights. Exposure to PFOS caused pathological changes in the liver characterized by bile duct hyperplasia, periportal inflammation, and hepatic cell necrosis at doses as low as 1.0 μg PFOS/g egg. Perfluorooctane sulfonate concentrations in the liver increased in a dose-dependent manner. Based on reduced hatchability, the lowest-observed-adverse-effect level was 0.1 μg PFOS/g egg.
Altered porphyrin excretion and histopathology of greylag geese (Anser anser) exposed to soil contaminated with lead and arsenic in the guadalquivir marshes, southwestern Spain
Authors: Mateo Rafael , Taggart Mark A. , Green Andy J. , Cristòfol Carles , Ramis Antoni , Lefranc Hugues , Figuerola Jordi , Meharg Andy A. 
Published: January 2006

Abstract
Greylag geese (Anser anser) in the Guadalquivir Marshes (southwestern Spain) can be exposed to sources of inorganic pollution such as heavy metals and arsenic from mining activities or Pb shot used for hunting. We have sampled 270 fecal excreta in different areas of the marshes in 2001 to 2002 to evaluate the exposure to Pb, Zn, Cu, Mn, and As and to determine its relationship with soil ingestion and with the excretion of porphyrins and biliverdin as biomarkers. These effects and the histopathology of liver, kidney, and pancreas were also studied in 50 geese shot in 2002 to 2004. None of the geese had ingested Pb shot in the gizzard. This contrasts with earlier samplings before the ban of Pb shot for waterfowl hunting in 2001 and the removal of Pb shot in points of the Doñana National Park (Spain) in 1999 to 2000. The highest exposure through direct soil ingestion to Pb and other studied elements was observed in samples from Entremuros, the area of the Doñana Natural Park affected by the Aznalcóllar mine spill in 1998. Birds from Entremuros also more frequently showed mononuclear infiltrates in liver and kidney than birds from the unaffected areas, although other more specific lesions of Pb or Zn poisoning were not observed. The excretion of coproporphyrins, especially of the isomer I, was positively related to the fecal As concentration, and the ratio of coproporphyrin III/I was positively related to fecal Pb concentration. Biliary protoporphyrin IX concentration was also slightly related to hepatic Pb concentration. This study reflects biological effects on terrestrial animals by the mining pollution in Doñana that can be monitored with the simple noninvasive sampling of feces.
Marine ecotoxic effect of pulse emissions in life cycle impact assessment
Authors: Pettersen Johan , Peters Glen P. , Hertwich Edgar G. 
Published: January 2006

Abstract
Characterization factors for ecotoxicity in life cycle impact assessment are traditionally calculated as the product of effect and fate factors. Steady-state multiple compartment models are used to calculate the fate factor, while effect factors are derived from species sensitivity distributions (SSDs) for multiple substances using average or marginal gradients. Others have shown that steady-state multicompartment models can be used to calculate characterization factors if linear dose–response functions are used. Average gradients are linear dose–response functions per definition. Marginal gradients are first-order Taylor approximations of the effect function and require marginal exposure at all points of the compartment. Instantaneous mixing, giving marginal exposure within compartments, is an implicit assumption of the multicompartment model. This paper investigates if the assumption of marginal exposure results in significant errors for the characterization factor. Ecotoxic effect of pulse emissions is simulated in a transient three-dimensional single compartment model of the marine aquatic environment. Results show that the error in characterization factors for the Taylor approximation is less than a factor of two for multisubstance SSDs assuming concentration addition only in the aggregation of toxic effect of substances. Assuming a combination of response and concentration addition may result in a deviation of several orders of magnitude.
Presence of nonylphenol ethoxylate surfactants in a watershed in central Mexico and removal from domestic sewage in a treatment wetland
Authors: Belmont Marco A. , Ikonomou Michael , Metcalfe Chris D. 
Published: January 2006

Abstract
The Texcoco River in central Mexico is polluted with domestic wastewater as a result of discharges of untreated or inadequately treated sewage. Since nonylphenol ethoxylate (NPEO) surfactants and their intermediate degradation products such as nonylphenol (NP) and NP mono- and diethoxylate (NP1EO, NP2EO) have been found in domestic wastewater and in surface waters near wastewater discharges in industrialized countries, the Texcoco River was sampled to determine whether these compounds were present. The results indicated that NPEOs were present at very high concentrations (&gt;100 μg/L) in the lower reaches of the Texcoco River, but unlike rivers in industrialized countries, relatively low concentrations of intermediate degradation products, including NP1EO, NP2EO, and NP, were present. The presence and fate of NPEOs compounds in wastewater treatment plants have been studied only in conventional treatment systems in industrialized countries. In this study, the fate of these compounds was studied in a pilot-scale treatment wetland constructed in the small community of Santa Maria Nativitas in the Texcoco River watershed. The treatment wetland removed &gt;75% of NPEOs from the domestic wastewater, but the greatest proportion of removal occurred in parts of the treatment wetland where sedimentation existed. This is the first report of NPEO compounds in the water resources of a developing country. These data indicate that construction of low-cost and technologically simple treatment wetlands may be one solution to reducing the impacts of contaminants from domestic sewage in developing countries, such as Mexico.
Chronic toxicity of lead to three freshwater invertebrates—Brachionus calyciflorus, Chironomus tentans, andLymnaea stagnalis
Authors: Grosell Martin , Gerdes Robert M. , Brix Kevin V. 
Published: January 2006

AbstractChronic lead (Pb) toxicity tests with Brachionus calyciflorus, Chironomus tentans, and Lymnaea stagnalis were performed in artificial freshwaters. The no-observable-effect concentration (NOEC), lowest-observable-effect concentration (LOEC), and calculated 20% effect concentration (EC20) for the rotifer B. calyciflorus were 194, 284, and 125 μg dissolved Pb/L, respectively. The midge C. tentans was less sensitive, with NOEC and LOEC of 109 and 497 μg dissolved Pb/L, respectively, and the snail L. stagnalis exhibited extreme sensitivity, evident by NOEC, LOEC, and EC20 of 12, 16, and &lt;4 μg dissolved Pb/L, respectively. Our findings are presented in the context of other reports on chronic Pb toxicity in freshwater organisms. The L. stagnalis results are in agreement with a previous report on pulmonate snails and should be viewed in the context of current U.S. Environmental Protection Agency (U.S. EPA) hardness adjusted water quality criteria of 8 μg Pb/L. The present findings and earlier reports indicate that freshwater pulmonate snails may not be protected by current regulatory standards. Measurements of whole-snail Na+ and Ca2+ concentrations following chronic Pb exposure revealed that Na+ homeostasis is disturbed by Pb exposure in juvenile snails in a complicated pattern, suggesting two physiological modes of action depending on the Pb exposure concentration. Substantially reduced growth in the snails that exhibit very high Ca2+ requirements may be related to reduced Ca2+ uptake and thereby reduced shell formation.
Dissipation kinetics and mobility of chlortetracycline, tylosin, and monensin in an agricultural soil in Northumberland County, Ontario, Canada
Authors: Carlson Jules C. , Mabury Scott A. 
Published: January 2006

Abstract
A robust high-throughput method was refined to extract three growth-promoting antibiotics, tylosin (TYL), chlortetracycline (CTC), and monensin (MON), from soil. Analysis was performed by electrospray liquid chromatography tandem mass spectrometry. Soil dissipation rate studies were performed in a farm field soil for antibiotics applied with and without manure. Tylosin, CTC, and MON followed first-order dissipation kinetics with half-lives of 4.5, 24, and 3.3 d, respectively, with the addition of manure and 6.1, 21, and 3.8 d, respectively, without manure. Manure application significantly increased TYL dissipation rate, perhaps because of the introduced microbial flora, but had no significant effect on CTC or MON. Monensin dissipation half-life was found to be much shorter in the field study than in a controlled laboratory study, perhaps because of differences in microbial communities. The antimicrobials were not highly mobile. Chlortetracycline was the only antibiotic detected at 25 to 35 cm depth and only up to 2% of the initial concentration in a sandy loam soil. These antibiotics are therefore expected to degrade primarily in agricultural soils before moving to greater depths or to groundwater in significant concentrations in most agricultural systems.
Influence of developmental stage on sensitivity to ammonium nitrate of aquatic stages of amphibians
Authors: Ortiz-Santaliestra Manuel E. , Marco Adolfo , Fernández María José , Lizana Miguel 
Published: January 2006

AbstractIn static renewal experiments, we studied how developmental stage influences the effect of ammonium nitrate on embryonic and larval stages of anuran amphibians. The observed lethal effects caused by ammonium nitrate increased with both concentration and duration of exposure. Significant differences were observed in sensitivity to ammonium nitrate as a function of developmental stage in Discoglossus galganoi, Pelobates cultripes, and Bufo calamita. In D. galganoi and P. cultripes, younger individuals displayed greater acute effects from the chemical fertilizer compared with older individuals. For example, 100% of P. cultripes hatchlings died after 4 d of exposure to a nominal concentration of 225.8 mg N-NO3NH4/L, whereas less than 40% of individuals from older larval stages died when exposed to this concentration. A delay of 4 d in the beginning of the exposure to the chemical was enough to cause significant differences in sensitivity. Bufo calamita showed a higher sensitivity in later larval stages after 12 d of exposure. Hyla meridionalis and B. calamita were less sensitive than the other two species. Peak ammonium nitrate concentrations usually occur when amphibians are breeding and, thus, when the most sensitive aquatic stage is in the water. The developmental stage of the test animals should be considered when evaluating the risk of ammonium nitrate to amphibians.
Effects of microcystins on fish
Authors: Malbrouck Christelle , Kestemont Patrick 
Published: January 2006

Abstract
Microcystins (MCs) are hepatotoxic heptapeptides released into water during or on senescence of cyanobacterial blooms. This review details the different effects of the MCs on fish and discusses their potential consequences in aquatic food webs. In early life stages, exposure to MCs causes, in a dose-dependent manner, perturbations to embryonic hatching, decrease in survival and growth rate, as well as histopathological effects (enlarged and opaque yolk sac, small head, curved body and tail, hepatobiliary abnormalities, ultrastructural alterations in hepatocytes, heart rate perturbations). In adults and juveniles, field and experimental studies demonstrated that after ingestion MCs accumulate mainly in liver but can also be found in muscle and viscera. Microcystin exposure has been shown to affect growth rate and osmoregulation, increase liver enzyme activities in the serum and heart rate, modify behavior, and exert histopathological effects in the liver, intestine, kidneys, heart, spleen, or gills, but the degree to which these effects were seen depends on the exposure route. The detoxication pathway of MCs in fish begins with a conjugation reaction to glutathione catalyzed by glutathione S-transferases, and this is comparable to the reaction demonstrated in other organisms, from plants to mammals. It appears that MC concentrations found in nature can potently affect several trophic levels in the aquatic ecosystems, in particular by inducing failure of sensitive stages (e.g., fish fry) to develop and accumulating in the food chains. The need of further quantitative studies on the sublethal effects, accumulation, and fate of MCs in aquatic food chains still remains.
Effects of atrazine on sexual maturation in female Japanese quail induced by photostimulation or exogenous gonadotropin
Authors: Wilhelms Kelly W. , Cutler Sara A. , Proudman John A. , Anderson Lloyd L. , Scanes Colin G. 
Published: January 2006

Abstract
The herbicide atrazine has gained recent attention for its reported effects on reproduction in amphibians. The present study examined the putative effects of atrazine during sexual maturation in the photostimulated female Japanese quail. Furthermore, the effects of atrazine on birds administered exogenous gonadotropin (pregnant mare serum gonadotropin [PMSG]) were investigated. Atrazine was administered up to 1,000 ppm in the diet to female quail undergoing photoperiodically induced sexual maturation. At high dietary concentrations, atrazine exhibits signs of overt toxicity with reductions in growth, feed intake, and liver weights, but these effects were dependent on the timing of treatment administration. Atrazine did not influence the weights of reproductive tissues (ovary and oviduct) or circulating concentrations of luteinizing hormone (LH). However, high concentrations of atrazine depressed circulating concentrations of estradiol. Treatment with atrazine for four weeks during sexual maturation inhibited growth but did not affect any other parameter assessed (feed intake, liver, ovary, or oviduct weights or the circulating concentrations of LH and estradiol). In birds receiving daily injections of PMSG, atrazine reduced growth, feed intake, and liver weights. However, PMSG-induced gonadal and oviduct growth was not affected by atrazine. The present results suggest that dietary atrazine exhibits limited reproductive toxicity in female quail during sexual maturation and only at concentrations above ecological relevance.
A method of assessing ecological risk to night heron,Nycticorax nycticorax, population persistence from dichlorodiphenyltrichloroethane exposure
Authors: An Wei , Hu Jian-ying , Yao Fang 
Published: January 2006

AbstractThis paper first introduces a probabilistic method for quantitatively evaluating the effects of chemical pollutants in the environment on a wildlife population, which was applied to assess the ecological risk to night heron (Nycticorax nycticorax) population persistence from dichlorodiphenyltrichloroethane (DDE) exposure in Tai Lake, China. Intrinsic rate of population increase (r) calculated with a population age-structured matrix model was used to measure the adverse effect on population. To perform a probabilistic analysis of risk, lost intrinsic rate of population increase (ΔZ) because of DDE exposure was applied to express the exact extent of risk. The result showed that the risk (i.e., the expectancy of ΔZ of the night heron population exposed to DDE in Tai Lake) was 0.0259, indicating a decrease in gross population size of 2.56% every year compared with that of the previous year without DDE exposure.
Biochemical and spectroscopic studies of the response of Convolvulus arvensis L. to chromium(III) and chromium(VI) stress
Authors: Montes-Holguin Milka O. , Peralta-Videa Jose R. , Meitzner George , Martinez-Martinez Alejandro , de la Rosa Guadalupe , Castillo-Michel Hiram A. , Gardea-Torresdey Jorge L. 
Published: January 2006

Abstract
The objective of the present study was to determine the oxidative stress caused by hexavalent chromium (Cr[VI]), the chromium (Cr) uptake, and the Cr speciation in Convolvulus arvensis L. plants grown in hydroponics media containing either Cr(VI) or Cr(III). The results demonstrated that C. arvensis plants exposed to Cr(VI) concentrations ranging from 0 to 40 mg/L expressed higher ascorbate peroxidase specific activity in roots than in shoots. On the other hand, catalase activity monitored in plants exposed to 2 mg/L of Cr(VI) for 24 h increased in roots after a few hours of exposure. However, catalase activity in shoots revealed a decrement almost immediately after treatment was initiated. The results from x-ray absorption spectroscopic studies indicated that the oxidation state of the supplied Cr(III) remained the same in plant tissues. The supplied Cr(VI), however, was reduced to the trivalent form in plant tissues. The results of inductively coupled plasma/optical emission spectroscopy demonstrated that after 5 d, the roots of plants exposed to 40 mg/L of Cr(III) or Cr(VI) accumulated approximately 25,000 and 3,500 mg/kg dry weight of Cr, respectively. Nevertheless, shoots concentrated 1,500 and 2,000 mg/kg dry weight of Cr from Cr(III) and Cr(VI), respectively, which indicated that Cr moved faster into C. arvensis plants when supplied as Cr(VI).