bluuebunny/crossref_metadata_2025 huggingface dataset:
Statistical analysis of honeybee survival after chronic exposure to insecticides
Authors: Moncharmont François-Xavier Dechaume , Decourtye Axel , Hennequet-Hantier Christelle , Pons Odile , Pham-Delègue Minh-Hà
Published: March 2005

Studies concerning long-term survival of honeybees raise the problem of the statistical analysis of mortality data. In the present study, we used a modeling approach of survival data of caged bees under chronic exposure to two pesticides (imidacloprid and deltamethrin). Our model, based on a Cox proportional hazard model, is not restricted to a specific hazard functional form, such as in parametric approaches, but takes into account multiple covariates. We consider not only the pesticide treatment but also a nuisance variable (variability between replicates). Moreover, considering the occurrence of social interactions, the model integrates the fact that bees do not die independently of each other. We demonstrate the chronic toxicity induced by imidacloprid and deltamethrin. Our results also underline the role of the replicate effect, the density-dependent effect, and their interactions with the treatment effect. None of these parameters can be neglected in the assessment of chronic toxicity of pesticides to the honeybee.
Persistent organic pollutants in air and vegetation from the canadian rocky mountains
Authors: Davidson Deborah A. , Wilkinson Andrew C. , Kimpe Lynda E. , Blais Jules M.
Published: March 2005

The exchange of chlorinated organic pollutants between air and vegetation in cold, mountain environments was investigated through the extraction of coniferous vegetation and high-volume air samples collected from the Canadian Rocky Mountains during the summers of 1999 and 2000. Concentrations of several compounds in vegetation increased as temperatures decreased, whereas atmospheric concentrations were not related to temperature. Daily cycling of these compounds between air and vegetation as a result of diurnal temperature changes was not observed. Compared with concentrations in vegetation from the Canadian Rocky Mountains, plant samples from the western valley in British Columbia (Canada) showed higher pollutant levels. Chemical partitioning between vegetation and air was not correlated with temperature, indicating that air contamination is governed by long-range transport and not by local revolatilization events. Based on these observations, we show that both deposition at higher altitudes and long-range atmospheric transport influence chemical accumulation in vegetation from the Canadian Rocky Mountains.
European starling (Sturnus vulgaris): Avian model and monitor of polychlorinated biphenyl contamination at a Superfund site in Southern Illinois, USA
Authors: Arenal Christine A. , Halbrook Richard S. , Woodruff Maryjo
Published: March 2005

Accumulation and effects of polychlorinated biphenyls (PCBs) in avian species were evaluated at a Superfund site located at Crab Orchard National Wildlife Refuge (IL, USA). European starlings (Sturnus vulgaris) were monitored at nest boxes constructed at each of two study and two reference sites. During the breeding season, starling productivity and adult provisioning behavior were monitored. At 15 d after hatch, chicks and adults were collected for contaminant and biomarker analyses. Chicks and adults were necropsied, ethoxyresorufin-O-deethylase (EROD) activity was measured in liver tissue, and polychlorinated biphenyl (PCB; Aroclor 1254) and 34 chlorinated biphenyl (CB) congener concentrations were measured in carcasses. Polychlorinated biphenyl and CB concentrations also were measured in eggs that failed to hatch. Mean Aroclor 1254 and quantified CB concentrations were greater (p < 0.001) in eggs that failed to hatch, 15-d-old chicks, and adults collected from PCB-contaminated sites (hereafter PCB sites) compared to those collected from reference sites. The EROD activity was greater (p = 0.005) in 15-d-old chicks, but not adults (p = 0.972), collected from PCB sites compared to those collected from reference sites. No differences were found among study and reference sites in number of eggs laid or percent of eggs hatched; however, reduced nest provisioning behavior and decreased chick survival were observed at PCB sites. Polychlorinated biphenyl concentrations measured in samples collected from the PCB sites are similar to concentrations previously associated with adverse effects in avian species. Other avian species utilizing these sites also may be exposed to PCBs with associated adverse effects. This study demonstrates that starling nestlings are good biological monitors of local contamination and continued monitoring may provide useful data for evaluating the effectiveness of proposed remediation.
Copper tolerance in fathead minnows: II. Maternal transfer
Authors: Peake Elizabeth B. , Locke Jessica C. , Tierney Laura L. , Kolok Alan S.
Published: March 2005

Female fathead minnows (Pimephales promelas) exposed to copper (Cu) maternally transfer Cu tolerance to their larval offspring. Larvae produced after female parents received a sublethal 5-d, 100 μg/L Cu exposure had significantly greater survivorship in potentially lethal Cu solutions than larvae produced before those females were exposed to Cu.
Assessment of bioavailability limitations during slurry biodegradation of petroleum hydrocarbons in aged soils
Authors: Huesemann Michael H. , Hausmann Tom S. , Fortman Tim J.
Published: March 2005

In an effort to determine whether bioavailability limitations are responsible for the slow or incomplete hydrocarbon biodegradation in aged soils, both the rate of desorption (rdes) and biodegradation (rbio) was measured for n-alkanes and polynuclear aromatic hydrocarbons (PAHs) at different times during the slurry biotreatment of six different soils. While all n-alkanes were biodegraded to various degrees depending on their respective carbon number and the soil organic matter content, none of them were desorbed to a significant extent, indicating that these saturated hydrocarbons do not need to be transferred from the soil particles into the aqueous phase in order to be metabolized by microorganisms. Most two- and three-ring PAHs biodegraded as fast as they were desorbed (rbio = rdes); that is, desorption rates controlled biodegradation rates. By contrast, the biodegradation kinetics of four-, five-, and six-ring PAHs was limited by microbial factors during the initial phase (rbio < rdes) while becoming mass-transfer rate limited during the final phase of bioremediation treatment (rbio = rdes). Whenever PAH biodegradation stalled or did not occur at all (rbio = 0), it was never due to bioavailability limitations (rdes ≫ 0) but was more likely caused by microbial factors, such as the absence of specific PAH degraders or cometabolic substrates. Consequently, PAHs that are found to be microbially recalcitrant in aged soils may not be so because of limited bioavailability and thus could pose a greater risk to the environment than previously thought.
Mechanisms of cadmium toxicity in terrestrial pulmonates: Programmed cell death and metallothionein overload
Authors: Chabicovsky Monika , Klepal Waltraud , Dallinger Reinhard
Published: March 2005

A sublethal dose of cadmium (Cd2+) administered via the diet during short-term exposure over 10 d induced programmed cell death in the hepatopancreas of the terrestrial pulmonate snail Helix pomatia. Condensed cell residues were predominantly phagocytosed by calcium cells, suggesting a specific function of these epithelial cells in metal detoxification or in clearing the organ of cellular debris from cell death. The considerable cell loss recorded by histological analysis was accompanied by enhanced cell proliferation. Intoxication with Cd was further associated with the pronounced abundance of residual bodies, predominantly recorded in excretory cells, and with pathological changes in the endoplasmic reticulum. During long-term Cd exposure, mortality increased with increasing Cd concentrations in the diet, as demonstrated by feeding experiments in the laboratory. Lethal effects of Cd appeared to be correlated with Cd overloading of the Cd-specific metallothionein isoform (Cd-MT), isolated and characterized previously from the animal's hepatopancreas. Stoichiometric analysis shows that the capacity of Cd-MT to bind six molar equivalents of Cd corresponds to a tissue Cd concentration of approximately 4 μmol/g dry weight. At this tissue concentration, all high-affinity metal-binding sites of Cd-MT are occupied by Cd2+. Cadmium exposure beyond this level gives rise to progressive destabilization of Cd-MT cluster structure in vitro, resulting in increasing proportions of weakly bound, or even unbound, Cd2+ ions. Our results suggest that in vivo, the observed overburdening of Cd-MT with Cd2+ reduces the viability of affected animals.
Acute and chronic toxicity of nickel to a cladoceran (Ceriodaphnia dubia) and an amphipod (Hyalella azteca)
Authors: Keithly James , Brooker John A. , Deforest David K. , Wu Benjamin K. , Brix Kevin V.
Published: March 2005

This study evaluated acute and chronic nickel (Ni) toxicity to Ceriodaphnia dubia and Hyalella azteca with the objective of generating information for the development of a biotic ligand model for Ni. Testing with C. dubia was used to evaluate the effect of ambient hardness on Ni toxicity, whereas the larger H. azteca was used to derive lethal body burden information for Ni toxicity. As was expected, acute C. dubia median lethal concentrations (LC50s) for Ni increased with increasing water hardness. The 48-hLC50s were 81, 148, 261, and 400 μg/L at hardnesses of 50, 113, 161, and 253 mg/L (as CaCO3), respectively. Ceriodaphnia dubia was found to be significantly more sensitive in chronic exposures than other species tested (including other daphnids such as Daphnia magna); chronic toxicity was less dependent on hardness than was acute toxicity. Chronic 20% effective concentrations (EC20s) were estimated at <3.8, 4.7, 4.0, and 6.9 μg/L at hardnesses of 50, 113, 161, and 253 mg/L, respectively. Testing with H. azteca resulted in a 96-h LC50 of 3,045 μg/L and a 14-d EC20 of 61 μg/L at a hardness of 98 mg/L (as CaCO3). Survival was more sensitive than was growth in the chronic study with H. azteca. The 20% lethal accumulation effect level based on measured Ni body burdens was 247 nmol/g wet weight.
Toxicity of endosulfan to Atalophlebia spp. (Ephemeroptera) in the laboratory, mesocosm, and field
Authors: Hose Grant C. , Hyne Ross V. , Lim Richard P.
Published: March 2005

A series of single-species toxicity tests was conducted in the laboratory and in outdoor stream mesocosms. The mayfly nymphs of Atalophlebia spp. (A. av2 and A. av6) were exposed to the organochlorine pesticide endosulfan for either 12- or 48-h periods, with mortality recorded after 96 h. For both exposure periods, the lethal concentration (LC50 and LC10) values were not significantly different between laboratory and mesocosm single-species tests, suggesting that the absence of natural environmental conditions and biological interactions in laboratory single-species tests did not influence the toxicity of technical endosulfan to Atalophlebia spp. Interpolation of toxicity test data indicates that peak endosulfan concentrations recorded in the rivers during storm events are likely to cause only minimal impact on Atalophlebia spp. populations. This suggests that changes in the abundance of populations observed in the field, if due to total endosulfan alone, are the result of chronic rather than acute exposure.
Gender and spatial patterns in metal concentrations in brown anoles (Anolis sagrei) in Southern Florida, USA
Authors: Burger Joanna , Campbell Kym Rouse , Campbell Todd S.
Published: March 2005

Comparatively little is known about heavy metal levels in reptiles, particularly for lizards. Yet lizards often are common predators that could serve as bioindicators of contamination on a small spatial scale. This study examined the differences in metal concentrations of adult brown anoles (Anolis sagrei) for arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in six locations in southern Florida, USA, from Lake Okeechobee (Pahokee) south to Key West. We predicted that levels of contaminants would be higher in the industrialized ports (Port Everglades, Port of Miami) and at a landfill (in Key West) compared to a campground, tropical garden, and marine laboratory. Males were significantly larger than females, as expected. Although there were significant locational differences in metal concentrations, they did not fit a consistent pattern, either among sites or between reference and study sites. However, the lowest levels were generally found at Everglades Marina and Campground (except for selenium) and at Fairchild Tropical Garden (except for manganese). For females, size was significantly correlated with cadmium, lead, and mercury levels, while for males, there were significant correlations between length and arsenic, chromium, and manganese concentrations. Where there were gender differences in metal levels, females had significantly higher levels than males even though they were smaller. We attribute these gender differences to differences in diet due to microhabitat differences in foraging locations. Females spend more time feeding near the ground and males spend more time feeding on tree trunks and branches where they consume more flying insects. This is the first study that examines concentrations of metals in lizards in the United States, and suggests that nonnative lizards may be useful in toxicological studies.
A comparison of the fish bioconcentration factors for brominated flame retardants with their nonbrominated analogues
Authors: Hardy Marcia L.
Published: March 2005

Flame retardants (FR) play a significant role in reducing the flammability of many consumer products. On a volume basis, approximately 25% of the FRs in use today utilize bromine as the active flame-retarding moiety. Their applications are those requiring high FR performance or in resins needing an FR that is active during the gas phase. Laboratory fish bioconcentration factors (BCFs) for 11 brominated FRs (BFRs) or their components were compared with those for their nonbrominated analogues. Bioconcentration, defined here as a BCF of greater than 1,000, was not observed in those brominated molecules examined with molecular weights of 700 or greater. These included the decabromodiphenyl oxide and octabromodiphenyl oxide commercial products, ethane 1,2-bis(pentabromophenyl), ethylene bis-tetrabromophthalimide, and decabromobiphenyl. Tetrabromobisphenol A, with a molecular weight of less than 700, also did not bioconcentrate. This likely relates to the ease with which it is metabolized and eliminated. Within the BFR class of polybrominated diphenyl oxides/ethers, the BCFs for those congeners with molecular weights of between approximately 450 and 700 varied with the number and position of the bromine atoms. The BCF of hexabromocyclododecane appeared to be related to its cyclododecane substructure, not to its bromine content. Bioconcentration was not a characteristic feature of the BFRs examined here.
Microbial transformation of pyrethroid insecticides in aqueous and sediment phases
Authors: Lee Sangjin , Gan Jianying , Kim Jong-Sik , Kabashima John N. , Crowley David E.
Published: March 2005

Recent studies showed that synthetic pyrethroids(SPs)can move via surface runoff into aquatic systems. Fifty-six of SP-degrading bacteria strains were isolated from contaminated sediments, of which six were evaluated for their ability to transform bifenthrin and permethrin in the aqueous phase and bifenthrin in the sediment phase. In the aqueous phase, bifenthrin was rapidly degraded by strains of Stenotrophomonas acidaminiphila, and the half-life (t1/2) was reduced from >700 h to 30 to 131 h. Permethrin isomers were degraded by Aeromonas sobria, Erwinia carotovora, and Yersinia frederiksenii. Similar to bifenthrin, the t1/2 of cis- and trans -permethrin was reduced by approximately 10-fold after bacteria inoculation. However, bifenthrin degradation by S. acidaminiphila was significantly inhibited in the presence of sediment, and the effect was likely caused by strong adsorption to the solid phase. Bifenthrin t1/2 was 343 to 466 h for a field sediment, and increased to 980 to 1200 h for a creek sediment. Bifenthrin degradation in the inoculated slurry treatments was not greatly enhanced when compared with the noninoculated system. Therefore, although SP-degrading bacteria may be widespread in aquatic systems, adsorption to sediment could render SPs unavailable to the degraders, thus prolonging their persistence.
Fipronil effects on estuarine copepod (Amphiascus tenuiremis) development, fertility, and reproduction: A rapid life-cycle assay in 96-well microplate format
Authors: Chandler G. Thomas , Cary Tawnya L. , Volz David C. , Walse Spencer S. , Ferry John L. , Klosterhaus Susan L.
Published: March 2005

Fipronil is a novel γ-aminobutyric acid receptor-specific phenylpyrazole insecticide commonly used near estuarine environments for rice production, turf-grass management, and residential insect control. In this study, we evaluated the acute, developmental, and reproductive toxicity of fipronil to the estuarine harpacticoid copepod Amphiascus tenuiremis. Fipronil was highly toxic to A. tenuiremis (adult 96-h median lethal concentration [LC50] = 6.8 μg/L) and was more toxic to male copepods (96-h LC50 = 3.5 μg/L) than to nongravid female copepods (96-h LC50 = 13.0 μg/L). By using a newly developed 96-well microplate-based life-cycle toxicity test, we successfully reared single individuals of A. tenuiremis to adulthood in 200-μl microwells and concurrently assessed developmental and reproductive effects (after paired virginal matings) of environmentally relevant aqueous fipronil concentrations (0.16, 0.22, and 0.42 μg/L measured). Throughout the entire life cycle, copepod survival in all treatments was >90%. However, fipronil at 0.22 μg/L and higher significantly delayed male and female development from stage 1 copepodite to adult by approximately 2 d. More importantly, fipronil significantly halted female egg extrusion by 71% in the 0.22-μg/L fipronil treatment, and nearly eliminated reproduction (94% failure) in the 0.42-μg/L fipronil treatment. A three-generation Leslie matrix-based population growth model of fipronil reproductive and life-cycle impacts predicted a 62% decline in population size of A. tenuiremis relative to controls at only 0.16 μg/L.
Trivalent chromium alters gene expression in the mummichog (Fundulus heteroclitus)
Authors: Maples Nikki L. , Bain L Isa J.
Published: March 2005

Mummichogs (Fundulus heteroclitus) were used as a model fish species to study the effects of trivalent chromium exposure. To ascertain chromium's effects, we examined altered gene expression by differential display between fish exposed in the laboratory and fish collected from a chromium-impacted estuarine site. Twenty differentially expressed genes were found from either laboratory-exposed fish or in fish collected from the field site. Database sequence searches indicated that several of these genes are highly homologous to known sequences, including a fatty acid-binding protein (FABP), cytochrome P4502N2 (CYP2N2), and a precursor to the translation initiation factor eIF2B. Verification of the differentially expressed genes by real-time polymerase chain reaction (PCR) revealed that the fatty acid-binding protein was repressed to a 3.6-times greater extent (3.6-fold) in the field-site animals as compared to a reference site, eIF2B was repressed 2-fold, and an expressed sequence tag (EST) termed A31 was induced 2.6-fold. In the laboratory-exposed animals, A31 was also induced between 2- and 4-fold. However, in contrast to the field-site fish, FABP was upregulated in the chromium-exposed animals. We hope to be able to use A31 as a biomarker for ascertaining the impacts of chromium exposure on fish.
Recommendations for the assessment of TNT toxicity in sediment
Authors: Conder Jason M. , La Point Thomas W. , Steevens Jeffery A. , Lotufo Guilherme R.
Published: March 2005

Previous investigations of the ecotoxicity of TNT in spiked sediments noted the rapid degradation and disappearance of the toxicant, yet little is understood regarding the effects of this process on toxicity and subsequent derivation of toxicity reference values. We conducted environmental fate studies and 28-d sediment toxicity tests with benthic oligochaete worms (Tubifex tubifex) with sediments spiked at three different TNT concentrations (440, 1,409, and 4,403 nmol/g dry wt) aged for 1, 8, and 29 d. Because of rapid degradation of TNT, disappearance of degradation products, and partitioning to overlying water, only 25 to 40% of the added nitroaromatic mass balance was associated with sediment immediately after spiking. Lethal toxicity decreased with aging time and was best described by measured sediment nitroaromatic concentrations (sum of TNT and degradation products) at the beginning of exposure, with a median lethal concentration of nitroaromatic compounds of 184 nmol/g dry weight. To accurately describe the ephemeral exposure doses of TNT and its degradation products during toxicity tests with spiked sediments, we suggest that sediments should be aged at least 8 to 14 d after spiking, exposure should be based on measured sediment concentrations or chemical measures of availability, exchange of overlying water should be avoided or minimized, and short-term toxicity tests should be considered.
Biomonitoring of contaminants in birds from two trophic levels in the North Pacific
Authors: Rocque Deborah A. , Winker Kevin
Published: March 2005

The presence and accumulation of persistent contaminants at high latitudes from long-range transport is an important environmental issue. Atmospheric transport has been identified as the source of pollutants in several arctic ecosystems and has the potential to severely impact high-latitude populations. Elevated levels of contaminants in Aleutian Island avifauna have been documented, but the great distance from potential industrial sources and the region's complex military history have confounded identification of contaminant origins. We sampled bird species across the natural longitudinal transect of the Aleutian Archipelago to test three contaminant source hypotheses. We detected patterns in some polychlorinated biphenyl congeners and mercury that indicate abandoned military installations as likely local point sources. Carbon isotopes were distinct among island groups, enabling us to rule out transfer through migratory prey species as a contaminant source. The long-range transport hypothesis was supported by significant west-to-east declines in contaminant concentrations for most detected organochlorines and some trace metals. Although relatively low at present, concentrations may increase in Aleutian fauna as Asian industrialization increases and emitted contaminants are atmospherically transported into the region, necessitating continued monitoring in this unique ecosystem.
Sorption of steroid estrogens to soils and sediments
Authors: Yu Zhiqiang , Xiao Baohua , Huang Weilin , Peng Ping'An
Published: March 2005

Steroid estrogens at sub-micrograms per liter levels are frequently detected in surface water, and increasingly cause public concern of their potential impacts on ecosystems and human health. Assessing the environmental fate and risks of steroid estrogens requires accurate characterization of various physicochemical and biological processes involving these chemicals in aquatic systems. This paper reports sorption of three estrogens, 17β-estradiol (estradiol), estrone, and 17α-ethinyl estradiol (EE2), by seven soil and sediment samples at both equilibrium and rate-limiting conditions. The results indicated that attainment of sorption equilibrium needs about 2 d when aqueous estrogen concentrations (Cts) are 25 to 50% of their solubility limits (SWs), but equilibrium requires 10 to 14 d when the Ct is 20 times lower than the SW. The measured sorption isotherms are all nonlinear, with the Freundlich model parameter n ranging from 0.475 to 0.893. The observed isotherm nonlinearity correlates to a gradual increase of single-point organic carbon-normalized sorption distribution coefficient (capacity) (KOC) as the equilibrium estrogen concentration (Ce) decreases. At Ce = 0.5SW, all three estrogens have log KOC values of 3.14 to 3.49, whereas at Ce = 0.02SW, the log KOC values for estrone, EE2, and estradiol are within ranges of 3.40 to 3.81, 3.45 to 3.85, and 3.71 to 4.12, respectively. This study suggests that, when at sub-micrograms per liter levels, these estrogenic chemicals may exhibit even slower rates and greater capacities of sorption by soils and sediments.
Determination of degradation products of alkylphenol polyethoxylates in municipal wastewaters and rivers in Tokyo, Japan
Authors: Isobe Tomohiko , Takada Hideshige
Published: March 2005

An analytical method for the simultaneous determination of nonylphenoxy acetic acid (NP1EC), nonylphenol monoethoxy acetic acid (NP2EC), nonylphenol (NP), octylphenol (OP), and nonylphenol monoethoxylate (NP1EO) was developed. The method was applied to environmental samples to demonstrate the distribution and behavior of nonylphenol polyethoxylates and their degradation intermediates in aquatic environments in Tokyo, Japan. In sewage treatment plants, more than 85% of NP, OP, and NP1EO were removed, whereas NP1EC and NP2EC were generated during the treatment. Concentrations of NP1EC and NP2EC in secondary effluents (1.9–2.9 μg/L) were higher than those of NP and NP1EO (0.12–0.63 μg/L). In river waters, NP1EC and NP2EC concentrations (0.11–2.8 μg/L) were higher than NP and NP1EO concentrations (<0.015-3.4 μg/L), with some exceptions. In surface sediments, neither NP1EC nor NP2EC was detectable (<0.01 μg/g dry wt) whereas NP and NP1EO were detected significantly (0.03–1.82 μg/g dry wt and 0.04–0.46 μg/g dry wt, respectively).
Bioavailability and assimilation of sediment-associated benzo[a]pyrene by Ilyodrilus templetoni (oligochaeta)
Authors: Lu Xiaoxia , Reible Danny D. , Fleeger John W.
Published: March 2005

Benzo[a]pyrene (BaP)-amended sediment was desorbed by a sequential batch method using an isopropanol solution wash. The observed isotherm showed no evidence of desorption resistance, as indicated by increased partitioning to the solid phase at low concentrations. This was consistent with the prediction of minimal desorption resistance for highly hydrophobic compounds using a biphasic model. Bioavailability of BaP in desorbed sediments was assessed by toxicokinetic measures of uptake, bioaccumulation, and elimination in the deposit-feeding, freshwater tubificid oligochaete Ilyodrilus templetoni. Worms were exposed to sediments with BaP concentrations of approximately 26 and 11 μg/g dry weight sediment after desorption for one and three batches, respectively. The I. templetoni tissue concentration attained an apparent steady state after approximately one month and resulted in a biota-sediment accumulation factor of approximately 1.3 for both sediments. This is consistent with the paradigm that pore-water concentration predicts the uptake of organic contaminants into lipids despite the literature data showing that the major uptake route for BaP is likely from the ingestion of sediment particles. Ilyodrilus templetoni exhibited a high assimilation efficiency (80%) during a single-gut passage, a low elimination rate (ke = 0.0032 h−1), and negligible biotransformation of sediment-associated BaP.
A comparative study of an accelerated life-test model and a toxicokinetics-based model for the analysis of Porcellio scaber survival data
Authors: Ren Shijin
Published: March 2005

Statistical models have long been used for reliability analysis and risk assessment. In the present study, an accelerated life-test model was used to analyze a set of dose-time-response data obtained with the terrestrial isopod Porcellio scaber. Survival data were experimentally obtained by exposing P. scaber to diazinon (a nonpersistent insecticide) at six concentrations between 2 and 11.31 μg/g (toxicant/soil). Survival data are presented on a weekly basis. The accelerated life-test model assumed a log-normal distribution and constant variance across all diazinon concentrations. Model parameters were obtained by maximum likelihood estimation. The accelerated life-test model was compared to a toxicokinetics-based model reported in the literature. Survival predictions made by both models were compared with the observed data. Both the accelerated life-test model and the toxicokineticsbased model underestimated toxicity at a diazinon concentration of 8 μg/g. Overall, however, the accelerated life-test model outperformed the toxicokinetics-based model, with survival predictions closer to the observed data in most cases and a stronger correlation between predicted and observed survivals. However, as a statistical model, the accelerated life-test model did not reveal mechanistic information, and only statistical and distributional interpretations of its model parameters could be made.
Thyroid hormone status in gray seal (Halichoerus grypus) pups from the baltic sea and the atlantic ocean in relation to organochlorine pollutants
Authors: Sørmo Eugen Gravningen , Jussi Ivar , Jussi Mart , Braathen Marte , Skaare Janneche Utne , Jenssen BJørn Munro
Published: March 2005

Mrine apex predators, such as the gray seal (Halichoerus grypus), are exposed to high concentrations of organochlorine (OC) compounds via biomagnification in the food web. These lipophilic pollutants are transferred from the female to her offspring during lactation, and there is particular concern for endocrine disruption in the offspring. Herein we examined associations between the blubber concentrations of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and metabolites, chlordanes, hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB), and plasma concentrations of thyroid hormones (thyroxine [T4] and tri-iodothyronine [T3]) in free-ranging, newly weaned gray seal pups from the Baltic Sea and the Norwegian waters of the Atlantic Ocean. Concentrations of total T3 (TT3) and free T3 (FT3) were significantly lower in the polluted seals from the Baltic Sea. Blubber concentrations of the sum of the analyzed PCB congeners (ΣPCBs) and the sum of the DDT compounds (ΣDDTs) were correlated negatively with plasma TT3 and FT3 concentrations. The results from this study indicate that OCs may affect levels of thyroid hormones in free-ranging gray seal pups, and that more focus should be put on T3 when addressing the possible effects of OCs on thyroid hormone function and status in nonrodent species.
Bioaccumulation of metals in Eisenia fetida after exposure to a metal-loaded bauxsol™ reagent
Authors: Maddocks Greg , Reichelt-Brushett Amanda , McConchie David , Vangronsveld Jaco
Published: March 2005

The present sudy investigated the acute toxic effects of a metal-loaded Bauxsol™ reagent (MLBR), containing more than 6,450 mg kg−1 of bound metal, on the earthworm Eisenia fetida. Bauxsol is manufactured by Virotec Global Solutions of Gold Coast, Queensland, Australia. The E. fetida were exposed to 0, 10, 20, 40, 60, and 80% treatments of MLBR plus cow manure for 28 d. Good motility and no mortality of E. fetida were found in all treatments after 28 d of exposure. The greatest bioaccumulation of metals by E. fetida occurred in the 20 and 40% MLBR treatments. The bioaccumulation of metals in the worms and bioaccumulation factors (BAFs) were less than the reported toxicity thresholds to cause mortality and less than the reported BAF for moderately contaminated soils, indicating that metals bound to Bauxsol reagents are mostly nonbioavailable. Analyses of the 20% MLBR treatment at 28 d using a sequential extraction procedure showed that more than 95% of the metals are bound within the Fe/Mn oxide fractions. However, changes occurred in metal fractionation after exposure to E. fetida for Cd/Cr, and Fe/Mn. The data also showed that the exchangeable (1 M MgCl2) and the toxicity characteristic leaching procedure extractant are useful as indicators of metal bioavailability from MLBR to E. fetida.
Importance of acclimation to environmentally relevant zinc concentrations on the sensitivity of Daphnia magna toward zinc
Authors: Muyssen Brita T. A. , Janssen Colin R.
Published: March 2005

Daphnia magna was acclimated for six generations to an acclimation range of 0.02 to 74 μg/L of Zn2+. This range was determined by combining physicochemical water characteristics of European surface waters with total Zn concentrations in these waters in such a way that they resulted in minimal and maximal free (i.e., assumed bioavailable) Zn ion activities. No significant differences were found in acute Zn tolerance between the different acclimation concentrations: Average 48-h median effective concentration (EC50) values ranged from 608 ± 94 to 713 ± 249 μg/L of Zn2+. Also, no significant shifts in chronic tolerance were observed: Average 21-d EC50 (based on net reproductive rate) ranged from 91 ± 20 to 124 ± 22 μg/L of Zn2+. However, at test concentrations less than the 21-d EC50, acclimation significantly increased the reproductive capacity of the offspring produced. This indicates that metal acclimation is not necessarily accompanied by an increase in tolerance but also may manifest in other responses (e.g., reproduction rate). Organisms acclimated to a range from 6 to 22 μg/L of Zn2+ produced significantly more offspring than organisms acclimated to lower and higher Zn concentrations in test concentrations up to 50 μg/L of Zn2+. This range corresponds to a previously established optimal concentration range for D. magna. Bioconcentration factors indicated that Zn was actively regulated in the acclimation range tested.
Effects of sulfachlorpyridazine in MS·3-arable land: A multispecies soil system for assessing the environmental fate and effects of veterinary medicines
Authors: Boleas Sara , Alonso Carmen , Pro Javier , Babín M. Mar , Fernández Carlos , Carbonell Gregoria , Tarazona José V.
Published: March 2005

A multispecies soil system (MS·3) has been used to evaluate the ecological effects of veterinary pharmaceuticals in soil as a result of routine agricultural practices. Different experimental conditions were tested and the variation of the different parameters was evaluated for a final design. A protocol for the MS·3-arable land is presented here. Emergence of seedlings, plant elongation and biomass, earthworm mortality, and soil microbial enzymatic activities have been selected as toxicological endpoints for soil organisms. Toxicity tests were conducted with the leachate on aquatic organisms (in vitro fish cell lines, daphnids, and algae). The system was used for assessing the effects of the antimicrobial sulfachlorpyridazine that was tested in triplicate at concentrations of 0.01, 1, and 100 mg/kg. The chemical was mixed uniformly with a 20-cm depth soil column to resemble the distribution of manure within arable soil. Reversible and nonreversible effects on soil enzymatic activities were observed at 1 and 100 mg/kg, respectively. Earthworms were not affected. Significant reduction of plant elongation and biomass was observed at the highest concentration. Degradation and leaching contributed to the dissipation of sulfachlorpyridazine from the soil column. The undiluted leachate was highly toxic to Daphnia magna. The parent chemical was assumed responsible for the leachate toxicity although the role of mobile metabolites could not be excluded fully. No significant effects were observed for green algae Chlorella vulgaris and for the rainbow trout established cell lines RTG-2 (rainbow trout gonads) and RTL-W1 (rainbow trout liver). The MS·3 system offers a cost-effective experimental approach to measure simultaneously fate and effects of chemicals on a realistic soil system under controlled laboratory conditions. The advantages of using MS·3-effect endpoints are discussed.
Early–life-stage toxicity in offspring from exposed parent medaka, Oryzias latipes, to mixtures of tributyltin and polychlorinated biphenyls
Authors: Nakayama Kei , Oshima Yuji , Nagafuchi Ken , Hano Takeshi , Shimasaki Yohei , Honjo Tsuneo
Published: March 2005

The present study examined the effectsoftributyltin (TBT), polychlorinated biphenyls (PCBs), and mixtures ofboth chemicals on reproduction in Japanese medaka, Oryzias latipes. For 21 d we gave groups of medaka freeze-dried brine shrimp flakes contaminated with a mixture of either 0, 1, 5, or 25 μg TBT g1 plus 0 or 25 μg PCBs g1. We measured the fecundity and fertility of the parent fish and assessed the deformity, hatchability, time-to-hatching, and swim-up failure rate of the next generation. Fertilization success in the third week of the administration period was significantly decreased by administration of 25 μg TBT g−1 (77%) compared with the control group (87%). Both TBT and PCBs were transferred maternally into the eggs of the next generation, causing early life–stage toxicity. Administration of 1 μg TBT g1 was not toxic to embryological development, but abnormal eye development (i.e., small eyes or no eyes) occurred when TBT at the same concentration was mixed with PCBs (6.4%). Administration of TBT alone significantly decreased hatchability and increased swim-up failure, and administration of PCBs alone significantly increased time-to-hatching. Statistical analysis by two-way analysis of variance detected an interaction between TBT and PCBs in these three parameters. TBT induces abnormal development of the eyes, reduced hatchability, and increased swim-up failure, whereas PCBs delay time-to-hatching. Administration of mixtures of TBT and PCBs has more adverse effects on the developmental stage of medaka than does that of each chemical alone.
Variations of nitrate and sulfate in the atmosphere on days of high and low particulate matters
Authors: Kuo Chung-Yih , Chen Hsin-Hong , Shih Jeng-Fu , Wong Ruey-Hong
Published: March 2005

Particulate matters with aerodynamicdiameter less than 10 μm (PM10) were collected with high-volume samplers for four periods of consecutive samplings. Each period included a high PM10 (defined as PM10 ≥110 μg/m3) episode. The concentrations of all ionic species of high PM10 day (HPD) samples were higher than those of low PM10 (defined as PM10 < 110μg/m3) d (LPD) samples. Using the ionic concentrations of HPD samples at each station divided by those of LPD samples at respective stations, the results showed thatNO 3− increased most from LPD to HPD among the eight ionic species examined. A high mean value (3.15) of NO 3−/elemental carbon (EC) ratio of HPD divided by that of LPD indicates that concentration variations due to chemical formation and nonchemical factors apparently were higher than those of the concentration variations due to nonchemical factors alone. The NO 3−/SO 2−4 ratio of HPD divided by that of LPD ranged from 1.62 to 3.92 for the four periods. The results indicate that more nitrate than sulfate had formed during high PM10 episodes. Multiple linear regression analysis showed that the percentage of NH 4+ associated with nitrate and sulfate decreased and the percentage that could be explained by Ca2+ and Na+ increased on HPD. The reactions of HNO3 and H2SO4 with sea salt particles and with aqueous carbonates on soil particles during HPD were considered the main causes leading to these variations.
Effect of interaction between density dependence and toxicant exposure on population growth rate of the potworm Enchytraeus doerjesi
Authors: Kramarz Paulina , Zwolak Malgorzata , Laskowski Ryszard
Published: March 2005

Laboratory cultures of the potworm Enchytreaus doerjesi were exposed to zinc-contaminated soil at nominal concentrations 0, 75, 150, 300, or 600 mg Zn/kg dry weight for four weeks (one generation) at five different initial densities (5, 10, 20, 40, or 80 individuals per 20 g soil). The final culture numbers and the instantaneous population growth rate, ri were used as measures of culture response to both factors. In all treatments, the number of individuals increased during the experiment; thus, all the cultures exhibited positive ri values. The population growth rates decreased significantly with increasing Zn concentration and were also affected by the initial density. However, the latter effect was nonlinear and the initial density of 20 individuals resulted in the highest ri values throughout the whole range of Zn concentrations tested, while the lowest population growth rates were recorded for the highest initial density. Significant interaction between zinc toxicity and population size was found for the two lowest initial densities, where synergistic effects were noted. No effect of density on zinc toxicity was found at initial densities of 20 to 80 individuals, most probably because the animals were fed ad libitum and thus were not food limited.
Three patients with hallucal polydactyly and WAGR syndrome, including discordant expression of Wilms tumor in MZ twins
Authors: Brémond‐Gignac Dominique , Gérard‐Blanluet Marion , Copin Henri , Bitoun Pierre , Baumann Clarisse , Crolla J.A. , Benzacken Brigitte , Verloes Alain
Published: March 2005

The WAGR contiguous gene deletion syndrome is a combination of Wilms tumor, Aniridia, Genito‐urinary abnormalities, and growth and mental retardation which is invariably associated with an 11p13 deletion. We report two monozygotic twins and a third, unrelated patient with WAGR syndrome and additional clinical features not usually associated with WAGR. Both twins had developmental delay, growth deficiency, severe ocular involvement (nystagmus, aniridia, cataracts), atrial septal defect and two uncommon findings: agenesis of the corpus callosum and duplication of the halluces. One twin developed Wilms tumors aged 19 months while her sister remained tumor free by the age of 6.5 years. The singleton patient showed typical WAGR syndrome and preaxial hallucal polydactyly. Molecular cytogenetic studies refined the identification of the extent of the deleted segments, which were not identical in the two families. The two deletions included the PAX6 and WT1 genes as previously reported in typical WAGR patients. The unusual anomalies described in this report, may represent the expression of low penetrant traits associated with haploinsufficency of one or more of the genes present in the deletion (PAX6 is expressed in CNS) or may indicate epistatic influences of modifier genes on the expression of gene(s) present in the WAGR region. © 2005 Wiley‐Liss, Inc.
Autosomal recessive mesoaxial synostotic syndactyly with phalangeal reduction maps to chromosome 17p13.3
Authors: Malik Sajid , Percin Ferda E. , Ahmad Wasim , Percin Sitki , Akarsu Nurten A. , Koch Manuela C. , Grzeschik Karl‐Heinz
Published: March 2005

Previously we have described a novel and distinct form of non‐syndromic osseous syndactyly segregating in an autosomal recessive pattern in a consanguineous Pakistani family. The limb findings include mesoaxial reduction of the fingers, synostoses of the third and fourth metacarpals with associated single phalanges, fifth finger clinodactyly, and preaxial webbing of toes. We identified another published report of this phenotype in a large, inbred Turkish family. In the present study we mapped the phenotype in the Pakistani and Turkish families to chromosome 17p13.3 (multipoint LOD score 5.1). The identification of a single locus for this complex limb malformation in two families with distinct ethnic backgrounds supports the hypothesis that this is a distinct form of syndactyly. Since this form of syndactyly is phenotypically distinct from the previously described eight types, we propose to name this phenotype mesoaxial synostotic syndactyly with phalangeal reduction (MSSD, type IX syndactyly, Malik–Percin type). © 2005 Wiley‐Liss, Inc.
Why are rare traits unilaterally expressed?: Trait frequency and unilateral expression for cranial nonmetric traits in humans
Authors: Hallgrímsson Benedikt , Donnabháin Barra Ó , Blom Deborah E. , Lozada Maria C. , Willmore Katherine T.
Published: March 2005

Based on an analysis of nonmetric trait databases from several large skeletal series in Northern Europe and South America, representing 27 bilateral traits, we report a predictable relationship between the frequency of nonmetric traits and the probability that they are expressed bilaterally. In a wider sampling of traits and populations, this study thus confirms the findings of an earlier study by Ossenberg ([1981] Am. J. Phys. Anthropol. 54:471–479), which reported the same relationship for two mandibular traits. This trend was previously explained by extending the multifactorial threshold model for discontinuous traits to incorporate either separate thresholds for unilateral or bilateral expression, or by a fuzzy threshold in which the probability of bilateral expression increases away from the median threshold value. We show that the trend is produced under the standard multifactorial threshold model for discontinuous traits simply if the within‐individual or developmental instability variance remains relatively constant across the range of liability. Under this assumption, the number of individuals in which one side but not the other is pushed over the threshold for trait formation will be a larger proportion of the number of individuals expressing the trait when the trait frequency is low. As trait frequency increases, the significance of within‐individual variance as a determinant of trait formation decreases relative to the genetic and among‐individual environmental variance. These results have implications for interpreting nonmetric trait data as well as for understanding the prevalence of unilateral vs. bilateral expression of a wide variety of discontinuous traits, including dysmorphologies in humans. Am J Phys Anthropol 128:14–25, 2005. © 2005 Wiley‐Liss, Inc.
Genetic diversity of JC virus in the Saami and the Finns: Implications for their population history
Authors: Ikegaya Hiroshi , Zheng Huai‐Ying , Saukko Pekka J. , Varesmaa‐Korhonen Leena , Hovi Tapani , Vesikari Timo , Suganami Hideki , Takasaka Tomokazu , Sugimoto Chie , Ohasi Yasuo , Kitamura Tadaichi , Yogo Yoshiaki
Published: March 2005

The JC virus (JCV) genotyping method was used to gain insights into the population history of the Saami and the Finns, both speaking Finno‐Ugric languages and living in close geographic proximity. Urine samples from Saami and Finns, collected in northern and southern Finland, respectively, were used to amplify a 610‐bp JCV‐DNA region containing abundant type‐specific mutations. Based on restriction site polymorphisms in the amplified fragments, we classified JCV isolates into one of the three superclusters of JCV, type A, B, or C. All 15 Saami isolates analyzed and 41 of 43 Finnish isolates analyzed were classified as type A, the European type, and two samples from Finns were classified as type B, the African/Asian type. We then amplified and sequenced a 583‐bp JCV‐DNA region from the type A isolates of Saami and Finns. According to type‐determining nucleotides within the region, we classified type A isolates into EU‐a1, ‐a2, or ‐b. Most type A isolates from Saami were classified as EU‐a1, while type A isolates from Finns were distributed among EU‐a1, EU‐a2, and EU‐b. This trend in the JCV‐genotype distribution was statistically significant. On a phylogenetic tree based on complete sequences, most of the type A isolates from Saami were clustered in a single clade within EU‐a1, while those from Finns were distributed throughout EU‐a1, EU‐a2, and EU‐b. These findings are discussed in the context of the population history of the Saami and the Finns. This study provides new complete JCV DNA sequences derived from populations of anthropological interest. Am J Phys Anthropol 128:185‐193, 2005. © 2005 Wiley‐Liss, Inc.