bluuebunny/crossref_metadata_2025 huggingface dataset:
Metal accumulation byCeratitis capitata(Diptera) and transfer to the parasitic waspCoptera occidentalis(Hymenoptera)
Authors: Kazimírová Mária , Ortel Johanna
Published: March 2010

Accumulation of lead (Pb), cadmium (Cd), and copper (Cu) (from food) by the fruit fly (Ceratitis capitata Wiedemann; Diptera, Tephritidae) and the transfer of the metals to the internal solitary pupal parasitoid Coptera occidentalis Muesebeck (Hymenoptera, Proctotrupoidea, Diapriidae) were investigated experimentally by exposing host larvae to contaminated diets. Each metal was added to the diet at two concentrations: Cd, 50 and 100 μg/g; Pb and Cu, 400 and 800 μg/g diet dry weight. Whole-body concentrations of the applied metals and of zinc (Zn) in the host and parasitoid were determined by atomic absorption photospectrometry. Concentration factors (CFs) for all metals (based on initial dietary concentrations) were lower at the higher food contamination level. Cadmium (CF = 3.2–7.05) and Zn (CF = 2.79–7.05) were accumulated by fruit fly larvae more efficiently than were Pb (CF = 0.95–1.02) and Cu (CF = 0.35–0.78, except control: 37.2). Considerable quantities of the metals taken up by host larvae and retained in their pupae were eliminated via the meconium after eclosion of flies (Cd, 33%; Pb, 33–51%; Cu 24–39% of pupal metal burdens). Low proportions of the host metal content were transferred to the parasitoid (0.4–5.6% and 0.3–1.4% to pupae and adults, respectively, depending on the applied metal). The remaining amounts of the metals were detected in the host puparia that remained after wasp eclosion. Vitality and fecundity of the parasitoid were not impaired by host metal contamination. Thus, the parasitic wasp probably possesses an efficient regulatory mechanism that mediates excretion of toxic metals before pupation and that diminishes the potential hazard of high metal loads in the host.
Seasonal variation in radiocesium levels of largemouth bass (Micropterus salmoides): Implications for humans and sensitive wildlife species
Authors: Peles John D , Philippi Tom , Smith Michael H , Brisbin I Lehr , Gibbons J Whitfield
Published: March 2010

To examine seasonal variation in levels of radiocesium (137Cs) within largemouth bass (Micropterus salmoides; N = 589), fish were collected monthly over a one-year period from an abandoned reactor cooling reservoir. Month of collection, sex, age, and body mass (log transformed) were all significant factors influencing 137Cs concentrations. Levels of 137Cs reached a peak in late winter/early spring (February/March), and minimum values occurred in the fall (October). An asymmetric sawtooth model with a four-month period of increase and an eight-month period of decrease fit the data for monthly 137Cs values significantly better than symmetric sinusoidal and sawtooth models. The mean concentration of 137Cs for bass collected during all months was 7.09 Bq/g wet mass. All individuals examined, regardless of month, sex, age, or body mass, had 137Cs levels (2.95–12.60 Bq/g) that were much higher than the maximum level (0.60 Bq/g wet mass) generally considered safe for human consumption. Radiocesium is relatively long-lived within this reservoir and will continue to remain an important issue in risk assessments for both humans and wildlife species.
Growth of fathead minnows in oilsand-processed wastewater in laboratory and field
Authors: Siwik Paula L , Van Meer Terry , MacKinnon Michael D , Paszkowski Cynthia A
Published: March 2010

Two waste products of Syncrude Canada Ltd. (SCL) oilsands mine are mature fine tailings (MFT), a toxic aqueous suspension of particles, organic acids, bitumen, and metals, and tailings pond water (TPW), a saline solution containing organic and inorganic contaminants. The chemical profiles of MFT interstitial water and TPW are very similar. Syncrude Canada has proposed disposing of MFT in constructed lakes, which would be lined with MFT and capped with clean water. As the MFT consolidates, MFT-associated water would be released into the overlying watercap. Prototype ponds support fathead minnows (Pimephales promelas), but the long-term viability of these populations is unknown. This study attempts to determine if exposure to MFT and TPW, a related waste product, affected growth of fathead minnow larvae in the laboratory and field. Laboratory larval growth bioassays (7 and 56 d) on whole effluent from numerous prototype ponds yielded no significant differences in dry weight, but one 7-d bioassay showed reduced survival in two SCL sites. A 56-d growth bioassay showed significant increases in length of fish exposed to SCL wastewater at 7 d but not at 28 or 56 d. Larvae exposed as embryos and then introduced into field mesocosms did display significant differences in dry weight. In this instance, fish exposed to wastewater were significantly larger during the laboratory portion of the test (initial), but after 21 d in a field mesocosm (final), they were similar in size or smaller than fish growing in nonprocessed water.
Development of sediment toxicity test with tropical peneid shrimps
Authors: Moraes Rosane B C , Pfeiffer Wolfgang C , Guimarães Jean R D , Borges Alexandre Luiz N. , Campos Alexandre N
Published: March 2010

A methodology to test the toxicity of marine and estuarine sediments was developed using postlarval organisms of the marine shrimp Penaeus schmitti and P. paulensis. The tests were conducted in aquariums with a water feedback system and a sediment layer of 2 cm. The postlarvae exposure time to the sediments was 10, 28, and 52 d. The tested sediments were collected in contaminated sites of Guanabara and Sepetiba Bays and at the reference site of Ilha Grande inlet in Rio de Janerio, Brazil. The toxicity of the sediments was evidenced with exposures of 28 d or longer. The sediment from Saco do Engenho (Sepetiba Bay) was the most toxic, affecting the survival of both P. schmitti and P. paulensis. The sediment from Guanabara Bay was toxic to P. schmitti, affecting its survival after 28 d of exposure.
Kinetic analysis of zinc accumulation in the gills of juvenile rainbow trout: Effects of zinc acclimation and implications for biotic ligand modeling
Authors: Alsop Derek H , Wood Chris M
Published: March 2010

Juvenile rainbow trout were acclimated to hard water (Ca2+ = 1.0 mM, Mg2+ = 0.2 mM; hardness = 120 mg CaCO3/L) and hard water plus 250 μg/L Zn (3.8 μM). After 30 d of exposure, there was no difference in the total Zn levels of the gills of Zn-exposed and control fish (˜70 μg Zn/g gill). Exposure of both groups to a range of Zn concentrations (0–2,900 μg/L Zn) for up to 7 d also had no effect on the measured total Zn levels in the gills. However, using radiolabeled 65Zn, measurement of new Zn appearance in the gills was possible. Trout were exposed to a range of Zn concentrations (with 65Zn) and the gills were sampled at times ranging from 0.5 to 72 h. The fast turnover pool of Zn in the gills increased with increasing acute Zn exposure concentration, while the maximum size of the fast pool was about ninefold larger in Zn-acclimated fish (4.14 μg Zn/g gill) versus control fish (0.45 μg Zn/g gill). At all sampling times, gill 65Zn accumulation exhibited saturation kinetics, allowing calculation of binding capacity (Bmax) and affinity (Kd). In both control and Zn-acclimated trout, Kd decreased rapidly (affinity increased) from 0.5 to 3 h and then remained constant up to 72 h. Bmax increased rapidly from 0.5 to 3 h in both groups, then the rate of increase began to subside but was still increasing from 24 to 72 h. At all times, the Kd of Zn-acclimated fish was higher (i.e., lower affinity) and Bmax was greater than controls. The stabilized Kds (>3 h) were approximately 280 μg/L total Zn (log K = 5.6 as Zn2+) and 575 μg/L total Zn (log K = 5.3 as Zn2+) in control and Zn-acclimated fish, respectively. The Bmax of control fish at 0.5 h was 0.37 μg Zn/g gill and increased to 8.63 μg Zn/g gill by 72 h. The Bmax of Zn-acclimated fish increased from 0.70 to 11.61 μg Zn/g gill over the same time period. Preexposure to 250 μg/L Zn appeared to have little effect on acute zinc toxicity, though the 96-h LC50s for both groups were relatively high (˜3,000 μg/L Zn) in comparison to previous measurements. The relationship between gill binding constants for different metals and relative toxicity is critically assessed with respect to biotic ligand modeling.
Acute toxicity data: A comprehensive comparison of results of fish, daphnia, and algae tests with new substances notified in the European Union
Authors: Weyers Arnd , Sokull-Klüttgen Birgit , Baraibar-Fentanes Joaquin , Vollmer Gerald
Published: March 2010

Acute toxicity data from the New Chemicals Database of the European Chemicals Bureau were compared for fish, Daphnia, and algae. The algal growth inhibition test was the most sensitive. Correlation between fish and Daphnia toxicity values was better than the correlation with algae. Toxicity values among the three organisms correlated more strongly than any with log Pow.
Evaluation of methods to remove ammonia interference in marine sediment toxicity tests
Authors: Ferretti James A , Calesso Diane F , Hermon Tonia R
Published: March 2010

Ammonia naturally accumulates to high concentrations in nonsurficial marine sediments. It can also interfere and confound interpretation of toxicity from persistent anthropogenic chemicals in tests with laboratory amphipods. Renewal of overlying water has become a standardized procedure to decrease pore-water ammonia. Our objective was to propose an alternative technique for decreasing pore-water ammonia concentrations. Sediment samples with ammonia concentrations of 70 and 155 mg/L were purged of toxic concentrations in pore-water ammonia using the existing procedure of performing two renewals of overlying water per day. A thin-layer technique, which involved increasing the sediment surface area during the purging period, decreased the ammonia concentration by as much as 4.5-fold faster than the conventional purging protocol. Minimal decreases in concentrations of polycyclic aromatic hydrocarbons, heavy metals, and total organic carbon were found among all the purging techniques. Toxicity tests with the marine amphipod Ampelisca abdita suggest that minimizing the time required to purge a sediment of ammonia is critical in maintaining the integrity of the sample. The thin-layer purging technique appears to be an effective method of decreasing pore-water ammonia concentrations in sediments before laboratory toxicity testing with amphipods.
Pesticide residues in the aquatic environment of banana plantation areas in the North Atlantic Zone of Costa Rica
Authors: Castillo Luisa E. , Ruepert Clemens , Solis Efrain
Published: March 2010

A study of pesticide residues in surface waters and sediments was undertaken in the Suerte River Basin, Costa Rica, that drains into the Tortuguero conservation area. Samples were collected in streams, packing plants, and the Suerte River. The most frequently measured compounds in surface water samples were the fungicides thiabendazole, propiconazole, and imazalil; the nematicides terbufos and cadusafos; and the insecticide chlorpyrifos. At the conservation area, propiconazole was detected in 43% of the samples at concentrations ranging from 0.05 to 1.0 μg/L. In 25% of the samples collected at this site, a nematicide (cadusafos, carbofuran, or ethoprophos) was detected (0.06–6.2 μg/L). According to this study, most of the insecticide-nematicides analyzed pose a risk for acute or chronic toxicity to aquatic organisms based on the exposure levels and toxicity values from the literature. Ametryn, imazalil, and thiabendazole also exceeded the calculated chronic risk ratio. The most frequently detected compounds in sediments were thiabendazole, chlorpyrifos, imazalil, and propiconazole. The occurrence was higher in the packing plants and streams. Pesticides in waters and sediments of Tortuguero conservation area could pose a threat to this wetland and an additional stress to the endangered species that inhabit this area. More information is needed regarding the distribution and stability of pesticides in the lagoon system as well as of the effects of mixtures of low levels of pesticides and their degradation products on representative species of the Tortuguero ecosystem. Meanwhile, all measures to reduce the emissions of pesticides from the banana plantations and the packing plants should be taken.
Competitive displacement reactions of cadmium, copper, and zinc added to a polluted, sulfidic estuarine sediment
Authors: Simpson Stuart L , Rosner Joanne , Ellis John
Published: March 2010

The competitive displacement reactions occurring after the addition of Cd, Cu, and Zn to a polluted, sulfidic estuarine sediment were studied. Pore-water metal measurements indicated that added Cd and Zn reacted quantitatively with the acid-volatile sulfide (AVS) fraction (primarily FeS) of the sediments to form CdS and ZnS, whereas Cu reacted to form Cu2S, not CuS as is often assumed. The titration of a synthetic FeS phase, with Cu(II) in a strictly oxygen-free environment was used to provide a mechanistic illustration of the formation of Cu2S involving the reduction of Cu(II) to Cu(I) by Fe(II). Although this reduction reaction is not thermodynamically favorable in acidic solutions, in near-neutral pH environments the dual precipitation of Cu2S (reduced phase) and FeOOH (oxidized phase) is the driving force for the reaction. Only when the sedimentary AVS (FeS) phase had been exhausted did the added Cu displace Zn and Cd ions from their respective binding phases. Likewise, Cd added in excess of the molar AVS (FeS) concentration displaced Zn from less stable solid phases. These observations, although commonly predicted by thermodynamics, have seldom been demonstrated in real sediments and provide evidence that AVS (FeS) is the most reactive phase in anoxic sediments. The metal additions caused large disturbances to the sediment redox potential. This was attributed to disruption of the HS-/SO 42− redox equilibrium position by precipitation of HS− as metal sulfide phases. Although these redox changes did not seem to affect the partitioning of Cd, Cu, or Zn to the reactive sulfide phase (AVS), significant changes to the pore-water metal speciation may be expected. The effects of these observations on metal bioavailability for sediment toxicology studies that utilize metal-spiked sediments during method development are discussed.
Diffusion and degradation of atrazine in a water/sediment system
Authors: Mersie Wondi , McNamee Clyde , Seybold Cathy A , Tierney Dennis P
Published: March 2010

This study determined the effects of temperature and residence time on diffusion and degradation of [14C]atrazine applied to the surface of sterilized and nonsterilized river water over a sediment. Water and sediment were placed in glass columns and incubated at 5 or 24°C. Samples were collected at 0, 7, 14, 28, 42, 56, and 112 d before and after disturbance. The warmer temperature (24°C) initially increased the rate of 14C distribution in the aqueous phase. Disturbance caused approximately 15% of the total 14C to be removed from the aqueous phase by sterile or unsterile sediment incubated at 5°C. At 24°C, the level of 14C in disturbed sediments incubated for more than 28 d gradually increased. This increased retention of 14C by sediment coincided with greater detection of the polar metabolite hydroxyatrazine (HA). More HA was recovered in nonsterilized than in sterilized sediments, indicating the contribution of biological processes to the production of this metabolite. In undisturbed sediments at 24°C, approximately 32% and 10% of the applied 14C permeated the top and bottom 1-cm segments, respectively. In columns incubated at 5°C, less than 5% of the 14C reached the surface of the submerged sediment. The potential impact of atrazine on biota associated with sediment would diminish with time because of dilution in the aqueous phase, transformation to HA, and bound residue formation.
Association of organotin compounds with aquatic and terrestrial humic substances
Authors: O'Loughlin Edward J , Traina Samuel J , Chin Yu-Ping
Published: March 2010

Organotin-humic substance (OT-HS) binding constants ( Kdoc) were determined by equilibrium-binding studies using dialysis techniques. The OT-HS binding was characterized by linear isotherms. The Kdoc values measured in this study were several orders of magnitude greater than would be predicted based only on nonpolar interactions with HS (as estimated by Kow). Binding of tri-n-butyltin (TBT) by Aldrich humic acid decreased with increasing salinity and pH, indicating that ionic interactions predominate in TBT-HS binding. Thus, the binding of OT by HS observed in this study occurs primarily through complexation, with secondary contributions from nonpolar interactions. The effects of the physicochemical properties of HS (e.g., molecular weight, % aromaticity, oxygen content) on TBT-HS binding was examined with HS from a range of sources, including a commercial humic acid and HS from aquatic and terrestrial sources. Although binding of organic contaminants by HS has been correlated with various structural features of HS, no meaningful relationship between any of the HS properties examined in this study and the extent of TBT-HS binding was found.
Differential binding of endogenous steroids and chemicals to androgen receptors in rainbow trout and goldfish
Authors: Wells Kelly , Van Der Kraak Glen
Published: March 2010

Androgen receptors (ARs) from fish were characterized in order to evaluate differences in the binding affinities of steroids and environmental chemicals between mammals and fish, among species offish, and among target tissues within a species of fish. High-affinity, low-capacity ARs were identified in cytosolic fractions of rainbow trout brains (Oncorhynchus mykiss) and the brains, ovaries, and testes of goldfish (Carassius auratus) using [3H]testosterone. The binding specificities of endogenous steroids to the ARs did not differ between goldfish tissues but did differ between goldfish and rainbow trout. Interspecies differences in binding specificities were also seen using cyproterone acetate, which bound to the ARs in the goldfish tissues, but not in the rainbow trout brains. The mammalian antiandrogens flutamide, vinclozolin and its metabolites 2-(((3,5)-dichlorophenyl-carbamo-yl)oxy)-2-methyl-3-butenoic acid and 3′,5′-dichloro-2-hydroxy-2-methylbut-3-enanilide, along with procymidone did not bind to the ARs in any of the fish tissues tested. However, other mammalian antiandrogens including methoxychlor and its metabolite 2,2-bis(p-hydroxyphenyl)-1,1,1-trichloroethane, o,p′-DDT, o,p′-dichlorodiphenyldichloroethylene (DDE) and p,p′-DDE did bind to the fish ARs, but only in the goldfish testes, demonstrating tissue differences in AR binding specificities of environmental chemicals. These results may be due to the presence of multiple AR isoforms in the different fish species and tissues. This study supports the growing evidence of species differences in the potency and actions of endocrine-disrupting chemicals and suggests that multiple species need to be tested when screening the receptor binding ability of potential endocrine-disrupting chemicals.
Implication of polymer toxicity in a municipal wastewater effluent
Authors: Rowland Carolyn D , Burton G Allen , Morrison Stephen M
Published: March 2010

The use of cationic polymers as flocculants and coagulant aids to control suspended solid levels in the water and wastewater treatment industry is widespread in most developed countries. Today, the most frequently used clarification polymers, polyacrylamides, are often proprietary, and little information exists on the ecological impacts of these products. Following standard U.S. Environmental Protection Agency (U.S. EPA) whole effluent toxicity testing (WET) protocols, effluent toxicity can be detected via organism response, yet methods to positively characterize cationic polymers in effluents are not provided in U.S. EPA Phase I toxicity identification evaluation (TIE) protocols. Implication of cationic polymer toxicity in a municipal wastewater effluent was achieved through a series of Ceriodaphnia dubia toxicity testing with toxicant elimination steps that included extensive effluent characterization and effluent manipulation. Key in the identification was a discrepancy in effluent toxicity with respect to the type of container in which the effluents were stored. All effluent toxicity was lost within 48 h of storage in plastic containers, while on the contrary, effluent toxicity persisted in glass-contained samples for up to 4 weeks of 4°C storage. A weight-of-evidence approach suggested that the cationic polyacrilamide polymer, Hyperfloc®, was the primary source of acute toxicity in the effluent. Removal of this polymer significantly reduced effluent toxicity. This study suggests that cationic polymer-related toxicity might not be detected if effluent samples are stored in plastic containers.
Results of an interlaboratory evaluation of an analytical screening method for assessing persistent bioaccumulative toxic chemicals in sediment samples
Authors: Silva-Wilkinson Robin A , DeGraeve G Michael , Burkhard Lawrence P , Tholen Daniel W , Sheedy Barbara R
Published: March 2010

An inter- and intralaboratory evaluation was performed on a recently developed sediment screening method designed to detect a wide range of persistent bioaccumulative toxins (PBTs). Ten participating laboratories analyzed sediment samples, and their results were evaluated. The analyses demonstrated that laboratories that were better prepared to perform the screening method generally characterized each of the sediment samples in a similar fashion and had 80% average interlaboratory agreement in reporting the presence or absence of chemical classes in the samples. The results of this study suggest that the sediment screening method for PBTs is reasonably reproducible when performed by properly prepared and experienced laboratories.
Environmental contaminants in Texas, USA, wetland reptiles: Evaluation using blood samples
Authors: Clark Donald R , Bickham John W , Baker Denise L , Cowman Deborah F
Published: March 2010

Four species of reptiles (diamondback water snake [Nerodia rhombifer], blotched water snake [N. erythrogaster], cottonmouth [Agkistrodon piscivorus], and red-eared slider [Trachemys scripta]) were collected at two contaminated and three reference sites in Texas, USA. Old River Slough has received intensive applications of agricultural chemicals since the 1950s. Municipal Lake received industrial arsenic wastes continuously from 1940 to 1993. Blood samples were analyzed for organochlorines, potentially toxic elements, genetic damage, and plasma cholinesterase (ChE). Dichlorodiphenyldichloroethylene (DDE) concentrations reached as high as 3.0 ppm (wet weight) in whole blood of a diamondback water snake at Old River Slough, a level probably roughly equivalent to the maximum concentration found in plasma of peregrine falcons (Falco peregrinus) in 1978 to 1979 when DDE peaked in this sensitive species. Possible impacts on diamondback water snakes are unknown, but at least one diamondback water snake was gravid when captured, indicating active reproduction. Arsenic was not found in red-eared sliders (only species sampled) from Municipal Lake. Red-eared sliders of both sexes at Old River Slough showed declining levels of ChE with increasing mass, suggesting a life-long decrease of ChE levels. Possible negative population consequences are unknown, but no evidence was found in body condition (mass relative to carapace length) that red-eared sliders at either contaminated site were harmed.
Biomarker response and health of polychlorinated biphenyl- and chlordane-contaminated paddlefish from the Ohio River Basin, USA
Authors: Gundersen Deke T , Miller Ruthellen , Mischler Amy , Elpers Krista , Mims Steve D , Millar Jody G , Blazer Vicki
Published: March 2010

Fifty paddlefish (Polyodon spathula) collected from two sites on the Ohio River and from one site on the Cumberland River, USA, were examined to determine gonad polychlorinated biphenyl (PCB) and chlordane concentrations, amounts of plasma sex steroids (testosterone and estradiol), hepatic microsomal ethoxyresorufin-O-deethylase (EROD) activity, and the presence of immunoreactive cytochrome P450 1A (CYP1A) protein. Percent hatch and liver, spleen, and kidney histology were also determined. Gonad PCB and chlordane concentrations were significantly higher in Ohio River paddlefish than in Cumberland River paddlefish. Gonad PCB and chlordane concentration and gonad percent lipid were correlated in Ohio River paddlefish. Five of 10 Ohio River egg samples exceeded the Food and Drug Administration's action limit for chlordane (0.30 μg/g). Polychlorinated biphenyl congener-specific analysis detected predominantly the tetra-, penta-, and hexachlorobiphenyls in paddlefish testes. Plasma testosterone levels were significantly lower in males collected from the upper Ohio River site than those collected from the lower part of the river. There was no measurable hepatic microsomal EROD activity in any of the 50 paddlefish collected from the three sites. Western blotting analysis confirmed that a rabbit antitrout CYP1A1 IgG antibody did not recognize a CYP1A protein in paddlefish liver microsomes. Percent hatch was not significantly different in eggs collected from the Cumberland (88–96%) and Ohio Rivers (90–95%). Histological analysis of liver, spleen, and kidney detected the presence of hepatic steatosis and hemosiderosis, splenic lymphoid cell depletion, and hyperplasia of interrenal and chromaffin tissues. Immunosuppression, hepatic metabolic disorders, and altered neuroendocrine function may be occurring in Ohio River paddlefish. Results presented here suggest that organochlorine exposure may be jeopardizing the long-term health of Ohio River paddlefish and that additional investigation of contaminant effects on immune system function and hormone levels in paddlefish is warranted.
Effects of pesticide spraying on chick growth, behavior, and parental care in tree swallows (Tachycineta bicolor) nesting in an apple orchard in Ontario, Canada
Authors: Bishop Christine A , Ng Peggy , Mineau Pierre , Quinn James S , Struger John
Published: March 2010

The objective of this study was to investigate the consequences of the use of cholinesterase (ChE)-inhibiting insecticides in an apple orchard on behavior and growth of tree swallows (Tachycineta bicolor). In a sprayed apple orchard and two nonsprayed sites in southern Ontario, Canada, in 1996 through 1997, hunger signaling and growth of chicks, feeding activities of adults, and aerial invertebrate abundance were studied before and after insecticide spray events. In the orchard, persistent and significant increases occurred in hunger signaling by tree swallow chicks after organophosphorus (OP) insecticide spray events in both years and, after a second OP insecticide spray in 1996, significant decreases occurred in the number of feeding trips by parent birds. These trends did not occur in the control sites. After spray events in the orchard, the trends in feeding sorties of adult birds during chick-rearing did not coincide with known experimental responses in tree swallows subjected to reduced food resources. However, trends were consistent with those predicted to occur in adult passerines exposed to ChE-inhibiting insecticides. In contrast, the increased hunger signaling by chicks may reflect chronically low food resources available in the orchard but does not indicate ChE depression. Few differences were found among sites in the size and type of aerial invertebrates caught in traps. Very low densities of invertebrates occurred in the orchard relative to the other locations but the abundance did not vary significantly with insecticide events. Despite changes in avian behaviors associated with insecticide sprays, differences in masses of chicks among sites and after spray events were not related to insecticide use in the orchard. Because first-year survival of tree swallow chicks is correlated with their mass at fledging, this suggests a need to maintain relatively natural habitats with abundant food resources near sprayed agricultural areas.
Physiological effects of chronic copper exposure to rainbow trout (Oncorhynchus mykiss) in hard and soft water: Evaluation of chronic indicators
Authors: Taylor Lisa N , McGeer James C , Wood Chris M , McDonald D Gordon
Published: March 2010

Effects of chronic copper exposure on a suite of indicators were examined: acute toxicity, acclimation, growth, sprint performance, whole-body electrolytes, tissue residues, and gill copper binding characteristics. Juvenile rainbow trout were exposed for 30 d to waterborne copper in hard water (hardness = 120 mg/L as CaCO3, pH = 8.0, Cu = 20 and 60 μg/L) and soft water (hardness = 20 mg/L as CaCO3, pH = 7.2, Cu = 1 and 2 μg/L). Significant acclimation to the metal occurred only in fish exposed to 60 μg/L, as seen by an approx. twofold increase in 96-h LC50 (153 vs 91 μg Cu/L). Chronic copper exposure had little or no effect on survival, growth, or swimming performance in either water hardness, nor was there any initial whole-body electrolyte loss (Na+ and Cl−). The present data suggest that the availability of food (3% wet body weight/day, distributed as three 1% meals) prevented growth inhibition and initial ion losses that usually result from Cu exposure. Elevated metal burdens in the gills and livers of exposed fish were measures of chronic copper exposure but not of effect. Initial gill binding experiments revealed the necessity of using radiolabeled Cu (64Cu) to detect newly accumulated Cu against gill background levels. Using this method, we verified the presence of saturable Cu-binding sites in the gills of juvenile rainbow trout and were able to make estimates of copper-binding affinity (log Kgill=Cu) and capacity (Bmax). Furthermore, we showed that both chronic exposure to Cu and to low water calcium had important effects on the Cu-binding characteristics of the gills.
Three lines of evidence in a sediment toxicity evaluation for hexachlorobutadiene
Authors: Fuchsman Phyllis C , Sferra James C , Barber Timothy R
Published: March 2010

Three approaches were used in a site-specific sediment toxicity evaluation for hexachlorobutadiene (HCBD), a chemical not previously tested for toxicity in sediment. The results of a sediment dilution study, spiked sediment toxicity tests, and a probabilistic model based on equilibrium partitioning theory were used to estimate ecological effects thresholds for HCBD in sediments of a Gulf Coast estuary. Twenty-nine sediment samples, including 11 undiluted samples and six dilution series, were tested for toxicity under estuarine conditions (10%0 salinity) using Hyalella azteca and Leptocheirus plumulosus. Site sediment was used as diluent, and all samples were assayed for a range of organic and inorganic chemicals. A logistic relationship was observed between HCBD concentrations and organism response, and nonlinear regression explained approximately 90% of the observed variation in amphipod survival as a function of HCBD. Spiked sediment toxicity test results generally agreed with the results of the dilution study, demonstrating the causality of the observed concentration–response relationship. Effects thresholds were estimated as HCBD concentrations corresponding to 80% amphipod survival. The most conservative effects thresholds from the spiked sediment and dilution studies were 0.63 mg/kg normalized to 1% total organic carbon (mg/kg1%OC) for H. azteca and 1.4 mg/kg1%OC for L. plumulosus. Aquatic LC50s for 10 species and a measured acute–chronic ratio from the published literature were used to predict a distribution of sediment effects thresholds for HCBD, with 10th and 90th percentile values of 2.6 and 45 mg/kg1%OC, respectively. The predicted and observed sediment effects thresholds thus agreed relatively well, although the H. azteca and L. plumulosus test results from this study seem to be somewhat more conservative than the majority of published aquatic toxicity test results.
Predictability of the toxicity of a multiple mixture of dissimilarly acting chemicals toVibrio fischeri
Authors: Backhaus Thomas , Altenburger Rolf , Boedeker Wolfgang , Faust Michael , Scholze Martin , Grimme L Horst
Published: March 2010

A promising tool for the risk assessment of chemical mixtures is the prediction of their toxicities from the effects of the individual components. For that purpose, concentration addition is uniformly regarded as valid for mixtures of similarly acting chemicals. Whether this concept or the competing notion of independent action is more appropriate for mixtures of dissimilarly acting chemicals is still in dispute. Therefore, the presented study analyzed and compared the predictive capabilities of both concepts for a multiple mixture designed of strictly dissimilarly acting compounds. Experimental investigations were conducted using a long-term bioluminescence inhibition assay with Vibrio fischeri. Results show an excellent predictive power of independent action, while concentration addition overestimates the mixture toxicity. Thus, the precise prediction of mixture toxicities depends on a valid assessment of the similarity/dissimilarity of the mixture components. However, concentration addition underestimates the EC50 of the mixture only by a factor of less than three. As the similarity of components is often unknown for mixtures found in the environment, it is concluded that concentration addition may give a realistic worst case estimation of mixture toxicities for risk assessment procedures.
Priority setting for existing chemicals: Automated data selection routine
Authors: van Haelst Anniek G , Hansen Bjorn G
Published: March 2010

One of the four steps within Council Regulation 793/93/EEC on the evaluation and control of existing chemicals is the priority setting step. The priority setting step is concerned with selecting high-priority substances from a large number of substances, initially starting with 2,474 high-production-volume chemicals. In order to be able to efficiently carry out the priority setting step, an automated priority setting method was developed, the so-called European Union risk ranking method (EURAM). The EURAM produces rankings among the high-production-volume chemicals appearing in the International Uniform ChemicaL Information Database (IUCLID). As part of a publication series, this paper deals with the data selection criteria used in EURAM and furthermore with data validation of the selected data. To validate the selected data in EURAM, comparisons are made with validated data of priority chemicals for which European Union risk assessment reports have been completed or with data of priority chemicals from the Screening Information Data Set initial assessment reports of the Organization for Economic Cooperation and Development. Regression analysis between the selected data in EURAM and the data selected by expert judgment in the assessment procedure resulted in good correlation for physicochemical properties and aquatic toxicity data. In addition, the type of biodegradation (i.e., readily biodegradable, inherently biodegradable, or nonbiodegradable) selected by EURAM also was in agreement with the type of biodegradation selected by expert judgment in the risk assessment procedure. Hence, the good correlation between the automated data selection procedure of EURAM and the data selection by expert judgment indicates that the data selection criteria of EURAM, which are developed in order to select data for priority purposes among high-production-volume chemicals in IUCLID, seem to perform well.
Quantification of in vivo biotransformation of the anionic surfactant C12-2-linear alkylbenzene sulfonate in fathead minnows
Authors: Tolls Johannes , Lehmann Michael P , Sijm Dick THM.
Published: March 2010

Linear alkylbenzene sulfonate (LAS) is a major surfactant in household detergents and enters the environment via the wastewater. Aquatic organisms are thus exposed to LAS and can bioaccumulate this compound. Even though the extent of bio-accumulation is determined by the organisms' capability of metabolizing LAS, little is known about metabolism of LAS in small aquatic organisms. In the present investigation, we present a novel approach to quantify in vivo biotransformation. Fish (fathead minnows [Pimephales promelas]) were exposed to the LAS constituent 2-n-(p-sulfophenyl)-dodecane (C12-2-LAS). The parent surfactant and its biotransformation product 3-n-(p-sulfophenyl)-butyric acid (C4-3-SPC) were determined in fish tissue. On the average, the concentration of C4-3-SPC in fish was 70 to 80% of that of C12-2-LAS. The first-order one-compartment model of bioconcentration was extended to include biotransformation as an explicit process. Analysis of the C4-3-SPC/C12-2-LASconcentration ratio in fish allowed estimating a rate constant for in vivo biotransformation of C12-2-LAS in fathead minnows. With the estimates of the biotransformation rate constant (kBT,LAS) ranging between 0.31 and 0.72/d, biotransformation contributes to more than 40% of the elimination of C12-2-LAS in fathead minnows. This indicates that biotransformation is a significant process in reducing the bioaccumulation potential of LAS. Moreover, the present investigation demonstrates that the combination of measurements of parent compound and metabolite with an extended bioaccumulation model is a viable approach for quantification of biotransformation in small aquatic test animals.
Spiking hydrophobic organic compounds into soil and sediment: A review and critique of adopted procedures
Authors: Northcott Grant L , Jones Kevin C
Published: March 2010

Studies on the fate and effects of organic pollutants in soil and sediment are often carried out under laboratory conditions and often require the study compound to be introduced, or spiked, into the test substrate. The procedures adopted to spike relatively large amounts of hydrophobic organic compounds into soil and sediment can introduce interferences into experiments that have the potential to dominate the process(es) under investigation. This review identifies and discusses key factors of spiking procedures that can introduce significant interferences to experiments. These include soil or sediment drying and rewetting, effects of carrier solvents, and the homogeneity of spike distribution. The persistence of solvents, and therefore their contribution to soil and sediment organic carbon, is discussed with reference to potential effects on the partitioning behavior of spiked compounds. We have summarized the spiking procedures used in 64 published articles and have evaluated the information supplied by authors. From this analysis, we conclude that, in general, authors should report more detailed information regarding the procedural aspects of compound spiking. We conclude that standard operating procedures need to be validated and recommended for spiking organic compounds into soil and sediment by recommended organizations. As an aid to this process, we recommend a number of practices to observe when spiking organic compounds into soil and sediment.
Biodegradability properties of sulfonamides in activated sludge
Authors: Ingerslev Flemming , Halling-Sørensen Bent
Published: March 2010

Twelve different sulfonamides were selected for a biodegradation study using a respirometric screening test and an activated sludge simulation test. A simple bacterial growth inhibition test was applied to show that the sulfonamides did not affect the bacteria at the concentration levels used. None of the compounds were degraded in the screening test, leading to the conclusion that sulfonamides cannot be classified as readily biodegradable. In the simulation test, primary degradation of mixtures of four compounds at concentration levels of 250 to 500 μg/L were tested and analyzed using high-performance liquid chromatography. Biodegradation occurred after lag phases of 7 to 10 d at 20°C when nonadapted sludge was applied. Test compounds were degraded within a few days. At 6°C, degradation lag phases and degradation rates were three to four times longer. Degradation curves fit well to the logistic growth model, indicating growth of specific degraders in the test system. Sulfonamide adapted bacterial cultures were able to degrade either the same compounds as previously added or four other sulfonamides in a rapid and uniform way (t1/2 from 0.2 to 3 d). This finding shows that if capable of degrading one sulfonamide substance, these bacteria may also degrade many other sulfonamides. In practice, this implies that because the biodegradation rate is found to be identical for several sulfonamides in the sludge, the compounds may be assessed as a group by studying only a few compounds in applications such as environmental fate assessments. The mechanism for inducement of sulfonamide adaptation to the bacteria was not revealed in this study.
Influence of zwitterionic pH buffers on the bioavailability and toxicity of copper to the alga Amphidinium carterae
Authors: Vasconcelos M Teresa SD , Almeida Cristina MR , Lage Olga M , Sansonetty Filipe
Published: March 2010

The culture and testing of algae frequently requires stabilization of pH levels to maintain the availability of trace metals. In this work we evaluated the influence of 25 × 10−3 M N-[2-hydroxyethyl]piperazine-N′-[2-hydroxypropanesulfonic acid] (HEPPSO) and piperazine-N,N′-bis[2-hydroxypropanesulfonic acid] (POPSO) pH buffers, at pH 8.0, on the biological response of Amphidinium carterae Hulburt. Growth rate, copper uptake, mean cell size, mean cell complexity, and fluoresce in labeling of algae cultures were studied in enriched solutions of artificial seawater (ESAWs) containing a range of total copper(II) concentrations between 23 × 10−9 M (level before copper addition) and 15 × 10−6 M. The ESAW (without a pH buffer, initial pH = 8.0) was used as the control medium. Initial free copper (Cufree) was between 53 × 10−15 and 72 × 10−10 M, which represents ranges of concentrations typical of unimpacted and polluted surface seawater. These ranges were achieved using ehtylenediaminetetraacetic acid (EDTA) alone and in combination with the two buffers. Biological data endpoints were interpreted based on the cellular copper (Cucelluar, in fmol/cell) and on the estimated initial inorganic copper (Cuinorg = Cufree plus that bound with inorganic ligands) in the medium. At innocuous Cuinorg, up to 10 × 10−9 M (Cufree ≤ 4 × 10−11 M), the Cucellular was independent of the presence of the buffer and very little dependent of Cuinorg. For Cuinorg up to 0.40 × 10−9 M, the Cucellular was approximately constant (0.1-0.2 fmol/cell) and when Cuinorg ranged between 1.1 × 10−9 M and 10 × 10−9 M the Cucellular was three times higher but also constant. The POPSO enhanced copper uptake and toxicity. The HEPPSO reduced uptake and toxicity of copper because of its enhanced binding capacity compared to POPSO. Both HEPPSO and POPSO altered copper effects on mean cell size, mean cell complexity and fluorescein labeling of A. carterae, but the inherent mechanisms differed between the two buffers. This present work demonstrated that the chemical binding affinity of HEPPSO and POPSO differed and that it resulted in altered uptake and effects of copper on algae. These observations have important implications in culture and testing of algae that require metals as micronutrients yet are sensitive to metals at concentrations that exceed basic metabolic needs.
Soil and plant diet exposure routes and toxicokinetics of lindane in a terrestrial isopod
Authors: Sousa José Paulo , Loureiro Susana , Pieper Silvia , Frost Mathias , Kratz Werner , Nogueira António JA , Soares Amadeu MVM.
Published: March 2010

In most studies dealing with effects of toxic substances in saprotrophic isopods, animals are exposed to the test substance through contaminated food. Because these animals can be in a close contact with the soil surface, the substrate, as an exposure pathway, should not be neglected. Here the authors analyze the toxicokinetic behavior of lindane (γ-hexachlorocyclohexane [γ-HCH]) in the isopod species Porcellionides pruinosus, comparing two exposure routes: food and two soil types (artificial Organisation for Economic Cooperation and Development [OECD] soil and a natural agricultural soil). In the feeding experiment, a strong decrease of γ-HCH concentration over time was observed on the food material, with the animals showing a broader range in chemical assimilation efficiency values (averaging 17.7% and ranging from 10 to 40%). The γ-HCH bioaccumulation results indicate that when animals incubated under both soil types reached a steady state, they displayed much higher body burdens (1,359.60 pg/animal on OECD soil and 1,085.30 pg/animal on natural soil) than those exposed to contaminated food (43.75 pg/animal). Kinetic models also revealed much lower assimilation and elimination rates in the food experiment (20.66 pg/d and 0.10 pg/d) than in both soil experiments (238.60 pg/d and 350.54 pg/d for the assimilation rate and 0.19 pg/d and 0.32 pg/d for the elimination rate). Differences in results between exposure routes are discussed according to equilibrium-partitioning theory and the enhanced relevance of the substrate exposure route is analyzed under future prospects on chemical toxicity testing using isopods.
Ecotoxicological and analytical assessment of effects of bioremediation on hydrocarbon-containing soils
Authors: Saterbak Ann , Toy Robin J , McMain Bruce J , Williams M Patty , Dorn Philip B
Published: March 2010

Ecotoxicological assessments of contaminated soils require an understanding of the impact of chemicals on the terrestrial ecosystem. Eight hydrocarbon-containing field soils were evaluated using physical-chemical, hydrocarbon, and ecotoxicological assays during 11 to 13 months of laboratory bioremediation. Ecotoxicity tests included earthworm (Eisenia fetida) 14-d survival and reproduction assays and seed germination and root length assays using corn, lettuce, mustard, and wheat seeds. During bioremediation, freon-extractable total petroleum hydrocarbon decreased by 26 to 84%, depending on the soil. In most soils, earthworm survival increased to or remained at 100% following bioremediation. Earthworm reproduction increased or remained the same relative to control soils. Lettuce and mustard seed germination increased following bioremediation except in two soils with high salt concentrations. Corn and wheat germination was high on most soils and did not change following bioremediation. Root length responses varied among seeds and soils, increasing in some soils and remaining unchanged in others. The responses of organisms to hydrocarbon-containing field soils directionally improved with bioremediation.