bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of 2,3,7,8-TCDD exposure on survival, growth, and behavior of ospreys breeding in Wisconsin, USA
Authors: Woodford James E , Karasov William H , Meyer Michael W , Chambers Laura
Published: March 2010

Osprey (Pandion halieatus) eggs collected from areas (Castle Rock and Petenwell Flowages) 7 km downstream from two bleached-kraft mill facilities from 1992 to 1996 contained much higher levels of 2,3,7,8-tetrachlordibenzo-p-dioxin (range = 29 to 162 pg/g wet weight, n = 18) than eggs collected from two reference areas upstream (range = below detection limits to 23.8 pg/g, n = 15). Levels in eggs of the remaining planar halogenated hydrocarbon congeners and other nonplanar organochlorines were not statistically different between the contaminated and upstream areas (p > 0.05). We placed eggs from the contaminated area into nests at both reference areas (group A) and eggs from the reference areas into nests at the contaminated area (group B). No significant differences in egg hatching or chick fledging rates were observed between these groups and nests left unmanipulated at both reference areas (group C) and the contaminated area (group D). Mass increase rates of chicks differed significantly (p = 0.03), with the highest rates from group C and the lowest rates from group B. This difference cannot be easily attributed to differences in parental nest attentiveness or food provisioning, which were greater at the contaminated area. We conclude that although current planar halogenated hydrocarbon exposure levels were not affecting hatching and fledging rates, they may have affected chick growth.
The functional integrity of northern leopard frog (Rana pipiens) and green frog (Rana clamitans) populations in orchard wetlands. II. Effects of pesticides and eutrophic conditions on early life stage development
Authors: Harris Megan L , Bishop Christine A , Struger John , Ripley Brian , Bogart James P
Published: March 2010

Premetamorphic northern leopard frogs (Rana pipiens) and green frogs (Rana clamitans) were evaluated at seven wetland sites, four of which were within apple orchards, to determine if environmental conditions associated with orchard management in southern Ontario, Canada, affected frog early development. Synchronous with breeding events (May–July), embryos and tadpoles were exposed, in situ and in the laboratory, to study site pond water for 2 to 3 weeks. Six pesticides commonly applied in apple orchards (Guthion® 50WP, Imidan® 50WP, Thiodan® 50WP, Dithane® DG, Nova® 40W, and Basudin® 500EC) and technical grade diazinon were also evaluated for direct toxicity to green frogs using continuous and discontinuous toxicity tests. Embryos and larvae exhibited poor hatching success and survival at some orchard sites during in situ assays, but no specific water source produced consistently poor developmental success. Reduced tadpole growth occurred at several study sites, showing no clear distinction between reference and orchard sites. Despite the collection of substantial environmental data, only surface water temperature appeared to be correlated with growth rates. Basudin 500EC, technical grade diazinon, and Dithane DG caused mortality, deformities, or growth inhibition during early development at environmentally relevant concentrations (<0.01 mg/L), whereas Imidan 50WP, Guthion 50WP, and Nova 40W produced survival or growth effects at much higher levels (5–10 mg/L). Dithane DG (mancozeb) was acutely toxic during prolonged exposures, and sublethal growth and deformity responses occurred at nominal concentrations greater than 0.01 mg/L. Diazinon was the most toxic to green frogs, with median lethal concentrations of 2.8 to 5 μg/L and median effective concentrations of 6 to 14 μg/L for formulation and technical grades, respectively. The combined results of in situ and laboratory tests of green frog and leopard frog developmental success suggested that embryo—larval development of these two species could be accomplished at all study sites, independent of the association with apple orchards.
Effects of azinphos-methyl on northern bobwhite: A comparison of laboratory and field results
Authors: Matz Angela C , Bennett Richard S , Landis Wayne G
Published: March 2010

The U.S. Environmental Protection Agency's (U.S. EPA's) ecological risk assessment process uses laboratory toxicity data in quotient indices to characterize risks to wildlife, but with poor understanding of the relationship between these data and actual field effects. To explore this relationship, we compared toxicity results from a controlled field study to those from a dietary toxicity (median lethal concentration) laboratory test. In the field test, northern bobwhite (Colinus virginianus) chicks were cross-fostered to bantam chicken (Gallus domesticus) hens. Then, 12-d-old broods in enclosed alfalfa fields were exposed to sprayed azinphos-methyl (Guthion® 2S) at three application rates (0 [control], 0.77, and 3.11 kg active ingredient/ha). Chick survival was significantly lower at 3.11 kg/ha 0 to 5 d postspray and at both application rates 6 to 10 d postspray compared to control (p < 0.05). Chick brain acetylcholinesterase (AChE) activity, growth, and weight of crop contents were significantly reduced in treatments compared to control (p < 0.05). In the laboratory test, 12-d-old bobwhite were exposed to dietary concentrations of 0 (control), 150, 240, 380, and 600 ppm azinphos-methyl for 5 d. Survival was significantly lower at 600 ppm compared to control, and brain AChE activity and growth rates were significantly reduced from control for all concentrations (p < 0.05). Chick survival, brain AChE activity, and growth in the field were significantly different from equivalent exposures in the laboratory (p < 0.05), with equivalency determined by U.S. EPA's vegetation residue estimates, and temporal patterns of effects differed between field and laboratory. We conclude that the effects observed in the field differed from that predicted by risk quotients because the quotient method does not consider alternate routes of exposure, behavioral responses, influence of spatial and temporal environmental variability, or indirect effects.
Acute toxicity of nonpolar versus polar narcosis: Is there a difference?
Authors: Vaes Wouter H J , Ramos Eñaut Urrestarazu , Verhaar Henk J M , Hermens Joop L M
Published: March 2010

Narcosis I and II chemicals exhibit different lethal body burdens (LBBs) and acute toxicities (median lethal concentrations [LC50's]) in fish, when compared with their log n-octanol-water partition coefficient (Kow). The higher toxicity of polar narcosis chemicals has often been suggested to be related to the polar group in these molecules. Recently we showed that membrane (L-α-dimyristoyl phosphatidyl-choline [DMPC])–water partition coefficients (log KDMPC) are higher than log Kow for narcosis II chemicals. Using log KDMPC to model the acute toxicities to fish (log LC50) of the two classes of chemicals together, gives one high-quality quantitative structure-activity relationship (R2 = 0.98, Q2 = 0.97). In addition, assuming that the apolar fat-water partition coefficient behaves like the n-octanol–water partition coefficient, differences in LBB can also be explained. Thus, using log KDMPCs, all earlier reported quantitative differences between narcosis I and II chemicals can be explained.
Effects of a mixture of non-ortho- and mono-ortho-polychlorinated biphenyls on reproduction in Fundulus heteroclitus (Linnaeus)
Authors: Black Dianne E , Gutjahr-Gobell Ruth , Pruell Richard J , Bergen Barbara , McElroy Anne E
Published: March 2010

To assess the effects of polychlorinated biphenyls (PCBs) on reproduction, female Fundulus heteroclitus were exposed to a mixture of non-ortho- and mono-ortho-PCBs, mimicking the mixture found in fish collected from New Bedford Harbor, Massachusetts, USA, a PCB-contaminated estuary. Exposure was by intraperitoneal injection of the mixture dissolved in corn oil. Doses of 0.76, 3.8, and 19 μg PCB mixture per gram of wet weight produced liver concentrations of 2.99, 12.2, and 32.8 μg non-ortho-and mono-ortho-PCBs per gram of dry liver, with dioxin toxic equivalency concentrations (TEQs) of 0.063, 0.409, and 0.720 ng/g, respectively. Female mortality was 58%, and egg production was reduced by 77% at the highest dose, compared to controls. Food consumption declined with increasing PCB concentration, suggesting that PCBs act indirectly to reduce fecundity through an energetic effect. Pituitary gonadotropin content appeared to be suppressed at the highest dose, but the ability of ovarian follicles to produce estradiol and testosterone in vitro was not impaired. Significant residue-effects linkages were found, with TEQ emerging as a potential indicator of adverse effects. Mortality was directly related, and egg production was inversely related to log10TEQ. Multiple regression analysis indicated that egg production was directly related to pituitary gonadotropin content and food consumption.
Derivation of soil quality criteria using predicted chemical speciation of Pb2+ and Cu2+
Authors: Sauvé Sébastien , Dumestre Alain , McBride Murray , Hendershot William
Published: March 2010

A review is made of soil toxicological data that report soil total lead or copper in combination with soil pH. Using these data, free metal activities in the soil solution of those tests are estimated using published regressions that describe the relationships between metal activities and the total metal content, pH, and soil organic matter content. The toxicological significance of the predicted free metal activities is compared to that of total metal contents. In a majority of cases, estimated free metal activity improves the prediction for toxic effects on crops, soil organisms, or soil microbial processes. The free metal activity level corresponding to a defined level of risk can be used to derive a pH-dependent soil criterion for total metal content that should generate a soil solution-free metal activity below the determined critical level.
Toxicity to embryo and adult zebrafish of copper complexes with two malonic acids as models for dissolved organic matter
Authors: Palmer Felicity B. , Butler Catherine A. , Timperley Michael H. , Evans Clive W.
Published: March 2010

The toxicity to embryo and adult zebrafish (Danio rerio) of Cu complexes with two substituted malonic acids, benzyl‐ and n‐hexadecyl‐, chosen as models for low‐molecular‐weight natural dissolved organic matter, were investigated. Toxicity test solutions at pH 6.5 ± 0.1 with the required Cu speciation were designed using the chemical speciation model MINTEQA2, and the speciation was confirmed by Cu ion‐specific electrode. In the absence of malonic acids, concentrations of Cu2+ up to 1.13 μmol/ L increased the embryo hatching time from approx. 2 d in control solutions (no Cu or malonic acid) and solutions containing malonic acids without Cu to approx. 8 d. The Cu‐benzylmalonic acid complex (n‐octanol/water distribution coefficient [ρow] = 0.00) in the presence of inorganic Cu species did not delay hatching beyond that attributable to Cu2+, In contrast, 0.60 μmol/L Cu‐n‐hexadecylmalonic complexes (ρow = 6.89) delayed hatching by 5.5 d in excess of that attributable to 1.13 μmol/L Cu2+, assuming that the hatching delays caused by the different Cu species were additive, possibly because of Cu entry into the embryo as the lipophilic Cu‐ n‐hexadecylmalonic complex. None of the Cu‐malonic acid complexes was acutely toxic to adult zebrafish at concentrations up to 1.4 μmol/L, possibly because Cu was removed from the Cu‐malonic acid complexes by stronger chelating groups at the gill surface. Substituted malonic acids with similar proton and Cu association constants can be readily prepared with a variety of simple substituents, radiolabeled if required. Our results show that these acids could be useful ligands for investigating intracellular transport and metabolism of metal‐organic complexes.
Evaluation of the immunotoxicity of chlorothalonil to striped bass phagocytes following in vitro exposure
Authors: Baier-Anderson Cal , Anderson Robert S
Published: March 2010

The fungicide chlorothalonil (TCIN), with both agricultural and horticultural applications, is a common aquatic pollutant. The immunotoxic potential of TCIN was investigated following a 20-h in vitro exposure of striped bass (Morone saxatilus) macrophages to a range of sublethal concentrations. Cells from the anterior kidney were separated by density-gradient centrifugation to obtain a macrophage-enriched cell population. Following TCIN exposure, reactive oxygen species (ROS) production was evaluated using luminol-augmented chemiluminescence; phagocytic capacity was measured by the ingestion of fluorescein isothiocyanate-conjugated yeast; and NADPH production was estimated by monitoring the reduction of a water-soluble tetrazolium, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt. Results indicate that TCIN, at concentrations ≥250 μg/L, decreased ROS production in both zymosan- and phorbol myristate acetate (PMA)-stimulated cells in a dose-dependent manner. The PMA-stimulated NADPH production coincident with the respiratory burst was also decreased at concentration ≥250 μg/L. The TCIN did not appear to alter phagocytic ability. Taken together, these results indicate that the mechanism of toxicity affects the activation or function of the NADPH oxidase but not the uptake of particles by phagocytosis, and that these effects can probably be localized to the signal transduction pathway or the assemblage of NADPH oxidase.
Acute toxicity of a didecyldimethylammonium chloride-based wood preservative, bardac 2280, to aquatic species
Authors: Farrell Anthony P , Kennedy Christopher J , Wood Antony , Johnston Blair D , Bennett William R
Published: March 2010

The acute toxicity of the antisapstain wood preservative Bardac 2280 (principal active ingredient 80% didecyldimethylammonium chloride, DDAC) was tested with four fish and four aquatic invertebrate species. White sturgeon fry (Acipenser transmontanus) were the most sensitive fish species tested with a 24-h 50% lethal concentration (LC50) value between 1 and 10 ppb Bardac 2280. The 96-h LC50 values for the three other fish species ranged from 0.39 ppm for fathead minnows (Pimephales promelas) to 2.0 ppm for juvenile starry flounder (Platichthys stellatus). Developmental stage altered the sensitivity of coho salmon to Bardac 2280, with alevins being approximately twice as sensitive as smolts. Altering salinity up to 30‰ seawater had no significant effect on the toxicity of Bardac 2280 to coho smolts. The 48-h LC50 values for Daphnia magna, Mysidopsis bahia, Hyalella azteca, and Neomysis mercedis were 0.037 ppm, 0.039 ppm, 0.106 ppm, and 0.947 ppm, respectively. Bardac 2280 characteristically produced steep concentration–response curves for fish, i.e., a concentration range considerably less than 10-fold for a complete range of mortality, and caused no major symptoms of sublethal stress in juvenile starry flounder following a 24-h exposure.
Toxicity of water-soluble fractions derived from whole creosote and creosote-contaminated sediments
Authors: Padma Tiruponithura V , Hale Robert C , Roberts Morris H
Published: March 2010

Creosote, a complex mixture of aromatic compounds (ACs), contaminates numerous sites in the USA and elsewhere. In addition to pollution of the water column directly after a creosote spill, contaminated sediments can continue to act as source of pollution for many years, because natural and anthropogenic perturbations may redissolve or resuspend sediment-associated contaminants. A 48-h static renewal assay compared survival of the bay mysid, Mysidopsis bahia, exposed to water-soluble fractions (WSFs) generated from two different sources: whole creosote and creosote-contaminated sediment. Sediment was obtained from a Super Fund site located on the Southern Branch of the Elizabeth River in Virginia, USA. Whole creosote, contaminated sediment, and WSFs derived from these source materials were characterized. Median lethal concentrations of WSFs generated from whole creosote and sediment (expressed as total identified ACs) were 180 μg/L and 700 μg/L, respectively. The creosote-derived WSF consisted of more than 70% low molecular weight nitrogen heterocyclics. These heterocyclics were below detectable limits in the sediment-generated WSF, suggesting that losses of these compounds had occurred via weathering. Nitrogen heterocyclics likely contributed to the acute toxicity of the whole creosote WSF.
Risk identification associated with iron-dominated mine discharges and their effect upon freshwater bivalves
Authors: Milam Cristin D , Farris Jerry L
Published: March 2010

The controlled release of a partially treated mine-water discharge dominated by iron was evaluated for impact on the aquatic community during July and August of 1993 in southeastern Ohio. The discovery of an endangered mussel species, Lampsilis abrupta, prompted further validation of a lowest observable effect concentration for the discharge as it was diluted by the Ohio River. In-stream monitoring detected no significant postrelease responses among individuals of the surrogate species Quadrula quadrula from sites above and below the release. To evaluate the effects of the mine water on bivalve mollusks, laboratory simulation of the controlled release conditions using artificial streams and 30 daily renewals of mine water revealed that cellulolytic activity of Corbicula fluminea was reduced in mine-water exposures as low as 1.25% (0.19 mg Fe[II]/L). Recovery was evaluated for 30 d after initial exposure and indicated that specific response thresholds for siphoning and bioconcentration were apparent for the bioavailable form of iron and that enzyme activity for exposed Corbicula could return to prestress conditions. Bivalve responses to this threshold limit for the iron-dominated mine effluent were compared to other standardized test responses (acute and chronic effects using Daphnia pulex, Ceriodaphnia dubia, and Pimephales promelas) and resulted in support of criteria for the bioavailable form of iron at 0.37 mg ferrous iron/L.
Hydroxylated and methylsulfonyl polychlorinated biphenyl metabolites in albatrosses from Midway Atoll, North Pacific Ocean
Authors: Klasson-Wehler Eva , Bergman Åke , Athanasiadou Maria , Ludwig James P , Auman Heidi J , Kannan Kurunthachalam , Berg Martin Van Den , Murk Albertinka J , Feyk Lori A , Giesy John P
Published: March 2010

Concentrations of hydroxylated metabolites of polychlorinated biphenyls (PCBs) (OH-PCBs) and methylsulfonyl metabolites of PCBs (MeSO2-PCBs) were determined in plasma and liver of albatrosses collected from the Midway Atoll in the central North Pacific Ocean. The mean total concentrations of OH-PCBs in plasma of Laysan albatrosses (Diomedea immutabilis) and black-footed albatrosses (Diomedea nigripes) were 11.5 and 27.1 ng/g wet weight, respectively. Total concentrations of OH-PCBs were only one- to fivefold less than those of total PCBs. 4-hydroxy-2,2′,3,4′,5,5′,6-heptachlorinated biphenyl and 4-hydroxy-2,2′,3,4′,5,5′-hexachlorinated biphenyl were the predominant polychlorinated biphenylols, constituting 70 to 90% of the total OH-PCBs. Concentrations of MeSO2-PCBs in liver were between 10.6 and 77 ng/g, lipid weight, approximately 250 times less than those of total PCBs. The MeSO2-PCBs congeners retained in the liver were dominated by those having the methylsulfonyl group in the 3-position.
Metapopulation dynamics: Indirect effects and multiple distinct outcomes in ecological risk assessment
Authors: Spromberg Julann A , John Bettina M , Landis Wayne G
Published: March 2010

A toxicant-dosed metapopulation model was used to explore the range of possible dynamics of populations in contaminated field sites. A single species metapopulation model was developed that is discrete, deterministic, and incorporates doseresponse curves and biotic growth rates to describe the effects of contamination on a metapopulation. The distribution of the chemical contamination is assumed limited to one patch and contagious within that patch. Both persistent and degradable toxicants were modeled. Five principal conclusions resulted from our simulation studies. (1) Mortality in one subpopulation has ecologically significant effects on nondosed subpopulations. This hypothesis we term “action at a distance” because no direct contact with a toxicant has occurred except in the dosed patch. (2) Because uncontaminated sites connected to the contaminated site by migration of the biota are affected, these uncontaminated sites cannot be reference sites. (3) The arrangement of the patches is critical to the dynamics of the system and the overall impact of a toxicant. (4) Due to the contagious distribution of the toxicant and the stochastic function describing exposure effect, multiple discrete outcomes often are possible from the same initial conditions. These outcomes can range from extinction to the reaching of the carrying capacity for a patch. (5) If sufficient cleanup is not possible, it may be necessary to isolate the contaminated patch, allowing the formerly connected patches to regain more typical population dynamics.
Bioconcentration kinetics of hydrophobic chemicals in different densities of Chlorella pyrenoidosa
Authors: Sijm Dick T H M , Broersen Kelvin W , de Roode Daphne F , Mayer Philipp
Published: March 2010

Algal density-dependent bioconcentration factors and rate constants were determined for a series of hydrophobic compounds in Chlorella pyrenoidosa. The apparent uptake rate constants of the hydrophobic compounds in algae varied between 200 and 710,000 L/kg/d, slightly increased with hydrophobicity within an experiment, were relatively constant for each algal density, and fitted fairly within existing allometric relationships. The bioavailability of the hydrophobic test compounds was significantly reduced by sorption by algal exudates. The sorption coefficients of the hydrophobic compounds to the algal exudates were between 80 and 1,200 L/kg, and were for most algal densities in the same order of magnitude as the apparent bioconcentration factors to the algae, that is, between 80 and 60,200 L/kg. In typical field situations, however, no significant reduction in bioavailability due to exudates is expected. The apparent elimination rate constants of the hydrophobic compounds were high and fairly constant for each algal density and varied between 2 and 190/d. Because the apparent elimination rate constants were higher than the growth rate constant, and were independent of hydrophobicity, we speculated that other factors dominate excretion, such as exudate excretion-enhanced elimination. Bioconcentration factors increased less than proportional with hydrophobicity, i.e., the octanol–water partition coefficient [Kow]. The role of algal composition in bioconcentration is evaluated. Bioconcentrations (kinetics) of hydrophobic compounds that are determined at high algal densities should be applied with caution to field situations.
Removal of alcohol ethoxylates, alkyl ethoxylate sulfates, and linear alkylbenzene sulfonates in wastewater treatment
Authors: McAvoy Drew C , Dyer Scott D , Fendinger Nicholas J , Eckhoff William S , Lawrence David L , Begley William M
Published: March 2010

An environmental monitoring study was conducted to assess the removal of alkyl ethoxylate sulfates (AESs), alcohol ethoxylates (AEs), and linear alkylbenzene sulfonates (LASs) during wastewater treatment. Samples were obtained from six trickling filter and four activated sludge treatment plants located in the midwestern United States. The average removal rates for AESs, AEs, and LASs in activated sludge treatment were 98, 97, and >99%, respectively. Lower and more variable removal rates were observed at trickling filter treatment plants with average values of 83, 90, and 82% for AESs, AEs, and LASs, respectively. Using average influent concentrations and removal rates, the predicted exposure concentrations for these surfactants in U.S. receiving waters immediately below treatment plant outfalls were less than their corresponding biological predicted no-effect concentrations in greater than 98% of the locations under low-flow conditions.
Environmental transformation mechanisms of thiodiglycol
Authors: Lee K Patrick , Allen Herbert E
Published: March 2010

The fate of thiodiglycol (TDG) in environmental samples was studied through analysis of batch solid-solution suspensions. We monitored aqueous-phase TDG concentrations and thiodiglycolic acid (TGDA) concentrations by high-performance liquid chromatography with ultraviolet detection. We investigated TDG and TDGA sorption to six soils. Thiodiglycol sorption was insignificant, with a maximum sorption capacity of less than 10 mg/kg. Sorption of TDGA varied, with maximum sorption capacities ranging from 19.9 to 427.4 mg/kg. Photolysis, hydrolysis, and the presence of iron oxide and aluminum oxide had little effect on the fate of TDG and TDGA. However, manganese oxide sorbed TDG and was pH dependent. Biological transformation of TDG to TDGA, with the formation of [(2-hydroxyethyl)thio]acetic acid (TDGMA) as an intermediate, occurred with zero-order rate coefficients ranging from 0 to 6.26 × 10−6 mol/L·h−1. Biological toxins hindered this transformation. The major process affecting TDG was biotransformation to form TDGMA and subsequently its biotransformation to TDGA.
Estrogenicity of selected biphenyls evaluated using a recombinant yeast assay
Authors: Schultz T. Wayne , Kraut Daniel H , Sayler Gary S , Layton Alice C
Published: March 2010

The estrogenic activity of biphenyl and 4-hydroxylatedderivatives with varied levels of chloro- and/or hydroxyl substitution was measured in a Saccharomyces cerevisiae-based lac-Z (β-galactosidase) reporter assay. β-Galactosidase activity was compared with competitive binding to soluble mouse uterine estrogen receptor protein. The comparison of relative potency for biphenyls hydroxylated on one ring and chlorinated on the other ring (n = 5) revealed excellent correlation between the two systems (r2 = 0.995). However, estrogenicities of biphenyls hydroxylated and chlorinated on the same ring were not in agreement. Although weak ligand binding was demonstrated for these compounds, β-galactosidase activity was not observed. Rather, these compounds were shown to be cytotoxic to yeast. The results of this study further support the hypothesis that both an unhindered phenolic ring and molecular symmetry are structural features associated with estrogenicity.
Chemical accumulation and toxicological stress in three brown bullhead (Ameiurus nebulosus) populations of the Detroit River, Michigan, USA
Authors: Leadley Todd A , Balch Gordon , Metcalfe Chris D , Lazar Rodica , Mazak Edward , Habowsky Joseph , Haffner G Douglas
Published: March 2010

Three populations of brown bullheads (Ameiurus nebulosus) were sampled in the Detroit River and analyzed for concentrations of persistent organic contaminants as well as incidences of external lesions and liver histopathology. Chemical analysis revealed that both the sediments and the bullheads of the Trenton Channel had the highest concentrations of organochlorine compounds, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons compared with the other two sites (Amherstburg Channel and Peche Island). Furthermore, the Trenton Channel bullhead population had a higher prevalence of external abnormalities such as lip and skin lesions as well as truncated barbels. Histopathological analysis of the livers revealed higher prevalences of cholangiocarcinomas, cholangiomas, and other lesions in the Trenton Channel population. These observations support the conclusion that the health of the Trenton Channel bullhead population in the Detroit River is affected by exposure to organic chemicals, primarily through exposure to contaminated sediments.
Profenofos toxicity to the eastern rainbow fish (Melanotaenia duboulayi)
Authors: Kumar A , Chapman John C
Published: March 2010

The 96-h median lethal concentration for profenofos in the Australian eastern rainbow fish (Melanotaenia duboulayi) was 0.9 mg/L, corresponding with an 83% reduction in acetylcholinesterase (AChE) activity in fish head. This is an order of magnitude less sensitive than the figure reported for crucian carp (Carassius carassius). Higher lethal body burdens were found in rainbow fish exposed to high concentrations of profenofos but the inhibition of AChE activity in these fish was less than in those killed by longer, normally sublethal, exposures. During sublethal exposure to 10 μg/L for 10 d, the fish accumulated profenofos residues of 5.3 mg/kg associated with a 70% reduction in AChE activity in fish head. Decreases in food intake, food conversion efficiency, and growth were observed at 10 d and significant loss of weight was noted at 21 d. These were associated with markedly increased swimming activity and response to light. A clear relationship existed between the depression of AChE activity and observed behavioral responses, such as swimming activity and food intake.
Effects of copper on immune system parameters of rainbow trout (Oncorhynchus mykiss)
Authors: Dethloff Gail M , Bailey Howard C
Published: March 2010

Aricultural, urban, industrial, and mining sources release metals into waterways. The effects of sublethal concentrations of metals on integrated physiological processes in fish, such as immunocompetency, are not well understood. The objective of this study was to determine the physiological effects of a range of sublethal copper concentrations (6.4, 16.0, and 26.9 μg Cu/L) on Shasta-strain rainbow trout (Oncorhynchus mykiss) exposed in soft water. Trout were sampled after 3, 7, 14, and 21 d of exposure to copper. The percentage of monocytes was consistently elevated at 26.9 μg Cu/L, and the percentage of lymphocytes was decreased. A consistent increase in the percentage of neutrophils occurred at 26.9 and 6.4 μg Cu/L. Respiratory burst activity was decreased for all concentrations at all sampling days, but a significant reduction occurred only at 14 and 21 d of exposure to copper. B-like cell proliferation was decreased by exposure to the higher copper concentrations. Proliferation results, however, had high variability. T-like cell proliferation and phagocytosis were not altered. Hepatic copper concentration was consistently elevated in trout exposed to 26.9 μg Cu/L; no correlation was found between hepatic copper concentration and the immune system responses investigated. Consistent alterations in immunological parameters suggest that these parameters could serve as indicators of chronic metal toxicity in natural systems.
Comparative sensitivity of five species of macrophytes and six species of algae to atrazine, metribuzin, alachlor, and metolachlor
Authors: Fairchild James F , Ruessler D Shane , Carlson A Ron
Published: March 2010

This study determined the relative sensitivity of five species of aquatic macrophytes and six species of algae to four commonly used herbicides (atrazine, metribuzin, alachlor, and metolachlor). Toxicity tests consisted of 96-h (duckweed and algae) or 14-d (submerged macrophytes) static exposures. The triazine herbicides (atrazine and metribuzin) were significantly more toxic to aquatic plants than were the acetanilide herbicides (alachlor and metolachlor). Toxicity studies ranked metribuzin > atrazine > alachlor > metolachlor in decreasing order of overall toxicity to aquatic plants. Relative sensitivities of macrophytes to these herbicides decreased in the order of Ceratophyllum > Najas > Elodea > Lemna > Myriophyllum. Relative sensitivities of algae to herbicides decreased in the order of Selenastrum > Chlorella > Chlamydomonas > Microcystis > Scenedesmus > Anabaena. Algae and macrophytes were of similar overall sensitivities to herbicides. Data indicated that Selenastrum, a commonly tested green alga, was generally more sensitive compared to other plant species. Lemna minor, a commonly tested floating vascular plant, was of intermediate sensitivity, and was fivefold less sensitive than Ceratophyllum, which was the most sensitive species tested. The results indicated that no species was consistently most sensitive, and that a suite of aquatic plant test species may be needed to perform accurate risk assessments of herbicides.
Recovery of brain acetylcholinesterase and plasma cholinesterase activities in quail (Coturnix coturnix) after chlorpyriphos administration and effect of pralidoxime treatment
Authors: Soler-Rodriguez Francisco , Miguez-Santiyan Maria-Prado , Reja-Sanchez Antonio , Roncero-Cordero Vicente , Garcia-Cambero Jesus-Pablo
Published: March 2010

Chlorpyriphos (13 mg/kg) was administered to quail (Coturnix coturnix), and the responses of brain acetylcholinesterase (AChE) and plasma cholinesterase (ChE) were studied. Both enzymes responded rapidly, and the maximal inhibition (76.6 and 86.1%, respectively) ocurred 8 h postadministration. Plasma ChE recovered rapidly, and even on day 4, ChE values of quail that had received chlorpyriphos were higher than those of controls. The recovery of brain AChE activity was slower than that of plasma; it reached 59% of controls 2 d after chlorpyriphos administration, then it recovered slowly, and only at day 11 was its level not depressed with respect to controls. This recovery followed the logarithmic pattern Y = a + b(log X), where Y is the AChE activity expressed as the percentage with respect to controls and X is the day after dosing, giving a significant correlation (r = 0.9746, p < 0.001 when using group means and r = 0.9219, p < 0.001 when using individual values). No clinical signs or mortality were observed, and histopathological observations in the central nervous system (encephalytic reaction, necrotic Purkinje cells), liver (congestion, vacuolation), and kidney (congestion, nephrosis) were not severe and did not endanger the life of the quail. Sixteen hours after chlorpyriphos administration, some quail were treated with pralidoxime, which significantly reactivated brain AChE but not plasma ChE. However, this effect did not last for the rest of the experiment; because no signs of toxicosis appeared, the experiment was not repeated.
Action of resin acids in nerve ending fractions isolated from fish central nervous system
Authors: Zheng Jian , Nicholson Russell A
Published: March 2010

The actions of three resin acids (abietic acid, dehydroabietic acid, and 12,14-dichlorodehydroabieticacid) were investigated using synaptosomes isolated from the whole brain of the rainbow trout (Oncorhynchus mykiss). Exposure of synaptosomes to resin acids caused a concentration-dependent increase in synaptosomal free [Ca2+] that was unaffected by tetrodotoxin. 12,14-Dichlorodehydroabietic acid (EC50 = 12 μM) was five- to sixfold more potent as a calcium mobilizing agent compared to its nonchlorinated analog dehydroabietic acid (IC50 = 68 μM) and maximum increases in synaptosomal free [Ca2+] were estimated at approximately 325 nM and 260 nM, respectively. Although closer to dehydroabietic acid in potency, abietic acid was more efficacious, increasing synaptosomal free [Ca2+] by 500 nM at 133 μM. The requirement for extracellular Ca2+ was greatest for dehydroabietic acid compared to abietic acid or 12,14-dichlorodehydroabietic acid; however, none of the study compounds was capable of stimulating 45Ca2+ uptake or reducing 45Ca2+ efflux from synaptosomes. For 12,14-dichlorodehydroabietic and dehydroabietic acids only, the rises in synaptosomal free [Ca2+] were accompanied by significant reductions in synaptosomal adenosine triphosphate levels and increases in synaptosomal oxygen consumption. Electron microscopic studies have shown that the vesicular content of synaptosomes was dramatically reduced by treatment with all three study compounds. Our investigation suggests that resin acids have a strong calcium mobilizing action in nerve endings isolated from fish brain and chlorination increases potency. We postulate that resin acids mobilize Ca2+ from intracellular stores to facilitate neurotransmitter release and that for dehydroabietic acid (and to a lesser extent for abietic and 12,14-dichlorodehydroabietic acids), extracellular calcium is required for efficient penetration of the plasma membrane. The bioenergetic and respiratory disruption we observe is not closely linked to changes in cytosolic free [Ca2+].
Elemental fish tissue contamination in Northeastern U.S. Lakes: Evaluation of an approach to regional assessment
Authors: Yeardley Roger B , Lazorchak James M , Paulsen Steven G
Published: March 2010

The approach of the Environmental Monitoring and Assessment Program (EMA) to monitoring of fish tissue contaminants is shown to have utility for regional assessment, and for discrimination of regional from local contamination. The survey sampling design employed by EMAP can be used to make regional assessments without conducting a complete resource inventory. The Environmental Monitoring and Assessment Program—Surface Waters conducted a survey of 167 lakes in the northeastern United States during 1992 through 1994 and analyzed whole fish composite samples for contaminants, including Al, As, Cd, Cr, Cu, Fe, Hg, Ni, Pb, Se, and Zn. Using fish tissue contaminant consumption risk levels derived from U.S. Environmental Protection Agency hazard assessment models, methylmercury (MeHg) was determined to be the elemental contaminant of regional concern to fish consumers: 26% of lakes contained fish with MeHg exceeding a human critical value of 0.2 μg/g; 54 and 98% of lakes contained fish with MeHg exceeding wildlife critical values for piscivorous mammals (0.1 μg/g) and birds (0.02 μg/g), respectively. The other elements analyzed appeared to be at safe levels on a regional scale, or only of localized concern with regard to human health.
Accumulation of metals, polycyclic (halogenated) aromatic hydrocarbons, and biocides in zebra mussel and eel from the rhine and meuse rivers
Authors: Hendriks A Jan , Pieters Henk , de Boer Jacob
Published: March 2010

Concentrations of heavy metals and various groups of organic microcontaminants were measured in zebra mussel and eel from the Rhine–Meuse basin. Residues in mussel from the Rhine and Meuse were on average 2.3 and 2.9 times higher than in those from the reference location of IJsselmeer. Total body burdens of organic microcontaminants in mussel and eel varied between 0.05 to 0.07 mmol/kg fat weight in six out of seven samples. The largest contribution in mussels and eel came from polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), respectively. Concentrations of bromodiphenylethers, chlorobenzenes, chloronitrobenzenes, chloroterphenyls, and chlorobenzyltoluenes were lower. Total polybrominated biphenyl residues appear lower than total PCB levels. The largest chlorobiocide residues were noted for 4,4′-DDE, toxaphene, trichlorophenylmethane, and γ-hexachlorocyclohexane. An extraordinary high body burden of 1.2 mmol/kg fat weight, largely consisting of acenaphthene, was observed in one sample. Ratios of concentrations in organism fat and dry organic suspended solids varied between 1 and 10 for traditionally monitored organochlorines, independent of the octanol–water partition coefficient (Kow; for Kow < 106). The values did not deviate significantly from a value of about 3.3, expected for equilibrium partitioning of persistent chemicals. Lower values were observed for PAHs and some chloro(nitro)benzenes. Most ratios of concentrations in eel and mussel fat were within the range of 1 to 10, also largely independent of Kow. Yet, values tended to be higher at Kow > 106. Ratios below 1 were noted for pentabromodiphenylether, pentachloro(thio)anisol, chlorobenzyltoluenes, and some chloronitrobenzenes, chlorobiphenyls, and chlorobiocides. These field data confirm recent modeling efforts on bioconcentration and biomagnification. For heavy metals, atomic mass explained 67% of the variation in zebra mussel residues.
Sorption coefficients of polycyclic aromatic hydrocarbons for two lake sediments: Influence of the bactericide sodium azide
Authors: de Maagd P Gert-Jan , Sinnige Theo L , Schrap S Marca , Opperhuizen Antoon , Sum Dick T.H.M
Published: March 2010

Sorption coefficients (Kps) of a series of polycyclic aromatic hydrocarbons (PAHs) were determined in two Dutch freshwater lake sediments to improve the insight into sorption in the aquatic environment. The influence of experimental factors, such as compound concentration, equilibration time, and influence of a bactericide on Kp, was studied. No significant influence of compound concentration on Kp was found. A contact time of 48 h was sufficient to reach equilibrium between PAHs in the sediment and water phase. In the absence of the bactericide, sodium azide, incomplete mass balances, and high Kp of low molecular weight PAHs were found that were not caused by volatilization from, photodegradation in, or sorption by the test system. In the presence of sodium azide, however, high mass balances and lower Kp were found for these compounds. This suggested that significant biodegradation of these compounds occurred in the water phase in the absence of sodium azide. The organic carbon-normalized sorption coefficients (Koc) of the PAHs in Lake Oostvaardersplassen were two to three times higher than those in Lake Ketelmeer sediment. Although Koc of the PAHs differed for the two sediments, a clear relationship was found between Koc and the octanol/water partition coefficient for both sediments and between the Koc of both sediments. In conclusion, the methodology to determine Kp of biodegradable compounds should include the prevention of bacterial activity, e.g., by addition of sodium azide. Sorption of PAHs in the Dutch lake sediments is determined by the hydrophobicity of the PAH, the organic carbon content of the sediment, and one or more unspecified sediment-specific characteristics.
Wet deposition of current-use pesticides in the Sierra Nevada mountain range, California, USA
Authors: McConnell Laura L , LeNoir James S , Datta Seema , Seiber James N
Published: March 2010

Atmospheric inputs of pesticides transported from California's Central Valley to the Sierra Nevada mountains (California, USA) were investigated by collecting winter-spring precipitation (rain and snow) from Sequoia National Park and from the Lake Tahoe basin. Pesticides currently used in California's Central Valley were detected in snow and rain samples from two elevations in Sequoia National Park (SNP) in the southern Sierras. At the lower elevation site (533 m), chlorothalonil was present at the highest levels (<0.4–85 ng/L), followed by malathion (<0.046–24 ng/L), diazinon (<0.21–19 ng/L), and chlorpyrifos (1.3–4.4 ng/L). At 1,920 m elevation, chlorothalonil was also present at the highest levels (<0.57–13 ng/L) followed by diazinon (<0.057–14 ng/L), chlorpyrifos (1.1–13 ng/L), and malathion (<0.045–6 ng/L). Trifluralin, α- and γ-hexachlorocyclohexane (HCH), and α-and β-endosulfan were also detected at both locations and at lower concentrations, generally ranging from 0.5 to 2 ng/L. In the Lake Tahoe basin, elevation 2,200 m, malathion was also found in snow at concentrations ranging from <0.046 to 18 ng/L, as was diazinon (<0.057–7 ng/L), chlorpyrifos (0.30–3.4 ng/L), and chlorothalonil (0.66–1.7 ng/L). Chlorothalonil, chlorpryifos, α-and γ-HCH, and α-endosulfan were found in surface and deep water samples at two locations in Lake Tahoe and at concentrations similar to those found in snow within the lake basin. Lake Tahoe basin snow samples in general had lower concentrations than those from SNP. This difference in concentration levels reflects the closer proximity of downwind pesticide usage to SNP than the Lake Tahoe basin. An estimated annual loading of one chemical, chlorpyrifos, of 24 to 31 kg/year was made for the SNP land area. Comparisons of observed concentrations were made with reported aquatic toxicity and water criteria levels.
Comparison of toxicities and mechanism of action ofn-alkanols in the submitochondrial particle and theVibrio fischeribioluminescence (Microtox®) bioassay
Authors: Gustavson Karl E , Svenson Anders , Harkin John M
Published: March 2010

Many studies on the toxicity of n-alkanols have been conducted and quantitative structure-activity relationships (QSARs) established comparing bioassay toxicity data to carbon number. The results typically indicate increasing toxicity with increasing n-alkanol chain length, but often higher homologues are not assessed, where toxicity no longer increases with carbon number—a phenomenon commonly called the cutoff effect. The mode of toxic action of these compounds has been designated narcosis I; however, the specific mechanism is unknown and widely debated. This study compares results for two commonly used bioassays, the submitochondrial particle (SMP) and the Microtox® bioassay, for the homologous series of n-alkanols ranging from methanol (C1-OH) to stearyl alcohol (C18-OH). Analysis of dose-response curve slopes indicates that the SMP assay exhibits a general mechanism of toxicity, whereas the Microtox assay exhibits this general mechanism to short-chain alkanols, but subsequently switches to specific interaction with the higher alkanols. This specific interaction is likely competitive inhibition of the bacterial luciferase. Comparison of the toxicities in these assays with octanol/water partition coeffients (Kow), the results of whole-organism tests, and a bacterial luciferase assay further substantiate this claim and indicate that the SMP is a better model of toxicity in whole organisms.
Volatilization of extensively dechlorinated polychlorinated biphenyls from historically contaminated sediments
Authors: Bushart Sean P , Bush Brian , Barnard Edward L , Bott Amelie
Published: March 2010

A study was conducted as a preliminary characterization of the ability of Aroclor® 1248 polychlorinated biphenyl (PCB)-contaminated sediments to volatilize PCBs into the air upon drying under conditions meant to be environmentally relevant. Sediments collected from the St. Lawrence River contained high levels (-600 ppm) of PCBs. The PCB contamination consisted of high levels of mainly ortho-substituted mono- and dichlorobiphenyls, suggesting that the original contamination had been transformed by microbial reductive dechlorination. These sediments lost 0.07 to 1.7% of their total PCB content to the air during a 24-h drying cycle. Sediments with varying amounts of overlying water (40 g of sediment with 25-100 ml of water) lost significantly less PCB to the air within the first few cycles than native sediments with no overlying water. Losses due to PCB volatilization were well correlated to sediment PCB concentration and water loss but not to drying temperatures (4–43°C) within 24-h drying cycles. The PCB congeners (mostly ortho-substituted mono-, di-, and trichlorobiphenyls) representing >90% of those volatilized within the first 24 h of drying were those produced in the sediment samples as a result of microbial reductive dechlorination of the original Aroclor 1248 contamination. The presence of these congeners in volatilized air samples was positively confirmed by gas chromatography-mass spectrometry with Fourier transform infrared detection (FTIR). These results strongly suggest that significant amounts of mono-, di-, and trichlorobiphenyls may be volatilized from Aroclor 1248-contaminated sediments at ambient environmental conditions and that this PCB volatilization may be enhanced by microbial reductive dechlorination.