bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence for particle-mediated transport of 2,3,7,8-tetrachlorodibenzofuran during gas sparging of natural water
Authors: Friesen Kenneth J. , Loewen Mark D. , Fairchild Wayne L. , Lawrence Sharon G. , Holoka Morris H. , Muir Derek C. G.
Published: March 2010

Gas sparging was conducted in lake enclosures previously treated with [4,6-3H]-2,3,7,8-tetrachlorodibenzofuran (TCDF) to determine the fugacity or dissolved concentration of this hydrophobic contaminant under field conditions. Using a Henry's law constant for TCDF of 1.7 ± 0.8 Pa.m3/mol, measured experimentally by gas sparging, apparent dissolved TCDF concentrations of 7 to 22 pg/L were determined. These results were 100 times greater than concentrations of TCDF obtained by extraction of water samples from the same enclosures with dichloromethane. TCDF was found to be highly associated with naturally occurring particles in the water column, with 40% of sorbed TCDF associated with the 0.1- to 3-μm size fraction. The results are interpreted in light of previous reports that indicate that bubbles are effective scavengers of bacteria and particulates in natural waters, transporting these solids across the water/air interface as bubbles burst at the water surface. In the laboratory addition of a yeast suspension increased the amount of TCDF sparged from aqueous solutions, confirming that particle-mediated movement of highly sorbed contaminants can influence apparent water concentrations measured by gas sparging of natural waters.
Bird fat reductions in forests treated with dimilin®
Authors: Whitmore Robert C. , Cooper Robert J. , Sample Bradley E.
Published: March 2010

Indirect, nonacutely toxic, effects of pesticide applications on birds have been largely overlooked. Diflubenzuron (trade name Dimilin®) has extremely low toxicity to birds (LD50 > 3,762 mg/kg for red-winged blackbirds, Agelaius phoeniceus). It has gained widespread use for control of gypsy moth (Lymantria dispar) populations in Eastern forests. However, Dimilin® has been implicated in mortality of nontarget insects, many of which have been shown to be food for birds. This study examined the overall condition of birds breeding on Dimilin®-treated and untreated plots by determining the percentage of dry weight fat for a group of common forest songbirds. It was found that seven of the nine tested bird species had significantly (p < 0.05) lower fat reserves on treated plots than those on nontreated plots. Although the two nonsignificantly different bird species were permanent residents (black-capped chickadee and tufted titmouse), all of the remaining seven species were neotropical migrants. Possible causes of the fat reductions center on (a) reduction in food, resulting in a decrease in biomass of ingested food; (b) increase cost in obtaining food; and (c) reduction in food quality. Whether or not the reduced fat levels cause concomitant reductions in adult/juvenile survival could not be demonstrated.
Bioaccumulation of 2,3,7,8-tetrachlorodibenzo-P-dioxin in feral fish collected from a bleach-kraft paper mill receiving stream
Authors: Schell John D. , Campbell Dean M. , Lowe Edgar
Published: March 2010

Bleach-kraft mill (BKM) processes may result in the formation and release of a number of chlorinated organic compounds, including 2,3,7,8-tetrachIorodibenzo-p-dioxin (TCDD). Contamination of aquatic ecosystems by TCDD is of concern due to the chemical's toxicity, bioaccu-mulation potential, and persistence in the environment. Sediment samples and tissues from three species of fish and one invertebrate were collected downstream from a BKM facility and were analyzed for TCDD. Concentrations of TCDD were greatest in the bowfin, particularly in the ovary of a gravid female (46.1 pg/g). There appeared to be no correlation between either trophic position or habitat classification (i.e., epibenthic or pelagic) and TCDD tissue concentrations. Sediments collected near the mill outfall contained elevated levels of TCDD as great as 52.8 ppt. Sediment-based BAFs and lipid- and carbon-normalized bioavailability indexes (BI) were calculated for the fish livers and gonads, and blue crab hepatopancreas. BAF*s varied by a factor of 27, depending on species and organ, whereas Bis had an approximate seven-fold variation. It appears that organic carbon-and lipid-normalization factors may be more accurate predictors of the extent of bioaccumulation in resident biota from TCDD-contaminated sediments than either BAF*s or BCFs. As there is currently only a limited understanding of species variability in absorption and deposition of TCDD, a more accurate estimation of TCDD levels in feral fish tissues may not be possible.
Toxicity and bioaccumulation of soil PCBs in crickets: Comparison of laboratory and field studies
Authors: Paine Jennifer M. , McKee Michael J. , Ryan Maryann E.
Published: March 2010

Laboratory and field studies were used to investigate toxicity and bioaccumulation of PCBs in crickets exposed to contaminated soil A 14-d laboratory soil bioassay with the house cricket (Acheta domesticus) yielded an LC50 of 1,200 ppm Aroclor 1254 Mean whole body concentrations of Aro-clor 1254 in exposed crickets were 11, 48, 92, 149, and 144 ppm for soil test concentrations of 100, 250, 500, 1,000, and 2,000 ppm, respectively A whole body concentration of about 150 ppm appears to be a threshold concentration above which acute mortality will be observed House crickets placed in cages on a PCB contaminated landfill accumulated 1 6 and 0 9 ppm of PCBs (whole body concentration) after 3 and 7 d of exposure, respectively Although this represents a rapid uptake of PCBs, whole body concentrations remained considerably below levels expected to cause acute mortality Abundance of another species, the field cricket (Gryllus pennsylvamcus), was investigated using pitfall traps placed at the PCB contaminated landfill and a reference site No adverse effect on abundance was observed at the contaminated site, nor was pitfall trap success correlated to soil PCB concentration These data indicate that PCBs in soil can rapidly move into epigeic fauna but that the likelihood of acquiring sufficient body burdens to cause acute mortality is low
Wetlands: History, current status, and future
Authors: Hook Donal D.
Published: March 2010

Wetlands have been intricately linked with humankind throughout the ages. Evidence of rice culture dates to the earliest age of humans, long before the era of historical records. Drain-field and raised-field agriculture occurred in wetlands throughout large areas of Mesoamerica before Hispanic exploration of the region. About 40% of the world's population uses rice as a major staple; rice culture currently occupies about 15% of the world's wetland area. Wetlands are valued for high biological productivity; as filters, sinks, and transformers for sediments, nutrients, and pollutants; and as buffers between aquatic systems and human activities on upland areas. Because of their varied ecological functions, wetlands are of interest to ecotoxicologists as potential sites for detoxifying pollutants. Estimates are that wetlands occupy about 3 to 6% of the world's land area. Attempts to define, delineate, monitor, and regulate the use of wetlands in the United States have proven to be extremely complex. Considerable progress has been made in classifying and monitoring changes in wetland areas on a nationwide basis, but less success has been achieved in defining and delineating wetlands. The United States experience should be a useful model for developing countries to study as they attempt to deal with wetland management and protection. As long as the world's population continues to grow at exponential rates, it seems highly probable that pressure to use wetlands to meet society's demands will increase. Consequently, opportunities to set aside reserves will decrease, and the role that wetlands play in maintaining quality of life will depend more and more on our collective ability to develop and promote compatible uses on wetlands.
Geochemical processes and nutrient uptake by plants in hydric soils
Authors: McKee William H. , McKevlin Martha R.
Published: March 2010

Soil reduction caused by flooding has profound effects on species adaptation and mineral nutrition of higher plants. Anaerobic conditions inhibit normal root respiration of higher plants. Alternate metabolic pathways may be utilized in combination with the development of anatomical characteristics that result in the internal movement of oxygen to the roots. Soil organisms use other oxidants when the oxygen supply is interrupted, which results in profound changes in oxidative states of many metals and nonmetals, and changes in soil reaction and conductivity. The products of reduction are primarily nitrogen gas, manganous manganese, ferrous iron, sulfide sulfur, methane, and organic acids. These reduction products alter the availability of soil nutrients and can drastically alter the soil acidity. Plant-soil interactions on flooded soils can sometimes be altered, as has been demonstrated by the use of phosphorus fertilizer on southern pine and zinc on rice.
Sexual dimorphism in Chironomus riparius (meigen): Impact on interpretation of growth in whole-sediment toxicity tests
Authors: Day K.E. , Kirby R. Scott , Reynoldson T.B.
Published: March 2010

Sexual dimorphism in fourth-instar larvae and adults was studied for Chironomus riparius. Wet weight of fourth-instar male chironomids was on average 29.4% lower than that of fourth-instar female chironomids at day 10 post-hatch of eggs, when organisms were reared individually in 250-ml beakers with 60 g sediment. This weight differential continued to the adult stage and was enhanced with males weighing 39.8% less than females (dry weight). When animals were reared in groups of 15 larvae per beaker, differences between the sexes in larval wet weight were not statistically significant, but males were still 7.4% smaller than females; however, adult males weighed an average of 42.7% less than females upon emergence. Stage of development (fourth instar) was confirmed by head capsule measurement; no significant differences in head capsule widths were detected between the sexes. Animals reared alone, regardless of sex, weighed more than animals reared as a group, indicating that initial larval densities and size of bioassay container can significantly affect larval growth. The probability of making a type I error in sediment toxicity tests due to sexual dimorphism in weight was estimated to be only 3% when dimorphism was most enhanced, that is, for animals reared individually. The effect of dimorphism on data interpretation when animals are reared in groups of 15 to 50 animals per container is thought to be minimal. It is recommended that both larval weight and head capsule width (millimeters) be measured as end points in sediment toxicity tests to differentiate reduced growth from retardation of instar development.
Acute toxicity of 4-nitrophenol, 2,4-dinitrophenol, terbufos and trichlorfon to grass shrimp (Palaemonetes spp.) and sheepshead minnows (Cyprinodon variegatus) as affected by salinity and temperature
Authors: Brecken-Folse Jeri A. , Mayer Foster L. , Pedigo Leslie E. , Marking Leif L.
Published: March 2010

The toxicities of two industrial chemicals (4-nitrophenol and 2,4-dinitrophenol) and two organophosphate insecticides (terbufos and trichlorfon) to juvenile grass shrimp (Palaemonetes spp.) and sheepshead minnows (Cyprinodon variega-tus) were determined by static, 96-h toxicity tests in a factorial design with 12 combinations of salinity and temperature (15, 20, 25, 30 ppt × 17, 22, 27°C). Concentrations of the toxicants, including bioconcentration, were determined as appropriate by gas or liquid chromatography and the use of 14C-labeled compounds. The 96-h LC50s for 4-nitrophenol ranged from 12 to 31 mg/L and for 2,4-dinitrophenol from 13 to 50 mg/L. Toxicity decreased as salinity increased for 4-nitrophenol and both test organisms. Toxicity decreased as salinity increased for 2,4-dinitrophenol and sheepshead minnows, but toxicity to grass shrimp increased as salinity increased. Toxicity decreased with increased temperature for grass shrimp exposed to 2,4-dinitrophenol and sheepshead minnows exposed to 4-nitrophenol, increased with temperature for sheepshead minnows exposed to 2,4-dinitrophenol, and no change was observed for grass shrimp exposed to 4-nitrophenol. Bioconcentration of phenols in both test organisms increased as concentration increased. The 96-h LC50s for terbufos ranged from 3.4 to 6.6 μg/L and for trichlorfon from 6.3 to 19,300 μg/L. Terbufos and trichlorfon toxicity to grass shrimp and sheepshead minnows increased with increased temperature. BCFs for terbufos were greater in sheepshead minnows than grass shrimp, but were reversed for trichlorfon.
Ecotoxicity of mixtures of metals to the zebra mussel Dreissena polymorpha
Authors: Kraak Michiel H.S. , Lavy Daphna , Schoon Hans , Toussaint Merel , Peeters Wilma H.M. , van Straalen Nico M.
Published: March 2010

The effects of equitoxic mixtures of CuCl2, ZnCl2, and CdCl2 on the filtration rate of the freshwater mussel Dreissena polymorpha were determined. The amounts of added metals were expressed in toxic units, and a range of toxic units was tested. Cu + Zn was less than concentration additive, Zn + Cd was concentration additive, and Cu + Cd was more than concentration additive in their effects on the filtration rate of Dreissena polymorpha. An equitoxic mixture of all three metals was concentration additive. The effect of a mixture could not be predicted from the effects of the single metals. The concentrations at which Cu and Cd contributed to the toxicity of a mixture of Cu + Zn + Cd were at or below the NOECs for these metals, determined in single-metal toxicity tests. At low but elevated Cu and Zn concentrations in water, no accumulation of these metals in the mussels took place; Cd, on the contrary, was accumulated at all Cd concentrations in the water.
Interactive effects of prochloraz and malathion in pigeon, starling and hybrid red-legged partridge
Authors: Johnston Gail , Walker Colin H. , Dawson Alistair
Published: March 2010

Recent laboratory studies with hybrid red-legged partridges have shown that the interaction of certain combinations of agricultural pesticides can lead to an enhancement of toxicity. In view of this finding, captive feral pigeons (Columba livia) and European starlings (Sturnus vulgaris), in addition to hybrid red-legged partridges (Alectoris rufa cross), were used in a laboratory study to extend investigations of the enhancement of toxicity of the organophosphorus (OP) insecticide malathion in birds predosed with the ergosterol-biosynthesis-inhibiting (EBI) fungicide, prochloraz. Following pretreatment with either 90 or 180 mg/kg prochloraz, both pigeons and partridges showed significantly greater inhibition of serum butyrylcholinesterase (BuChE) activity (1.4- to 2.1-fold increase for pigeons and 1.3- to 3.8-fold increase for partridges) when dosed with malathion than control birds; this difference was evident at some or all of the blood-sampling time points. On the other hand, starlings given either 180 or 300 mg/kg prochloraz showed no difference from controls in serum BuChE inhibition after dosing with malathion. The enhanced inhibition of serum BuChE in the pigeon and the partridge after malathion dosing was attributed to the increased activation of malathion to malaoxon following induction of the hepatic monooxygenase system by prochloraz. Serum BuChE inhibition may be useful in studying the interactive effects of OPs and EBI fungicides in the field.
Evaluation of equilibrium partitioning theory for predicting acute toxicity of field-collected sediments contaminated with DDT, DDE and DDD to the amphipodHyalella azteca
Authors: Hoke R.A. , Cotter A.M. , Goldenstein T. , Kosian P.A. , van dermeiden F.M. , Ankley G.T. , Phipps G.L.
Published: March 2010

DDT is a persistent and toxic nonionic organic chemical commonly present as a contaminant in aquatic sediments. As a result of effluent discharges by a chemical company manufacturing DDT on the Redstone Army Arsenal near Huntsville, Alabama, the water column, sediment, and biota of the Huntsville Spring Branch-Indian Creek stream system (HSB-IC) became heavily contaminated with DDT and its metabolites, DDE and DDD. Because DDT appeared to be the primary contaminant in the system, an investigation was begun to evaluate equilibrium partitioning theory (EqP) as a basis for predicting the free pore-water concentrations in and toxicity of DDT-contaminated sediments from the system. In 10-d laboratory, flow-through, water-only exposures with the amphipod Hyalella azteca, LC50 values of 0.07 (0.06-0.28), 1.66 (1.55-1.78), and 0.19 (0.16-0.41) μg/L were determined for p,p′-DDT, DDE, and DDD, respectively. Bulk sediment toxicity assays also were conducted with Hyalella azteca and pore waters analyzed for the p,p′- and o,p′-isomers of DDT, DDE, and DDD. Measured and EqP-predicted pore-water chemical concentrations generally agreed within one order of magnitude. Predicted or measured Hyalella azteca 10-d pore-water LC50 values for DDT and DDD also were similar to water-only LC50 values for Hyalella azteca. These data demonstrate an effect-based EqP prediction of the toxicity of field-collected sediments contaminated by a nonionic organic compound and the potential utility of the EqP approach for developing sediment quality criteria.
Joint toxicity of ethyleneamines to algae, daphnids and fish
Authors: van Wijk R J , Postma J F , van Houwelingen H
Published: March 2010

The joint toxicity of some ethyleneamines to Selenastrum capricornutum Daphria magna, and Poecilia reticulata have been determined as a contribution to the environmental risk assessment of wastewater discharges A few combinations showed antagonistic or synergistic effects, but the majority of combinations were additive at the lethal level Thus additivity appears to be a reasonable assumption for risk assessment purposes of wastewater discharges The design of tests and the bio metrical approach using models describing isobolograms to evaluate test results are described in detail This method and subse quent statistical evaluation procedure were found to be very suitable to determine additivity in aquatic toxicity tests
Chemical fate and transport in a domestic septic system: Site description and attenuation of dichlorobenzene
Authors: Robertson W.D.
Published: March 2010

The mobility and attenuation of dichlorobenzene (DCB) in a septic system groundwater contaminant plume with a very detailed monitoring network was evaluated by conducting a tracer experiment in which 450 ml of a plumbing line cleaner containing DCB and 1 kg NaBr were injected into the septic system. DCB concentrations of up to 3,460 μg/L were observed in the septic tank effluent, up to 650 μg/L in the unsaturated zone 0.45 m below the tile bed, and up to 13 μg/L at the water table at 2 m depth. Peak DCB concentrations arrived at the water table after 57 d at a source-normalized concentration of 0.02, whereas peak Br− concentrations arrived at the water table after only 10 d at a normalized concentration of 0.61, thus demonstrating DCB attenuation and retardation during migration through the aerobic unsaturated zone at this site. Model simulations of DCB breakthrough at the water table provided an adequate fit with the field data when a retardation factor of 6.5 and decay half-life of 15 d were used. Evidence for biodegradation of DCB was provided by the occurrence of a 7-d lag (biota acclimation period), after which increased attenuation of DCB was observed in the unsaturated zone and by the preferential attenuation of two of the three isomers of DCB. Vigorous biodegradation of trace volatile organic compounds such as halogenated and substituted benzenes was indicated in the unsaturated zone below this septic system.
Metabolism of aniline under different anaerobic electron-accepting and nutritional conditions
Authors: Alexandra De M. , O'Connor Owen A. , Kosson David S.
Published: March 2010

The biodegradability of aniline was evaluated under two different anaerobic conditions, denitrifying and methano-genic. In addition, under denitrifying conditions, the influence of bicarbonate was studied. Anaerobic sewage digester sludge and estuarine sediment were used as heterogeneous sources of bacteria. Under anaerobic denitrifying conditions amended with bicarbonate, aniline was completely mineralized to CO2 and N2. After an initial lag period, N2 recoveries of 74 and 100% were obtained for sludge and sediment cultures, respectively. Under anaerobic denitrifying conditions with no bicarbonate, aniline depletion was observed; however, stoichiometric quantities of N2 were not produced from mineralization and were in fact inhibited below background controls. Under methanogenic conditions, aniline concentrations remained unchanged for >31 weeks. A metabolite of aniline, 4-hydroxybenzoate, was detected in bicarbonate-amended denitrifying cultures.
Comparative toxicity of chemicals to earthworms
Authors: Callahan C A , Skirazi M A , Neuhauser E F
Published: March 2010

The concentration-response (mortality) relationships of four species of earthworms, Eisenia fetida (Savigny), Allo lobophora tuberculata (Eisen), Eudrilus eugemae (Kinberg), and Perionyx excavatus (Perrier) are summarized for 62 chemi cals and two test protocols A Weibull function is used to summarize these data for each chemical in terms of sensitivity and toxicity in addition to the LC50 The estimation of the Weibull parameters a and k summarize the entire concentration response relationship This technique should be applicable to a variety of testing protocols with different species whenever the goal is summarizing the shape of the concentration-response curves to fully evaluate chemical impact on organisms In some cases for these data four orders of magnitude separate LC50s of the soil test and the contact test for the same chemical and species All four species appear to be similar in range of toxicity and tolerance to these chemicals, suggesting that Eisenia fetida may be rep resentative of these four species and these chemicals
Bioaccumulation of 2,3,7,8-tetrachlorodibenzo-p-dioxin, 2,3,7,8-tetrachlorodibenzofuran and extractable organic chlorine at a bleached-kraft mill site in a northern canadian river system
Authors: Owens J.W , Swanson S M , Birkholz D.A.
Published: March 2010

Abiotic and biotic environmental compartments in a northern Canadian river system have been analyzed for poly chlorinated dibenzo p-dioxins (PCDDs), polychlonnated dibenzofurans (PCDFs), and extractable organochlormes (EOC1) down stream of a bleached-kraft mill The water column, deposited and suspended sediments, invertebrates, and tissues from several fish species were analyzed The data indicate that (a) conversion of the mill bleaching process to 100% chlorine dioxide virtu ally eliminated the discharge of PCDDs and PCDFs, (b) PCDD, PCDF, and EOCl transport occurred primarily in suspended sediments, and (c) the food choice of filter feeding insects by specific fish species such as the mountain whitefish (Prosopium wdhamsoni) was an important determinant in the food chain transfer of the principal compounds, 2,3,7,8 tetrachlorodibenzo-p dioxin (TCDD) and 2,3,7,8 tetrachlorodibenzofuran (TCDF) Relative to mountain whitefish, TCDD and TCDF levels in another bottom feeding species, longnose sucker (Catostomus catostomus), were at least an order of magnitude lower Food chain biomagmfication of TCDD and TCDF was not observed in omnivorous and predatory species, burbot (Lota lota) and walleye (Stizostedmm vitreum), for which hpid-adjusted levels were similar to those in the longnose sucker These data indicate that organism lipid levels alone are not sufficient to predict species specific bioaccumulation of these hydrophobic compounds, and that site specific transport and species food choice parameters should be included in bioaccumulation models for hydrophobic compounds such as PCDDs and PCDFs
Biodegradation in soil of hydrophobic pollutants in nonaqueous-phase liquids (NAPLs)
Authors: Efroymson Rebecca A. , Alexander Martin
Published: March 2010

A study was conducted to determine the mineralization in soil and subsoil of hydrophobic organic compounds present in several nonaqueous-phase liquids (NAPLs). When present in soil in some NAPLs, di(2-ethylhexyl) phthalate (DEHP) was not appreciably mineralized, phenanthrene was slowly transformed after an acclimation phase, and hexadecane and naphthalene were biodegraded rapidly. The extent of suppression of biodegradation of test compounds varied with different solvents as NAPLs. The rate of mineralization in subsoil of phenanthrene dissolved in some NAPLs was very slow, but additions of N and P enhanced the degradation. The addition of N and P to soil did not increase the mineralization of DEHP dissolved in NAPLs. The existence of a NAPL in polluted environments may thus markedly affect the susceptibility of organic compounds to biodegradation.
Effects of three concentrations of mixed fatty acids on dechlorination of tetrachloroethene in aquifer microcosms
Authors: Gibson Susan A. , Roberson D. Scott , Russell Hugh H. , Sewell Guy W.
Published: March 2010

Chloroethenes are among the most common organic contaminants of ground water. The biotransformation of these compounds by reductive dechlorination is a promising technology for in situ treatment. The effects of three concentrations of a fatty acids mixture on the reductive dehalogenation of tetrachloroethene (PCE) were studied in methanogenic microcosms. These microcosms were constructed with slurries of aquifer solids collected from an area impacted both by aviation gasoline and chlorinated ethenes at Traverse City, Michigan. The microcosms were amended with approximately 30 μM PCE and one of three concentrations (0.1, 1, or 10 mM total acids) of a mixture of low-molecular-weight organic acids, or were part of a control set that received no amendment. The observed lag or adaptation times before the onset of PCE dehalogenation were 51 d (10 mM acids), 65 d (1 mM acids), 86 d (0.1 mM acids), and >233 d (no acids). After 233 d of incubation, no PCE was detectable in any of the fatty-acid-supplemented microcosms, but 23 to 27 μM of combined tri- and dichloroethenes (TCEs, DCEs) was detected. PCE was not dechlonnated in microcosms without a fatty acid supplement. Although there were observed differences in the length of the lag time, the amount of ultimately dechlorinated PCE was similar. A zero-order rate constant of 0.3 μM d−1 was calculated for PCE dechlorination and for TCE dechlorination for the two series of microcosms receiving 0.1 and 1.0 mM fatty acid supplements. Of the fatty acids tested in the mixture, butyrate oxidation appeared to be the most probable link to PCE dechlorination.
Microbial potential for the anaerobic degradation of simple aromatic compounds in sediments of the Milwaukee Harbor, Green Bay and Lake Erie
Authors: Myers Charles R. , Alatalo Laura J. , Myers Judith M.
Published: March 2010

The ability of microbial populations to mediate the anaerobic transformation of six aromatic compounds in sedi ments from the Milwaukee Harbor, Green Bay, and Lake Erie was examined Sediment slurries were incubated in an anaerobic mineral salts medium that was amended with multiple electron acceptors, including manganese(IV) and Fe(III) oxides, and the concentrations of the aromatic substrates were followed over a six to 18 month period Most sediment samples showed a com plete loss of benzoate and 4 hydroxybenzoate within approximately two months Benzoate losses were partially to markedly inhibited by the addition of molybdate, whereas losses of 4 hydroxybenzoate were not molybdate inhibited Significant losses of aniline, 3 chlorobenzoate, and 2,4-dichlorophenoxyacetic acid were observed with many of the sediments after approximately 18 months Molybdate markedly inhibited the metabolism of 3 chlorobenzoate with all sediments, and of aniline with some sed lments Increases in free chloride, which are indicative of reductive dechlorination were coincident with losses of 3 chlorobenzoate and 2,4 dichlorophenoxyacetic acid No significant metabolism of 4 chlorobenzoate was apparent in any of the sediments Over all, the results indicate that microbes with the ability to degrade at least certain aromatic compounds are present at various sites within these environments
Polychlorinated dibenzo-P-dioxins and dibenzofurans in mya arenaria in the newark/raritan bay estuary
Authors: Brown Richard P. , Cooper Keith R. , Cristini Angela , Rappe Christoffer , Bergqvist Per-Anders
Published: March 2010

The objectives of this study were to examine the bioavailability, bioaccumulation, and elimination of several poly-chlorinated dibenzo-p-dioxins and dibenzofurans in the soft-shell clam, Mya arenaria Linneaus. Clams were collected from three sites in the Newark/Raritan Bay estuary (Newark, NJ; Elizabeth, NJ; Wards Point, NY), from Little Egg Harbor (Tuckerton, NJ), and from the Chesapeake Bay (Prince Frederick, MD). Collections were made between 1986 and 1990, and samples were prepared for isomer-specific analysis. Clams from the Newark site contained TCDD concentrations that ranged from 11 to 20 parts per trillion (pptr), from the Elizabeth site 4.8 to 10 pptr, and from Wards Point 0.5 to 1.1 pptr. Clams collected from Tuckerton and Chesapeake Bay ranged from 0.1 to 0.6 pptr. Transplantation of clams from Chesapeake Bay into the Elizabeth site resulted in bioaccumulation of dioxins and furans to concentrations comparable with the natural Elizabeth population by three months post-transplant. Transplantation of soft-shell clams from the Elizabeth into the Tuckerton site resulted in elimination of dioxins and furans to concentrations comparable with the natural Tuckerton population within four months post-transplant. The calculated half-life of elimination for TCDD was 45 d, for TCDF 111d, and for I-TEF 66 d.
Modeling the reactions of 1-naphthylamine and 4-methylaniline with humic acids: Spectroscopic investigations of the covalent linkages
Authors: Ononye Aloysius I. , Graveel John G.
Published: March 2010

The covalent binding of two aromatic amines, 1-naphthylamine and 4-methylaniline, to substituted quinones in aqueous solutions has been studied as a model for the covalent binding of amines to humic acids. An inline compound was the only type of product identified for the reactions between 1-naphthylamine and selected quinones. Reactions of 4-methylaniline with the same quinones gave a 1,4- addition product in addition to the imine compound, although only the imine product was formed when the quinone had bulky substituents at the 2- and 6- positions. These results provide additional insight into the reactions of aromatic amines with humic acid quinones.
Assessing acute toxicities of pre- and post-treatment industrial wastewaters with Hydra attenuata: A comparative study of acute toxicity with the fathead minnow, Pimephales promelas
Authors: Fu Li-Jie , Staples Robert E , Stahl Ralph G
Published: March 2010

This study was undertaken to (a) determine wastewater treatment effectiveness using two freshwater organisms (b) compare acute toxicity results from the two species exposed to the wastewaters, and (c) link acute and potential develop mental toxicity of wastewaters in one organism The acute toxicities of several pretreatment and post treatment industrial waste water samples were evaluated with adult Hydra attenuata (92 or 96 h exposure) and fathead minnows (96 h exposure) The acute LC50s agreed closely when results in Hydra attenuata were compared with those from fathead minnow tests Acute LC50s ranged from 3 to > 100% of sample with hydra, and from 1 0 to > 100% of sample with fathead minnows The results provided strong evidence of treatment effectiveness because toxicity decreased with progressive stages of treatment Previously the Hydra Developmental Toxicity Assay (Hydra Assay) was used as a prescreen mainly for in vitro assessment of developmental toxicity with pure compounds and to prioritize toxicants according to selective toxicity to the developing embryo (A/D ratio) Recently we modified the assay for testing natural waters and wastewaters, hence, some of the wastewater samples also were tested for their developmental toxicity In this case, the relative selective toxicity (A/D ratio) of these wastewater samples ranged from 0 7 to 2 1, indicating that no sample was uniquely toxic to the developing embryo, although acute toxicity was manifested Over all, our results indicate the Hydra Assay functions appropriately in assessments of acute and developmental toxicity of industrial wastewaters and may be a simple and useful tool in a battery of tests for broader scale detection of environmental hazards
Temporal changes in lead levels in common tern feathers in New York and relationship of field levels to adverse effects in the laboratory
Authors: Burger Joanna , Lavery Meredith Horoszewski , Gochfeld Michael
Published: March 2010

In this paper we examine lead levels in the feathers of adult common terns (Sterna hirundo) from 1978 to 1992, compare them to values for other species breeding in the same or nearby colonies from one year (1989), and contrast these levels with those associated with sublethal behavioral and physiological effects in the lab. Lead levels in feathers of common tern decreased significantly from 1978 through 1985, were stable until 1988, and then increased through 1992. The mean levels of lead in feathers of roseate tern (Sterna dougallii), herring gull (Larus argentatus), and black skimmer (Rynchops niger) were slightly higher than those for common terns in 1989. Levels in feathers of some individuals of all species in the wild were within the range associated with behavioral impairment and growth retardation in the lab.
Phytoplankton colonization and seasonal succession in new experimental ponds
Authors: Rosenzweig Michael S. , Buikema Arthur L.
Published: March 2010

Following the U.S. Environmental Protection Agency's specifications for pesticide registration tests, 12 experimental ponds were constructed. Colonization and succession of the pond phytoplankton communities were investigated during the first year after filling. Taxon richness and densities and biomass as chlorophyll-a were measured. In addition, water-quality data were collected and analyzed. The dominant taxonomic groups were the Cyanophyceae, Chlorophyceae (with Desmidiaceae dominating), Dinobryon (in the Chrysophyceae), Dinophyceae, and Bacillariophyceae. Similar successional patterns in all 12 ponds occurred; however, the community structure between ponds was not similar at any time. Although the ponds had statistically similar environmental characteristics, they varied in their community structure, indicating that after one year they were not mature enough for use as replicate test systems. The heterogeneity of the pond phytoplankton communities indicates that meso-cosms need to be managed to produce replicate experimental units.
Lysozyme activity in earthworm (Lumbricus terrestris) coelomic fluid and coelomocytes: Enzyme assay for immunotoxicity of xenobiotics
Authors: Goven Arthur J. , Chen Shing Chong , Fitzpatrick Lloyd C. , Venables Barney J.
Published: March 2010

Lysozyme activity in earthworm (Lumbricus terrestris) coelomic fluid and coelomocytes appears sufficiently sensitive for use as a nonmammalian biomarker to detect toxic effects of sublethal body burdens of Cu2+ (28.5 ± 2.67 and 73.1 ± 5.68 μg/g dry mass). Lysozyme, a phylogenetically conserved enzyme, is capable of bactericidal activity via action on peptido-glycan of gram-positive bacterial cell walls and functions as a component of an organism's innate antimicrobial defense mechanism. Coelomic fluid and coelomocyte lysozyme activities, which exhibited temperature-response patterns similar to those of human saliva, plasma, serum and leukocyte extracts, were sensitive to Cu2+ exposure. Lysozyme activity of coelomic fluid and coelomocyte extracts from earthworms exposed for 5 d to CuSO4, using filter paper contact exposure, decreased with increasing sublethal Cu2+ concentrations of 0.05 and 0.1 μg/cm2. Compared to controls, coelomic fluid lysozyme activity was suppressed significantly at both exposure concentrations, whereas coelomocyte extract lysozyme activity was suppressed significantly at the 0.1-μg/cm2 exposure concentration. Low inherent natural variability and sensitivity to sublethal Cu2+ body burdens indicate that lysozyme activity has potential as a biomarker for assaying immunotoxicity of metals.
Interactive effects between EBI fungicides (prochloraz, propiconazole and penconazole) and OP insecticides (dimethoate, chlorpyrifos, diazinon and malathion) in the hybrid red-legged partridge
Authors: Johnston Gail , Walker Colin H. , Dawson Alistair
Published: March 2010

The toxicokinetic interactions between the ergosterol-biosynthesis-inhibiting (EBI) fungicides prochloraz, propicon-azole, and penconazole and the organophosphorus (OP) insecticides dimethoate, chlorpyrifos, and diazinon have been studied in the hybrid red-legged partridge. The inhibition of serum butyrylcholinesterase (BuChE) activity provided a useful biochemical indicator of the generation of the toxic oxon metabolites of these OP insecticides. Birds pretreated with 180 mg/kg prochloraz tended to show a greater inhibition of serum BuChE activity at 1, 4, and 24 h following oral exposure to either of the OPs dimethoate (3 mg/kg) or chlorpyrifos (9 mg/kg) compared to birds pretreated with corn oil. Prochloraz-pretreated birds also showed a tendency toward an increased inhibition at 24 h following dosing with the OP diazinon (4.3 mg/kg) compared to corn oil controls. In the case of dimethoate, the inhibition of serum BuChE activity was significantly greater in treated birds than controls at 24 h. Birds pretreated with the EBI fungicide propiconazole (200 mg/kg) showed a similar inhibition of serum BuChE activity to those pretreated with corn oil following administration of 167 mg/kg malathion. Pretreatment with the EBI fungicide penconazole (200 mg/kg) produced significantly greater depression of serum BuChE activity at 1, 4, and 24 h after dosing with malathion, when compared to corn oil controls. The tendency toward increased inhibition of serum BuChE activity by each of the OPs in prochloraz-pretreated birds was attributed to an increased activation of the compound to its active oxon form as a consequence of induction of microsomal monooxygenases by prochloraz.
Comparative effects of oil dispersants to the early life stages of topsmelt (Atherinops affinis) and kelp (Macrocystis pyrifera)
Authors: Singer Michael M , George Saji , Jacobson Susan , Lee Ina , Tjeerdema Ronald S , Sowby Michael L
Published: March 2010

The acute effects of two oilspill dispersants were compared using the early life stages of two common nearshore marine organisms the topsmelt (Athennops affinis), a common fish in bays and estuaries, and the giant kelp (Macrocystis pyrifera), a canopy forming brown alga Testing was done under closed, flow through conditions, with spiked dispersant concentrations measured in real time using UV spectrophotometry Both dispersants were composed of complex mixtures of anionic and nonionic surfactants and solvents Median effect concentration data showed Athennops tests to be more sensitive to both dispersants than Macrocystis tests, with values ranging from 48 2 to 72 9 ppm (LC50) and 73 0 to 79 4 ppm (IC50), respectively, for Nokomis® 3, and from 43 7 to 45 8 ppm (LC50) and 73 0 to 95 9 ppm (IC50), respectively, for Slik A Way A different pattern was seen in NOECs, in which both species showed significantly higher sensitivity to Slik A Way than to Nokomis 3 (α = 0 05) Comparison of the present data with those previously compiled for the same products with two other species the red abalone (Hahotis rufescens) and a mysid (Holmesimysis costata), showed fairly consistent interspecific patterns among three of the four species, Holmesimysis tests were seen to be least sensitive to Nokomis 3 and second most sensitive to Shk A Way In addition, Shk A Way was more toxic to all species except Macrocystis
Effects of low concentrations of forest-use pesticides on frog embryos and tadpoles
Authors: Berrill Michael , Bertram Susan , McGilliray Lise , Kolohon Mark , Pauli Bruce
Published: March 2010

Management of coniferous forests of eastern Canada may involve spraying with the insecticide femtrothion and the herbicides triclopyr and hexazinone Because ranid frogs breed in ponds that are unavoidably contaminated by spraying, we measured the toxicity of these chemicals to embryos and tadpoles of Rana pipiens (leopard frog), Rana clamitans (green frog), and Rana catesbeiana (bullfrog) under lab conditions Embryos were exposed during late neurula stage and tadpoles within 48 h after hatching to femtrothion (24 h, 0 5-8 0 ppm), tnclopyr (48 h, 0 6-4 8 ppm), and hexazmone (8 d, 100 ppm) We measured hatching success of embryos, and for tadpoles, mortality, ability to swim away when prodded, and total body length one week after exposure Hexazinone had no effects on embryos or tadpoles, even at the unreasonably high levels to which they were exposed Hatching success of embryos and subsequent avoidance behavior were unaffected in all species by exposures to triclopyr and femtrothion Newly hatched tadpoles of all species were very sensitive to 2 4 and 4 8 ppm tnclopyr and to 4 0 and 8 0 ppm femtrothion, either dying or remaining paralyzed following exposure Tadpoles initially affected by exposure to lower concentrations of femtrothion or tnclopyr usually recovered within 1 to 3 d Bullfrog and green frog tadpoles appear to be more sensitive than leopard frog tadpoles, and bullfrog tadpoles were consistently more sensitive than green frog tadpoles
Predicting chronic lethality of chemicals to fishes from acute toxicity test data: Concepts and linear regression analysis
Authors: Mayer Foster L , Krause Gary F , Ellersieck Mark R , Lee Gunhee , Buckler Denny R
Published: March 2010

A comprehensive approach to predicting chronic lethality from acute toxicity data was developed in which simultaneous consideration is given to concentration, degree of response, and time course of effect A consistent end point (lethality) and degree of response (0%) were used to compare acute and chronic tests Predicted NOECs were highly accurate 84 to 92% of the time (within a factor of 2 0 of the limits of the maximum acceptable toxicant concentrations for lethality) and did not vary by more than a factor of 3 6 97% of the time when the technique was applied to a database of 18 chemicals and seven fish species Growth effects can be predicted from chronic lethality, but reproductive or other chronic effects should not
Substrate- and nutrient-limited toluene biotransformation in sandy soil
Authors: Allen-King Richeixe M. , Barker James F. , Gillham Robert W. , Jensen BjøRn K.
Published: March 2010

Lab microcosm tests of the rate of toluene biodegradation were performed using soil from the A, B, and C horizons of the unsaturated zone of a sandy field site. Most of the soil samples had been previously exposed to toluene. Toluene biodegradation was rapid, occurring at a time scale comparable to the rate of sorption in many of the microcosms and demonstrating the potential for bioremediation of these contaminants in unsaturated soil. In the A horizon, with an initial toluene concentration in the solution phase of 4.5 mg/L, degradation was controlled by substrate-limited growth on toluene as the primary substrate. Soil from the B and C horizons initially showed similar behavior with a lower toluene concentration of about 2.5 mg/L. The maximum utilization rate (μmax) for soil from all three depths was 2.0 d−1. With repeated exposure to moderate to high concentrations of toluene, transformation in the B- and C-horizon soil appeared to be zero order, at a rate of 1.0 to 2.0 μg tol-uene/g soil/d. In C-horizon soil that had been taken directly from the field, the transformation rate was almost immeasurably slow. Addition of nitrogen as either ammonium or nitrate accelerated the degradation, showing that nitrogen was the most limiting nutrient.

The apparent adaptation period observed before rapid toluene removal was fit by a substrate-limited growth model. Greater numbers of toluene-degrading microorganisms were found in soil exposed to toluene than in unexposed soil, supporting bio-mass growth as the explanation for the adaptation period. The results of enumeration of heterotrophs compared to the numbers of toluene degraders suggested that a small proportion of the total viable microorganisms were responsible for degradation of toluene.
Synchronous fluorometric measurement of metabolites of polycyclic aromatic hydrocarbons in the bile of brown bullhead
Authors: Lin Edith L. C. , Cormier Susan M. , Racine Richard N.
Published: March 2010

A synchronous fluorescent spectroscopy (SFS) method was developed to measure pyrene-type metabolites in the bile of brown bullhead (Ameiurus nebulosus) and to estimate the exposure of fish to PAHs in four Lake Erie tributaries collected in the spring and fall of 1990 and 1991. For comparison, fish biliary benzo[a]pyrene (B[a]P) metabolites were also measured by HPLC/fluorescent detection (HPLC/F). Both methods showed that concentrations of biliary PAH metabolites of fish collected in polluted rivers were significantly higher than those collected from reference rivers. Concentrations of biliary metabolites of fish caught in the Black River were five to 20 times greater than those collected in Old Woman Creek by SFS and three to five times greater by HPLC/F. Fish from the Cuyahoga River had four to 24 times more biliary PAH metabolites than fish from Old Woman Creek, measured by SFS, and five to 10 times more, measured by HPLC/F. Brown bullhead from the Tous-saint River had fewer PAH metabolites than fish from Old Woman Creek. Correlation analyses of the two sets of data obtained by SFS and HPLC/F showed significance by both Pearson's sample correlation and Spearman's rank correlation. This study indicates that pyrene-type metabolites determined by SFS can be used to estimate B[a]P-type metabolites in fish bile. SFS appears to be a highly sensitive method for detecting PAH metabolites and, because of its simplicity, a cost-efficient method for screening large numbers of samples for exposure to PAHs in fish.
Mercury pollution in doha (Qatar) coastal environment
Authors: Al-Madfa H. , Dahab O. Aboul , Holail H.
Published: March 2010

Surface water and sediment samples were collected from the Doha coastal area and analyzed for content of physico-chemical forms of mercury. Dissolved reactive Hg (2.9 ng L−1) represented 81.0% of the total dissolved Hg (3.5 ng L−1). Organic Hg (0.6 ng L−1) contributed only 5.0% of total Hg. Mercury showed a strong tendency to be associated with suspended matter in Doha coastal waters, as it represented about 73.0% of the total. Total Hg in bulk Doha surface sediments fluctuated between 0.14 and 1.75 μg g−1 dry weight, with an average of 0.54 ± 0.46 μg g−1 dry weight. The sediment fraction past 63 μm contained 0.73 μ0.60μg g−1 dry weight total Hg. Leachable and methyl Hg averaged 0.10 ± 0.11 and 0.02 ±0.03 μg g−1 dry weight, respectively, in the <63-μm sediment fraction. There is a general trend for all Hg species determined in water and sediments to decrease seaward. The significantly elevated Hg levels at certain locations indicated that the main Hg sources to Doha coastal environment are leachate from the solid waste disposal site, the two harbors, and surface-water discharge.