bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gut bacterial community structure (Porcellio Scaber, Isopoda, Crustacea) as a measure of community level response to long-term and short-term metal pollution
Authors: Lapanje Ales , Rupnik Maja , Drobne Damjana 
Published: June 2007

Abstract
Prokaryotes are of high importance in the assessment of environmental pollution effects. Due to fast responsiveness of bacterial communities to environmental physicochemical factors, it is difficult to compare results of bacterial community investigations on the temporal and spatial scale. To reduce the effects of variable physicochemical environmental conditions on bacterial microbiota when investigating the specific impact of contaminants on bacterial communities, we investigated the bacterial community in the gut of terrestrial isopods (Porcellio scaber, Isopoda, Crustacea) from clean and metal-polluted environments. Animals were collected from a chronically mercury-polluted site, a chronically multiple metal-(Cd, Pb, Zn) polluted site, and two reference sites. In addition, animals from an unpolluted site were laboratory exposed to 5 μg Hg/g food in order to compare the effect of acute and chronic Hg exposure. The bacterial gut microbiota was investigated by temporal temperature gradient gel electrophoresis (TTGE) and clone library construction based on polymerase chain reaction amplified 16S rRNA genes. The major bacterial representatives of the emptied gut microbiota in the animals from the chronically polluted environments seemed not affected when analyzed by TTGE. The detailed bacterial community structure investigated by 16S rRNA clone library construction, however, showed that the community from the Hg-polluted site also was affected severely (242.4 operational taxonomic units [OTU] in the polluted and 650.6 OTU in the unpolluted environment). When animals were acutely exposed to mercury, changes of bacterial community structures already were seen on TTGE profiles and no additional analysis was needed. We suggest the use of P. scaber gut bacterial community structure as a measure of effects caused by both long- and short-term exposure to pollution.
A novel method using cyanobacteria for ecotoxicity test of veterinary antimicrobial agents
Authors: Ando Tomonori , Nagase Hiroyasu , Eguchi Kaoru , Hirooka Takashi , Nakamura Takanori , Miyamoto Kazuhisa , Hirata Kazumasa 
Published: June 2007

Abstract
The effect of antimicrobial agents for veterinary use on the growth of cyanobacteria was investigated by measuring minimum inhibitory concentration, medium effective concentration (EC50), and no-observed-effect concentration of seven antimicrobial agents for eight cyanobacteria. The results demonstrated that the seven antimicrobial agents, even at low concentrations, inhibited the growth of cyanobacteria. Microcystis aeruginosa and Synechococcus sp. had the highest sensitivity to the antimicrobial agents used in the present study. It is considered that the utilization of cyanobacteria would enable easy and highly sensitive assessment of the toxicity of such chemicals as antimicrobial agents. We suggest that cyanobacteria be used for ecotoxicity test in addition to the hitherto established method that uses green algae.
Accumulation of polycyclic aromatic hydrocarbons in rural soils based on mass balances at the catchment scale
Authors: Gocht Tilman , Ligouis Bertrand , Hinderer Matthias , Grathwohl Peter 
Published: June 2007

Abstract
Polycyclic aromatic hydrocarbons (PAHs) are hydrophobic organic pollutants that are ubiquitously distributed in the environment at relatively high concentrations. In our study we investigated the long-term fate of atmospheric PAHs in soils of rural areas, resulting from diffuse pollution based on mass balances at the catchment scale. By determining PAHs in several environmental compartments, estimates of soil storages and water fluxes were made and compared with atmospheric deposition. The results indicate that more than 90% of the incoming PAHs remain in the catchments and accumulate in the topsoils. Furthermore, revolatilization of PAHs from soils and degradation in the soils is very limited, resulting in ongoing accumulation in topsoils, in particular for low-volatile PAHs. Combustion-derived carbonaceous particles were detected in atmospheric deposition as well as in the soil samples. Since these particles are very strong adsorbents, they are suspected to play a key role in the environmental fate of the diffuse distributed PAHs.
Structural and functional responses of river biofilm communities to the nonsteroidal anti-inflammatory diclofenac
Authors: Lawrence John R. , Swerhone George D.W. , Topp Edward , Korber Darren R. , Neu Thomas R. , Wassenaar Leonard I. 
Published: June 2007

Abstract
Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) that has been detected widely in surface waters in North America and Europe. The impact of diclofenac on river biofilm communities was investigated at exposures of 10 and 100 μg L−1 of diclofenac or its molar equivalent in carbon and nutrients. Experiments were carried out with river water during spring and summer using rotating annular reactors as model systems. Diclofenac or nutrients at 10 μg L−1 were observed to have no significant effect on algal, bacterial, and cyanobacterial biomass in spring, whereas in the summer the nutrient equivalent reduced algal biomass and diclofenac reduced cyanobacterial biomass relative to control biofilms (p &lt; 0.05). In contrast, at 100 μg L−1 diclofenac or nutrients, the result was increased cyanobacterial and bacterial biomass, respectively, relative to control biofilms in spring. In summer, 100 μg L−1 diclofenac significantly increased bacterial biomass and the nutrient treatment had no significant effect (p &lt; 0.05); both treatments resulted in increased biofilm thickness. The glycoconjugate composition of the exopolysaccharide matrix was influenced differentially by the treatments in both seasons. Biolog assessments of carbon use indicated that 100 μg L−1 diclofenac or nutrients resulted in significant depressions in the use of carbon sources in summer and significant increases in spring. Impacts on protozoan and micrometazoan populations also were assessed. Denaturing gradient gel electrophoresis analyses of community DNA and fluorescent in situ hybridization studies indicated that diclofenac had significant effects on the nature of the bacterial community in comparison with control and nutrient-treated river biofilm communities.
Risk assessment of great horned owls (Bubo virginianus) exposed to polychlorinated biphenyls and DDT along the Kalamazoo River, Michigan, USA
Authors: Strause Karl D. , Zwiernik Matthew J. , Im Sook Hyeon , Bradley Patrick W. , Moseley Pamela P. , Kay Denise P. , Park Cyrus S. , Jones Paul D. , Blankenship Alan L. , Newsted John L. , Giesy John P. 
Published: June 2007

AbstractThe great horned owl (GHO; Bubo virginianus) was used in a multiple lines of evidence study of polychlorinated biphenyls (PCBs) and p,p′-dichlorodiphenyltrichloroethane (DDT) exposures at the Kalamazoo River Superfund Site (KRSS), Kalamazoo, Michigan, USA. The study examined risks from total PCBs, including 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQWorld Health Organization [WHo-Avian Toxicity Equivalency Factor [TEF], and total DDTs (sum of DDT, dichlorodiphenyldichloroethylene [DDE], and dichlorodiphenyldichloroethane [DDD]; ΣDDT) by measuring concentrations in eggs and nestling blood plasma in two regions of the KRSS (upper, lower) and an upstream reference area (RA). An ecological risk assessment compared concentrations of the contaminants of concern (COCs) in eggs or plasma to toxicity reference values. Productivity and relative abundance measures for KRSS GHOs were compared with other GHO populations. Egg shell thickness was measured to assess effects of p,p′-DDE. The concentrations of PCBs in eggs were as great as 4.7 × 102 and 4.0 × 104 ng PCB/g, wet weight at the RA and combined KRSS sites, respectively. Egg TEQWHo-Avian calculated from aryl hydrocarbon receptor–active PCB congeners and WHO TEFs ranged to 8.0 and 1.9 × 102 pg TEQWHO-Avian/g, (wet wt) at the RA and combined KRSS, respectively. Egg ΣDDT concentrations were as great as 4.2 × 102 and 5.0 × 103 ng ΣDDT/g (wet wt) at the RA and combined KRSS, respectively. Hazard quotients (HQs) for the upper 95% confidence interval (UCI) (geometric mean) and least observable adverse effect concentration (LOAEC) for COCs in eggs were ≤1.0 for all sites. Hazard quotient values based on the no observable adverse effect concentration (NOAEC) 95% UCI in eggs were ≤1.0, except at the LKRSS (PCB HQ = 3.1; TEQWHO-Avian HQ = 1.3). Productivity and relative abundance measures indicated no population level effects in the UKRSS.
Acute toxicity of arsenic to Daphnia pulex: Influence of organic functional groups and oxidation state
Authors: Shaw Joseph R. , Glaholt Stephen P. , Greenberg Noah S. , Sierra-Alvarez Reyes , Folt Carol L. 
Published: June 2007

Abstract
Investigations were conducted to determine the influence of organic functional groups (i.e., methyl, phenyl) and valence state (i.e., III, V) on acute (48-h) arsenic toxicity in Daphnia pulex. These included toxicity texts with a suite of inorganic (arsenite, arsenate) and organic arsenicals (trivalent and pentavalent methylated arsenicals, roxarsone, p-arsanilic acid). Toxicity, based on median lethal concentrations (LC50 values), clustered the arsenicals into three groups and followed the order (most toxic to least toxic) of monomethylarsonous acid (MMAIII), 120 μg/L &gt; inorganic arsenic, 2,500 to 3,900 μg/L &gt; pentavalent methylated arsenicals and phenylarsonic compounds, 13,800 to 15,700 μg/L. Pentavalent organic arsenicals were less toxic than inorganic forms regardless of functional group. In contrast, the trivalent organic species (MMAIII) was the most toxic arsenical studied. These findings, which are the first to include an aquatic organism, add to the growing body of evidence that find that MMAIII is an extremely toxic intermediate of arsenic methylation and contradict theories of arsenic toxicity that regard methylation as a detoxication event.
Water chemistry-based classification of streams and implications for restoring mined Appalachian watersheds
Authors: Merovich George T. , Stiles James M. , Petty J. Todd , Ziemkiewicz Paul F. , Fulton Jennifer B. 
Published: June 2007

Abstract
We analyzed seasonal water samples from the Cheat and Tygart Valley river basins, West Virginia, USA, in an attempt to classify streams based on water chemistry in this coal-mining region. We also examined temporal variability among water samples. Principal component analysis identified two important dimensions of variation in water chemistry. This variation was determined largely by mining-related factors (elevated metals, sulfates, and conductivity) and an alkalinity-hardness gradient. Cluster analysis grouped water samples into six types that we described as reference, soft, hard, transitional, moderate acid mine drainage, and severe acid mine drainage. These types were statistically distinguishable in multidimensional space. Classification tree analysis confirmed that chemical constituents related to acid mine drainage and acid rain distinguished these six groups. Hard, soft, and severe acid mine drainage type streams were temporally constant compared to streams identified as reference, transitional, and moderate acid mine drainage type, which had a greater tendency to shift to a different water type between seasons. Our research is the first to establish a statistically supported stream classification system in mined watersheds. The results suggest that human-related stressors superimposed on geology are responsible for producing distinct water quality types in this region as opposed to more continuous variation in chemistry that would be expected in an unimpacted setting. These findings provide a basis for simplifying stream monitoring efforts, developing generalized remediation strategies, and identifying specific remediation priorities in mined Appalachian watersheds.
Evaluating polycyclic aromatic hydrocarbons using a yeast bioassay
Authors: Alnafisi Abeer , Hughes Janet , Wang Guangdi , Miller Charles A. 
Published: June 2007

AbstractSixteen polycyclic aromatic hydrocarbons (PAHs) were evaluated for the ability to activate aryl hydrocarbon (Ah) receptor signaling in a yeast-based bioassay. Individual PAHs were classified as inactive or as weakly, moderately, or strongly active based on induction of human Ah receptor signaling. Indeno[1,2,3-cd]pyrene, chrysene, benzo[a]anthracene, benzo[a]pyrene, benzo[j]fluoranthene, and benzo[k]fluoranthene were the most potent activators of human Ah receptor signaling. Various mixtures of PAHs had additive or synergistic effects in the bioassay. Environmental samples from the New Orleans (Louisiana, USA) and Detroit (Michigan, USA) areas that were previously analyzed for PAH composition and quantity were tested in this bioassay. Weak but statistically significant relationships were found when the analytically measured levels of PAHs were correlated with sample dilutions that gave 25% effective concentration signaling levels in the Ah receptor assay. We conclude that this Ah receptor signaling assay may be useful for preliminary biomonitoring of samples for PAHs and other Ah receptor ligands.
Aryl hydrocarbon receptor ligand activity of polycyclic aromatic ketones and polycyclic aromatic quinones
Authors: Misaki Kentaro , Kawami Hirofumi , Tanaka Tota , Handa Hiroshi , Nakamura Masafumi , Matsui Saburo , Matsuda Tomonari 
Published: June 2007

Abstract
Polycyclic aromatic ketones (PAKs) and polycyclic aromatic quinones (PAQs) are oxygenated polycyclic aromatic hydrocarbons (PAHs), and reports about the aryl hydrocarbon receptor (AhR) ligand activities of these compounds are few. In this study, activation of AhR by 41 polycyclic aromatic compounds (PACs), focusing especially on PAKs and PAQs, was determined by measuring β-galactosidase activity from a reporter plasmid in yeast engineered to express human AhR and the AhR nuclear translocator proteins and by measuring luciferase activity from mouse hepatoma (H1L1) cells (chemical-activated luciferase expression [CALUX] assay). The PACs used in these experiments included 11 PAKs, seven PAQs, and 21 PAHs. In this study, the PAKs 11H-benzo[a]fluoren-11-one (B[a]FO), 11H-benzo[b]fluoren-11-one (B[b]FO) and 7H-benzo[c]fluoren-7-one and the PAQs 5,12-naphthacenequinone, 1,4-chrysenequinone, and 7,12-benz[a]anthracenequinone showed high AhR activities in H1L1 cells, although these values were not as high as that for benzo[a]pyrene (B[a]P). These PAKs and PAQs showed significantly stronger activities in yeast cells relative to B[a]P. It was predicted that PAKs such as B[a]FO and B[b]FO occupied 0.06% to 1.3% of the total induction equivalents, and each contribution matched the contribution of PAHs such as B[a]P, chrysene, and benz[a]anthracene in gasoline exhaust particulates and airborne particulates using data of CALUX assay.
Perchlorate assessment of the Nakdong and Yeongsan watersheds, Republic of Korea
Authors: Quiñones Oscar , Oh Jeong-Eun , Vanderford Brett , Kim Joon Ha , Cho Jaeweon , Snyder Shane A. 
Published: June 2007

Abstract
The objective of the present study was to conduct a preliminary assessment for perchlorate in surface water, drinking water, and wastewater treatment plant effluent samples obtained from the Nakdong and Yeongsan watersheds in the Republic of Korea. Samples were analyzed for perchlorate using ion chromatography with suppressed conductivity detection (IC-CD) and/or liquid chromatography with tandem mass spectrometry detection (LC-MS/MS). Method reporting limits were 5.0 μg/L for IC-CD and 0.05 μg/L for LC-MS/MS analysis. At perchlorate levels above 5.0 μg/L, IC-CD and LC-MS/MS provided comparable results. The levels of perchlorate detected in the samples procured from the Yeongsan watershed were &lt;5.0 μg/L in each case. However, Nakdong watershed samples contained perchlorate at levels up to 60 μg/L. The highest concentrations of perchlorate were found in surface water samples, although drinking water contained perchlorate at concentrations up to 35 μg/L. In a subset of samples analyzed by LC-MS/MS, chlorate and bromate also were detected at concentrations ranging from &lt;0.10 to 44 μg/L and &lt;0.10 to 2.6 μg/L, respectively. To the best of the authors' knowledge, this is the first perchlorate assessment reported for water sources in the Republic of Korea.
Oviposition site selection: Pesticide avoidance by gray treefrogs
Authors: Takahashi Mizuki 
Published: June 2007

Abstract
Effects of glyphosate-formulated herbicides on nontarget organisms have received much recent attention. Although previous studies have explored the effects of pesticides on growth, development, and mortality of various amphibian species, no studies have tested the potential effects of herbicides on oviposition site selection by amphibians. Recent studies have found that a combination of pesticide and predatory cues lead to significantly increased mortality of tadpoles of several anuran species relative to that caused by pesticide alone. In the present study, I tested two hypotheses: First, adult gray treefrogs avoid oviposition sites based on the presence of glyphosate formulation (Roundup®). Second, pesticide avoidance is manifested to a greater degree when combined with predatory cues. In the spring of 2006, I conducted an outdoor experiment using artificial ponds by setting up four treatments: Predatory fish cue, Roundup (2.4 mg glyphosate acid equivalent [a.e.]/L), a combination of predatory fish cue + Roundup, and a control. This experiment was designed to assess oviposition site choice among the four treatments by gray treefrogs based on the number of eggs laid in each treatment. Gray treefrogs avoided oviposition in pools contaminated with fish cue and/ or Roundup and placed the significant majority of their eggs in control pools, which suggests that breeding adults may be able to prevent lethal exposure of herbicide to their offspring through oviposition site selection. The present study provided the first evidence that the concentration of herbicide that is expected to be found in the field potentially alters oviposition site choice by amphibians. However, the concentration of 2.4 mg a.e./L is unlikely ubiquitous in nature. Thus, the further investigation of environmental relevancy of this finding is critical.
Effect of River Sediment on Phosphorus Chemistry of Similarly Aged Natural and Created Wetlands in the Atchafalaya Delta, Louisiana, USA
Authors: Poach M. E. , Faulkner S. P. 
Published: June 2007

AbstractThe goal of wetland creation is to produce an artificial wetland that functions as a natural wetland. Studies comparing created wetlands to similarly aged natural wetlands provide important information about creation techniques and their improvement so as to attain that goal. We hypothesized that differences in sediment phosphorus accretion, deposition, and chemistry between created and natural wetlands in the Atchafalaya Delta, Louisiana, USA were a function of creation technique and natural river processes. Sediment deposition was determined with feldspar marker horizons located in created and natural wetlands belonging to three age classes (<3, 5–10, and 15–20 yr old). Phosphorus fractions were measured in these deposited sediments and in suspended and bedload sediment from the Atchafalaya River. Bedload sediment had significantly lower iron‐ and aluminum‐bound, reductant‐soluble, and total phosphorus than suspended sediment due to its high sand percentage. This result indicates that wetlands artificially created in the Atchafalaya Delta using bedload sediment will initially differ from natural wetlands of the same age. Even so, similarities between the mudflat stratum of the <1‐ to 3‐yr‐old created wetland and the mudflat stratum of the 15‐ to 20‐yr‐old natural wetland support the contention that created wetlands in the Atchafalaya Delta can develop natural characteristics through the deposition of river suspended sediment. Differences between three created wetland strata, the 15‐ to 20‐yr‐old willow stratum and the <1‐ to 3‐yr‐old willow and mixed marsh strata, and their natural counterparts were linked to design elements of the created wetlands that prevented the direct deposition of the river's suspended sediment.
Sulfamethazine Uptake by Plants from Manure‐Amended Soil
Authors: Dolliver Holly , Kumar Kuldip , Gupta Satish 
Published: June 2007

AbstractAnimal manure is applied to agricultural land as a means to provide crop nutrients. However, animal manure often contains antibiotics as a result of extensive therapeutic and subtherapeutic use in livestock production. The objective of this study was to evaluate plant uptake of a sulfonamide‐class antibiotic, sulfamethazine, in corn (Zea mays L.), lettuce (Lactuca sativa L.), and potato (Solanum tuberosum L.) grown in a manure‐amended soil. The treatments were 0, 50, and 100 μg sulfamethazine mL−1 manure applied at a rate of 56 000 L ha−1 Results from the 45‐d greenhouse experiment showed that sulfamethazine was taken up by all three crops, with concentrations in plant tissue ranging from 0.1 to 1.2 mg kg−1 dry weight. Sulfamethazine concentrations in plant tissue increased with corresponding increase of sulfamethazine in manure. Highest plant tissue concentrations were found in corn and lettuce, followed by potato. Total accumulation of sulfamethazine in plant tissue after 45 d of growth was less than 0.1% of the amount applied to soil in manure. These results raise potential human health concerns of consuming low levels of antibiotics from produce grown on manure‐amended soils.
Biological Aspects of Metal Waste Reclamation with Biosolids
Authors: Stuczynski Tomasz , Siebielec Grzegorz , Daniels Walter L. , McCarty Greg , Chaney Rufus L. 
Published: June 2007

AbstractSmelter waste deposits pose an environmental threat worldwide. Biosolids are potentialy useful in reclamation of such sites. Biological aspects of revegetation of Zn and Pb smelter wastelands using biosolids are discussed in this report. The goal of the studies was to assess to what extent biosolid treatment would support ecosystem functioning as measured by biological indicators such as enzyme activities of revegetated metal waste or plant growth. Another crucial aspect was related to the assessment of metal transfer to the ecosystem which could affect the health of local fauna and also create a food chain risk. A field experiment was conducted on a smelter waste deposit in Piekary Slaskie, Silesia, Poland, with two separate fields—established on wastes from the Welz and Doerschel smelting processes. The tested methods allowed revegetation of the fields—application of municipal biosolid at the rate 300 dry t ha−1 combined with the incorporation of commercial lime in a mixed oxide and carbonate form at the rate of 1.5 and 30 t for Welz waste or use of a 30 cm by‐product lime cap followed by incorporation of biosolid at a rate of 300 t ha−1 for the more acidic Doerschel waste. Studies on biological activities demonstrated that the reclamation methods used are an effective way to establish new, fully‐functioning ecosystems that support plant growth. They also provided strong evidence that forage crops grown on Zn, Cd and Pb contaminated sites reclaimed using lime and biosolids do not pose identified risk for wildlife and food safety.