Forgot your password?
New user?
New Window Opens on the Secret Life of Microbes: Scientists Develop First Microbial Profiles of Ecosystems
CAS announces the release of SciFinder Scholar for Mac OS X
Press Releases
Press Releases
| Check out our New Publishers' Select for Free Articles |
Archives of Environmental Contamination and Toxicology (v.32, #3)
Characterization of Ambient Air Particle Size Fractions in Three German Cities with the Aid of Electron Microscopy by K. H. Friedrichs; H. Behrendt (pp. 229-231).
Multistage-filtration samplers offer the opportunity to analyze dust fractions deposited on corresponding stages of the sampler. In this investigation, a typical two-stage sampler was used in the cities of Dortmund (mining and steel industry), Düsseldorf (lesser industrial activities), and Duisburg (steel industry), North Rhine Westphalia. The purpose of this study was to compare the composition of dust fractions with the aid of analytical electron transmission microscopical methods. The particle size distribution was similar in the cities, the 50% value of the equivalent diameter was 0.8 μm. Analytical results are presented for different mineral classes with approximately 30 single minerals in all cities. The highest concentration values in the fine dust fraction were silicate minerals, while the sulfate content was very high in the coarse dust fraction in all cities.
Distribution of Polychlorinated Naphthalene Congeners in Environmental and Source-Related Samples by U. Järnberg; L. Asplund; C. de Wit; A.-L. Egebäck; U. Wideqvist; E. Jakobsson (pp. 232-245).
Polychlorinated naphthalene (CN) congener profiles in environmental and source related samples were compared graphically and by principal component analysis. Samples investigated included biological, sediment, water, and air samples, technical polychlorinated biphenyl (PCB) and polychlorinated naphthalene (PCN) formulations, as well as municipal waste incineration (MWI) fly ash and graphite electrode sludge. Biological samples showed a preferential enrichment of planar, 1,3,5,7-substituted tetra-, penta-, and hexachlorinated congeners and most of these samples showed profiles that displayed some similarity to those found in the technical PCB formulations. Sediment samples representing diffuse pollution, i.e., sediment samples from remote sites, showed an elevated abundance of the planar hexa- and heptaCN congeners (1,2,3,4,6,7-/1,2,3,5,6,7- and 1,2,3,4,5,6,7-). The CN congener profile found in these sediment samples and the two air samples were more similar to the technical PCB formulations than to the investigated MWI and graphite sludge samples. Samples from three PCB contaminated lakes displayed similar congener profiles as Aroclor 1242, 1254 and Clophen A40. Two sediment samples and a pike sample collected from the vicinity of a chloroalkali plant showed profiles that were closely related to the investigated graphite electrode sludge sample. None of the environmental samples displayed profiles similar to low or medium chlorinated technical PCN (Halowax 1099, 1013, and 1014).
Concentration, Distribution, and Comparison of Selected Trace Elements in Bed Sediment and Fish Tissue in the South Platte River Basin, USA, 1992–1993 by J. S. Heiny; C. M. Tate (pp. 246-259).
During August–November 1992 and August 1993, bed sediment and fish liver were sampled in the South Platte River Basin and analyzed for 45 elements in bed sediment and 19 elements in fish liver. The results for aluminum, arsenic, cadmium, chromium, copper, iron, lead, manganese, selenium, silver, uranium, and zinc are presented here. All 12 trace elements were detected in bed sediment, but not all were detected in fish liver or in all species of fish. A background concentration of trace elements in bed sediment was calculated using the cumulative frequency curves of trace element concentrations at all sites. Arsenic, cadmium, copper, lead, manganese, silver, uranium, and zinc concentrations were greater than background concentrations at sites in mining areas or at sites that have natural sources of these elements. Trace element concentrations in fish liver generally did not follow the same patterns as concentrations in bed sediment, although concentrations of aluminum and cadmium were higher in fish liver collected at mountain sites that had been disturbed by mining. Concentrations of aluminum, arsenic, cadmium, chromium, copper, iron, lead, silver, and zinc increased in bed sediments in urban areas. Iron, silver, and zinc concentrations in fish liver also increased in urban areas. Concentrations of cadmium, copper, silver, and zinc in fish liver increased in the agricultural areas of the basin. Downstream changes in trace element concentrations may be the result of geological changes in addition to changes in land use along the river.
Assessment of Sediment Toxicity Using Different Trophic Organisms by Y. H. Cheung; A. Neller; K. H. Chu; N. F. Y. Tam; C. K. Wong; Y. S. Wong; M. H. Wong (pp. 260-267).
The main aim of the present project is to study the feasibility of using different trophic organisms for evaluating the toxicity of dredged sediments arising in Hong Kong. A total of eight sediment samples (duplicate samples collected from four selected sites: Kowloon Bay, Tsing Yi, Chek Lap Kok, and Double Haven) of Hong Kong coastal waters were analyzed for the total concentrations of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn, total organic carbon, acid volatile sulfides, simultaneously extracted metals, redox potential, and 12 organic micropollutants. The sediment elutriates were also analysed for the various metal concentrations, as well as contents of ammonia-N, nitrate, total sulfide, sulfate, and total organic carbon. Elutriate Sediment Toxicity Tests (ESTT) were also conducted, using two microalgae (Skeletonema costatum, a diatom and Dunaliella tertiolecta, a flagellate), juvenile shrimp (Metapenaeus ensis) and juvenile fish (Trachinotus obtaus). Two commercially available tests using bacteria (Microtox Test and Toxi-Chromotest) also were employed to test both the solid phase and elutriates of the sediments. The results of Microtox test on the solid phase, and bioassay tests using diatom on the sediment elutriate, especially the former, were correlated significantly (p < 0.05) with a number of physico-chemical properties of sediments and elutriates. It is recommended that a combination of a liquid-phase bioassay using diatom and a solid-phase bioassay using Microtox test should be used for screening a large number of sediment samples. However, the presence of ammonia in the sediments containing a high content of organic matter seemed to interfere the detection of contamination impacts.
Phototoxicity Identification by Solid Phase Extraction and Photoinduced Toxicity to Daphnia magna by A.-S. Wernersson; G. Dave (pp. 268-273).
The photoinduced toxicity of several environmental pollutants (some Polycyclic Aromatic Hydrocarbons [PAHs]) is a potential threat to aquatic organisms. To identify the cause/s of photoinduced toxicity of a sample, it is not sufficient to simply analyze the content of some known phototoxic compounds; so far too few substances of environmental concern have ever been tested for their photoinduced toxicity. The PAHs as well as other known phototoxic compounds are hydrophobic and are expected to bind to C18 columns. The use of Solid Phase Extraction (SPE) is typically part of the procedure identifying any primary nonpolar toxicant/s, and adding phototoxicity tests to these manipulations would not substantially increase the workload. In this study, therefore, the difference in acute toxicity to Daphnia magna before and after 2 h of UV irradiation was determined for six PAHs. The ratio between EC50 values before and after UV irradiation ranged from 4.6 (for benzo[a]pyrene) to >244 (for 3,4-benzofluoranthene), demonstrating that the UV enhances the PAH-toxicity. A further characterization technique using binding to Sep-Pak SPE C18 columns and recovery with methanol as an eluting agent was then tested in combination with UV irradiation. The mean recovered UV induced toxicity after binding and elution of the six PAHs was 119% according to the phototoxicity tests made. A linear relationship, between the log10 Kow values for the PAHs and the log10 for the concentration of methanol at peak elution was found. The combined use of C18 column separation and UV activation may, therefore, be used in toxicity identification evaluations (TIE) of organic phototoxic compounds.
Environmental Health Assessment of the Benthic Habitat Adjacent to a Pulp Mill Discharge. I. Acute and Chronic Toxicity of Sediments to Benthic Macroinvertebrates by P. K. Sibley; J. Legler; D. G. Dixon; D. R. Barton (pp. 274-284).
In this study, we assessed the acute and chronic toxicity of sediments contaminated by bleached kraft pulp mill effluent (BKME). Sediments were collected in August 1991 and 1992, and May 1993 from eight stations exposed directly to the effluent and from four reference sites. Acute toxicity was determined for five macroinvertebrates (Hyalella azteca, Daphnia magna, Chironomus riparius, Hexagenia spp., and Tubifex tubifex) using pore water, elutriate, and bulk sediment exposures. Chronic toxicity was assessed using C. tentans and H. azteca (growth and survival) and D. magna and T. tubifex (reproduction) in bulk sediment exposures. Mortality declined with decreasing proximity to the outfall; acute toxicity (>20% mortality after 48 h) was observed at the two stations closest to the outfall (300 and 400 m). At 300 m, pore water was consistently more toxic than elutriate or bulk sediment phases, resulting in 100% mortality for all invertebrates except T. tubifex (23%). Elutriate exposures were toxic to C. riparius (88%), D. magna (54%), and Hexagenia (47%), but not H. azteca. Bulk sediments were toxic to Hexagenia (100%) and D. magna (88%), but not to C. riparius or H. azteca. In chronic tests, mortality in H. azteca and T. tubifex was highest at 300 and 400 m, indicating that toxicity observed in the short-term aqueous exposures adequately predicted long-term toxicity in bulk sediments. In both acute and chronic tests, mortality was significantly correlated with the concentration of extractable organic chlorines (EOCl) in the sediment, with LC50 values ranging from 4500 to 5500 mg EOCl/kg organic carbon. Growth of C. tentans larvae was depressed at 300 and 400 m in August 91 but enhanced in May 93 relative to the reference sites. Growth of H. azteca also declined near the outfall in August 91 sediments and was approximately one half that observed in 92/93 sediments; however, growth did not differ among stations in 92 or 93. Reproductive output in D. magna (neonates) and T. tubifex (cocoons) was highest at 300 and 400 m. In T. tubifex, the number of hatched young was lowest at these stations. This study provides evidence that toxicity may occur in sediments exposed to BKME, and emphasizes the need to incorporate sediment toxicity bioassessment as part of efforts directed toward remedial action in the pulp and paper industry.
The Influence of Air Pollution on the Concentration of Airborne Elements and on the Production of Stress-Ethylene in the Lichen Usnea hirta (L.) Weber em. Mot. Transplanted in Urban Sites in Oulu, N. Finland by J. Garty; M. Kauppi; A. Kauppi (pp. 285-290).
The purpose of the present study was to examine the response, as indicated by the production of stress-ethylene, of the lichen Usnea hirta, to a buffered acidic solution and to a solution containing bisulfite ion, both at pH 4.0. In addition, the study investigated the accumulation capacity of U. hirta transplanted either to the vicinity of two streets with slow traffic, or to the vicinity of a highway in the city of Oulu, N. Finland for a short period (45 d), and to analyze the comparative production of stress-ethylene and the amounts of airborne elements accumulated in the thallus. Thalli of U. hirta manifested a high accumulation capacity for K, Ca, Na, Mg, Fe, Zn, and Mn in samples exposed in one of the two streets with slow traffic in Oulu, in comparison with thalli left at the control site in the forest outside of the city. Two of the observed elements, Pb and Ca, exhibited a positive correlation with the concentration of ethylene detected consecutive to the treatment of lichen thalli with H2O (pH 6.8). The concentrations of stress-ethylene in lichen thalli retrieved from the streets with slow traffic and less cars (14,000 per day), soaked in solutions of NaHSO3 (pH 4.0), were higher than those produced by thalli retrieved from a site near the highway (with 25,000 cars per day) and by thalli left in the forest. It is suggested that the streets with slow traffic and less cars are more polluted than the highway as a result of bad ventilation conditions and a slow rate of dispersion of airborne pollutants.
Immuno-Modulator Effects of Carbaryl and 2,4 D in the Earthworm Eisenia fetida andrei by P. Ville; P. Roch; E. L. Cooper; J.-F. Narbonne (pp. 291-297).
Carbaryl and 2,4 dichlorophenoxy acetic acid (2,4 D) exerted differential effects on the earthworm E. f. andrei functions related to immuno defense. As determined by contact test assay, carbaryl activity is characterized by a low LC50 value of 3.4 μg/cm2, compared to 18 μg/cm2 for 2,4 D. Incubating earthworms with doses of carbaryl as low as 0.1 μg/cm2 resulted in the inhibition of the lysozyme activity detected in the cytosol (CL). A strong inhibition of phagocytosis was also obtained but with 1.5 μg/cm2. On the other hand, low doses of carbaryl significantly stimulated cytolysis (0.1 μg/cm2), serine protease activity (0.1 μg/cm2) in the coelomic fluid (CF) and serine protease activity in the CL (0.05 μg/cm2). Concerning 2,4 D, both cytolysis in the CF and serine protease activity in the CL were stimulated by respectively 3.5 μg/cm2 and 18 μg/cm2. Phagocytosis was inhibited only with 18 μg/cm2. Lysozyme and serine protease inhibitor activities were not affected. The immuno toxicological assays we developed in earthworms, allow to distinguish between chemicals with different immuno-modulatory properties. Moreover, earthworms appear to be a particularly well adapted sentinel organism for the evaluation of soil contamination.
Lethal and Sublethal Effects of Nitrogen Fertilizer Ammonium Nitrate on Common Toad (Bufo bufo) Tadpoles by Q. Xu; R. S. Oldham (pp. 298-303).
The impact of elevated ammonium nitrate concentrations on the survival and development of common toad (Bufo bufo) tadpoles was investigated in the laboratory. 1,704 mg/L and 1,637 mg/L nitrate (equivalent to 2,198.7 mg/L and 2,112.3 mg/L ammonium nitrate) were recorded as 96 h and 168 h LC50s respectively. These are well above field levels (10–250 mg/L) observed in freshwater in Britain. The exposure of tadpoles to nominal concentration of 100 mg/L nitrate for 24, 48, and 72 h caused a significant decrease in their activity but no clear reduction in food consumption or delay of the development. In subchronic exposures at the nominal concentrations of 50 and 100 mg/L nitrate, the metamorphosis started earlier and took less time to complete than in the control. However, some of the results were equivocal, at 50 mg NO3/L the metamorphs were significantly larger than the controls, while at 100 mg NO3/L metamorphs were not significantly different from the controls. Certain deformities and unusual swimming patterns were also found in tadpoles exposed to various concentrations of ammonium nitrate.
Relation Between Age and Heavy Metal Content in the Otoliths of Pomadasys stridens Forskål 1775 Collected from the Arabian Gulf by S. Ahmad; S. M. Al-Ghais (pp. 304-308).
A total of 216 otolith samples (89 male, 127 female) from Pomadasys stridens (Forskål 1775), a common fish of the Arabian Gulf, were analyzed for the concentrations of heavy metals. Standard length, age, sex, body, and otolith weight were recorded for each fish. Otolith weight from male fish was found in the range of 0.047–0.143 g with a mean value 0.101 ± 0.023 g, whereas, mean otolith weight from female fish samples was 0.111 ± 0.019 in the range of 0.062–0.151 g. Average concentration of zinc, copper, manganese, nickel, cadmium and lead was found 0.965, 0.229, 0.195, 0.122, 0.100, and 0.119 μg per otolith in case of male fish and in females it was 1.371, 0.241, 0.297, 0.133, 0.089, and 0.123 μg per otolith, respectively. At the age of two to three years, concentrations of all the analyzed elements, except for Cd, were found higher in otoliths of female fish samples, but at the age of four years this difference becomes minimum and mostly opposite, i.e., otoliths of male fish have little higher concentrations as compared to otoliths from females. The concentration variation of different elements was different in males and in females, but was not statistically significant. The otolith weight at the age two years was significantly different with other age group samples and among both sexes.
Liver Cell Estrogen Receptor Binding in Prespawning Female Largemouth Bass, Micropterus salmoides, Environmentally Exposed to Polychlorinated Biphenyls by E. F. Garcia; R. J. McPherson; T. H. Martin; R. A. Poth; M. S. Greeley Jr (pp. 309-315).
Estrogen-receptor–like binding was partially characterized in liver tissue of prespawning female largemouth bass, Micropterus salmoides (LMB). Saturation and Scatchard analyses exhibited estrogen binding activity with high affinity (Kd in the 10−9 M range) and limited capacity (nuclear = 37.4 fmol/g tissue; cytosol = 234 fmol/g tissue). Androgens, progestins, and cortisol competed poorly for binding in competition studies. Thus, LMB liver estrogen binding activity possesses similar properties to estrogen receptors (ER) described in other vertebrates.In a study of prespawning female LMB from Lake Hartwell, SC/GA, a reservoir contaminated by polychlorinated biphenyls (PCBs), individuals environmentally exposed to high levels of PCBs had significantly lower ER binding capacity (Bmax) and higher nonspecific binding (NS) than fish from a relatively uncontaminated reference location. Fish obtained at a site with intermediate levels of PCBs did not exhibit the expected decrease in Bmax. The lower Bmax observed in fish from the location with high PCB contamination is consistent with the reported behavior of liver ER in fish experimentally exposed to PCBs. Increased NS in the ER assays could be related to elevations in albumin associated with the PCB exposure.
Organochlorine Contaminants in Double-Crested Cormorants from Green Bay, Wisconsin: II. Effects of an Extract Derived from Cormorant Eggs on the Chicken Embryo by D. C. Powell; R. J. Aulerich; J. C. Meadows; D. E. Tillitt; K. L. Stromborg; T. J. Kubiak; J. P. Giesy; S. J. Bursian (pp. 316-322).
White Leghorn chicken (Gallus domesticus) eggs were injected prior to incubation with one of four concentrations (0.001, 0.01, 0.1, and 1.0 egg-equivalent) of an extract derived from 1,000 double-crested cormorant (Phalacrocorax auritus) eggs collected at Spider Island adjacent to Green Bay in Lake Michigan. One egg-equivalent corresponded to the concentration of contaminants present in an average cormorant egg. This was approximately 322 pg toxic equivalents (TEQs)/g, ww egg with polychlorinatedbiphenyl congener 126 (3,3′,4,4′,5-pentachlorobiphenyl) accounting for over 70% of the TEQs. Injection of 1.0 egg-equivalent resulted in 77% mortality at hatch. The incidence of developmental abnormalities (structural defects or edema) was not affected by injection of the extract. Body weight gain of chicks was reduced in the 1.0 egg-equivalent dose group in the first, second, and third week's post-hatch. Relative brain weights were greater and relative bursa weights were less in the 1.0 egg-equivalent dose group than in the vehicle control at three weeks of age. There were no significant differences in the relative weights of the heart, liver, spleen, testes, or comb among treated and control birds.
Tissue Mercury Concentrations in Alligators (Alligator mississippiensis) from the Florida Everglades and the Savannah River Site, South Carolina by G. M. Yanochko; C. H. Jagoe; I. L. Brisbin Jr. (pp. 323-328).
Mercury pollution is a serious problem in some areas of the southeastern United States. Due to biomagnification, long-lived predators should have high Hg concentrations in affected areas. American alligators (Alligator mississippiensis) are important predators in many southwestern wetlands, but little information is available on Hg concentrations in this species. We collected tissues from alligators inhabiting two sites in the Everglades, Florida (n = 18) and a manmade reservoir in South Carolina (Par Pond; n = 44), all with documented histories of Hg contamination, and analyzed them for total Hg. Mean concentrations in kidney, liver, muscle, and dermal scutes of alligators from the Everglades (expressed as mg Hg/kg dry mass ± S.E.M.) were 36.42 ± 5.23, 41.09 ± 5.90, 5.57 ± 0.47, and 5.83 ± 1.04, respectively. Concentrations in liver, muscle, and scutes from Par Pond alligators were 17.73 ± 2.56, 4.08 ± 0.46, and 4.58 ± 0.63, respectively. Blood from Par Pond alligators contained 2.20 ± 0.38 mg Hg/kg wet mass. Mercury concentrations did not differ among sexes at any location. Tissue Hg levels did not differ significantly between Everglades locations, but were lower in Par Pond. In Everglades alligators, Hg concentrations in all tissues were positively correlated, as were tissue Hg and total length. Only total length and scute Hg were correlated in Par Pond alligators. Regression revealed a significant relationship between muscle and scute Hg concentrations in Everglades alligators, but not Par Pond alligators. Alligators living in polluted areas can accumulate substantial concentrations of Hg, but relationships among Hg concentrations in specific tissues may vary with location or age and size of the animals sampled.
Monitoring of Polychlorinated Biphenyls in Human Blood Plasma: Methodological Developments and Influence of Age, Lactation, and Fish Consumption by E. Grimvall; L. Rylander; P. Nilsson-Ehle; U. Nilsson; U. Strömberg; L. Hagmar; C. Östman (pp. 329-336).
Human plasma samples from 50 wives of fishermen have been analyzed with respect to PCBs. The non-ortho-substituted PCB congeners CB-126 and CB-169 were determined by mass spectrometry in negative ion chemical ionization mode, which demonstrated a limit of detection of 30 fg. The recoveries of the internal standards used for determination of ortho-substituted CBs were approximately 95%. Two methods, one gravimetric and the other based on enzymatic determinations of triglycerides, cholesterol and phospholipids, were compared for the determination of total amount of lipids in the plasma samples; the correlation coefficient was 0.82 and the slope 0.98. For practical reasons, enzymatic determinations are recommended for further use. The total, lipid-adjusted concentrations of PCBs in plasma were influenced by age, total lactation time and consumption of fatty fish from the Baltic Sea.