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Seasonal variations in the activities of selected hepatic biotransformation and antioxidant enzymes in eelpout (Zoarces viviparus).

The eelpout (Zoarces viviparus) is used in Swedish and German environmental monitoring of pollutant effects in fish and is being considered for the same purpose in other countries, mainly around the Baltic Sea. The activities of several hepatic biotransformation and antioxidant enzymes were monitored during the period of 12 months from August 1996 to July 1997, using newly caught feral eelpout from Kattegat, off the west coast of Sweden. In females, the biotransformation enzyme activities showed significant seasonal variations, although the amplitude of the changes was limited; CYP1A-activity, measured as ethoxyresorufin-O-deethylase (EROD), was highest in February-March and decreased afterwards, possibly due to rising estrogen levels. UDP-glucuronosyltransferase activity was lowest in November, while the glutathione-S-transferase activity markedly decreased during the winter. The antioxidant enzymes, catalase, glutathione peroxidase and glutathione reductase showed small variations in their activity. The number of male fish was limited and the seasonal variations less clear. However, in both sexes, glutathione reductase and peroxidase activities were highest in autumn and May, respectively. This study establishes a baseline for the activities of the selected enzymes in female eelpout, which is important for the environmental monitoring using this fish species.

Animals↗

Priority volatile organic compounds in surface waters of the southern North Sea.

The occurrence of 25 volatile organic compounds (VOCs) was studied from April 1998 to October 2000 in the southern North Sea. Target VOCs were selected from lists of priority pollutants for the marine environment and included, e.g., chlorinated short-chain hydrocarbons (CHCs), monocyclic aromatic hydrocarbons (MAHs), and chlorinated monocyclic aromatic hydrocarbons (CMAHs). Water samples were taken from the Channel, the Belgian Continental Shelf, the mouth of the Scheldt estuary and the Southern Bight, and were analysed by purge-and-trap and high-resolution gas chromatography-mass spectrometry. All data were produced by analyses deemed 'in control' by a rigorous quality assurance/quality control program provided by QUASIMEME (Quality Assurance of Information for Marine Environmental Monitoring in Europe). Chloroform and trichloroethene were commonly detected at concentrations up to 1900 and 270 ng l(-1), respectively. The other CHCs were generally found below 5 ng l(-1), and rarely exceeded 10 ng l(-1). Concentrations of MAHs were at least one order of magnitude higher than those of the CHCs. The higher levels were attributed to anthropogenic emissions from oil-related activities in coastal areas. CMAHs, except chlorobenzene and 1,4-dichlorobenzene, were hardly detected in North Sea waters. The levels of several CHCs and MAHs were shown to decrease compared to previous investigations in 1994-1995, probably as a result of on-going emission reduction efforts. The occurrence of 1,1,1-trichloroethane, for instance, was substantially reduced since the Montreal Protocol was implemented in 1995.

Chloroform↗

Detection of toxin-producing cyanobacteria by use of paramagnetic beads for cell concentration and DNA purification.

Early detection of water blooms caused by potential toxin-producing cyanobacteria is important in environmental monitoring. We present a new nucleic acid-based method for detection of cyanobacteria in water that utilizes the same paramagnetic solid phase (beads) for both bacterial cell concentration and subsequent DNA purification. In the cell concentration step, the beads were attracted to a magnet after cell adsorption (in an alcohol- and salt-containing solution), and the supernatant was removed. For DNA purification, a buffer containing guanidine thiocyanate and Sarkosyl lysed the concentrated cells. The addition of alcohol precipitated the released DNA onto the same solid phase as was used for the cell concentration. Finally, to remove PCR inhibitors, the DNA was washed twice in alcohol while bound to the beads. All of the bead-DNA complex was used in the subsequent PCR amplification. The detection limit, as measured by 16S rDNA PCR amplification, was 50 cells in a 0.5-ml water sample, which is considerably lower than the limit (500 cells/ml) of toxic cyanobacteria tolerated in drinking water (New South Wales Blue-Green Algae Task Force, 1992). Testing of water from natural habitats showed a detection limit in the same range as that for the defined samples. The detection limits and the simplicity of the method (paramagnetic beads can be handled in automated systems) suggest that our method is suitable for routine environmental monitoring.

Automation↗

Comparison of RBCA and CalTOX for setting risk-based cleanup levels based on inhalation exposure.

Risk-based corrective action (RBCA) and CalTOX (California EPA) are often used to develop risk-based soil cleanup levels. The determination of the entry parameters, including slope factors, degradation assumption, methodologies, and dispersion models for these two approaches greatly affect the onsite/offsite cleanup levels, risk distribution, and ranking of the influential factors. The subsurface soil-to-ambient air was considered as the only significant exposure pathway in this study. RBCA and CalTOX apply analytical equations and multimedia fugacity model, respectively, to simulate the transport of contaminants from subsurface soil to ambient air. Nine carcinogenic organic contaminants were selected as the target compounds. Environmental monitoring data collected from a contaminated site in southern Taiwan was used as model inputs. In this study, degradation assumption had greater influence on CalTOX evaluation than slope factors. The cleanup soil levels of all target chemicals developed by both models were close under the same slope factors and degradation assumptions, except for vinyl chloride and hexachlorobenzene. Furthermore, RBCA generally had larger offsite dispersion ratios than CalTOX, especially for long distances. The risk distribution obtained by RBCA was much board than by CalTOX. When 95th percentile was considered as the starting point, the SSTLs derived by RBCA were much stricter than by CalTOX. The ranking of influential factors in the onsite risk assessment for these two models were completely different because of their distinct model methodologies.

Body Weight↗

Disorder and recovery of environmental health monitored by means of lysosomal stability in liver of European flounder (Platichthys flesus L.).

From 1995 to 2000 biological effects were studied in liver of flounder (Platichtysflesus L.) from the German Bight. During the study period deleterious consequences of acute discharges of DDT and PCBs in early spring 1996 and after 1998 due to remobilization of contaminants from riverbed deepening of the River Elbe became evident. As core biomarker which reflects toxically induced liver pathologies and integrates effects of various classes of pollutants we measured the integrity of lysosomal membranes in individual flounder liver. During the study period, twice statistically significant disturbances of lysosomal function was detected in fish from the River Elbe: in summer 1996 and in spring 1999. Yet, the detrimental contaminant effects were not only restricted to individuals from the Elbe but expanded to those flounder inhabiting formerly less polluted reference areas. In contrast to flounder of the Elbe, their ability to recover from the lysosomal disorders were limited. While in autumn 2000 Elbe individuals showed clear signs of recovery, those fish caught in areas more distant to the source of toxicant input still maintained significantly decreased lysosomal membrane integrity. It can be speculated that fish populations which are not continuously exposed to chronic anthropogenic stress may have a lower potential or need a longer period to recover from the effects of pollution.

Animals↗

Sorption and bioreduction of hexavalent uranium at a military facility by the Chesapeake Bay.

Directly adjacent to the Chesapeake Bay lies the Aberdeen Proving Ground, a U.S. Army facility where testing of armor-piercing ammunitions has resulted in the deposition of >70,000 kg of depleted uranium (DU) to local soils and sediments. Results of previous environmental monitoring suggested limited mobilization in the impact area and no transport of DU into the nation's largest estuary. To determine if physical and biological reactions constitute mechanisms involved in limiting contaminant transport, the sorption and biotransformation behavior of the radionuclide was studied using geochemical modeling and laboratory microcosms (500 ppb U(VI) initially). An immediate decline in dissolved U(VI) concentrations was observed under both sterile and non-sterile conditions due to rapid association of U(VI) with natural organic matter in the sediment. Reduction of U(VI) to U(IV) occurred only in non-sterile microcosms. In the non-sterile samples, intrinsic bioreduction of uranium involved bacteria of the order Clostridiales and was only moderately enhanced by the addition of acetate (41% vs. 56% in 121 days). Overall, this study demonstrates that the migration of depleted uranium from the APG site into the Chesapeake Bay may be limited by a combination of processes that include rapid sorption of U(VI) species to natural organic matter, followed by slow, intrinsic bioreduction to U(IV).

Adsorption↗

PCB congener profiles in nestling tree swallows and their insect prey.

Tree swallows (Tachycineta bicolor) are widely used as indicators of local polychlorinated biphenyl (PCB) contamination in North America. Although determining total PCB residues in tissues is useful in environmental monitoring, analysis of PCB congener profiles may reveal sources of contamination and thus prove to be a more refined tool to track contaminants through the food web. To show how differences in PCB congener patterns in birds can be linked to the PCB patterns in their prey, we evaluated PCB congeners in tissues of tree swallow nestlings and their insect prey using principal component analysis and Euclidean similarities. The PC1 scores for PCB residues in nestlings fell between those of the Hexagenia (Ephemeroptera, mayflies) and Chironomidae (Diptera, midges), the two major prey groups of the nestlings. The congener pattern was not related to the location of nest boxes within the study area. However, Hexagenia insects and the nestlings that consumed them were richer in less chlorinated congeners and had higher PC1 scores than Chironomidae insect. In concordance, congener pattern of nestlings that hatched earlier and consumed more mayflies was more similar than that of other nestling to the pattern of nestings texagenia as calculated by Euclidean similarities. We point to the importance of understanding the seasonal availability of specific types of insect prey and their PCB congener pattern before these data are applied in models of trophic transfer of individual PCB congeners within a food web.

Animals↗

[Study on the effects of lead from small industry of battery recycling on environment and children's health].

OBJECTIVE: In order to minimize lead pollution and to protect the identified individuals with high blood lead level from lead contamination, an epidemiological study was carried on children living around the village and township-owned lead industries in Tianying town. METHODS: Environmental monitoring: lead levels in air, soil, drinking water and crops were measured. Biological monitoring: 959 children aged 5 - 12 years were selected from villages where the lead smelters located near the residential areas and the battery disassembling was done in some families. The control children (207 pupils) were from other villages without lead exposure. Blood lead, ZnPP and teeth lead were determined. Height, weight and head circle of children and IQ scores were measured. RESULTS: The environment was seriously polluted. The average lead concentrations in air and soils were 8.5 times and 10 times of the MACs (national health standard) respectively. Eighty-five per cent the air samples with lead concentrations higher than the national health standard. Local crops and wheat at farmers' home were also contaminated by lead dust, with. Lead content being 24 times higher than the standard. The mean blood lead and ZnPP levels of children lived in the polluted areas were 496 microgram/L and 9.41 microgram/g Hb respectively. The lead exposure caused adverse effects on children's IQ and physical development. CONCLUSION: It is necessary to remove and reduce currently active sources of lead pollution in the community and to increase public awareness of potential health effects of lead exposure.

Air Pollutants↗

A semi-automated, microplate version of the SOS Chromotest for the analysis of complex environmental extracts.

Environmental monitoring for genotoxicity requires that a large number of measurements be made across space and time. This requirement demands a rapid and efficient bioassay system. The SOS Chromotest is a rapid, efficient bacterial system for the detection of DNA damaging agents. Over 100 publications have described its use on a variety of samples. Relatively few studies have used the test to examine complex mixtures. Effective testing of complex samples poses a variety of problems. Although solutions have been proposed, few have validated the resulting protocol. In this work we present a semi-automated microplate version of the SOS Chromotest for the examination of complex mixtures. Experiments were conducted to determine the optimal cell concentration, exposure time, substrate conversion time and S9 enzyme concentration. The performance of the method was evaluated using 6 reference genotoxins and 3 complex mixtures. The complex mixtures examined are extracts of diesel particulate matter, urban dust and coal tar. The results obtained indicate that optimal responses often require fewer cells (approximately equal to 5-10 x 10(6) CFU/ml) and a longer exposure (3 h) than that recommended in the original protocol. Interfering effects of colored and turbid samples are removed using centrifugation and initial optical density readings taken 60 min after cell resuspension and lysis. The performance of the established protocol was evaluated using mitomycin C and benzo[a]pyrene results for 207 microplates and solvent control results for 293 microplates. The results indicate that the established method is accurate, sensitive and precise. Coefficient of variation on mean SOSIP values for mitomycin C and benzo[a]pyrene are < 5%. Solvent control data indicate that the standard threshold for determination of a positive response (induction factor > 1.5) is excessively conservative. All liquid transfers were automated using the Biomek automated laboratory workstation. Automation permits a throughput of up to 72 samples per day and maintains excellent precision and accuracy.

Automation↗

Activation of a stress-induced gene by insecticides in the midge, Chironomus yoshimatsui.

Stress proteins (heat shock proteins, HSPs) have been proposed as general biomarkers for environmental monitoring. In the present study, we evaluated the environmental stress-burden on the aquatic midge Chironomus yoshimatsui using hsp70 expression. Larvae collected from streams receiving polluted runoff (field strain) were resistant to the organophosphorus insecticide, fenitrothion (F), and the synthetic pyrethroid, ethofenprox (E), whereas a strain originally collected from an unpolluted area (susceptible strain) showed low resistance to insecticide exposure. To examine the expression of an HSP70 gene in C. yoshimatsui, an hsp70 cDNA probe was prepared using RNA obtained from the field strain larvae and used for Northern blot analyses. The expression of this HSP70 gene in larvae collected from two field sites in May about 1 week after insecticide spraying in the fields was 2.3 (p = 0.018) to 3.3 fold higher than that in the susceptible strain and was also 4.6 and 1.4 (p = 0.033) fold higher than those collected in November 3 months after the cessation of insecticide spraying. In order to identify potential inducers of the HSP70 gene of the field strain, larvae of the susceptible strain were exposed to F or E for 24 h and hsp70 mRNA levels determined. Exposures to F at 0.4 microg/L and E at 1.1 microg/L increased hsp70 mRNA levels 2.7 (p = 0.049) and 4.4 (p = 0.043) fold over controls, respectively. These results suggest that larvae collected from polluted areas are burdened by environmental stressors and the tested insecticides are potential inducers of HSP70. The results also support the suggestion that HSP70 gene expression is a sensitive indicator of low level (nonlethal) exposures to certain insecticides.

Amino Acid Sequence↗

Bank voles as monitors of environmental contamination by heavy metals. A remote wilderness area in Poland imperiled.

Concentrations of heavy metals (Cd, Pb, Cu, Zn, Fe) were determined in the tissues of bank voles collected in polluted forest sites in southern Poland and in Białowieza National Park. The highest cadmium concentrations were found in livers (0.9-12.8 microg g(-1)) and kidneys (3.2-29.6 microg g(-1)), whereas the lowest were in bones (0.2-0.9 microg g(-1)). The lead concentrations found in kidneys and bones ranged from 9.5 to 40.0 microg g(-1). The ranges of zinc, iron and copper concentrations in the tissues of animals were: 137-343 microg g(-1), 206-1017 microg(-1) and 12.0-73.8 microg(-1), respectively. Some of the differences between the levels found in various sites were statistically significant.

Journal Article↗

Near-infrared diode laser spectroscopy in chemical process and environmental air monitoring.

This review covers the rapidly expanding field of near-infrared tunable diode laser spectroscopy where the availability of new lasers has led to the development of simple and inexpensive spectroscopic systems for the detection and monitoring of gas species. The latest diode lasers and the specific techniques associated with diode laser spectroscopy are described. Specific examples covering chemical vapour deposition reaction diagnostics, remote vehicle emission sensing, balloon-borne atmospheric monitoring and combustion diagnostics then illustrate the technique advantages of rapid, highly selective, in situ monitoring.

Air↗

Absence of symptoms in silver refiners with raised blood silver levels.

Silver has been implicated as a cause of ill health, related largely to its use in the medical setting as a treatment for burns and in prosthetic cements. This report discusses occupational silver exposure in two workers with blood silver levels of 49 micrograms/l and 74 micrograms/l who were asymptomatic and showed no signs of argyric neuropathy which has previously been described at blood silver levels as low as 10 micrograms/l. One of the men showed non-characteristic clinical signs of argyrosis. The clinical findings, results of environmental monitoring and effects of environmental improvements on blood silver levels are discussed.

Adult↗

Comparative analysis of antibiotic resistance, immunofluorescent colony staining, and a transgenic marker (bioluminescence) for monitoring the environmental fate of rhizobacterium.

Field releases of the wild-type plant growth-promoting rhizobacterium Pseudomonas fluorescens 89B-27, its bioluminescent derivative GEM-8 (89B-27::Tn4431), and a spontaneous rifampin-resistant variant estimating the wild-type population. Seed and root samples were taken 0, 7, 14, 21, or 28, 35 or 42, and 70 days after planting in each year and processed for enumeration by spiral plating or immunofluorescent colony staining (IFC). In both years, the populations of 89B-27, R34, and GEM-8, as measured by IFC, were not significantly different (P > 0.05) from each other at each sampling time. However, the populations of R34 and GEM-8, as measured by spiral plating and differentiation based on their respective phenotypes, were significantly lower (P < 0.05) than the wild-type populations and their IFC-determined populations. These data indicate that traditional marker systems may underestimate populations and hence the survival and colonization of genetically marked bacteria.

Anti-Bacterial Agents↗