Ecotoxicological evaluation for the screening of areas polluted by mining activities

The aim of this study was to evaluate the applicability of three bioassays representing multiple trophic levels, for the preliminary ecotoxicological screening of sediments from sites contaminated by mining activities. Of the bioassays used in this study, the ostracod test was the most responsive. Vibrio fischeri luminiscence inhibition assay was less sensitive to the toxicants in the sediments than the phytotoxicity assays. The general trend observed was an increase in toxicity values measured by the bioassays with increasing metal mobilization in sediment samples. Therefore, the test battery can be used as a rapid and sensitive tool to evaluate the heavy metal contamination in sediments.     

Overview of results from the WaterTox intercalibration and environmental testing phase II program: Part 1, statistical analysis of blind sample testing

There is an urgent need to evaluate the presence of toxicants in waters used for human consumption and to develop strategies to reduce and prevent their contamination. The International Development Research Centre undertook an intercalibration project to develop and validate a battery of bioassays for toxicity testing of water samples. The project was carried out in two phases by research institutions from eight countries that formed the WaterTox network. Results for the first phase were reported in the special September 2000 issue of Environmental Toxicology. Phase II involved toxicity screening tests of environmental and blind samples (chemical solutions of unknown composition to participating laboratories) using the following battery: Daphnia magna, Hydra attenuata, seed root inhibition with Lactuca sativa, and Selenastrum capricornutum. This battery was also used to assess potential toxicity in concentrated (10x) water samples. Results are presented for a set of six blind samples sent to the participating laboratories over a 1-year period. Analyses were performed for each bioassay to evaluate variations among laboratories of responses to negative controls, violations of test quality control criteria, false positive responses induced by sample concentration, and variability within and between labs of responses to toxic samples. Analyses of the data from all bioassays and labs provided comparisons of false positive rates (based on blind negative samples), test sensitivities to a metal or organic toxicant, and interlaboratory test variability. Results indicate that the battery was reliable in detecting toxicity when present. However, some false positives were identified with a concentrated soft-water sample and with the Lactuca and Hydra (sublethal end-point) tests. Probabilities of detecting false positives for individual and combined toxic responses of the four bioassays are presented. Overall, interlaboratory comparisons indicate a good reliability of the battery.     

A marine bioassay test set to assess marine water and sediment quality-its need,the approach and first results

There is a need for establishing a marine bioassay test set to assess marine water and sediment samples in Germany. The selected marine bioassay test set, two tests for the water phase (with the luminescence bacteria Vibrio fischeri and the algae Phaeodactylum tricornutum Bohlin) and a whole sediment test with the marine amphipod Corophium volutator (Pallas) is described and first results are shown.     

Comparisons between microscale and whole-sediment assays for freshwater sediment toxicity assessment

The use of several microscale assays for evaluating freshwater sediment toxicity was investigated to develop a representative and cost-effective test battery. The bioassays evaluated (18 assays total) included microscale assays performed on solid-phase, pore water, and organic extracts as well as conventional standardized whole-sediment assays with Chironomus riparius and Hyalella azteca on 10 sediment samples collected in the St. Lawrence/Great Lakes system. Selected sediment physical and chemical characteristics were also conducted to aid in the interpretation of results. Benthic invertebrate assays such as C. riparius and H. azteca endpoints were found to correlate well to contaminant levels. Microscale assays such as ATP (adenosine triphosphate) measurement of sediment microbial biomass gave promising results to predict whole-sediment toxicity to benthic invertebrates. Most assays on pore water did not adequately represent whole-sediment toxicity, whereas organic extracts appeared to be more representative, alleviating some potential confounding factors such as interference due to toxicity caused by ammonia. © 1998 John Wiley & Sons, Inc. Environ Toxicol Water Qual 13 : 93–110, 1998     

Acute toxicity evaluation of olive oil mill wastewaters: A comparative study of three aquatic organisms

Acute toxicity of olive mill wastewaters (traditional and continuous processes) collected from different regions of Portugal was evaluated using three test species (Vibrio fischeri formerly Photobacterium phosphoreum, Thamnocephalus platyurus, and Daphnia magna) and correlated with several physical and chemical parameters. Acute toxicity of these effluents, expressed in LC₅₀ or EC₅₀, ranged from: 0.16 to 1.24% in Microtox test, 0.73 to 12.54% in Thamnotoxkit F test, and 1.08 to 6.83% in Daphnia test. These values reflect the high toxicity of the olive mill wastewaters to all test species. Statistical analysis of the results shows a high correlation between the two microcrustacean bioassays. Microtox test did not correlate significantly with the other bioassays used. A significative correlation (p≤0.05) could also be established between L(E)C₅₀ obtained in the microcrustacean tests and some physicochemical parameters of the effluent. ©1999 John Wiley & Sons, Inc. Environ Toxicol 14: 263–269, 1999     

Toxicity evaluation of water samples collected near a hospital waste landfill through bioassays of genotoxicity piscine micronucleus test and comet assay in fish Astyanax and ecotoxicity Vibrio fischeri and Daphnia magna

In this study, we analyzed samples of water from a river and a lake located near a hospital waste landfill with respect to physico-chemical parameters and conducted bioassays of ecotoxicity using Vibrio fischeri and Daphnia magna, which are species commonly used to evaluate the water toxicity. We also evaluated damage to the genetic material of fish (Astyanax sp. B) that were exposed (96 h) to water from these two sites that were located near the tank ditch, using the alkaline comet assay and the piscine micronucleus test. Parameters including aluminum, manganese, biochemical oxygen demand, sulfide, conductivity, phenol, total coliforms and Escherichia coli counts, were above acceptable levels that have been established in environmental legislation. However, the toxicity bioassays that we carried out in Vibrio fischeri and Daphnia magna and the piscine micronucleus test in fish showed no immediate risk due to acute effects. Based on the results of the comet assay, however, it was possible to detect damage to genetic material in fish that were acutely exposed in the laboratory to water samples from the river and lake that are located near the trench septic tank. Thus, our results suggest that tests beyond those usually employed to test water toxicity, such as the comet assay we used in the fish, are required to assess the toxicity of water with greater accuracy.     

Integrated ecotoxicological assessment of marine sediments affected by land-based marine fish farm effluents: physicochemical, acute toxicity and benthic community analyses

An integrated ecotoxicological assessment of marine sediments affected by land-based marine fish farm effluents was developed using physicochemical and benthic community structure analyses and standardised laboratory bioassays with bacteria (Vibrio fischeri), amphipods (Ampelisca brevicornis) and sea urchin larvae (Paracentrotus lividus). Intertidal sediment samples were collected at five sites of the Rio San Pedro (RSP) creek, from the aquaculture effluent to a clean site. The effective concentration (EC₅₀) from bacterial bioluminescence and A. brevicornis survival on whole sediments and P. lividus larval developmental success on sediment elutriates were assessed. Numbers of species, abundance and Shannon diversity were the biodiversity indicators measured in benthic fauna of sediment samples. In parallel, redox potential, pH, organic matter and metal levels (Cd, Cu, Ni, Pb and Zn) in the sediment and dissolved oxygen in the interstitial water were measured in situ. Water and sediment physicochemical analysis revealed the exhibition of a spatial gradient in the RSP, evidenced by hypoxia/anoxia, reduced and acidic conditions, high organic enrichment and metal concentrations at the most contaminated sites. Whereas, the benthic fauna biodiversity decreased the bioassays depicted decreases in EC₅₀, A. brevicornis survival, P. lividus larval success at sampling sites closer to the studied fish farms. This study demonstrates that the sediments polluted by fish farm effluents may lead to alterations of the biodiversity of the exposed organisms.     

Comparison of the Ceriodaphnia dubia and MicrotoxR inhibition tests for toxicity assessment of industrial and municipal wastewaters

Toxicity tests on effluents from industrial production facilities, municipal and industrial wastewater treatment plants, and stormwater runoff were conducted with the freshwater invertebrate, Ceriodaphnia dubia, and the marine luminescent bacterium, Vibrio fischeri in the Microtox^R test system (Microtox is a registered trademark of AZUR Environmental, Carlsbad, CA.). Percent mortalities of C. dubia in whole effluent, generated in 24- and 48-h exposure periods during the conductance of static-renewal acute and chronic tests were compared with percent reductions in light output by V. fischeri after 15-min exposure periods in the Microtox Inhibition test. A total of 16 effluent and stormwater samples from seven sources were used in tests conducted over a 3-month period. Results of the Microtox Inhibition tests correctly predicted the results of C. dubia tests for all eight nontoxic samples after both 24- and 48-h exposure periods. Of three samples that were toxic to C. dubia within 24 h, the Microtox test also detected toxicity in two of those samples. Results from tests on the remaining five samples showed that while the Microtox Inhibition test indicated the presence of toxic components after 15 min exposure, C. dubia required exposure to potentially toxic samples for 48 h before producing a toxic response. ©1999 John Wiley & Sons, Inc. Environ Toxicol 14: 375–382, 1999     

Screening for sediment toxicity in the Rio Santiago basin: A baseline study

Toxicity testing of sediment samples from the Rio Santiago and its main tributaries was performed using a battery of tests that included the ECHA dipstick biocide monitor, the MetPad test, the lettuce seed germination and the root elongation test, the nematode test, spot plate test, and the SOS Chromotest. Assessment was carried out on organic extracts, pore water, and direct sediment. Results of bioassays showed toxicity sources from tributaries and canals flowing into the river and areas being degraded by insults from industrial spills. © by John Wiley & Sons, Inc.     

Acute toxicity of parabens and their chlorinated by‐products with Daphnia magna and Vibrio fischeri bioassays

The acute toxicity of 21 parabens and their chlorinated derivatives was investigated by means of two toxicity bioassays: Daphnia magna immobilization test and the inhibition of bioluminescence of Vibrio fischeri. The median effective concentration (EC₅₀) values of the tested parabens ranged from 2.2 to 62 mg l^?1 in the D. magna test and from 0.0038 to 5.9 mg l^?1 in the V. fischeri test at 15 min after exposure. The toxicity of dichlorinated methyl‐ and n‐propylparaben, the most commonly used preservatives in cosmetics, toward D. magna was 3.9‐ and 2.8‐fold that of their corresponding parent compounds. Toxicity toward D. magna showed a linear relationship with log P, indicating that toxicity increases with increasing hydrophobicity. On the other hand, the correlations of toxicity toward V. fischeri with hydrophobicity and with the degree of chlorination were poor. In addition, the results of the present study indicated that the V. fischeri test was more sensitive than the D. magna test for the determination of the acute toxicity of parabens. A complete assessment of the ecological and toxicological risks of parabens may require the examination of chlorinated parabens as well as the parent pollutants, as described in the present study. Copyright © 2008 John Wiley & Sons, Ltd.     

Assessment of the influence of use on ecotoxicological characteristics of synthetic ester lubricants

Synthetic ester lubricants need optimisation about their technical and their ecotoxicological characteristics. To determine the ecotoxicological potential the required examinations can be based on the procedure for a risk assessment of chemicals. At present risk classification of lubricant oils is carried out with new oil fluids that are normally prepared before application in aqueous bioassays. In order to improve the ecotoxicological characteristics of some lubricant oils, the quality of the preparation method has been optimised. The resulting preparation protocol leads to aqueous extracts of the oil fluids that can be tested using biological assays. The extent of the changes of the chemical composition caused by the use as well as the ecotoxicological effects caused by additives have to be taken into consideration. For this reason various used lubricants are tested in addition to new oil fluids. In this work various lubricant samples were examined with standardised bacterial growth assays with Vibrio fischeri and Pseudomonas putida , luminescence inhibition assay with V. fischeri , survival assay with Daphnia magna and algal growth inhibition assay with Scenedesmus subspicatus . The chemical characterisation of the aqueous extracts included the determination of pH, conductivity, heavy metals, the content of dissolved organic carbon, inorganic anions and the content of phosphorus. The results emphasize the thesis that environmentally acceptable lubricants can undergo a change of their ecotoxicological potential during the use. Some of the substances that are normally added to base fluids in order to enhance the applicability of the oils may possess a high toxicological potential.     

消炎去脂片抗炎作用实验研究

目的 :探讨消炎去脂片的抗炎作用。方法 :通过大鼠蛋清致足肿胀法和棉球肉芽法观察消炎去脂片连续用药1周后的大鼠足肿胀和棉球肉芽的干湿重量。结果 :消炎去脂片对大鼠足肿胀有明显的抑制作用 ,用药各组与空白组相比差异有显著性 (P<0.05) ;对肉芽重量及肉芽含水量均有明显的抑制作用 ,用药各组与空白组相比有显著性差异 (P<0.05)。结论 :消炎去脂片具有明显的抗炎作用。     

A pilot study of heavy metal concentration in various environments and fishes in the Upper Sakarya River Basin,Turkey

In this study, concentration of lead, cadmium, copper, cobalt, nickel, and manganese were measured in water, sediment, and fish (Cyprinus carpio and Barbus plebejus) samples at the upper Sakarya river basin in Sept. 1995–1996 period. Also, physical parameters of selected stations in the Sakarya river were measured. Mean concentrations of lead, cadmium, copper, nickel, and manganese differed between water, sediment, and fish samples by seasons. Mean concentrations of lead, cadmium, and cobalt increased in sediment samples in October and August. In water samples only cadmium and cobalt increased in October whereas lead and copper increased in August. Also, high levels of manganese concentrations were detected in water and sediment samples and fish tissue during the study. ©1999 John Wiley & Sons, Inc. Environ Toxicol 14: 367–373, 1999     

Effect of Extended Storage Time on the Toxicity of Sediment-Associated Cadmium on Midge Larvae (Chironomus tentans)

The effect of the duration of spiked sediment storage on cadmium toxicity was studied. Sediment samples were spiked with cadmium to obtain concentrations of 0.6,16.0, 29.0 and 53.0 g Cd per g sediment (dry weight). The spiked sediment was then stored in sealed plastic containers at 4°C in the dark. Sediment bioassays, using Chironomus tentans, were conducted immediately and at periodic intervals for up to 4 months. Though the levels of cadmium in the bulk sediment samples from different stored periods were not significantly different, different toxicity levels to C. tentans were observed. The toxicity was significantly different between subsequent storage times. There was a significant decrease in the bioaccumulation factor (BAF) values with extended storage times, indicating a reduction in the bioavailability of cadmium. This study suggests that the storage of spiked sediment used in sediment toxicity study can influence the results.     

Direct sediment toxicity testing procedure using sediment-chromotest kit

A semiquantitative direct sediment toxicity testing procedure using the Sediment-Chromotest was developed. This procedure has advantages over many other toxicity bioassays. It is simple, quick, and reliable, and does not require special instrumentation. The direct sediment toxicity testing procedure involves the use of serial dilutions of solid phase suspensions mixed with stressed bacteria (Escherichia coli) and a cocktail containing the specific inducer for the chromogenic enzyme and other essential factors. The assay is based on the ability of toxicants to inhibit the de novo synthesis of an inducible enzyme, beta-galactosidase. The amount of de novo synthesized enzyme is determined by a colorimetric reaction. This new procedure measures the presence of bioavailable toxicants in sediments, suspended sediments, soils, and other solid wastes directly without extraction and concentration. © by John Wiley & Sons, Inc.     

An assessment of the potential of the microbial assay for risk assessment (MARA) for ecotoxicological testing

Rapid microscale toxicity tests make it possible to screen large numbers of compounds and greatly simplify toxicity identification evaluation and other effect directed chemical analyses of effluents or environmental samples. Tests using Vibrio fischeri (such as Microtox?) detect toxicants that cause non-specific narcosis, but are insensitive to other important classes of contaminants. The microbial assay for risk assessment (MARA) is a 24 h multi-species test that seeks to address this problem by using a battery of ten bacteria and a fungus. But there has been little independent evaluation of this test, and there is no published information on its sensitivity to pesticides. Here, we assess the performance of MARA using a range of toxicants including reference chemicals, fungicides and environmental samples. Mean MARA microbial toxic concentrations and IC₂₀s (20% Inhibitory concentrations) indicate the toxicant concentrations affecting the more sensitive micro-organisms, while the mean IC₅₀ (50% Inhibitory concentration) was found to be the concentration that was toxic to most MARA species. For the two fungicides tested, the yeast (Pichia anomalia) was the most sensitive of the ten MARA species, and was more sensitive than the nine other yeasts tested. The test may be particularly valuable for work with fungicides. Mean MARA IC₅₀s were comparable to values for nine other yeast species and the lowest individual IC₅₀s for each toxicant were comparable to reported IC₅₀s for Daphnia magna, Selenastrum capricornutum and Microtox? bioassays. MARA organisms exhibited more variable sensitivities, with the most sensitive organism being different for different samples, enhancing the likelihood of toxicity detection and giving a toxicity “fingerprint” that may help identify toxicants. The test, therefore, has great potential and would be valuable for ecotoxicological testing of pollutants.     

Comparison of Procedures for Measuring the Quaternary N-Glucuronides of Amitriptyline and Diphenhydramine in Human Urine with and without Hydrolysis

The activities of β-glucuronidases from Helix pomatia, Escherichia coli and rat towards the N-glucuronides of amitriptyline and diphenhydramine were considerably lower than those towards standard substrates. The two N-glucuronides were analysed in urine samples by the following procedures: HPLC of the intact conjugate after solid-phase extraction on a cation exchanger cartridge or after direct injection of urine; HPLC of the aglycone after hydrolysis with β-glucuronidase from H. pomatia or E. coli or after alkaline hydrolysis. Solid-phase extraction led to the highest recovery and precision, and sensitivity can be improved by extracting a larger volume of urine. On application to samples from patients under treatment with amitriptyline, the results of all procedures except alkaline hydrolysis were in good agreement. When diphenhydramine N-glucuronide was analysed in urine samples of volunteers, solid-phase extraction, hydrolysis by E. coli glucuronidase and alkaline hydrolysis resulted in similar values.     

Statistical analysis of sediment toxicity by additive monotone regression splines

Modeling nonlinearity and thresholds in dose-effect relations is a major challenge, particularly in noisy data sets. Here we show the utility of nonlinear regression with additive monotone regression splines. These splines lead almost automatically to the estimation of thresholds. We applied this novel method to explore the relation between the toxicity of aquatic sediments, as observed in bioassays with Daphnia magna, Chironomus riparius and Vibrio fischeri, and the degree of contamination of the sediments. Despite the low signal-to-noise ratio in the data, some interesting thresholds and (non)linear effects were found. The method has added value compared to the linear multivariate methods applied earlier to these data. Percentages of explained variance remained low, but could be doubled by diminishing the effect of local variability.     

Sediment quality triad assessment survey of the Galveston Bay,Texas system

To characterize the quality of sediments at key sites in the Galveston Bay Estuary, sediment samples were collected concurrently for chemical and physical analyses, toxicity testing and an assessment of benthic community structure. Significant toxicity, as determined by the sea urchin (Arbacia punetulata) pore water embryological development assay, was observed at 12 of the 24 sites investigated in this study. No toxicity was observed at any of the sites with the amphipod (Grandidierella japonica) solid-phase test. There were a number of sites with elevated levels of trace metals and petroleum hydrocarbons. The chemistry, toxicity and benthic data were ranked by station and a scaled rank sum was calculated to facilitate comparisons among the stations. Five sites exhibited strong evidence of contaminant-induced degradation, while 15 stations showed no evidence of contaminant-induced degradation. At eight additional sites the sediment quality triad (SQT) data indicated that unmeasured chemicals or conditions were stressing the system. Contaminant impacts could be reduced or eliminated by alternative regulatory and management practices, including the restriction of produced water discharges into coastal estuaries and the use of dredge material disposal practices that minimize the reintroduction of sediment-associated contaminants to the bays.     

Enhancement of toxicant release from sediment by sonication and sodium ligninsulfonate

Organic solvents are commonly used in many sediment toxicity bioassays to facilitate the extraction and concentration of adsorbed contaminants from sediment samples. However, the inherent biotoxicity of most solvents to the bioassay organism may complicate greatly the interpretation of the toxicity test results. To alleviate this problem, a solvent-less extraction procedure was developed for use in the assessment of sediment toxicity. Basically, it involves the use of sonication and sodium ligninsulfonate to enhance the release of the adsorbed contaminants from the sediment. The procedure was applied to sediment samples collected from the St. Clair River at a site approximately 25 m offshore of Dow Chemicals (Sarnia, Ontario). Test results indicate that the most toxic components of the St. Clair River system near Dow Chemicals were associated mainly with the sediment fraction, and there appeared to be very little or no biotoxicity in the overlaying water column. Several of the major contaminants were identified as chlorinated hydrocarbons. The impact of these chemicals on the aquatic environment is discussed. © 1996 by John Wiley & Sons, Inc.