The toxicity of composted sediments from Mediterranean ports evaluated by several bioassays

This work investigates the ecotoxicological evaluation of contaminated dredged sediments from French Mediterranean navy harbour (A), commercial port (B) and two composite specimens (C) and (D) coming from the mixture of A and B with other port sediments. The toxicity of elutriates from these sediments is estimated using embryo-toxicity test, Microtox® solid phase test, LuminoTox, phytotoxicity tests and genotoxicity test. Bioassay responses are not clearly correlated with chemical contamination in the whole sediment and vary as a function of tested organisms. The highest contaminated samples (A and C) are almost always more toxic than the less contaminated samples (B and D). Among composite sediments, the mixture effect with other sediments is not efficient to decrease toxicity in sample C, suggesting that other parameters influence toxicity level such as particle size or organic matter content. These parameters should be taken into consideration in order to improve the efficiency of the mixture process and produce composite sediments with low toxicity.     

Interpretation of microbial bioassays using kinetic parameters

A method analogous to that used for enzyme kinetics was applied to estimate maximum growth rates and oxygen depletion rates as measures of microbial toxicity. Selected toxicants including phenol, formalin and CuSO4 were tested against an axenic culture of E. coli and a mixed culture derived from soil to determine reproducibility of the test procedures. Optical density was used as a measure of growth over time. Oxygen uptake over a short term (less than 20 min.) and over extended time (greater than 4 hrs.) was also monitored. Microbial growth rate constants (g) and oxygen depletion rate constants (k) were calculated and the EC50 values for toxicity were taken as one half the maximum growth rate or oxygen depletion rates, respectively. The method proved a reasonable and reliable measure of toxicity.     

Investigations of the determination and transformations of diazinon and malathion under environmental conditions using gas chromatography coupled with a flame ionisation detector

Degradation of two model insecticides, diazinon and malathion, and their degradation products 2-isopropyl-6-methyl-4-pyrimidinol--IMP (diazinon hydrolysis product) and malaoxon (malathion oxidation product) was compared and studied in the environment. The pesticides and their metabolites were extracted from samples (water, soil, chicory) with ethyl acetate and subsequently the extracts were analyzed by GC/FID. It was shown that hydrolysis is the major process in the degradation of these pesticides in water. In fact, 95% of diazinon was degraded, and only 10% of malathion was oxidised. In soil 30% of diazinon exposed to the sunlight was decomposed by photolysis, whereas in soil left in the darkness no degradation products were observed. In soil left under environmental conditions, 90% of diazinon was degraded and 40% from its initial concentration was transformed into IMP. The concentrations of the pesticides after 21 days on chicory were under maximal allowable concentration, which is 0.5 ppm for malathion and for diazinon. The concentration of malaoxon was more than twice as high as the allowable value, which is for the sum of malathion and malaoxon 3 ppm.     

Evaluating the environmental fate of atrazine in France

Atrazine is used in large quantities in U.S. and European countries as a weed-control agent. As a result, numerous data on its environmental fate and hazards have been published. Analysis of the literature shows that this herbicide can be found with appreciable concentrations in groundwaters, rivers, lakes, and estuaries. This contamination principally results from leaching and runoff processes. Atrazine can also pollute fog and rain due to its release into the atmosphere through spray applications. This large amount of information constitutes a very attractive basis for assessing the simulation performances of environmental fate models. In this context, CHEMFRANCE, a regional fugacity model level III which calculates the environmental distribution of organic chemicals in twelve defined regions of France has been used to estimate the environmental fate of atrazine. The calculated values are comparable with field and laboratory results. Therefore, CHEMFRANCE can be considered as a useful tool for simulating the environmental fate of this agrochemical.     

Evaluating the environmental fate of lindane in France

Lindane, a highly persistent and lipophilic pesticide, is still used in large quantities. This chemical can be found with appreciable concentrations in biota, atmosphere, and in other environmental compartments in the adsorbed form. This information provided a basis for assessing the simulation performances of CHEMFRANCE, a regional level III fugacity model allowing to generate environmental behavior profile of organic chemicals in France. The comparison between the estimated environmental fate and field and laboratory observations suggests that this fugacity model can be used to determine the processes that control the environmental fate of lindane in France. CHEMFRANCE also provides accurate estimates of environmental compartment contaminations.     

城市污泥堆肥产品施用对沙荒地土壤理化性质及高羊茅生长的影响

通过盆栽实验研究了城市污泥堆肥产品4种施用比例（0、10%、25%和50%）对沙荒地土壤理化性质及高羊茅生长的影响,结果表明：污泥堆肥产品的施加使混配土壤pH值向更利于高羊茅生长的pH范围（6.0~7.0）变化,土壤电导率随着施肥比例的增大有显著的增加,当施肥比例为10%、25%、50%时,土壤电导率分别为不施肥沙土的11.93、12.66和19.81倍;城市污泥堆肥产品施用后可显著提高沙荒地土壤中全氮、全磷、全钾及有机质含量,施肥比例为10%、25%和50%的沙土中有机质含量分别是不施肥沙土的3.69、4.22和5.65倍。污泥堆肥产品的施入有利于高羊茅对营养元素氮、磷和钾的吸收,进而促进了高羊茅的生长,但是这种促进作用在实验初期较为缓慢,直到实验后期方才显现出来。当施肥比例为25%时,高羊茅对营养物质的利用率达到最高,确定其为沙荒地土壤改良较为适宜的施肥比例。     

Comparison of solid and liquid-phase bioassays using ecoscores to assess contaminated soils

Bioassays on aqueous and solid phases of contaminated soils were compared, belonging to a wide array of trophic and response levels and using ecoscores for evaluating ecotoxicological and genotoxicological endpoints. The method was applied to four coke factory soils contaminated mainly with PAHs, but also to a lesser extent by heavy metals and cyanides. Aquatic bioassays do not differ from terrestrial bioassays when scaling soils according to toxicity but they are complementary from the viewpoint of ecological relevance. Both aquatic and terrestrial endpoints are strongly correlated with concentrations of 3-ring PAHs. This evaluation procedure allows us to propose a cost-effective battery which embraces a wide array of test organisms and response levels: it includes two rapid bioassays (Microtox(?) and springtail avoidance), a micronucleus test and three bioassays of a longer duration (algal growth, lettuce germination and springtail reproduction). This battery can be recommended for a cost-effective assessment of polluted/remediated soils.     

Ecotoxicological assessment of metal-polluted urban soils using bioassays with three soil invertebrates

This study aimed at assessing the quality of urban soils by integrating chemical and ecotoxicological approaches. Soils from five sites in downtown Naples, Italy, were sampled and characterized for physical-chemical properties and total and water-extractable metal concentrations. Bioassays with Eisenia andrei, Enchytraeus crypticus and Folsomia candida were performed to assess toxicity of the soils, using survival, reproduction and growth as the endpoints. Metal bioaccumulation in the animals was also measured. The properties and metal concentrations of the soils strongly differed. Metal bioaccumulation was related with total metal concentrations in soil and was highest in E. crypticus, which was more sensitive than E. andrei and F. candida. Responses of the three species to the investigated soils seemed due to both metal contamination and soil properties.     

An overview of environmental hazards and exposure risk of hydrofluorocarbons (HFCs)

Hydrofluorocarbons (HFCs) are being used as replacements for chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) that cause significantly stratospheric ozone depletion and global warming. HFCs under commercial uses as cleaning solvents in the electronic components, blowing agent in the foamed plastics, refrigerant in the air conditioning units and refrigerators, fire suppression agent in the fire protection, propellant in the metered dose inhalers (MDIs), and dry etching agent in the semiconductor manufacturing. Among these HFCs, 1,1,1,2-tetrafluoroethane (HFC-134a) is the most widely used one. From the environmental, ecological, and health points of view, it is urgent to mitigate and control the emissions of these HFCs from a diversity of commercial applications and industrial processes. This article aims to introduce these HFCs in commercial uses and environmental hazards (i.e., global warming, photochemical potential, flammability safety, environmental partition and ecotoxicity). Further, the updated data on the human toxicity, occupational exposure and health risk of these HFCs (esp., HFC-134a) are addressed in this review paper.     

Prioritisation of organic contaminants in a river basin using chemical analyses and bioassays

Region-specific contaminant prioritisation is an important prerequisite for sustainable and cost-effective monitoring due to the high number of different contaminants that may be present. Surface water and sediment samples from the Sava River, Croatia, were collected at four locations covering a 150-km-long river section characterised by well-defined pollution gradients. Analysis of contaminant profiles along the pollution gradients was performed by combining toxicity screening using a battery of small-scale or in vitro bioassays, which covered different modes of action, with detailed chemical characterisation based on gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). A large number of contaminants, belonging to different toxicant classes, were identified in both analysed matrices. Analyses of water samples showed that contaminants having polar character occurred in the highest concentrations, while in sediments, contributions from both non-polar and amphiphilic contaminants should be taken into account. Estimated contributions of individual contaminant classes to the overall toxicity indicated that, besides the classical pollutants, a number of emerging contaminants, including surfactants, pharmaceuticals, personal care products and plasticizers, should be taken into consideration in future monitoring activities. This work demonstrates the importance of the integrated chemical and bioanalytical approach for a systematic region-specific pollutant prioritisation. Finally, the results presented in this study confirm that hazard assessment in complex environmental matrices should be directed towards identification of key pollutants, rather than focusing on a priori selected contaminants alone.     

Assessment of water quality in the Alqueva Reservoir (Portugal) using bioassays

Background, aim, and scope  

Alqueva Reservoir is the biggest artificial freshwater reservoir in Europe and is an important water supply for human and agricultural consumption in the Alentejo region (Portugal). Pollution can impair environmental and human health status, and to assure water quality and ecological balance, it is crucial to frequently monitor water supplies. In this study, we used an ecotoxicological test battery to identify the potential toxicity of water from this reservoir.     

Assessing the genotoxicity of urban air pollutants using two in situ plant bioassays

Genotoxicity of urban air has been analysed almost exclusively in airborne particulates. We monitored the genotoxic effects of airborne pollutants in the urban air of Perugia (Central Italy). Two plant bioindicators with different genetic endpoints were used: micronuclei in meiotic pollen mother cells using Tradescantia-micronucleus bioassay (Trad-MCN) and DNA damage in nuclei of Nicotiana tabacum leaves using comet assay (Nicotiana-comet). Buds of Tradescantia clone # 4430 and young N. tabacum cv. Xanthi plants were exposed for 24 h at three sites with different pollution levels. One control site (indoor control) was also used. The two bioassays showed different sensitivities toward urban pollutants: Trad-MCN assay was the most sensitive, but DNA damage in N. tabacum showed a better correlation with the pollutant concentrations. In situ biomonitoring of airborne genotoxins using higher plants combined with chemical analysis is thus recommended for characterizing genotoxicity of urban air.     

Feasibility of vermicomposting dairy biosolids using a modified system to avoid earthworm mortality

A laboratory study was conducted to examine the feasibility of vermicomposting dairy biosolids (dairy sludge), either alone or with either of the bulking agents-cereal straw or wood shavings, using the epigeic earthworm-Eisinea andrei. Earthworms added directly to these three substrates died within 48 hours. A system was developed to overcome the toxic effect of unprocessed dairy biosolids. The substrates were placed over a layer of vermicomposted sheep manure into which the earthworms were inoculated. Within two weeks, all earthworms were within the upper layer of substrate. Compared to sheep manure which is a favourable substrate for vermicomposting, the three substrates containing dairy biosolids were more effective in supporting earthworm growth and reproduction. The final products obtained after 63 days of vermicomposting had 39-53% less organic carbon than the initial substrates. Organic fractionation indicated that vermicomposting increased the stability of the materials to biological decomposition. The vermicomposts obtained from the three substrates with dairy biosolids had low heavy metal contents and electrical conductivities, and did not inhibit plant growth when compared with a commercial vermicompost in a bioassay.     

Evaluating the environmental effects of economic openness: evidence from SAARC countries

Environmental Science and Pollution Research - This study investigates the possible environmental effects of economic openness, such as economic growth, foreign direct investment (FDI) inflows, and...     

Feasibility of vermicomposting dairy biosolids using a modified system to avoid earthworm mortality

Abstract

A laboratory study was conducted to examine the feasibility of vermicomposting dairy biosolids (dairy sludge), either alone or with either of the bulking agents ‐ cereal straw or wood shavings, using the epigeic earthworm ‐ Eisinea andrei. Earthworms added directly to these three substrates died within 48 hours. A system was developed to overcome the toxic effect of unprocessed dairy biosolids. The substrates were placed over a layer of vermicomposted sheep manure into which the earthworms were inoculated. Within two weeks, all earthworms were within the upper layer of substrate. Compared to sheep manure which is a favourable substrate for vermicomposting, the three substrates containing dairy biosolids were more effective in supporting earthworm growth and reproduction. The final products obtained after 63 days of vermicomposting had 39–53% less organic carbon than the initial substrates. Organic fractionation indicated that vermicomposting increased the stability of the materials to biological decomposition. The vermicomposts obtained from the three substrates with dairy biosolids had low heavy metal contents and electrical conductivities, and did not inhibit plant growth when compared with a commercial vermicompost in a bioassay.     

Soil screening for identifying ecological risk stressors using a battery of in vitro cell bioassays

Soil screening could be a process of identifying and defining areas, contaminants, and condition at the sites that warrant further attention for developing ecological risk assessments. In present work, a total of 41 surface soil samples from Tianjin, China were sampled and the soil organic extracts were evaluated using a battery of in vitro cell bioassays. The battery included ethoxyresorfin O-deethylase (EROD) with H4IIE rat hepatoma cells bioassay for Aryl hydrocarbon (Ah) receptor (Ah-agonists) effects, the SOS/umu bioassay for genotoxic effects, and human estrogen receptor recombinant yeast bioassay for estrogenic effects. The results have showed that total estrogenic effects in these soil samples was measured to be between 0.1 and 14.2ng EEQkg(-1) soil (d.w.); Ah-agonists effects assayed by EROD bioassay varied from 2.8ng TEQkg(-1) soil (d.w.) to 42.6ng TEQkg(-1) soil (d.w.), and the amounts of soil weight required for the extracts to lead positive result (IR 2.0) in the SOS/umu bioassay were between 3.9 and 31.3mg (d.w.) per well. In addition, the geographic distributions of Ah-agonists effects and genotoxic effects in Tianjin area exhibited a strong positive correlation with each other. However, the distribution of estrogenic effects with high levels in northwest Tianjin was markedly different from that of Ah-agonists effects, where the high levels were distributed in the urban of Tianjin, as well as coastal towns. It has been concluded that the toxicity assessment of surface soil using a battery of in vitro cell bioassays could provided meaningful information regarding characterization procedure in ecological risk assessment.     

Environmental hazard screening of a metal-polluted site using pressurized liquid extraction and two in vitro bioassays

Rapid screening methods can improve the cost effectiveness, throughput, and quality of risk assessments of contaminated sites. In the present case study, the objective was to evaluate a combination of pressurized liquid extraction and 2 in vitro bioassays for the hazard assessment of surface soil sampled from 46 points across a pyrotechnical industrial site. Pressurized liquid extraction was used to rapidly produce soil-water extracts compatible with 2 high-capacity bioassays. Hazard assessment using combined toxicological and chemical screening revealed zones with relatively high potential risks of metal pollution. Multivariate data analysis provided indications that significant inhibition in the bioassays was correlated with levels of metals in the extracts, suggesting an elevated toxic potential from certain metals. Low pH and high concentrations of dissolved organic carbon were associated with increased cytotoxicity of extracts, indicating that these factors influence metal bioavailability. The cytotoxicity observed was more strongly correlated to metal concentrations in the extracts than in the soil, suggesting that measurements of total metal concentrations in soils do not provide good indications of the soil's potential toxicity.     

Evaluation of the toxicity of two soils from Jales Mine (Portugal) using aquatic bioassays

Soil contamination can be one path for streams and groundwater contamination. As a complement of chemical analysis and total contaminants determination, bioassays can provide information on the bioavailable fraction of chemical compounds, focusing on the retention and habitat function of soils. In this study the evaluation of the toxicity of two soils from the abandoned Jales Mine (Portugal) regarded both functions. The buffer capacity of soils was tested with bioassays carried out using the cladoceran Daphnia magna and the marine bacteria Vibrio fischeri. The habitat function of soils was evaluated with the reproduction bioassay with the collembolan Folsomia candida. The Microtox solid-phase test was performed with V. fischeri using soil as test medium, and soil elutriates were extracted to perform the Microtox basic test, and an immobilization and reproduction bioassay with D. magna. The marine bacteria showed high sensitivity to the soil with low heavy metal content (JNC soil) and to JNC soil elutriates, while the soil with highest heavy metal content (JC soil) or soil elutriates exposure did not cause any toxic effect. In the bioassays with D. magna, organisms showed sensitivity to JNC and also to JC soil elutriates. Both mobilization and reproduction features were inhibited. The bioassay with F. candida did not reflect any influence of the contaminants on their reproduction. Although JNC soil presented lower heavy metal contents, elutriates showed different patterns of contamination when compared to JC soil and elutriates, which indicates different retention and buffer capacities between soils. Results obtained in this study underlined the sensitivity and importance of soil elutriate bioassays with aquatic organisms in the evaluation strategy in soil ERA processes.     

Identification of potential biomarkers for diazinon exposure to Japanese Medaka (Oryzias latipes) using annealing control primers

A new differential display-polymerase chain reaction (PCR) method based on annealing control primers was used to screen and identify potential biomarkers from differentially expressed genes (DEGs) in medaka exposed to sub-lethal concentration of diazinon (100 ppb). Among the differentially expressed genes identified, the majority were in functional categories of protein biosynthesis, transport and metabolism according to the gene ontology classification. The differential expression of ribosomal protein genes was quantified by real time PCR. The genes encoding ribosomal proteins including L3 and S17 were selected as potential biomarkers for diazinon exposure in medaka fish.