Genotoxic Effect of Phenol on the Cells of Onion (Allium cepa) Roots

The roots of onion (Allium cepa) stand out for having cells with large size and small number of chromosomes.These characteristics make them useful in bioassays for the measurement of a variety of cytogenetic and morphological parameters , in which they can be used as toxicity indicators of the induction and formation of micronuclei and chromosomal aberrations.Based on this background , the potential genotoxic effect of phenol concentration on cells of A.ceparoots was investigated either in terms of induced aberrations or micronuclei formation.The results demonstrated that the higher the concentration of phenol , the higher the incidence of abnormalities , thus confirming the genotoxicity of this pollutant.     

Assessment of micronuclei and chromosomal anomalies of five biocompatible materials in mice

In vivo genetic toxicology tests measure direct DNA damage or the formation of gene or chromosomal mutations, and are used to predict mutagenic and carcinogenic potential of compounds for regulatory purposes. These adverse genotoxic effects may be manifested in the form of gene mutations, structural chromosomal aberrations (CA), recombination, and numerical changes. The present investigation was carried to assess genotoxic effects of five different implantable biomaterials developed in different laborataries of Sree Chitra Tirunal Institute of Medical Sciences and Technology. All biomaterials were developed for clinical applications. CA and micronuclei (MN) studies are biomarkers of genotoxicity testing. Leachants from the extract of biomaterials are capable of inducing structural and numerical chromosomal changes. The studies were conducted in Swiss albino mice with the physiological saline extract of materials together with cyclophosphamide and physiological saline as positive and negative controls. Animals were administered intraperitoneally (ip) with a single injection of test, positive (cyclophosphamide), and negative (physiological saline) control and sacrificed after 24 or 48?h. Bone marrow cells were collected for CA and MN assays. Data showed that all five biomaterials did not significantly exert genotoxic effects. Hence, the study indicates that these biomaterials do not induce any chromosomal anomalies.     

Concentration of arsenic in water, sediments and fish species from naturally contaminated rivers

Arsenic (As) may occur in surface freshwater ecosystems as a consequence of both natural contamination and anthropogenic activities. In this paper, As concentrations in muscle samples of 10 fish species, sediments and surface water from three naturally contaminated rivers in a central region of Argentina are reported. The study area is one of the largest regions in the world with high As concentrations in groundwater. However, information of As in freshwater ecosystems and associated biota is scarce. An extensive spatial variability of As concentrations in water and sediments of sampled ecosystems was observed. Geochemical indices indicated that sediments ranged from mostly unpolluted to strongly polluted. The concentration of As in sediments averaged 6.58 μg/g ranging from 0.23 to 59.53 μg/g. Arsenic in sediments barely followed (r = 0.361; p = 0.118) the level of contamination of water. All rivers showed high concentrations of As in surface waters, ranging from 55 to 195 μg/L. The average concentration of As in fish was 1.76 μg/g. The level of contamination with As differed significantly between species. Moreover, the level of bioaccumulation of As in fish species related to the concentration of As in water and sediments also differed between species. Whilst some fish species seemed to be able to regulate the uptake of this metalloid, the concentration of As in the large catfish Rhamdia quelen mostly followed the concentration of As in abiotic compartments. The erratic pattern of As concentrations in fish and sediments regardless of the invariable high levels in surface waters suggests the existence of complex biogeochemical processes behind the distribution patterns of As in these naturally contaminated ecosystems.     

Genotoxicity evaluation of surface waters located in urban area of Xi’an City using Vicia faba bioassays

In this study, micronucleus （MCN） and chromosome aberration （CA） tests in Vicia faba root tip cells were carried out in order to assess the water quality and the comprehensive genotoxic potential of surface waters located in the urban area of Xi＇an City, China. For these evaluations, water samples from different surface waters （four rivers, two lakes, two biological treatment plant effluents） were collected, the ultra-pure water and methyl methanesulfonate solution was used as the negative and positive control, respectively. In our results, highly significant differences in MCN perrnillage （average number of micronuclei per 1000 cells）, CA frequencies and PI （pollution index） values were found among three rivers and two WWTP effluents, the tested samples from two rivers caused the decrease of mitotic index over 22% compared with the negative control. No significant changes were observed in micronuclei and chromosome aberrations frequencies at one river and two lakes during the period of test （wet season）. These results point out a poor state of the water quality and genotoxic activity of the main surface waters in Xi＇an City. It is recommended to establish a monitoring program for the presence of genotoxic agents in these surface waters.     

Stabilization of the As-contaminated soil from the metal mining areas in Korea

Phytoextraction is a remediation technology with a promising application for removing arsenic (As) from soils and waters. Several plant species were evaluated for their As accumulation capacity in hydroponic culture amended with As. Cucumis sativus (cucumber) displayed the highest tolerance against As among 4 plants tested in this study (corn, wheat, sorghum and cucumber). The germination ratio of Cucumis sativus was more than 50% at the high concentration of 5,000 mg-As/l. In Cucumis sativus grown in a solution contaminated with 25 mg-As/l, the accumulated As concentrations in the shoot and root were 675.5 ± 11.5 and 312.0 ± 163.4 mg/kg, respectively, and the corresponding values of the translocation and bioaccumulation factors for As were 1.9 ± 0.9 and 21.1 ± 8.4, respectively. These results indicate Cucumis sativus is to be a candidate plant for phytoextraction of As from soils and water.     

Potentially harmful elements in house dust from Estarreja,Portugal: characterization and genotoxicity of the bioaccessible fraction

Due to their behavioral characteristics, young children are vulnerable to the ingestion of indoor dust, often contaminated with chemicals that are potentially harmful. Exposure to potentially harmful elements (PHEs) is currently exacerbated by their widespread use in several industrial, agricultural, domestic and technological applications. PHEs cause adverse health effects on immune and nervous systems and can lead to cancer development via genotoxic mechanisms. The present study is an integrated approach that aims at assessing the genotoxicity of bioaccessible PHEs following ingestion of contaminated house dust. A multidisciplinary methodology associating chemical characterization of five house dust samples, extraction of the bioaccessible PHEs in gastric extracts by the unified BARGE method, determination of the bioaccessible fraction and in vitro genotoxicity of gastric extracts in adenocarcinoma gastric human (AGS) cells was developed. The five gastric extracts induced dose-dependent genotoxicity in AGS cells. Copper (bioaccessible concentration up to 111 mg/kg) was probably the prevalent PHE inducing primary DNA damage (up to 5.1-fold increase in tail DNA at 0.53 g/l of gastric extract). Lead (bioaccessible concentration up to 245 mg/kg) was the most prevalent PHE inducing chromosome-damaging effects (r = 0.55; p < 0.001 for micronucleated cells induction). The association of principal component analysis and Spearman’s correlations was decisive to understand the chromosome-damaging properties of the bioaccessible PHEs in AGS cells. This methodology could be used on a larger-scale study to provide useful information for science-based decision-making in regulatory policies, and a better estimation of human exposure and associated health risks.     

The infection of the European eel with the parasitic nematode Anguillicoloides crassus in inland and coastal waters of northern Germany

Recruitment of the European eel is in decline since three decades. So far, the reasons of the decline have not been fully understood. Beside other factors, infection with the exotic swimbladder parasite Anguillicoloides crassus has been discussed as a threat to the species. In the present study monitoring results for A. crassus in eels from North German waters are presented. Between 1996 and 2011, the swimbladders of 17,219 eels from eight freshwater and coastal water areas were analyzed. Prevalence, abundance of parasites, infection intensity and severity of the damage to the swimbladder were recorded by visual inspection. In the freshwaters the prevalence was in the range of 65–83 %, whereas significantly lower values were found in the brackish waters. The differences were less clear for infection intensity but significantly lower values were found in the outermost location in the Baltic Sea. Mean damage to the swimbladders was highest in eels from the Rivers Weser and Elbe and lowest in the Baltic coastal waters. Prevalence and damage degree were stable in all waters except for two rivers, where a decreasing trend in infection intensity was found.     

Lack of genotoxic potential of permethrin in mice evaluated by the comet assay and micronucleus test

Permethrin is a common insecticide that does not show genotoxic potential in standard in vitro and in vivo assays. To investigate the genotoxic potential of permethrin in more detail, two in vivo studies were conducted on female mice to assess DNA damage in tumor target organs by the comet assay and micronucleus test. For this, mice were administered permethrin at doses of 150, 300, or 600 mg/kg/day by gavage for 2 days, and their lung, liver, glandular stomach, peripheral blood, and bone marrow cells were examined for DNA damage. There were no significant increases in % tail DNA in the organs examined and no increase in micronuclei in peripheral blood by flow cytometry. Taken together, the present findings provide evidence that permethrin has no genotoxic, aneugenic, or clastogenic potential.     

Ecotoxicological risks of the abandoned F–Ba–Pb–Zn mining area of Osor (Spain)

Due to its potential toxic properties, metal mobilization is of major concern in areas surrounding Pb–Zn mines. In the present study, metal contents and toxicity of soils, aqueous extracts from soils and mine drainage waters from an abandoned F–Ba–Pb–Zn mining area in Osor (Girona, NE Spain) were evaluated through chemical extractions and ecotoxicity bioassays. Toxicity assessment in the terrestrial compartment included lethal and sublethal endpoints on earthworms Eisenia fetida, arthropods Folsomia candida and several plant species, whereas aquatic tests involved bacteria Vibrio fischeri, microalgae Raphidocelis subcapitata and crustaceans Daphnia magna. Total concentrations of Ba (250–5110 mg kg^?1), Pb (940 to >5000 mg kg^?1) and Zn (2370–11,300 mg kg^?1) in soils exceeded intervention values to protect human health. Risks for the aquatic compartment were identified in the release of drainage waters and in the potential leaching and runoff of metals from contaminated soils, with Cd (1.98–9.15 µg L^?1), Pb (2.11–326 µg L^?1) and Zn (280–2900 µg L^?1) concentrations in filtered water samples surpassing US EPA Water Quality Criteria (2016a, b). Terrestrial ecotoxicity tests were in accordance with metal quantifications and identified the most polluted soil as the most toxic. Avoidance and reproduction tests with earthworms showed the highest sensitivity to metal contamination. Aquatic bioassays performed in aqueous extracts from soils confirmed the results from terrestrial tests and also detected toxic effects caused by the mine drainage waters. Algal growth inhibition was the most sensitive aquatic endpoint. In view of the results, the application of a containment or remediative procedure in the area is encouraged.     

A study on genotoxicity of textile dyeing industry effluents from Rajshahi,Bangladesh, by the Allium cepa test

Textile dye effluents are believed to be toxic as they might exert various harmful effects on living organisms including genotoxicity. These effluents are the main source of direct and continuous input of pollutants into the aquatic ecosystems. In this study, dye effluents from a local silk dyeing industry were analysed for their genotoxic potential by the Allium cepa genotoxicity test. The A. cepa test is characterised as a genotoxicity test where the roots of A. cepa are grown in different concentrations of the test material. The macroscopic results clearly showed that the toxicity of the dye effluents prompted A. cepa root growth inhibition, and this effect increased with higher concentrations of the effluents. At the cellular level, no dividing cells were found at higher concentrations such as 60%, 80% and 100% of the effluents. However, at a lower concentration of 20%, dividing cells were identified, although the mitotic index was much lower than that of the control. Microscopic analysis showed that the dye effluents induced chromosomal aberrations at significant levels. Taken together, these results revealed that the textile dyeing industry effluents are toxic to eukaryotic cells and these dyes have genotoxic properties that can potentially lead to cancer development and adverse health conditions.     

Efficient arsenic depollution in water using modified maize powder

This article reports the synthesis of an efficient, low-cost material from maize powder to depollute arsenic-contaminated water. Arsenic is toxic for humans and other organisms even at low concentrations. The most well-known and severe case of arsenic poisoning through drinking water has been found in India and Bangladesh. Numerous inorganic materials have been tested for the removal of arsenic from water bodies over the last two decades. However, all such materials have several disadvantages such as unpredictable arsenic ion removal, high cost and the generation of toxic sludge that is often more difficult to manage. Alternatively, organic material from agricultural waste may be modified to enrich functional groups responsible for As sorption and, in turn, used to depollute contaminated waters. Here, Zea mays cob powder has been modified to remove arsenic species from water. Two modified materials were produced: an aminated maize powder and a thiolated maize powder. Amination was done using epichlorohydrin and dimethylamine. Thiolation was done using thioglycolic acids. Amination increased As (III) sorption from 70 to 75.8 % and As (V) sorption from 85 to 94.42 %, compared with unmodified maize powder. Thiolation increased As (III) sorption from 70 to 81.7 % and As (V) sorption from 85 to 90 %. Amination increased usability cycles from 3 to 5. Thiolation increased usability cycles from 3 to 6. The novel modified maize biosorbent has enough potential for the development of a low-cost technological pre-treatment step, prior to high-tech chemical treatments.     

Variability in the chemistry of private drinking water supplies and the impact of domestic treatment systems on water quality

Tap water from 497 properties using private water supplies, in an area of metalliferous and arsenic mineralisation (Cornwall, UK), was measured to assess the extent of compliance with chemical drinking water quality standards, and how this is influenced by householder water treatment decisions. The proportion of analyses exceeding water quality standards were high, with 65 % of tap water samples exceeding one or more chemical standards. The highest exceedances for health-based standards were nitrate (11 %) and arsenic (5 %). Arsenic had a maximum observed concentration of 440 µg/L. Exceedances were also high for pH (47 %), manganese (12 %) and aluminium (7 %), for which standards are set primarily on aesthetic grounds. However, the highest observed concentrations of manganese and aluminium also exceeded relevant health-based guidelines. Significant reductions in concentrations of aluminium, cadmium, copper, lead and/or nickel were found in tap waters where households were successfully treating low-pH groundwaters, and similar adventitious results were found for arsenic and nickel where treatment was installed for iron and/or manganese removal, and successful treatment specifically to decrease tap water arsenic concentrations was observed at two properties where it was installed. However, 31 % of samples where pH treatment was reported had pH < 6.5 (the minimum value in the drinking water regulations), suggesting widespread problems with system maintenance. Other examples of ineffectual treatment are seen in failed responses post-treatment, including for nitrate. This demonstrates that even where the tap waters are considered to be treated, they may still fail one or more drinking water quality standards. We find that the degree of drinking water standard exceedances warrant further work to understand environmental controls and the location of high concentrations. We also found that residents were more willing to accept drinking water with high metal (iron and manganese) concentrations than international guidelines assume. These findings point to the need for regulators to reinforce the guidance on drinking water quality standards to private water supply users, and the benefits to long-term health of complying with these, even in areas where treated mains water is widely available.     

Successful genetic bioaugmentation with Pseudomonas putida for toluene degradation in soil columns

There is a strong need for effective and sustainable treatment methods for remediating soils and waters contaminated by fossil fuel pollutants such as aromatic hydrocarbons. Remediation could be improved by genetic bioaugmentation that uses conjugation of catabolic plasmids between bacteria. Research on the conditions for success, effectiveness, and long-term impact of genetic bioaugmentation are therefore necessary. Here the effects of genetic bioaugmentation with Pseudomonas putida BBC 443 was studied in continuous-flow soil columns with or without glucose amendment. Results show that the highest transconjugant occurrence of 21.7 ± 2.1 %, and development of microbial communities with the highest overall toluene degradation potential of 0.0790 ± 0.0055 mg toluene/g soil/h, were achieved in soil columns that received a continuous addition of 1 g/L glucose. Plasmid transfer and toluene biodegradation did not depend on the survival of donor P. putida BBC443, suggesting that genetic bioaugmentation was successful. Furthermore, bacterial community structure analysis revealed that genetic bioaugmentation had limited long-term impact on the soil bacterial community structures, regardless of the specific treatment. Our findings show that genetic bioaugmentation was successful and resulted in limited long-term ecological impact, thus demonstrating that genetic bioaugmentation can provide an effective and sustainable method for in situ bioremediation.     

SETAC GLB — Gründung und Entwicklung

Goal, Scope, and Background

In the context of the ISO-standardisation of the in vitro micronucleus test for (waste) water testing (ISO/DIS 21427-2), a national collaborative study was organized by the German Federal Institute of Hydrology (BfG) involving ten laboratories of private companies, universities and public authorities. The formation of micronuclei (MN) is a special kind of chromosomal aberration. To meet the standardisation requirements for this method, encoded waste water samples, some of them spiked with known genotoxins, had to be tested in a collaborative study. The study should demonstrate practicability of the in vitro micronucleus test for waste water testing and should provide validity data.

Material and Methods

The micronucleus assay was performed with the permanently growing Chinese hamster lung fibroblast cell line V79. Four encoded samples from one municipal and one industrial wastewater treatment plant were tested with and without metabolic activation by S9-mix. Two of these samples were spiked in advance with defined concentrations of the clastogenic substances cyclophosphamide and mytomycin C. The defined assessment criterion for genotoxicity was the lowest dilution of a sample that does not show any significant induction of micronuclei (LID; lowest ineffective dilution). Cytotoxicity was judged by determining the survival-index, i.e. the percentage growth rate of the cells compared with the respective negative controls. As supplementary qualitative criteria, the mitotic index and the proliferation index were assessed.

Results

Although some of the laboratories had little or even no experience with the protocol of the in vitro micronucleus test described in the ISO-draft, all participants suceeded in establishing the assay within few weeks and in generating viable test results. The two nongenotoxic samples were detected as negative by 90% or 100% of the participants. The mitomycin C-spiked sample (expected to be positive without S9 supplementation) was correctly evaluated as positive by all laboratories. The cyclophosphamide-spiked sample (expected to be positive with S9 supplementation) was evaluated correctly as genotoxic by 80% of the laboratories. A post-test analysis found evidence that the false-negative results were due to technical failure, but not of a methodological nature. The sample LID values varied by no more than one dilution step around the median LID-value for all samples investigated. The survival index was proven to be a robust measure for estimation of cytotoxicity.

Discussion

The measurement of micronuclei is an important parameter for the detection of cytogenetic damage. In contrast to the single-cell gel electrophoresis assay (Comet assay), which is used as an indicator test, the in vitro micronucleus test detects non-repairable and thus manifested genetic damage. Consequently, the in vitro micronucleus test can be regarded as the more significant test system. A more frequent occurrence of micronuclei in treated cells suggests a risk of severe genetic damage for subsequent cell generations. In the interest of a precautionary environmental protection and health protection no municipal or industrial waste-water samples should show any significant induction of micronuclei in the treated cell populations.

Perspectives

The presented collaborative study was the first interlaboratory comparison of the in vitro micronucleus test using wastewater samples. The test system is intended to complement the already DIN- and ISO-standardised bacterial tests, i.e. the umu-test and the Ames plate incorporation assay. The data generated in the course of this project justify the transformation of the draft standard into the final draft international standard (FDIS), the preliminary stage of an international norm, so that a valid, standardised test system for the detection of cukaryotic genotoxicity in water samples might become available.     

Bioaccumulation and toxic effects of copper in common onion Allium cepa L.

The aim of this study was to investigate the potential utility of Allium cepa L. as a bioindicator organism for measuring copper bioaccumulation and toxicity in laboratory conditions. Onions were exposed to increasing concentrations of the metal (0, 0.1, 0.5, 1, 5 and 10 μg mL^?1) for 7 days. Root and leaf development were chosen as biological endpoints, while bioaccumulation was evaluated in roots, bulbs and leaves. Copper caused inhibition of root elongation with increasing effects at the higher doses, growth being reduced by almost 60% at 0.1 μg mL^?1 and up to 95% at 10 μg mL^?1. The elongation of leaves was significantly lower only in specimens exposed at 0.5 μg mL^?1, but a total absence of newly formed tissues was observed at 10 μg mL^?1. A marked bioaccumulation of copper was measured in roots, with values increasing up to almost four orders of magnitude compared to controls; only slight or even no significant differences were observed for copper levels in leaves and bulbs of treated A. cepa. Multiple linear correlations revealed a significant inverse relationship between copper concentrations and tissue length in both the roots and leaves, evidencing a sensitive responsiveness of this biological model. The overall results suggest the suitability of A. cepa as a robust species for easy and simple ecotoxicological bioassays to test the toxic effects and bioavailability of environmental pollutants, especially trace metals.     

Ecotoxicological assessment of metalworking fluids using the Allium cepa test procedure

Metalworking fluids (MWFs), which have a long history of use in industry and are in constant and ever-increasing use in parallel with advancements in mechanisation, are emulsions prepared with water. MWFs prepared as a 1/20 (MWF: water) mixture in practice, contain a large amount of water within their structure, and may become an aquatic toxic mixture in an ecosystem. In this study, half maximal effective concentration (EC₅₀) values for MWFs were determined using the Allium cepa test, an accepted ecotoxicological biomonitor, and test solutions were prepared (1/250, 1/500 and 1/1000). Depending on the MWF ratio at each concentration, a decrease in the mitotic index (MI), irregularities in the phase distribution and aberrations in the chromosomes were observed. When the amount of MWF in the water increased, chromosomal abnormalities such as stickiness were observed to occur; whereas abnormalities such as c-mitosis, fragments, bridges, vagrants and micronucleus increased as the amount of the MWF decreased. Over a second 24-h period, it was observed that values, in particular MI, showed a tendency to return to normal.     

砷细胞遗传毒理学研究的最近进展

本文对砷细胞遗传毒理学研究的最近进展进行了简要评述。着重介绍了砷对人体，试验动物及某些植物诱发染色体畸变，姊妹染色单体互换及微核的效应；对砷诱发体外培养的人类细胞和试验动物细胞染色体畸变，姊妹染色单体互换及微核效应也作了介绍。     

利用泥鳅红细胞核的遗传损伤监测福州市内河水质

利用泥鳅红细胞核的遗传损伤监测福州市内河水质,探讨红细胞核的遗传损伤与水质常规衡量指标间的相关性.结果表明:泥鳅红细胞微核率及核异变率的高低能够反映出河水的综合污染程度,差异达到显著或极显著.在一定范围内河水受污染程度越严重,微核及核异常率越高.但当染毒时间太长时,微核率及核异常率反而有所下降.微核率与水质的几项常规衡量指标间的相关程度依次为:高锰酸盐指数 >溶解氧 >氨氮比 >pH值;总核异常率与河水的几项常规指标间的相关程度依次为:高锰酸盐指数 >氨氮比>溶解氧>pH值.核异常率与微核率达到最高值的处理时间不完全同步.核异常率显著高于微核率,微核率与核异常率相关系数为 0. 44,这反映出生物体本身具有自动修复能力,能通过各种途径修复受损的DNA.此外,还探讨了泥鳅红细胞的微核来源和利用泥鳅红细胞核的遗传损伤监测河水水质的可行性及注意问题. 图 3表 6参 16     

2-硝基芴DNA加合物的研究

2-硝基芴直接与小牛胸腺DNA反应(in vitro),用~(32)P后标记方法能够测定出有多种DNA加合物生成.将定量的2-硝基芴一次注射入大鼠(SD)和经过Aroclor诱导的大鼠腹腔内,24h后取其肝、肾、肺、脾、血等诸器官,用P_1加强灵敏度的~(32)P后标记方法测定各组织中的DNA加合物.其结果是:在诱导和非诱导的大鼠体内各器官中均发现有DNA加合物的存在,Aroclor诱导对DNA加合物的生成有明显的促进作用.在非诱导的大鼠体内肝脏和血中,分别测出与体外反应相对应的多个DNA加合物,证明2-硝基芴有直接损伤生物体内DNA,形成DNA加合物的能力.     

High Cu removal from water using water hyacinth fixed on alginate

The occurrence of toxic metals in waters is a major health issue. Polluted waters can be cleaned by biosorption, which uses organisms such as algae, bacteria, fungi and plants that adsorb metals. In particular, water hyacinth—Eichhornia crassipes—is a promising biosorbent. Here we tested novel alginate-immobilised water hyacinth beads for the removal of Cu from aqueous solutions. Results show that successful service and regeneration continuous cycles were performed using a packed-bed, flow-through column of fixed internal diameter 1.2 cm, at room temperature and pH 5.1, with variation in initial metal concentration, bed depth and flow rate. The eluant used was 1 % w/v CaCl₂ acidified at pH 3. A concentration factor of 12 and elution efficiency up to 98 % were observed in five service and regeneration cycles performed. The equilibrium adsorption capacity of Cu remained almost constant at about 29 mg/g. To conclude, we show for the first time that alginate-immobilised water hyacinth beads can uptake and adsorb Cu very efficiently in a continuous-flow mode, hence highlighting their great potential for removal of toxic metals from aquatic environments.