长江、嘉陵江(重庆段)源水有机提取物的致突变活性及其季节变化

为了确定并比较重庆主城区段长江、嘉陵江源水有机提取物的致突变性及其季节变化规律，分别于春、夏、冬季采用GDX－120大孔树脂，对位于城区上游、城区中段、城区下游以长江、嘉陵江源水的5个水厂的进厂水进行了有机物的浓缩提取。提取物的致突变活性采用经典的Ames试验平板掺入法评估，测试菌株为TA98及TA100，同时做加与不加S9的比较。结果显示，嘉陵江及长江源水的有机提取物均有不同程度的致突变活性。嘉陵江源水明显大于长江源水，城区中段源水明显大于上游段及下游段源水。多数断面显示平水期致突变活较为显著并且移码型致突变性大于碱基置换型致密变性。研究结果提示，城市污染源已导致长江、嘉陵江源水具备致突变活性，控制两江沿岸的各种水污染源已成为当务之急。     

Formation of mutagens by photolysis of amino acids in neutral aqueous solution containing nitrite or nitrate ion

Nine amino acids, i.e., alanine, threonine, cysteine, glutamic acid, arginine, proline, tryptophan, phenylalanine and tyrosine, were irradiated with UV light in water containing nitrite or nitrate ion under neutral conditions. The mutagenicities of the ether extracts and the residual water layers of the reaction mixtures were assayed with and without S-9 mix using $\text{Salmonella typhimurium}$ TA98 and TA100. Three aromatic amino acids, tryptophan, phenylalanine and tyrosine, were found to give direct-acting and frameshift mutagens by irradiation in aqueous nitrite solution. Among them, the ether extract of tryptophan exhibited the strongest mutagenicity toward TA98. In the case of irradiation in aqueous nitrate solution, only the ether extract of tryptophan exhibited weak mutagenicity toward TA98 without S-9 mix. The effects of nitrite concentration, irradiation time and pH on mutagen formation from tryptophan and some characteristics of the produced mutagens were examined.     

The mutagenic potentials of tap water samples in Shanghai

The tap water samples were collected from the users' ends in several areas of Shanghai, which is located in Taihu Lake basin, Eastern China. Source water samples were also collected from two municipal source water facilities at the same time. Samples were assayed by three different short-term mutagenicity test systems: Salmonella/microsome assay (Ames test), the Arabinose resistance test (Ara test) and the SOS/umu test. The data showed that two source water samples did not display direct mutagenic potentials. Two tap water samples from city north, which were directly from Yangtze River, were also not mutagenic. Water samples from city south and middle which used source water originating from Taihu Lake were proved to be contaminated with mutagenic potentials by three different assay techniques. The boiled water displayed an even stronger mutagenic potential compared to its original tap water. The molecular mechanism of mutagenicity was associated with a reading frame-shifting potential. GC-MS analysis of tap water extracts from city middle and corresponding source water was compared. Qualitatively similar spectra were observed except for the peaks of three chlorinated aromatic hydrocarbon compounds, which existed only in the tap water. Since the water source has been polluted, raw water was heavily chlorinated in order to sterilize. More toxic compounds, including mutagens, might form during the multi-chlorination. Caution about the possibility of elevated cancer risks in the population that consumes heavily chlorinated water should be kept in mind. A cohort study in the residents of Shanghai is required.     

Changes in toxicity and genotoxicity of industrial sewage sludge samples containing nitro- and amino-aromatic compounds following treatment in bioreactors with different oxygen regimes

Goals, Scope and Background

From 2005, deposition of organic waste will be banned in Sweden. Likewise, in Germany and Austria, similar bans are being planned, and further countries will probably follow. Thus, there is a need to develop new methods and to refine established techniques for sludge management in the whole of the European Union. For this end, there is also an urgent need for appropriate ecotoxicological approaches to elucidate and assess the hazard potential of sewage sludge. Therefore, the present study was designed to assess the capacity of various established sludge treatment methods using different oxygen regimes to degrade recalcitrant nitro-substituted organic compounds and reduce their toxicity. Sewage sludge samples from a wastewater treatment plant in Sweden (Cambrex Karlskoga AB, industrial area Björkborn) receiving wastewater from industries manufacturing pharmaceutical substances, chemical intermediates and explosives were processed with different sludge treatment methods. Among other treatment methods, bioreactors (for anaerobic and aerobic sludge treatment) were used. In the present investigation, a battery ofin vitro bioassays was employed to compare the cytotoxic and genotoxic potentials of different fractions of sludge samples in order to elucidate whether the treatments were suitable to reduce the toxicity of the sludge.

Methods

In order to investigate the cytotoxicity of the extracts of treated and untreated sludge samples, the acute cytotoxicity test with the permanent cell line RTL-W1 was used. Genotoxicity was tested by means of the comet assay (single cell gel electro-phoresis) with RTL-W1cells, and mutagenicity was assessed with the Ames test using the Salmonella typhimurium strains TA98, TA98NR and TA100. Sludge toxicity was tested in different fractions of organic extracts produced by acetone and hexane extractions. The subsequent clean-up procedure (silica gel chro-matography and elution with hexane and dichloromethane) resulted in two fractions, a lipophilic hexane-fraction and a semi-lipophilic dichloromethane-fraction. For the genotoxicity and mutagenicity tests, these fractions were reunited at equal ratios.

Results and Discussion

The acute cytotoxicity test with RTL-Wl cells revealed a high cytotoxic potential for the semi-li-pophilic DM-fractions of all sludge samples with NR₅₀ values (= effective concentration for 50% cell death in the neutral red test) from 8.9 up to 20 mg sludge d.w./ml medium. A low cytotoxic potential for the hexane fractions of the untreated sludge samples (NR₅₀ 400 to < 400 mg sludge d.w./ml medium) was observed, whereas the hexane fractions of the treated sludge samples showed elevated cytotoxicity increasing further with treatment in the bioreactors. The comet assay indicated that three out of eight of the reunited fractions had a significant genotoxic potential. Whereas the genotoxic potential of one sample treated anaerobically was very high with an induction factor of 11.6, a similar sample (taken from the same anaerobic reactor four months later) and one untreated sample showed lower potentials. The samples treated in another anaerobic bioreactor as well as the samples treated aerobically showed no genotoxic potential. Results indicate that aerobic treatment was basically adequate for reducing the genotoxicity of the sludge, whereas anaerobic treatment was only partly useful for reduction of genotoxicity. The Ames test revealed a very high mutagenic potential for the reunited fractions of the untreated sludge samples with strain TA98 (maximum induction factors (IF_max up to 45) and a relatively high potential for one of the samples treated aerobically (S2, IF_max = 18 (TA98, S9-)), thus documenting the suitability of both anaerobic and aerobic treatments to reduce the mutagenicity of the samples, however, with the aerobic treatment being less effective. Conclusions. Overall, none of the microbiological treatments for wastewater sludge in bioreactors was found to be ideal for general toxicity reduction of the sludge samples. Whereas cytotoxicity of the sludge increased or levelled off in most cases following either treatment, genotoxicity both increased or decreased after anaerobic treatment, depending on the specific sample. However, mutagenicity could generally be reduced by anaerobic treatment and, to a lesser degree, by aerobic treatment. Recommendationsand Perspectives. The complex modification of the diverse damage potentials of sludge sample extracts by use of anin vitro biotest battery following treatment for toxicity reduction in bioreactors showed that considerations of different toxicological endpoints is essential for an adequate hazard assessment. Whereas in the case of cytotoxicity reduction, the reactors proved ineffective, mutagenicity could be reduced significantly at least in some cases in this case study.

     

Health care industries: potential generators of genotoxic waste

Health care waste includes all the waste generated by health care establishments, research facilities, and laboratories. This constitutes a variety of chemical substances, such as pharmaceuticals, radionuclides, solvents, and disinfectants. Recently, scientists and environmentalists have discovered that wastewater produced by hospitals possesses toxic properties due to various toxic chemicals and pharmaceuticals capable of causing environmental impacts and even lethal effects to organisms in aquatic ecosystems. Many of these compounds resist normal wastewater treatment and end up in surface waters. Besides aquatic organisms, humans can be exposed through drinking water produced from contaminated surface water. Indeed, some of the substances found in wastewaters are genotoxic and are suspected to be potential contributors to certain cancers. The aim of this study was to evaluate the genotoxic and cytotoxic potential of wastewaters from two hospitals and three clinical diagnostic centers located in Jaipur (Rajasthan State), India using the prokaryotic Salmonella mutagenicity assay (Ames assay) and the eukaryotic Saccharomyces cerevisiae respiration inhibition assay. In the Ames assay, untreated wastewaters from both of the health care sectors resulted in significantly increased numbers of revertant colonies up to 1,000–4,050 as measured by the Salmonella typhimurium TA98 and TA100 strains (with and without metabolic activation) after exposure to undiluted samples, which indicated the highly genotoxic nature of these wastewaters. Furthermore, both hospital and diagnostic samples were found to be highly cytotoxic. Effective concentrations at which 20 % (EC₂₀) and 50 % (EC₅₀) inhibition of the respiration rate of the cells occurred ranged between ～0.00 and 0.52 % and between 0.005 and 41.30 % (calculated with the help of the MS excel software XLSTAT 2012.1.01; Addinsoft), respectively, as determined by the S. cerevisiae assay. The results indicated that hospital wastewaters contain genotoxic and cytotoxic components. In addition, diagnostic centers also represent small but significant sources of genotoxic and cytotoxic wastes.     

The aqueous sulfite-nitrite system: Investigations on the mutagenicity of some known products

Some known reaction products of the two commonly used food additives, sulfite and nitrite, were examined for mutagenicity using the Salmonella/mammalian-microsome test. Potassium nitrosodisulfonate, potassium aminetrisulfonate and potassium hydroxylaminemonosulfonate were not mutagenic over a dose range of 0.01 – 10 mg/plate in the strains his G 46, TA 100 and TA 98. Potassium hydroxylaminedisulfonate showed a weak mutagenic activity in his G 46 and TA 100 with microsomal activation. Hydroxylamine-O-sulfonic acid was only weakly mutagenic in the excision-repair proficient strain his G 46 in the presence of S9.     

The Mutagenic Activity of Particulate Organic Matter Collected with a Dilution Sampler at Coal-Fired Power Plants

The Deep Creek Lake Study of 1983 provided an opportunity to obtain emission samples from coal-fired power plants with a dilution sampler for mutagenicity testing. Stack and ambient samples of particulate matter were collected with a dilution sampler at three coal-fired power plants in West Virginia. Samples were sequentially extracted with cyclohexane (CX), dichloromethane (DCM) and acetone (ACE) and tested for mutagenicity in the Ames Salmonella/microsome assay using TA98 (-S9). For the stack samples, the CX, DCM and ACE fractions constituted 1.0, 0.7 and 98.1 percent of the total extractable organic material (EOM), respectively, compared to 28.5, 7.4 and 64.1 percent for the ambient samples. In contrast, the mutagenic activity of the organic fractions was concentrated in the CX and DCM fractions.

The cyclohexane- and dichloromethane-soluble fractions of the stack samples from all locations exhibited mutagenicity when tested in the plate incorporation assay. No significant response was observed with the acetone fraction. When tested with Kado's modification of the preincubation assay, the acetone-soluble fraction did exhibit mutagenic activity comparable to that of the other fractions when expressed in units of revertants per milligram of particular matter. Chemical analyses of one of the acetone-soluble fractions indicated that half of the mass was sulfuric acid while the remainder consisted of C, H and O. More than 30 peaks were detected in the high pressure liquid chromatogram of this fraction.

Although little mutagenic activity was detected in the polar ACE fraction of the diluted stack emissions samples with this single bioassay, in view of the large mass of this fraction, further investigation of the chemical composition and genotoxic activity of this fraction would be prudent.     

Chemical and biological profiles of sediments as indicators of sources of contamination in Hamilton Harbour. Part II: bioassay-directed fractionation using the Ames Salmonella/microsome assay

Bottom sediment and suspended sediment samples from Hamilton Harbour (western Lake Ontario) and from a major tributary were profiled using a bioassay-directed fractionation approach. Sample extracts were fractionated using an alumina/Sephadex gel clean-up procedure to afford non-polar aromatic fractions which were characterized using chemical analyses and the Ames/microsome bacterial assay in Salmonella typhimurium strains YG1025 with the addition of oxidative metabolism (S9), and YG1024 without S9. Non-polar aromatic fractions of selected samples were separated by normal phase HPLC into 1-min fractions which were subjected to bioassay analyses. The bioassays using strain YG1025+S9, a TA100-type strain, were performed to assess genotoxicity arising from the presence of polycyclic aromatic hydrocarbons (PAH). Fractions which exhibited mutagenic activity contained PAH with molecular masses of 252, 276 and 278 amu; these fractions contained over 80% of the genotoxicity attributable to PAH. Individual compounds identified using Gas Chromatography-Mass Spectrometry analyses in these active fractions included benzo[a]pyrene, indeno[cd]pyrene and dibenz[a,h]anthracene. The YG1025+S9 mutagenic activity profiles were similar for all samples. Mutagenic activity profiles generated using strain YG1024-S9, a TA98-type strain sensitive to compounds characteristic of mobile source emissions, were very different. The mutagenic activities in strain YG1024-S9 were greatest for harbour-suspended sediment samples collected from sites impacted by a major tributary. Suspended sediments collected near areas known to contain high levels of coal tar-contamination in the bottom sediments contained higher levels of genotoxic PAH than suspended sediments collected from other areas of the harbour.     

Investigating the sources of the mutagenic activity found in a river using the Salmonella assay and different water extraction procedures

In the routine São Paulo state (Brazil) surface water quality-monitoring program, which includes the Salmonella microsome mutagenicity assay as one of its parameters, a river where water is taken and treated for drinking water purposes has repeatedly shown mutagenic activity. A textile dyeing facility employing azo-type dyes was the only identifiable source of mutagenic compounds. We extracted the river and drinking water samples with XAD4 at neutral and acidic pH and with blue rayon, which selectively adsorbs polycyclic compounds. We tested the industrial effluent, raw, and treated water and sediment samples with YG1041 and YG1042 and compared the results with the TA98 and TA100 strains. The elevated mutagenicity detected with YG-strains suggested that nitroaromatics and/or aromatic amines were causing the mutagenicity detected in the samples analyzed. Positive responses for the blue rayon extracts indicated that mutagenic polycyclic compounds were present in the water samples analyzed. The mutagen or mixture of mutagens present in the effluent and water samples cause mainly frameshift mutations and are positive with and without metabolic activation. The Salmonella assay combined with different extraction procedures proved to be very useful in the identification of the origin of the pollution and in the identification of the classes of chemical compounds causing the mutagenic activity in the river analyzed.     

Mutagenicity and identification of products formed by aqueous ozonation of humic acids of different origins

Ozonated soil-humic acid induced direct mutagenicity on TA98, TA100 and TA104, while not the ozonated reagent- and wastewater-humic acids. Oxygen radicals generated from mutagens such as glyoxal and hydrogen peroxide identified as the ozonation products might, in part, contribute to the mutagenicity of ozonated soil-humic acid.     

Application of semipermeable membrane device (SPMD) to assess air genotoxicity in an occupational environment

Semipermeable membrane device (SPMD) is a passive sampler that sequesters lipophilic contaminants, mimicking the bioconcentration in the fatty tissue of organisms. This study was designed to assess the use of SPMD and biological tests (Comet assay and Ames test) for air monitoring. For this purpose an occupational environment with expected polycyclic aromatic hydrocarbons (PAHs) contamination (coke plant) was selected for a case study. The SPMDs were deployed in five occupational contaminated sites and in a control site. The SPMD dialysates were chemically analysed and examined for in vitro DNA-damaging activity in human cells (Jurkat) by Comet assay and for mutagenicity with the Ames test (TA98 strain, w/o S9). Total suspended particulates were also collected and analysed (GC–MS). No biological effect of SPMD extract was revealed in the control site. On the other hand, air samples collected with SPMDs within the coke plant showed variable degrees of genotoxic and mutagenic activity. The highest effects were associated with the highest PAH level recovered in the SPMDs extracts and in particulate samples.Results obtained support the sensitivity of biological tests associated to SPMD sampling for evaluating the health risk of potentially contaminated work environments highlighting the usefulness of SPMDs for environmental air quality monitoring.     

潮汐对江水致突变性的影响

对某潮汐河流从下游至上游共设A、B、C、D、E五个采样点,用Ames试验、双微核试验及单细胞凝胶电泳试验(彗星试验)检测涨潮和落潮时江水中有机污染物的致突变性.结果表明,Ames试验各采样点样品都有致突变性,且从上游至下游逐渐增强;对TA98加S9致突变性增加;双微核试验、彗星试验检测出染色体及DNA损伤剂,并以A点作用最强.涨潮时各点致突变强度较落潮时强.     

用人淋巴细胞微核试验检测地面水致突变性

用胞质阻断微核试验（CBMN）来检测浙江某地区地面水有机提取物的致突变性,并与Ames试验结果进行了比较。结果表明,该水样中含有微量致突变物,CBMN试验和Ames试验结果基本相符,说明CBMN试验用作检测地面水致突变性是可行的,但灵敏度略低于Ames试验。     

Mutagenicity and genotoxicity assessment of industrial wastewaters

The genotoxicity of industrial wastewaters from Jajmau (Kanpur), was carried out by Ames Salmonella/microsome test, DNA repair-defective mutants, and Allium cepa anaphase–telophase test. Test samples showed maximum response with TA98 strain with and without metabolic activation. Amberlite resins concentrated wastewater samples were found to be more mutagenic as compared to those of liquid–liquid extracts (hexane and dichloromethane extracts). The damage in the DNA repair defective mutants in the presence of Amberlite resins concentrated water samples were found to be higher to that of liquid–liquid-extracted water samples at the dose level of 20 μl/ml culture. Among all the mutants, polA exhibited maximum decline with test samples. Mitotic index (MI) of root tip meristematic cells of A. cepa treated with 5, 10, 25, 50, and 100 % (v/v) wastewaters were significantly lower than the control. Complementary to the lower levels of MI, the wastewaters showed higher chromosomal aberration levels in all cases investigated.     

Toxicity and Mutagenicity of Component Classes of Oils Isolated from Soils at Petroleum- and Creosote-Contaminated Sites

Abstract

Microtox and Ames bioassays were employed to assess acute toxicity and mutagenicity of water soluble components of class–fractionated oils extracted from one creosote–and four petroleum–contaminated soils. Microtox results revealed that potential acute toxicity resides mainly in the polar class fractions at three sites and indicated potential synergistic and antagonistic effects between compounds in the total extracts at two sites. Ames Salmonella/microsome testing indicated that the polyaromatic fractions at two sites exhibit weak mutagenicity with enzymatic activation, while the polar fractions at two sites are weakly mutagenic without enzyme activation. Further chemical characterization of the polar and polyaromatic fractions is required to fully assess the potential of health and ecological risks at the creosote–and petroleum–contaminated sites exhibiting these toxic responses.     

Seasonal variations and trends in concentrations of filter-collected polycyclic aromatic hydrocarbons (PAH) and mutagenic activity in the San Francisco Bay area

Air monitoring in the San Francisco Bay Area was carried out to measure outdoor community air concentrations of polycyclic aromatic hydrocarbons (PAH) and mutagenic activity (mutagenicity) in particulate organic matter (POM). Monitoring began in 1979 and is currently conducted at six stations. PAH and mutagenicity tests were performed on organic extracts prepared from high volume (hi-vol) filters composited every four months, by meterological season. PAH were determined by high pressure liquid chromatography (HPLC) with fluorescence and ultraviolet detection. Mutagenicity was measured in the Ames Salmonella bioassay using strain TA98 with and without metabolic activation. The nine-year mean concentration of benzo(a)pyrene (BaP) was 0.4 ng/m3. The mutagenicity of this amount of BaP accounted for only about 0.2% of the observed mutagenicity in POM and other measured PAH accounted for even less. Concentrations of PAH and mutagenicity were three to nine times higher during the winter than during other seasons. Year-to-year wintertime trends in several PAH were also seen. Early in the 1980s, winter concentrations of BaP and benzo (g,h,i)perylene increased. However since the mid-1980's, their concentrations have fallen. The decrease in PAH concentrations may be the result of an increasing proportion of vehicles with relatively low organic emissions. In contrast to PAH, mutagenicity did not show significantly year-to-year time trends.     

The chemical and biogenotoxic characterization of organic xenobiotics in aquatic sediment materials 1. The application and comparison of chemically non-specific and biogenotoxic methods

The aim of this work was to evaluate the Ames assay and mixed function oxidase (MFO)-Induct Test used in parallel with chemical group tests (ECD fingerprint and PAH estimation) for the characterization of the organic pollution of water sediment materials. Sediment materials were collected from “clean” and relatively heavily polluted locations in the Middle Adriatic Sea, and from some locations in continental Croatia polluted with wastewaters from different enterprises. Characterization of the organic extracts of the sediment materials investigated was performed chemically using UV spectrofluorometry for the determination polyaromatic hydrocarbons (PAH) and gas chromatography for the determination of volatile EC detector sensitive materials. Genotoxic analysis of the extracts was performed using the MFO-Induct Test and mutagenicity testing using the Standard Plate Incorporation Test as described by Maron and Ames with Salmonella typhimurium TA 98. Measurement of the BaPMO enzyme activity in the livers of carp treated i.p. with total extracts of the sediment investigated confirmed that the methanol extracts generally contained more inducing matter than the petroleum ether extracts. Ames assay showed that for all the samples following the elimination of the sulfur, there was an increase in the number of revertants in comparison to the control number, which indicates that the samples contained mutagenic substances. The larger doses of extracts generally demonstrated cytotoxicity, as evidenced by a reduced number of spontaneous revertants in the Salmonella/Microsome Test. Investigation of the correlation of the chemical parameters with the biological parameter showed that the induction of BaPMO exhibited a statistically significant correlation with the level of the ECD fingerprint of the petroleum ether sediment extract.     

Genotoxicity potential of a new natural formicide

Background, aim, and scope

Assessment of environmental impacts from pesticide utilization should include genotoxicity studies, where the possible effects of mutagenic/genotoxic substances on individuals are assessed. In this study, the genotoxicity profile of the new formicide Macex® was evaluated with two genotoxicity tests, namely, the micronucleus test with mouse bone marrow and Vicia faba, and a mutagenicity test using the Ames Salmonella assay.

Materials and methods

The bacterial reverse mutation test (Salmonella typhimurium strains TA97, TA98, TA100, TA102, and TA1535), the Vicia root tip and mouse micronucleus tests were conducted according to published protocols.

Results

In the range of the formicide Macex® concentrations tested from 0.06 to 1.0 g?L^?1 (or mgkg^?1 in the mouse test), no genotoxicity was observed in the prokaryotic or eukaryotic test organisms. However, at Macex® concentrations of 0.5 g?L^?1 and above a significant decrease in the mitotic index (P?≤?0.05) in the V. faba was observed. Micronucleus formation was likewise increased in the test organism at concentrations starting at 2.0 g?L^?1.

Conclusions

These data allow us to classify this natural formicide preparation as a product with no geno-environmental-impact when applied at recommended concentrations.

     

Effect of a base-catalyzed dechlorination process on the genotoxicity of PCB-contaminated soil

We evaluated the genotoxicity of dichloromethane (DCM) extracts of PCB-contaminated soil before and after the soil had been treated by a base-catalyzed dechlorination process. The treatment process involves heating a mixture of the soil, polyethylene glycol (or hydrocarbons with boiling points of 310–387°C), and sodium hydroxide to 250–350°C. Dechlorination reduced by >99% the PCB concentration of the soil, which was initially 2,200 ppm. The DCM extracts of both control and treated soils were not mutagenic in strain TA100 of Salmonella, but they were mutagenic in strain TA98. Based on results in strain TA98, the base-catalyzed dechlorination process reduced the mutagenic potency of the soil by approximately one-half. The DCM extracts of the soils before and after treatment were equally genotoxic in a prophage-induction assay in . , which detects some chlorinated organic carcinogens that are not detected by the Salmonella mutagenicity assay. These results suggest that treatment of PCB-contaminated soil by base-catalyzed dechlorination reduced the mutagenicity of the soil slightly.