Efficacy of Two Wastewater Treatment Plants in Removing Genotoxins

The genotoxic potential of influents and effluents of two different wastewater treatment plants (WTP-A and WTP-B) located in the Rouen, France, area was evaluated by the SOS chromotest without metabolic activation (on Escherichia coli PQ37) and the Ames fluctuation test (on Salmonella typhimurium strains TA 98, 100, TA 102) with and without metabolic activation. The wastewater samples were taken during two 1-week periods in January and April 2003. The simultaneous use of the SOS chromotest and Ames fluctuation test allowed us to evaluate the efficacy of the wastewater treatment plants at removing genotoxins. Genotoxins were detected with the Ames test but not with the SOS chromotest. Out of a total of 24 influents tested (14 for WTP-A and 10 for WTP-B), almost all were genotoxic in at least one Ames test strain (71% for WTP-A and 100% for WTP-B). In contrast, all of the tested effluents were nongenotoxic. This work showed that the treatment process used in the 2 wastewater treatment plants studied (activated sludge) was able to remove the genotoxins detected in their influents. Nevertheless, studies could be undertaken to determine which step of the treatment process removes genotoxins and whether WTP sludge use could be a source of genotoxic contamination for humans and the environment.     

Influence of alkylphenols and trace elements in toxic, genotoxic, and endocrine disruption activity of wastewater treatment plants

Toxicity and endocrine interference of influent and effluent waters from domestic and industrial wastewater treatment plants were determined. In addition, chemical analyses were performed to detect the presence of 17beta-estradiol, 17alpha-ethinyl estradiol, nonylphenol, 4-octylphenol, and p-t-octylphenol as well as lead, copper, and cadmium in these matrices. The results showed that despite low acute toxic potential, most of the samples tested showed both genotoxicity and endocrine interference. Furthermore, to establish whether the observed effects were caused by the alkylphenols and the heavy metals detected, toxic, genotoxic, and endocrine interference tests also were performed on pure chemicals. The acute toxicity was measured on the crustacean Daphnia magna. The estrogenic activity was determined by using the yeast estrogen screen with Saccharomyces cerevisiae RMY326, whereas the SOS Chromotest and Ames test detected the genotoxicity on Escherichia coli PQ37 and Salmonella typhimurium TA98 and TA100, respectively. The results showed that the toxicity found in the matrices did not match the values found for pure chemicals, but a clear correlation was found between alkylphenols and genotoxicity. Both heavy metals and alkylphenols took part in the endocrine interference activity.     

Handling of cytostatic drugs and urine mutagenesis

Summary As part of a French national epidemiologic study on human reproduction among hospital personnel, we investigated urine mutagenicity of nurses and personnel from oncology units exposed to cytostatic drugs. During a first series of experiments, urine mutagenicity of 47 subjects working in six oncology units was investigated in the Marseille regional's hospital. A control group of 37 individuals working in one cardiology clinic was also included. Urinary mutagens were extracted on XAD-2 resin and tested by two bacterial mutagenicity tests: the Ames test with tester strains Salmonella typhimurium TA 97, TA 98, TA 100 and TA 102 with or without metabolic activation (S9 MIX) and the SOS Chromotest with tester strain Escherichia coli PQ 37-S9 MIX. Bactericidal activity towards the tester strains was found in 40% of the urine samples (36/90). During a second series of experiments, urine mutagenicity of 17 office clerks was also investigated. Toxicity was found in six of the 21 urine samples. No significant difference of toxicity distribution and no relationship between toxicity and cigarette smoking were found. Qualitative analysis of the data showed no significant difference among the exposed groups and the control group (Chi 2 = 0.529, df = 2) with tester strain TA 98 + S9 MIX. Cigarette smoking was found to be the main factor of increased urinary mutagenicity (Chi 2 = 0.529, df = 1). Quantitative analysis of the data showed that mutagenic potencies varied from 0.332 ±0.539 revertants/mg creatinine to 7.226 ± 6.743 revertants/mg creatinine with TA 98 + S9 MIX. A relationship between the number of cigarettes smoked and mutagenic potency was found (Spearman rank coefficient r _s = 0.412, P < 0.05). One urine sample was found to be mutagenic with tester strain TA 102 and PQ 37.     

Comparison of microbial tests for the detection of heavy metal genotoxicity

Heavy metal genotoxicity was evaluated by using different microbial tests. Four genotoxicity assays were employed: the Ames test, the E. coli WP2 test, the Mutatox test detecting mutagenicity, and the SOS assay with E. coli-detecting enzyme induction. All the metals tested (cadmium, chromium, copper, mercury, nickel, and zinc) were detected as genotoxic by the Mutatox and the SOS tests. The Ames test and the E. coli WP2 assay only detected chromium as genotoxic, causing a mutagenic effect. The sensitivity to metals of all the assays used was maintained when they were dissolved in sewage, although there was a slight increase in the sensitivity thresholds.     

Study on the interaction of ions of transient metals with ascorbic acid in the presence of different scavengers of active oxygen species in SOS chromotest

SOS chromotest was employed to study the interaction of ascorbic acid with free ions of transient metals in the presence of added catalase, superoxide dismutase or D-mannitol. Catalase diminished the genotoxic activity of the mixture of ascorbic acid with copper ions in E. coli strains PQ37 and PQ 300, but genotoxicity of this mixture was not suppressed by superoxide dismutase and D-mannitol. The results suggest that copper ions diminished the content of peroxide generated by ascorbic acid.     

三种微生物试验工业废水遗传毒性的比较

本研究应用Ames致突变试验、SOS/Umu测试法和酿酒酵母基因转变试验,对武汉市易家墩工业区三条排污渠水的遗传毒性进行检测,并对三种方法进行比较。初步结果表明,Ames试验与酿酒酵母基因转变试验对水样的测试结果基本一致,而SOS/Umu测试法的结果则与另两种试验结果不相符。此结果提示SOS/Umu测试法在对水中混合有机污染物遗传毒性的检测中尚不能代替Ames试验;而酿酒酵母检测系统可作为Ames试验的重要补充。     

自来水厂出厂水有机物遗传毒性及其影响因素

目的 研究某市不同自来水厂出厂水中有机物的遗传毒性作用,探讨水源、消毒剂种类、有无预加氯和活性炭二次过滤对出厂水有机物遗传毒性的影响.方法 于2008年5-6月,采集某市6家不同水源、不同水处理工艺的自来水厂(A、B、C、D、E、F)出厂水水样.通过鼠伤寒沙门菌致突变(Ames)试验(设0、0.25、0.50、1.00L/皿4个浓度)检测水样中有机物的致突变性,采用比活性的参数方法比较不同来源水样的致突变性强弱.结果 6个自来水厂出厂水中有机物的Ames试验结果均为阳性.各自来水厂出厂水中有机物的致突变比活性比较结果如下,TA98(-S9):E>D>C>A>F>B;TA98(+S9):E>C>F>D(A、B为阴性);TA100(-S9):E>F>C>A(D、B为阴性);TA100(+S9):仅E为阳性.结论 某市自来水厂出厂水中的有机物具有明显的致突变作用,且以移码突变为主;使用江河水、取消预加氯消毒、以二氧化氯消毒剂取代液氯消毒剂以及使用活性炭二次过滤技术可减少致突变有机物的生成.

Abstract：

Objective To study the genotoxicity of the organic extracts from the product water of water plants and the affection of water source.disinfechant type,prechlorination and bioactive carbon filtration on the genotoxicity.Methods Ames testWaS used to test the mutagenicity of water samples from six water plants from May to June.2008.Resnits All of the product watersamples of six water Works (A,B,C,D,E,F)showed positive results in Ames test.The mutagenicity showed as follows:TA98(-S9):E>D>C>A>F>B;TA98(+S9):E>C>F>D(A,B were negative);TA100(-S9):E>F>C>A(D、B were negative);As for TA100(+S9),only E Wag positive.Conclusion The mutagenicity of product water of six water works is relatively high,the type of mutagenicityiS mainly code.shifting.Taking river water as the water source.using chlorine dioxide and active carbon filtration and no usingpretreatment of chlorination may reduce the mutagenic organics.     

无铅汽油新型添加剂甲基叔丁基醚的致突变性研究

目的；研究甲基叔丁基醚（MTBE）的致突变性及遗传毒性。方法：采用Ames试验检测MTBE的遗传毒性，并用单细胞凝胶电泳法检测国产MTBE大鼠经口亚慢性染毒后血液有核细胞的DNA的损伤状况。结果：Ames试验（TA98和TA100菌株）中，在加与不加S9的情况下，MTBE均未表现出明显的致突变性。染毒大鼠血液有核细胞DNA的断裂损伤也较对照组未见统计学差异。结论：本研究结果未发现MTBE对受试系统有致突变性。     

Genotoxicity evaluation of effluents from textile industries of the region Fez-Boulmane, Morocco: a case study

In order to investigate the biological hazard of effluents from textile industries of Fez-Boulmane region in Morocco, mutagenicity and phytotoxicity tests were performed on different biological systems. Moreover, the efficiency of a Sequencing Batch Reactor (SBR) system, working by activated sludge on a laboratory scale, was estimated by comparing the ecotoxicity results observed before and after wastewater treatment. Evaluation of the genotoxic potential was investigated by means of classic mutagenicity tests on D7 strain of Saccharomyces cerevisiae and by phytotoxicity tests on Allium sativum L., Vicia faba L. and Lactuca sativa L., estimating micronuclei presence, mitotic index and cytogenetic anomalies. The results obtained by testing untreated wastewater demonstrated major genotoxicity effects in S. cerevisiae and various levels of phytotoxicity in the three plant systems, while after SBR treatment no more ecotoxicological consequences were observed. These data confirm the effectiveness of the SBR system in removing toxic substances from textile wastewaters in Fez-Boulmane region.     

Effect of butylated hydroxytoluene and butylated hydroxyanisole on the mutagenicity of 3,2´‐dimethyl‐4‐aminobiphenyl

This study was undertaken to investigate the possible antimutagenic effects of butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) on 3,2´‐dimethyl‐4‐aminobiphenyl (DMAB)‐induced mutagenicity, using the Ames Salmonella/mammalian microsome system. The addition of 100–250 μg of BHT or 25–500 μg of BHA/plate was found to inhibit DMAB‐induced mutagenicity in Salmonella strains TA 98 and TA 100. In TA 100, the mutagenicity was further inhibited with the addition of S9 prepared from the livers of rats fed a 0.6% BHT diet as compared to S9 from the animals fed a diet containing no BHT.     

激素类除草剂二氯喹啉酸遗传毒性比较

目的探讨激素类除草剂二氯喹啉酸的遗传毒性。方法应用鼠伤寒沙门菌体外回复突变试验(Amestest)和彗星实验(Comet assay)对激素类除草剂二氯喹啉酸的遗传毒性进行比较研究。结果Ames试验中TA97,TA98,TA100菌株无论代谢活化或非代谢活化,皆为阳性结果,而TA102菌株则为阴性结果。彗星实验在500,1 000,2 000 mg/(kg.bw)浓度下,二氯喹啉酸对小鼠骨髓细胞的DNA损伤与阴性对照组比较差异有统计学意义(P<0.01),且呈剂量-效应关系。结论激素类除草剂二氯喹啉酸具有一定的遗传毒性。     

Soil contamination detected using bacterial and plant mutagenicity tests and chemical analyses

Soil contaminants are common in industrialized countries, causing widespread contamination directly of soil and indirectly of ground water and food. Among these pollutants particular attention should be paid to soil mutagens and carcinogens due to their potentially hazardous effects on animal populations and human health. The aim of this research was to evaluate the genotoxicity of contaminated soils by means of an integrated chemical/biological approach, using a short-term bacterial mutagenicity test (Ames test), a plant genotoxicity test (Tradescantia/micronucleus test), and chemical analyses. Soil samples were collected in a highly industrialized area in the Lombardy region, in Northern Italy. Soil samples were extracted with water or with organic solvents. Water extracts of soil samples were tested using the Tradescantia genotoxicity test and organic solvent extracts were analyzed for their polycyclic aromatic hydrocarbon (PAH) concentrations and for their mutagenicity with the Ames test. Heavy metal concentrations were also studied. Some soil samples showed mutagenic activity with the Ames test and clastogenicity with the Tradescantia/micronucleus test. The same soils showed high concentrations of genotoxic PAH and heavy metals.     

Mutagenicity of rice-straw and -husk ashes by Ames test]

In the rice-producing district of Japan, environmental pollution by smoke from burnt rice straws has become a matter of concern. The mutagenicity of fly- and bottom-ashes of rice-straw and -husk was assayed by the Ames test, TA100 +/- S9 and TA98 +/- S9, and the relationship of combustion temperature to mutagenicity was investigated. Fly ash showed weak mutagenicity at 300 degrees C, with no remarkable change in mutagenic activity between 300 degrees C and 500 degrees C. Above 500 degrees C the mutagenic activity increased with a rise of temperature. The increasing rate of mutagenicity was much higher in the test system with S9 mix than that without S9. Moreover, the mutagenicity with TA100 was stronger than with TA98. With respect to bottom ash, weak mutagenic activity was observed at 300 degrees C, but at 400 degrees C decreased and at 500 degrees C or above could not be observed. Fly ash derived from burning 1 g of rice straw at 600 degrees C showed about 14 times and 2.5 times higher mutagenicity than main stream smoke condensates from the burning of 1 g of cigarette in TA100 + S9 and TA98 + S9 test systems respectively.     

Validity of mutagenic activity as an indicator of river water pollution

Objectives To investigate if mutagenicity could be expressed by known water pollution indicators, we determined the mutagenic activity of blue rayon extracts from sampled river water with the Ames test utilizing new strains of bacteria, and compared the results with those of known indicators of water pollution. Methods Water samples were collected by the blue rayon adsorption method at sixteen sites in six rivers in the North Kyushu district. The Assay of mutagenicity was carried out using the Ames test. The test strains wereSalmonella typhimurium TA100, YG1024, YG1041 and YG1042. B(a)P, Trp-P-1 and Trp-P-2 were quantified by HPLC. Determinations of SS, BOD, COD, T-N, T-P, DOC, and A₂₆₀/DOC were performed. Results The extracts from five sampling sites showed higher mutagenicity toward strain YG1024 with or without S9mix, and the extracts from two of these five sites showed higher mutagenicity toward strain YG1041 with and without S9mix. However, the water pollution indicators did not show specific trends that were consistent with the mutagenic activity. Conclusions Since the mutagenic activity of river water could not be predicted using known water pollution indicators, we recommend that biological examinations such as mutagenicity tests be added to the indicators that are currently in use.     

Determination of genotoxic polycyclic aromatic hydrocarbons in a sediment from the Black River (Ohio)

Polycyciic aromatic hydrocarbons (PAH) have been identified as genotoxic pollutants in sediment from the Black River, Ohio, where a high incidence of hepatoma was observed in brown bull-head catfish (Ictalurus nebulosus). Subfractions of PAH based on the number of aromatic carbons were isolated from the PAH fraction of a Black River sediment extract. Ten subfractions were analyzed by capillary column gas chromatographymass spectrometry, tested for mutagenicity using the Ames assay, and tested for induction of unscheduled DNA synthesis (UDS) in primary rat hepatocytes. The Ames assay indicated significant mutagenic activity in fractions which contained PAH with 4–6 aromatic rings; the majority of the activity was found in the fraction composed of 5-ring compounds. UDS was also significant in the same fractions, although the greatest genotoxicity was observed in thecata-condensed andperi-condensed 4-ring fractions which contained a large amount of alkylated-PAH.Contribution of the National Bureau of Standards, not subject to copyright     

Genotoxic and Mutagenic Potential of Agricultural Soil Irrigated with Tannery Effluents at Jajmau (Kanpur), India

It is a common practice in India to irrigate agricultural fields with wastewater originating from industries and domestic sources. At Jajmau (Kanpur), India, tannery effluent is used for irrigation purposes. This practice has been polluting the soil directly and groundwater and food crops indirectly. This study is aimed at evaluating the mutagenic impact of soil irrigated with tannery effluent. Soil extracts were prepared using four organic solvents (dichloromethane, methanol, acetonitrile, and acetone) and tested with Ames Salmonella/microsome test and DNA repair-defective E. coli k-12 mutants. Gas Chromatography-mass spectrometric analysis of soil samples revealed the presence of a large number of organic compounds including bis(2-ethylhexyl)phthalate, benzene, 1,3-hexadien-5-yne, 2,4-bis(1,1-dimethyl)phenol, Docosane, 10-methylnonadecane, and many higher alkanes. The soil extracts exhibited significant mutagenicity with Ames tester strains. TA98 was found to be the most sensitive strains to all the soil extracts, producing maximum response in terms of mutagenic index of 14.2 (–S9) and 13.6 (+S9) in the presence of dichloromethane extract. Dichloromethane-extracted soil exhibited a maximum mutagenic potential of 17.3 (–S9) and 20.0 (+S9) revertants/mg soil equivalent in TA100. Methanol, acetonitrile, and acetone extracts were also found to be mutagenic. A significant decline in the survival of DNA repair-defective E. coli K-12 mutants was observed compared to their isogenic wild-type counterparts when treated with different soil extracts. PolA mutant was found to be the most sensitive strain toward all four soil extracts.     

Acacia salicina extracts protect against DNA damage and mutagenesis in bacteria and human lymphoblast cell K562 cultures

Three extracts were prepared from the leaves of Acacia salicina: aqueous, methanol, and ethyl acetate extracts. The antigenotoxic properties of these extracts were investigated by assessing the inhibition of mutagenicity of the indirect-acting mutagen benzo[a]pyrene using the Ames assay and the genotoxicity of the direct-acting mutagen, hydrogen peroxide, using the “Comet assay.” Aqueous, methanol, and ethyl acetate extracts at doses of 500, 50, and 500 μg per plate reduced benzo[a]pyrene mutagenicity by 95%, 82%, and 40%, respectively, in Salmonella typhimurium TA98 strain and by 91%, 66% and 63%, respectively, at the same doses with a TA97 assay system. Human lymphoblast cells K562 were pretreated with 50% inhibition concentration of each extracts and then treated by H₂O₂, for the Comet assay. The Comet assay results showed that ethyl acetate and methanol extracts decreased the DNA damage caused by H₂O₂ by, respectively, 34.8% and 31.3%. We envisaged also the study of the antioxidant effect of these extracts by the enzymatic xanthine/xanthine oxidase assay. Results indicated that methanol and ethyl acetate extracts were potent inhibitors of xanthine oxidase and superoxide anion scavengers. We conclude that these integrated approaches to antigenotoxicity and antioxidant assessment may be useful to help compare the beneficial effects associated with using A salicina as medicinal and dietary plant.     

Synthesis and antigenotoxic activity of some naphtho[2,1-b]pyrano[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine derivatives

In this study, some pyranotriazolopyrimidine derivatives were synthesised by reacting ethoxymethyleneamino derivatives with hydrazides. Their structures were elucidated by IR, (1)H NMR, and (13)C NMR spectroscopic data and elemental analyses. Antigenotoxic activity of the obtained compounds was tested in Escherichia coli PQ37 by using the SOS chromotest.     

A mutagenic screening of various herbs,spices, and food additives

Chloroform and methanol extracts of various herbs and spices as well as food additives were screened for mutagenicity using the Salmonella/microsome assay of Ames and the Salmonella typhimurium strains TA100 and TA98. The results of this general screening, however, did not provide sufficient information to fully assess the mutagenic potential of certain herbs and spices since the assay of their respective extracts was accompanied by a growth inhibition of the bacterial tester strain. These findings were attributed to the effects of toxic compounds that were presumably contained within the complex mixtures that comprise both herbs and spices. An apparent reduction in the effects of toxicity was observed when separation methods were used as a means to obtain fewer compounds in each of the samples assayed for mutagenicity.

Following a separation by column chromatography of the chloroform and methanol extracts of cumin, a dose related response of weak mutagenicity was demonstrated toward TA100 but not TA98 with one of the 17 fractions collected. Positive responses to mutagenicity in the absence of toxicity were obtained when chloroform and methanol extracts and food additives were fed to rats, and the metabolites present in ether extracts of 24‐hour urine samples were subsequently assayed for mutagenicity. Weak mutagenic activities toward TA100 but not TA98 were observed with each of the urine extracts of rats fed the following samples: β terpineol, camphene, two separate combinations of the methanol fractions of cumin, a chloroform fraction of cumin, the combined chloroform and methanol fraction of star anise and either the chloroform or methanol fractions of tarragon. With the exception of the chloroform fraction of cumin, the extracts and food additives administered to rats appeared to require an in vivo metabolic activation to detect their mutagenic forms. Mutagenicity was only detected when the ether extracts of urinary metabolites were assayed, even though tests preceding the rat feedings were performed in the presence of the rat liver microsome fraction S9.     

Correlation between mutagenicity of airborne particles and air pollution parameters in eleven Italian towns

Organic extracts from airborne particles collected in 11 Italian towns between February and April, 1988, were tested for mutagenicity on TA98 and TA100 (± S9), and their nitroreductase (NR) deficient Salmonella strains, by the use of the Ames plate incorporation assay. Mutagenic responses were fitted by an equation which takes into account toxic effects on tester organisms. Generally parallel responses were obtained with the two Salmonella strains, but the TA98 gave, mostly, higher increases of revertants over the control level. No dramatic decreases in mutagenicity were observed with the NR derivative strains, except in a few cases with TA98NR and, more frequently, with TA100NR strains. During air sampling, temperature, atmospheric pressure, light, wind strength and direction, SO₂, CO, NO₂, O₃ and non‐methanic hydrocarbons (NMHC) concentrations were continuously monitored. Meteorological variables seem not to be significantly correlated with mutagenicity variations, while the highest correlation (r = 0.91) was observed between induced reversion in TA98 (+ S9) and NMHC concentration in air. Therefore, in spite of the wide range of different types of towns included in the study, air NMHC concentration can be considered a good predictor for the mutagenicity of the total organic material extracted from particles of urban air.