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Genotoxic potential of by-products in drinking water in relation to water disinfection: Survey of pre-ozonated and post-chlorinated drinking water by Ames-test
Abstract
Mutagenic potential of drinking water samples derived from ranneywells was studied. 100-100 l of untreated (rough) and ozone-treated as well as chlorinated-disinfected water were dropped on and adsorbed by macroreticular resin columns (Serdolit PAD-III and Amberlite XAD-2). The adsorbed material was desorbed by methanol and dichloromethane. After elimination of the solvents by vacuum distillation the adsorbed material was dissolved in dimethylsulfoxide. The mutagenic activity was tested in the Ames-Salmonella/rat liver microsome system. The tester strains were TA-98 and TA-100. The material adsorbed to Serdolit PAD-III from rough and also disinfected water did not induce mutagenicity in case of the TA-98 tester strain, irrespective of activation by liver microsomes. However, the material adsorbed to Amberlite XAD-2 exerted mutagenic effect on the TA-98 tester strain, with and without liver microsome activation, both in case of rough and disinfected water. The TA-100 tester strain showed mutation after, but not without activation, when treated with the material adsorbed by either Serdolit PAD-III or Amberlite XAD-2, in case of rough water. Material derived from disinfected water and adsorbed to Serdolit PAD-III, caused mutation of the TA tester strain also only after activation. The material derived from disinfected water and adsorbed to Amberlite XAD-2 proved to be mutagenic to the TA-100 tester strain both without and after activation. Mutagenic activity was exerted by the amount of concentrates derived from 0.28 to 0.83 l of rough and 0.83-2.5l of disinfected water. The mutagenic activity of drinking water raises the possibility of carcinogenic effect, too. Search for alternative methods of water disinfection may be recommended.
... All determinations were performed in triplicate. In general, a two-fold increase in the mutation ratio (MR 5 mutant colonies on test plate/spontaneous mutant colonies on negative control plate) and a dose-response relationship observed in a test sample is considered a positive mutagenic response 33,34 . ...
... SCIENTIFIC REPORTS | 5 : 9572 | DOI: 10.1038/srep09572 eliminated. The organic compounds in the water samples were mainly direct mutagens, though some indirect types may also be present 33,35 . Positive results were found for all of the TA98 (without S9) tests as the dose increased to 2 L/plate, whereas few TA100 tests (with or without S9 incubation) showed mutagenicity, which suggests that the organic compounds in the water were mainly frame-shift mutagens. ...
A total of 54 water samples were collected during three different hydrologic periods (level period, wet period, and dry period) from Plant A and Plant B (a source for Yangtze River and Hanshui River water, respectively), and several water parameters, such as chemical oxygen demand (COD), turbidity, and total organic carbon (TOC), were simultaneously analyzed. The mutagenicity of the water samples was evaluated using the Ames test with Salmonella typhimurium strains TA98 and TA100. According to the results, the organic compounds in the water were largely frame-shift mutagens, as positive results were found for most of the tests using TA98. All of the finished water samples exhibited stronger mutagenicity than the relative raw and distribution water samples, with water samples collected from Plant B presenting stronger mutagenic strength than those from Plant A. The finished water samples from Plant A displayed a seasonal-dependent variation. Water parameters including COD (r = 0.599, P = 0.009), TOC (r = 0.681, P = 0.02), UV254 (r = 0.711, P = 0.001), and total nitrogen (r = 0.570, P = 0.014) exhibited good correlations with mutagenicity (TA98), at 2.0 L/plate, which bolsters the argument of the importance of using mutagenicity as a new parameter to assess the quality of drinking water.
... Tradi onally, the Ames test (a.k.a. the bacterial reverse muta on assay with and without ac va on) has been used as an indicator of mutagenic effects of newly developed chemicals (Maron andAmes 1983, Mortelmans andZeiger 2000). The test has also been used to detect mutagenic compounds in drinking water (Vughs, 2018, Guan, et al, 2017, Sujbert, 2006, wastewater (Abbas et al 2019, Tabet et al 2015, river and surface water (Roubicek, 2020, Xiao, 2017, Sueiro, 2011, Wu, 2005, Vargas et al, 1993, sediment pore water (Parella, 2013), swimming pools (Manasfi, et al, 2016), tex le effluent (Vacchi, 2017), cigare e smoke (Thorne, 2015), biochars and ash from an incinerator (Piterina, 2017, Chen, 2015, and the mutagenicity of the UV filter (sunscreen) benzophenone and related compounds (Wang et al, 2018). The Ames test employs gene cally modified strains of Salmonella typhimurium with muta ons in the his dine operon, that disable his dine produc on. ...
Multiple assessment techniques (in situ active water samplers, Ames test, sea urchin development toxicity assay, Colitag, sediment analysis, foram community characterization) were used to assess the pollution status of Fagatele Bay, a unit of the National Marine Sanctuary of American Samoa. Pollution levels were generally low, but coastal managers can use these data to make sure that conditions don't deteriorate over time.
... Tradi onally, the Ames test (a.k.a. the bacterial reverse muta on assay with and without ac va on) has been used as an indicator of mutagenic effects of newly developed chemicals (Maron andAmes 1983, Mortelmans andZeiger 2000). The test has also been used to detect mutagenic compounds in drinking water (Vughs, 2018, Guan, et al, 2017, Sujbert, 2006, wastewater (Abbas et al 2019, Tabet et al 2015, river and surface water (Roubicek, 2020, Xiao, 2017, Sueiro, 2011, Wu, 2005, Vargas et al, 1993, sediment pore water (Parella, 2013), swimming pools (Manasfi, et al, 2016), tex le effluent (Vacchi, 2017), cigare e smoke (Thorne, 2015), biochars and ash from an incinerator (Piterina, 2017, Chen, 2015, and the mutagenicity of the UV filter (sunscreen) benzophenone and related compounds (Wang et al, 2018). The Ames test employs gene cally modified strains of Salmonella typhimurium with muta ons in the his dine operon, that disable his dine produc on. ...
Fagatele Bay is an embayment within the NaƟonal Marine Sanctuary of American Samoa for which there are minimal
data regarding contaminant distribuƟon in this protected area. Resource managers have significant concerns about the
potenƟal inputs of contaminants from an unlined, solid waste landfill located approximately 600 m upslope from the Bay.
Leachate from the landfi ll potenƟally includes both organic (e.g. PCBs, PAHs, personal care products) and inorganic (e.g.
heavy metals) pollutants, and could reach the Bay through surface runoff, or, given the permeability of the volcanically
derived soils, through groundwater flux. There is also the potenƟal for other land-based sources of polluƟon (LBSP, such
as pesƟcides) to reach the Bay.
The treatment of solid waste is a serious problem on most islands that can result in toxic substances entering the coastal
environment. The potenƟal transport of pollutants from the landfill to the Bay has not been previously quanƟfi ed. This
study addresses this important research quesƟon, i.e. what contaminants are present in Fagatele Bay? This assessment is
important for two reasons: 1) to determine the extent (magnitude and spaƟ al distribuƟon) of polluƟon in the Bay; and 2)
to serve as baseline for future assessment, and to evaluate the effecƟveness of future watershed management acƟviƟes
which might be designed to improve coral reef ecosystem health by reducing LBSP. The approach presented here
assessed contaminaƟon risk to the Bay using mulƟple techniques: acƟve in situ water samplers for organic chemistry
analysis, metals analysis of sediment samples, bacterial (Colitag) and nutrient analyses of boƩom water discrete
samples, sea urchin embryo development toxicity assays using SPE-concentrated site water, applicaƟon of the Salmonella
typhimurium reverse mutaƟon assay (Ames test) for mutagenic acƟvity of SPE-concentrated site water, and analysis of
foraminifera populaƟons as an indicator of stress. This study found 32 organic pollutants at detectable levels in the Bay.
These were all at relaƟvely low concentraƟons that are unlikely to be of acute toxicological concern. With the excepƟon
of nickel, sediment metal concentraƟons were below previously published Sediment Quality Guidelines, indicaƟ ng that
toxicity to benthic infauna is unlikely. Laboratory toxicity tesƟng of Fagatele Bay samples did not show signifi cant toxicity
using the sea urchin embryo development toxicity assay. None of the sample extracts analyzed exhibited mutagenicity
via the Ames test (strains TA98 or TA100). Six out of ten water samples tested posiƟve for Escherichia coli, and all
samples tested posiƟve for total coliform (Colitag test) demonstraƟng that mammalian (possibly human) or avian waste
is reaching the Bay. Examining the populaƟon of benthic foraminifera (FoRAM Index) was not conclusive, perhaps
because of the extremely coarse substrate which limited the number and variety of forams collected. Overall, these
methods suggest that while some pollutants are reaching the Bay, the water quality of the system is relaƟvely good.
Resource managers can use these data as a baseline to ensure that water quality does not degrade over Ɵme, and to be
aware of specific pollutant groups (e.g. pharmaceuƟcals) that might be of emerging concern.
... La baja actividad mutagénica de la cepa TA100 con y sin activación metabólica, en comparación con la TA98, tanto en el afluente como en la planta, puede ser atribuido a varios procesos de interacción entre metabolitos y blancos genéticos en la cepa TA100 (HisG46, G-C) [51]. Las aguas estudiadas, son alimentadas principalmente con desechos domiciliarios y no han sido sometidas a procesos de cloración, por lo tanto, no hay productos de cloración como trihalometanos y furanonas, que son mutágenos que revierten la cepa TA100 [52]. ...
Los Grupos de Investigación en Química y Biotecnología (QUIBIO) y Microbiología Industrial y Medio Ambiente (GIMIA) hacen parte del Centro de Estudios e Investigaciones en Ciencias Básicas Ambientales y Desarrollo Tecnológico (CICBA), adscrito a la Facultad de Ciencias Básicas de la Universidad Santiago de Cali. Desde su nacimiento el CICBA, a propendido por estar a la vanguardia al interior de la Universidad en la investigación, conciencia por el medio ambiente y desarrollo tecnológico. Los grupos de investigación acordes con esta macrolinea, se han preocupado por aportar sus desarrollos investigativos y de innovación en un marco de responsabilidad social, es así como en este libro de investigación titulado “LA CONTAMINACIÓN INDUSTRIAL DE AGUAS: Una Mirada Microbiológica y Molecular” se recopilan 4 trabajos de investigadores pertenecientes a los dos grupos de investigación con el fin de dar a conocer estudios realizados en Colombia y Venezuela sobre la problemática de la contaminación en cuerpos acuíferos.
... Most trihalomethans are of public health concern that (THMs) may cause cancer to humans. (3) Consequently, substantial Departures from Chick's law are common. ...
Background: Ozone is considered one of the most effective disinfectants that can inactivate resistant pathogenic microorganisms in which conventional disinfectant such as chlorine and chlorine dioxide faildue to its strong biocidal oxidizing property. Objective: The study aimed at modeling of ozone as a disinfectant of indicators bacteria in the drinking water. Methods: This work involved a series of batch experiments with raw water, taken from the intake of El-Nozha Water Purification Plant, Alexandria governorate. The ozone doses applied in this study were 1.2, 2.2, 3.4, and 4.3 mg/l. The disinfected effluent was collected at 5, 10, 20, and 30 min. The indicator microorganisms HPC bacteria, total coliforms, faecal coliforms and Streptococcus faecalis were examined before and after the ozonation. Results: The optimum ozone dosage applied in raw water to achieve 90% reduction of the indicator microorganisms was 2.5 mg/l. The optimum contact time to achieve 90% reduction of the indicator microorganisms in raw water was 8 min. By applying of ozone as post disinfection on filtered water, the reduction percent of the indicator microorganisms were 100%. This study estimated that the ozone cost was 1.76 piasters/m3. Conclusion and Recommendations: Ozone as a primary disinfection must be applied on raw water to reduce the formation of THMs due to pre-chlorination of raw water at present, in addition to effective killing power of ozone onto microorganisms that will improve water quality.
... CKS1B is an essential protein for normal cell division and growth (6), and is expressed at a high level in various cancer tissues including hepatocellular carcinoma (7), colon (8), lung (9), oral squamous cell carcinoma (10), breast cancer (11), and others. In MM, amplification of region 1q21, which includes the CKS1B gene, identifies a subpopulation with poor prognosis, an aggressive clinical course, and few therapeutic options (12,13). CKS1B amplification is also associated with transformation from both the benign state of monoclonal gammopathy of undetermined significance (MGUS) to MM and further progression to plasma cell leukemia (14). ...
CKS1B is significantly upregulated in multiple myeloma (MM) and associated with poor prognosis. The identification of novel therapies is essential for effective treatment of patients resistant to chemotherapy. The NEDD8 inhibitor MLN4924 selectively targets SCFSkp2 activation and offers a more specific approach to protein degradation inhibition than total proteasomal inhibition. The goal of this study was to evaluate whether MLN4924 is effective in high CKS1B conditions and identify mechanisms regulating drug potency.
Bortezomib and MLN4924 sensitivity was assessed through proliferation, viability, clonogenic potential, and senescence induction in cells overexpressing CKS1B. The mechanism for MLN4924 sensitivity was elucidated by immunoblot analysis of SCFskp substrates and confirmed by shRNA knockdown. The clinical relevance of the NEDD8 pathway was examined in GEPs derived from healthy people, patients with MGUS, and MM.
Cells overexpressing CKS1B were resistant to bortezomib but sensitive to MLN4924. Treatment of CKS1B-overexpressing cells with MLN4924 decreased proliferation, clonogenicity, and induced senescence. MLN4924, but not bortezomib, induced stabilization of p21 and knockdown of p21 resulted in loss of MLN4924 sensitivity. Patients with MGUS and MM exhibited increased expression of NEDD8-pathway genes relative to normal plasma cells. MM patients with high NEDD8 expression were linked to bortezomib resistance in clinical trials, and had inferior outcomes.
Our data demonstrate cells with elevated CKS1B expression are resistant to bortezomib but sensitive to MLN4924 and offer a mechanism through the stabilization of p21. These findings provide rationale for targeting the NEDD8 pathway in MM patients exhibiting elevated expression of CKS1B.
Copyright © 2015, American Association for Cancer Research.
... Meanwhile, we also suggest that the nanoscale material itself should be kept together with the by-product when environmental benefit is discussed. For these questions, we think that comprehensive toxicity assessment, such as exposure toxicity study [41], MTT test [42,43], Ames-test [44], and luminous bacteria detection [45,46], can become a science and feasible method for environmental benefits of by-products and environmental function material. ...
Due to the increasing levels of polybrominated diphenyl ethers (PBDEs) in the environment and their persistent toxicity, methods of removing PBDEs from the environment have become a necessary. Nanoscale zero-valent metallic particles (S-NZVI) were prepared from steel pickling waste liquor by chemical deposition and used to remove BDE209 in a water/tetrahydrofuran (4/6, v/v) solution. Nanoscale zero-valent iron particles (NZVI), nanoscale zero-valent and Ni/Fe particles were also prepared. These particles were characterized by BET, TEM, SEM, XRD, and EDS. The crystalline structure of S-NZVI was different from NZVI. However, the BET surface area of S-NZVI was the same as that of NZVI. The degradation rate of BDE209 by S-NZVI followed a pseudo-first order kinetics. The removal efficiency increased with increasing metal dosage but decreased with increasing initial BDE209 concentration. High reaction rate was observed at more water content solvent, indicating that hydrogen ion was the driving force of reaction. Comparing different nanoscale Fe-based materials, the removal of BDE209 by S-NZVI was found more effective than NZVI. By evaluating the cost and the significance of reclaimable iron resource, S-NZVI was found to give better compensation compared to other metals. Thus, the degradation of BDE209 by S-NZVI is both feasible and efficient.
... rev (0.5 L-eq/plate), 30.7-192.0 rev (1.0/L-eq/plate) and 45.1-266.7 rev (2.0 L-eq/plate) respectively. The mutagenicity of these surface or drinking water samples were comparable to those in other areas in China or other countries in Eastern Asia and Europe (Liu et al., 2007;Park et al., 2001;Sujbert et al., 2006). ...
... However, often, these additional controls have not been considered or have not been reported (e.g. Sujbert et al. 2006). The occurrence of mutagenic artefacts during drinking water concentration has, e.g. ...
Many pharmaceuticals and related metabolites are not efficiently removed in sewage treatment plants and enter into surface water. There, they might be subject of drinking water abstraction and treatment by ozonation. In this study, a systematic approach for producing and effect-based testing of transformation products (TPs) during the drinking water ozonation process is proposed. For this, two pharmaceutical parent substances, three metabolites and one environmental degradation product were investigated with respect to their biodegradability and fate during drinking water ozonation. The Ames test (TA98, TA100) was used for the identification of mutagenic activity present in the solutions after testing inherent biodegradability and/or after ozonation of the samples. Suspicious results were complemented with the umu test. Due to the low substrate concentration required for ozonation, all ozonated samples were concentrated via solid phase extraction (SPE) before performing the Ames test. With the exception of piracetam, all substances were only incompletely biodegradable, suggesting the formation of stable TPs. Metformin, piracetam and guanylurea could not be removed completely by the ozonation process. We received some evidence that technical TPs are formed by ozonation of metformin and piracetam, whereas all tested metabolites were not detectable by analytical means after ozonation. In the case of guanylurea, one ozonation TP was identified by LC/MS. None of the experiments showed an increase of mutagenic effects in the Ames test. However, the SPE concentration procedure might lead to false-positive results due to the generation of mutagenic artefacts or might lead to false-negative results by missing adequate recovery efficiency. Thus, these investigations should always be accompanied by process blank controls that are carried out along the whole ozonation and SPE procedure. The study presented here is a first attempt to investigate the significance of transformation products by a systematic approach. However, the adequacy and sensitivity of the methodology need to be further investigated. The approach of combining biodegradation and ozonation with effect-based assays is a promising tool for the early detection of potential hazards from TPs as drinking water contaminants. It can support the strategy for the evaluation of substances and metabolites in drinking water. A multitude of possible factors which influence the results have to be carefully considered, among them the selectivity and sensibility of the mutagenicity test applied, the extraction method for concentrating the relevant compounds and the biocompatibility of the solvent. Therefore, the results have to be carefully interpreted, and possible false-negative and false-positive results should be considered.
... humic and fulvic acids) in surface waters may react with disinfectants to produce volatile and non-volatile disinfection by-products (DBP) that are potentially harmful to human and aquatic organisms. In particular, it has been demonstrated that chlorination, the most widely used method for water disinfection, leads to the formation of DBP with mutagenic and/or carcinogenic activity (Sujbert et al., 2006; Umbuzeiro Gde et al., 2006; Schenck et al., 2009 ). Moreover, several epidemiological studies revealed a positive association between the use of chlorinated drinking water obtained from surface sources with the incidence of cancer (e.g. ...
... There are more and more genotoxic pollutants released into the aquatic environment following the developments of industry and agriculture (Turgeon et al. 2004;Rajaguru et al. 2002), which is threatening the safety of drinking water source and affecting the lives for hundreds of millions of people. Kusamran et al. (2003) and Sujbert et al. (2006) reported that the positive mutation of the minim organic pollutants existed in drinking water. Therefore, it is important to evaluate the effects of genotoxic agents in drinking water and in sources of drinking water on human health and on ecological population through biomonitoring approaches. ...
The potential toxicities of organic pollutants in the drinking water source at Meiliang Bay of Lake Taihu were investigated by comet assay and antioxidant enzyme approach on microalgae Euglena gracilis. The organic extracts of the water samples could induce DNA damage on microalgae cells. Statistically significant differences (P < 0.05) were observed at groups of 0.3x, 3x and 10x concentrations compared with the control and a solvent control (DMSO). The organic extracts also affected antioxidant enzyme activity and induced lipid peroxidation in the microalga. In the high dose group, there was an obvious increase in SOD content (P < 0.05). The results suggest that the concentrated organics from water sample extracts have adversary effects on E. gracilis and could possibly damage the ecosystem.
... More and more pollutants with genotoxic substances are released into the aquatic environment (Turgeon et al., 2004;Rajaguru et al., 2002), which is threatening the safety of drinking water. The positive mutation of the minim organic pollutants in drinking water was found (Kusamran et al., 2003;Sujbert et al., 2006). Since the early 1970s, the Environmental Protection Agency (EPA) first discovered the derivatives of chlorine in drinking water. ...
The potential harm of organic pollutants in drinking water to human health is widely focused on in the world; more and more pollutants with genotoxic substances are released into the aquatic environment. Water source samples were collected from 7 different localities of Nanjing City. The potential genotoxicity of organic extracts from drinking water sources were investigated by means of the comet assay in human peripheral lymphocytes. The results showed that all the organic extracts from all the water source samples could induce DNA damages of human peripheral blood lymphocytes at different levels. A significant difference (P < 0.01) was observed when compared with the solvent control. The DNA damage increased with the increase of the dosage of the original water source. Significant differences of DNA damage were observed in different drinking water sources, as shown by the multiple comparisons analysis at the dosage of 100x; the degree of DNA damage treated by Hushu waterworks (at town level) was the most serious, the arbitrary units (AU) was 141.62 +/- 6.96, however, that of Shangyuanmen waterworks (at city level) was only 109.64 +/- 2.97. The analysis also revealed that the genotoxicity of town's water sources was higher than that of the city. The results demonstrated that the comet assay can be successfully applied to the genotoxicity monitoring programs of drinking water sources.
Este trabajo tuvo como objetivo general: Evaluar el tratamiento con ozono en disolución
acuosa como desinfectante microbiológico para la hortaliza acelga (Beta vulgaris var. cicla
L.). Se caracterizó el vegetal fresco mediante análisis químico-físicos y microbiológicos y
se evaluó el efecto de tres factores sobre la solubilidad del ozono para lograr su mayor
concentración en agua. Se desinfectó con ozono acuoso e hipoclorito de calcio para
establecer una comparación en cuanto a la disminución de tres grupos de microorganismos
indicadores de calidad microbiológica. Se analizaron los efectos en la conservación por 7
días, después de la desinfección, para ambos tratamientos. Se aplicó un diseño factorial 32
tomándose como variables independientes el tiempo de burbujeo [t (O3)] y el tiempo de
tratamiento [t (trat)]. La caracterización químico-física estableció que las acelgas se
encontraron dentro de los parámetros establecidos de humedad y acidez. Las acelgas
presentaron altas concentraciones de coliformes totales, mohos y levaduras, encontrándose
no aptas para el consumo humano directo sin desinfección. Se obtuvo una máxima
concentración de ozono de 9.84 ppm en la columna. Los dos tratamientos logran niveles de
desinfección entre 0,33 y 1,33 log (ufc/g) para los microorganismos analizados siendo el
cloro más efectivo para el caso de coliformes totales y mesófilos aerobios. El ozono solo
demostró disminuir el crecimiento en refrigeración para coliformes totales, siendo el cloro
más efectivo por su poder residual. El costo de inversión de la tecnología es relativamente
alto por lo que debe estar asociado a la producción de alto valor agregado.
To verify the correlation between a Finnish model to predict the mutagenicity of drinking water from surface sources disinfected with chlorine and water mutagenicity determined byAmes'test, model research was conducted. Mutagenicity tests were carried out for differentTOC and ammonia concentrations. Disinfection was carried out with chlorine on the basis of the chlorine demand curve. Generally, the mutagenicity rate (MR) increased with the increase of the TOC and ammonia content. The highest MR growth with the increase of concentration rate was observed for the water with the highest analyzed TOC and ammonia parameters. The observed model water mutagenicity determined in the Ames assay showed a low correlation with the water mutagenicity as obtained by the Finnish model for the prediction of the mutagenicity of drinking water.
A case report of a Caucasian female born in 1927 is presented in which rapid recovery from vulvar extramammary Paget's disease (EMPD) without surgical intervention occurred following an abrupt change from fluoridated/chlorinated tap water (0.9- 1.0 mg F-/L) to low-fluoride spring and well water (both <0.1 mg F-/L) for drinking, cooking, bathing, and laundry purposes. Within weeks of switching from the tap water her condition completely cleared, with no recurrence after three years except when re-exposed to fluoridated tap water. EMPD primarily affects postmenopausal Caucasian women, but occasionally it also occurs in men. The condition presents as an itchy, rash-like condition that can be accompanied by invasive malignant changes to underlying dermal tissue, for which surgical excision of the affected region is the most common treatment. Possible reasons for recovery without surgery in this case are discussed.
OBJECTIVE: To explore the genotoxicity of organic extracts from finished water in 6 water plants A, B, C, D, E and F in a particular city. METHODS: The following in vitro and in vivo tests were conducted : Ames test with Salmonella typhimurium strains TA98 and TA100 with and without mammalian S9 activation component, microscale fluctuation test with 5. typhimurium strains TA98 and TA100 without mammalian S9 activation component, and mouse micronucleus test in mice polychromatic erythrocyte (PCE) stem cells. RESULTS: Positive results were obtained by Ames test and micronucleus assay from all the finished water samples in six water plants. The micronucleus frequency was shown in the following order; D>E=A>C>F>B. Microscale fluctuation test showed that at the concentration of 0. 25 L every plate and after post-chlorination treatment of plant C, the positive results in TA98 (- S9) and TA100 (- S9) (P < 0. 05) were obtained. CONCLUSION: Mutagenicity of finished water from 6 water plants in this city is relatively high and the type of mutagenicity is mainly code-shifting. Micronucleus assay is consistent with Ames test. Microscale fluctuation test is more sensitive than Ames test in mutagenicity detection.
Tests are conducted on the mutagenicity and acute toxicity of raw water sample, tap water sample, and filtered water sample from two sources by means of Ames test and luminescent bacterium bioassay. The types and number of organic pollutants in the water samples are analyzed by GC-MS (gas chromatography mass spectrograph). The results of the analysis show that for mutagenicity the average mutation rate of raw water sample, tap water sample and filtered water sample from Yangtze River are 3.26, 1.57, and 0.78 respectively, showing a declining tendency; for the three water samples from the lake are 0.97, 2.10, and 0.97 respectively, showing a 'Λ' tendency. For acute toxicity, the rates of luminosity of the three water samples from the Yangtze River are 64.38%, 87.76%, and 97.21% respectively, and for the three water samples from the lake are 84.08%, 1.57% and 90.49% respectively. The results from GC/MS analysis indicate that for the three water samples from the Yangtze River, the number of types of organic extracts are 12, 12 and 10 respectively, and for the water samples from the lake are 21, 27 and 15 respectively. The results of the analysis are in accordance with the results of the tests on mutagenicity and acute toxicity.
Groundwater micropollutant has been a steady threat to the rural residents with household-based water supply. In this work, a multi-barrier technology is designed, that is, rice husk ash (RHA) adsorption and enhanced coagulation, followed by heating and boiling (azotropic). The removal efficiency of nitrobenzene from groundwater was investigated using this household-based combined process. The experimental results indicate that the nitrobenzene concentration can be under the limit determination in the finished water, treated by the combined process. Ames test indicates that the combined process, especially RHA, is safe and reliable. The combined process is a cost-effective technology for emergent nitrobenzene removal in decentralized water supply.
Using micronucleus tests and comet assays, the genotoxicity of Changjiang River raw water, effluent water from conventional process (flocculation+sedimentation+sand filter), effluent water from enhanced conventional process (flocculation+sedimentation+biological enhanced activity filter), and effluent water from biological activated carbon process (flocculation+sedimentation+sand filter+biological activated carbon filter) are analyzed. The results show that comparing with the control group at dosage of 0.13 to 1.00 L/plate, the frequencies of micronuclei in human peripheral blood lymphocytes induced by Changjiang River raw water, effluent water from conventional processes, and effluent water from conventional processes are significantly increased while that caused by effluent water from biological activated carbon process keeps constant. Besides, DNA damages in human peripheral blood lymphocytes are induced by Changjiang River raw water, effluent water from conventional process, effluent water from enhanced conventional process, exhibiting dose-response relationships respectively. However, with biological activated carbon process, DNA damages are induced only at dosage of 0.5 L/plate. This study demonstrates that micronucleus tests and comet assays can be used for assessment of safety of effluents from different drinking water treatment process.
This monograph presents a superindividual/ecological approach in the human water toxicology. Hygienic water quality is defined as an intersection of social and physico-chemico-biological qualities. The author studies different types of water toxicities at population or subpopulation levels considering the varied vulnerability of the exposed groups. Toxicants and toxins are studied in drinking (tap and bottled) waters, in recreational (swimming-pool, bathing, thermal and medicinal) waters, and in surface and waste waters. Possible risks are caused by disinfection (e.g. chlorination) byproducts as chemical and asbestos fibres as physical contaminants in the tap water. Some of them are possible genotoxicants and/or carcinogens. Nowadays drinking of water rather means bottled mineral water consumption. In PET-bottled water a well-defined group of chemicals can be measured with unknown toxicity. During swimming and bathing people are exposed to relatively high concentrations of chlorine or its byproducts and/or autochtonous volatile organic compounds of the thermal (mineral) waters. The balneological toxicology may also become a crucial field of environmental toxicology since organics in mineral/thermal/medicinal waters and peloids (muds) have not been studied so far. First gas-chromatographic analyses of Hungarian thermal water samples are also reviewed here. Two registered Hungarian medicinal muds were studied for ecotoxicity and genotoxicity, and in a photobiological test, as well. Results are completely different by the origin and composition of muds. UV-protective effects of some samples were indicated and proved in bacterial cells. The quality and quantity of the surface waters of the recent Hungary, in relation to the manuipulations of upstream countries, are also discussed. The disproportional exposures of the populations (nations) mean a higher dimension of the classical environmental injustices based upon historical facts and political confrontations. Finally, new challanges of the discipline (exposure to endocrine disruptors, nanoparticles) are also mentioned.
Keywords: water hygiene, water toxicology, risk assessment, environmental epidemiology, disinfection byproducts, asbestos fibres, PET-bottles, bathing, balneology, thermal waters, peloids, cyanobacteria, environmental justice, superindividual environmental health
Despite increasing pressure to make more efficient use of water resources, the widespread use of reclaimed water still remains a contentious issue, primarily because of risks to human health arising from water pollution by organic compounds. Therefore, safety evaluation of reclaimed water is an urgent need. The aim of this study was to determine the genotoxic potential of reclaimed water during low and high water periods. Reverse phase C-18 solid-phase extraction (RP-C18SPE) was used for the extraction of organic compounds from water samples. The tests, namely, Ames, micronucleus and chromosome aberrations were used to determine the damage caused by water samples on genetic material. Ames tests showed that both influent and effluent reclaimed water, except influent after metabolism by S9 in high water period, induced mutation of TA98 and TA100 strains of Salmonella typhimurium in a concentration-response manner. There were no significant differences in micronucleus and chromosome aberration tests. Even after treatment, reclaimed water in Tianjin still showed mutational effects and new strategies for reduction of genotoxins need to be considered.
Disinfection of raw water is essential to the production of drinking water. However, by-products of disinfection may exert toxic effects. The potential toxic effects of two of these compounds, 4-ethylbenzaldehyde (EBA) and 2,4-difluoroaniline (DFA) were investigated using the zebrafish (Danio rerio) model. The two compounds, dissolved, were introduced in duplicate aquariums containing zebrafish in two different concentrations based on LC50 values. The aquarium water containing EBA or DFA was changed every 96 h throughout the 3 months of treatment. Behavior of the fish in each replicate was inspected twice daily. In course of treatment with both concentrations, fish exposed to DFA displayed behavior associated with visible anxiety, while EBA treated were lethargic and did not evade capture. Application of both concentrations of each component into the aquarium water resulted in dystrophic lesions in the liver, kidney and skin of the fish while preneoplastic lesions and tumors were not observed.
End points of reproductive toxicity were investigated in male mice (Mus musculus, ICR) fed Nanjing City tap water for 90 days. There was no significant alteration in body weights between treatment and control mice. In treated mice, flow cytometry analysis of testicular tissue indicated that the relative percentage of the elongated spermatid (HC) decreased significantly (P < 0.05). Also slight increases in the relative percentage of round spermatids (1C) and primary spermatocytes (4C) were noted. The ratios of 4C:2C (diploid germ cells) and 1C:2C increased, and testicular histopathology indicated an expansion of interstitial space and a decreased number and size of Leydig cells in treated mice. The current study suggests that Nanjing City tap water is toxic to the reproductive system of mice and additional study to evaluate its effects on other species, including human beings, would be warranted.
L'ingestion des parties périphériques du grain de blé, dans lesquelles sont concentrés la majorité des vitamines et minéraux, par la consommation d'aliments complets (farines complètes, pain complet, pâtes complètes) constitue un atout nutritionnel évident. Cette consommation est limitée par sa faible digestibilité ainsi que par la présence de contaminants chimiques et biologiques présentant un risque pour la santé humaine et animale. L'ozonation du blé par le procédé Oxygreen® facilite la digestibilité des parties périphériques du grain de blé et en élimine les contaminants. L'objet de cette thèse consiste plus spécifiquement en l'étude du potentiel décontaminant du procédé Oxygreen® en Ochratoxine A, mycotoxine fréquemment retrouvée dans le blé et dont la présence est limitée par une réglementation Européenne. Le traitement d'une solution aqueuse d'OTA par l'ozone conduit à une dégradation rapide de l'OTA, sans formation de dérivés. L'ozonation du blé contenant de l'OTA en réduit le taux de contamination. L'étude de la cytotoxicité, de la génotoxicité in vitro révèle que l'application du procédé Oxygreen® sur un blé de bonne qualité ne conduit pas à l'apparition de phénomènes de toxicité. La connaissance des effets toxiques de l'OTA est nécessaire à la détermination des doses maximales journalières tolérables pour l'homme par extrapolation des résultats obtenus chez l'animal. L'innocuité du procédé Oxygreen® ainsi que les effets d'une exposition subchronique à de faibles doses d'OTA ont été évalués chez des rats mâles et femelles. L'exposition, même faible (40ng/kg pc/jour l'OTA conduit à l'accumulation de l'OTA dans le compartiment sanguin ainsi que dans les différents organes. Des adduits à l'ADN sont observés dans les reins et foies des animaux. Bien que l'exposition des rats recevant un blé ozoné soit réduite, les études in vitro et in vivo suggèrent des précautions dans l'utilisation de ce procédé pour la décontamination en OTA du blé. Des optimisations de ce procédé sont à envisager afin d'augmenter l'efficacité de la décontamination. ABSTRACT : Ingestion of complete flour or complete bread has the advantage of providing a food with a high nutritional value (vitamins, trace elements). The consumption of these foods is limited because bran is not easy to digest and concentrates contaminants which could impact human and animal health. Ozone application via Oxygreen® process increases their digestibility and allows reducing the contamination rate. The aim of this thesis is to analyse the safety of Oxygreen® process applied on OTA contaminated wheat. OTA is a nephrotoxic and carcinogenic mycotoxin; its amount in food is regulated by EU community. The treatment of an aqueous OTA solution by ozone rapidly destroys OTA without generating new derivatives. In the same way, ozone applied on wheat reduces OTA level. In vitro analyses of cytotoxicity and genotoxicity reveal that Oxygreen® process applied on high quality wheat does not lead to any toxic effects. Oxygreen® safety and the effects of low OTA exposure were investigated in a sub-chronic study on male and female rats. Even with exposure as low as 40 ng/kg bw/day, OTA accumulates in blood and organs, leading to DNA adducts formation in target organs (liver and kidney). The reduction of rats exposure does not result in the total decrease of OTA toxic effects. This study suggests to take care about Oxygreen® use in view of mycotoxin decontamination, and to optimize the process.
The mutagenicity levels of tap water in Japan were surveyed using the Ames test. Tap water samples (179) were collected at 17 sampling sites located from the northern tip (Hokkaido) to the southern tip (Kagoshima Prefecture). The mutagenicity values ranged from under the detection limit to 3600 net rev x L(-1). The average mutagenicity was 1100 net rev x L(-1) and the levels were significantly higher in the wintertime than in the summertime. The average mutagenicity of each site ranged from under the detection limit to 2000 net rev x L(-1). There was no significant correlation of the mutagenicity with TOC, A(260) or THMs. The highest positive ratios of the Ames test and the umu test were 92% under the condition TA100-S9 and 9% under the condition NM2009-S9, respectively, which indicated that the Ames test has higher sensitivity for the test of tap water than the umu test. This survey incorporated the 1992-1993 survey. The comparison of these survey-results in a further study will reveal the improvement of Japanese tap water quality from the perspective of mutagenicity.
A previous study showed that the cancer mortalities are higher for residents who lived nearby the Songhua River heavily polluted by organic contamination. It is important to determine its risk of carcinogenic potential. Short-term genotoxic bio-assays using Salmonella, Sister Chromatid Exchange (SCE), and Micronuclei (MN) assays were employed to examine the genotoxic activity of ether extracts of water samples taken from the Songhua River. The results of the Salmonella bioassay indicated that there were indirect frame-shift mutagens in the water samples. A dose-response relationship for the SCE and MN assays was obtained. These results showed that organic extracts of water samples have genotoxic activity and the risk of carcinogenic potential to human health. The mutagenesis of water samples had changed compared to the results in 1994-1995. An increasing trend of risk of carcinogenic potential in the Songhua River after ten years should be noted and needs to be studied further.
In order to analyze potential carcinogenic and genotoxic responses caused by exposure to pollutants existing in environment, a screening method has been established in our laboratory that uses a stably transfected HepG2 cell lines containing gadd153 promoter regions which drive a luciferase reporter gene. Activation of the exogenous gadd153 promoter was quantified using the luciferase activity following drug exposure. Twenty four agents were used to evaluate this screening assay. We selected the agents, ranging from DNA alkylating agents, oxidative agent, radiation, DNA cross-linking agent, nongenotoxic carcinogens, precarcinogenic agents, which included cadmium chloride, chromium trichloride, mercuric chloride, lead nitrate, dichloro-diphenyl-trichloroethane, deltamethrin, biphenylamine, 2-aminofluorene, benzo[a]pyrene, 2,3,7,8,-tetracblorodibenzo-p-dioxin, diethyl-stilbestrol, carbon tetrachloride, mitomycin C, hydroxycamptothecin, UV, sodium fluoride, acrylamide, hydrogen peroxide. In addition, two complex genotoxic agents (water samples) existing in the environment were selected. The results showed that all 20 tested known carcinogenic and genotoxic agents were able to induce gadd153-Luc expression at a sublethal dose. In contrast, four tested non-carcinogens, included 4-acetylaminofluorene, pyrene, benzylpenicillin sodium and vitamin C, were unable to induce gadd153-Luc expression. In conclusion, this reporter system can facilitate in vitro screening for potential carcinogens. Therefore, the gadd153-Luc test system we have developed appears to be a useful and complementary system to existing genotoxic and mutagenic tests.
A case control study of drinking water treatment practices and female cancer mortality was conducted in Wisconsin. Cancer deaths for 1972-1977 from 28 Wisconsin counties and noncancer deaths matched to cancer deaths on age, year of death and county of residence, were compared for characteristics of drinking water supplied to their places of residence. Using logistic regression, estimates of relative risk associated with chlorinated water were examined allowing for the influence of indicators of water organics and the potential confounders of occupation, marital status and urbanicity. Only colon cancer appeared to be related significantly to chlorination in all models explored. A dose-response relationship was found between crude indicators of trihalomethane level (chlorination X organic contamination) and colon cancer death. The odds ratio for chlorinated surface water for colon cancer was 2.81 (p less than 0.01); approximately half this risk was found for chlorinated ground water. Consequently, a case control study of colon cancer and drinking water quality utilizing newly diagnosed patients is being conducted in Wisconsin.
The revised Salmonella/liver microsome system was used to screen the mutagenic potential of drinking water. An increase in the number of Salmonella revenants was found in three consecutive sample dilutions of different fractions (neutral, basic and acidic) of drinking‐water concentrates from the water‐network system of Budapest, Hungary, eluted from macroreticular XAD‐2 resin with methanol or dichloromethane as solvent, both without and with pre‐treatment with S9 fraction. Our results indicate the possibility of formation of genotoxic (mutagenic/carcinogenic) by‐products in drinking water and a potential risk for humans exposed to this contaminated water.
The current and historical literature pertaining to the use of Amberlite® XAD resins for isolating and concentrating organic compounds from water has been reviewed. The focus is on XAD-2 and XAD-4 resins and their use in concentrating organics from drinking water for mutagenicity studies. Factors affecting solute adsorption/desorption are addressed, as are resin cleaning and regeneration methods. The identification and elimination of resin artifacts are discussed as well as the possible mutagenic potential of these artifacts or of their disinfection by-products, principally resulting from their reaction with chlorine.
The methods for detecting carcinogens and mutagens with the Salmonella mutagenicity test were described previously (Ames et al., 1975b). The present paper is a revision of the methods. Two new tester strains, a frameshift strain (TA97) and a strain carrying an ochre mutation on a multicopy plasmid (TA102), are added to the standard tester set. TA97 replaces TA1537. TA1535 and TA1538 are removed from the recommended set but can be retained at the option of the investigator. TA98 and TA100 are retained. We discuss other special purpose strains and present some minor changes in procedure, principally in the growth, storage, and preservation of the tester strains. Two substitutions are made in diagnostic mutagens to eliminate MNNG and 9-aminoacridine. Some test modifications are discussed.
Drinking water is a major source of microbial pathogens in developing regions, although poor sanitation and food sources are integral to enteric pathogen exposure. Gastrointestinal disease outcomes are also more severe, due to under-nutrition and lack of intervention strategies in these regions. Poor water quality, sanitation and hygiene account for some 1.7 million deaths a year world-wide (3.1% of all deaths and 3.7% of all DALY's), mainly through infectious diarrhoea. Nine out of 10 such deaths are in children and virtually all of the deaths are in developing countries. Major enteric pathogens in these children include: rotavirus, Campylobacter jejuni, enterotoxigenic Escherichia coli, Shigella spp. and Vibrio cholerae O1, and possibly enteropathogenic E. coli, Aeromonas spp. V. cholerae O139, enterotoxigenic Bacteroides fragilis, Clostridium difficile and Cryptosporidium parvum. All except the latter are easily control by chlorination of water, but recontamination of treated water is a huge problem. Emerging environmental pathogens, such as Helicobacter pylori and Burkholderia pseudomallei, may well be of significance in some regions. In adults, much less is understood of various sequellae such as myocarditis, diabetes, reactive arthritis and cancers some months-years after initial infections. So in addition to the traditional pathogens (helminths, Entamoeba histolytica, Giardia lamblia hepatitis A and E) various enteroviruses, C. jejuni and H. pylori are emerging issues in adults.
The apoptosis-inducing activity of concentrated sediments of disinfected and non-disinfected water samples from the waterworks in Budapest, Hungary, was investigated using cultures of human peripherial blood lymphocytes. Chlorine-treated water and untreated (raw) water sediments were concentrated with the use of Amberlite XAD-2 resin columns. The concentrates were dissolved in dimethyl sulfoxide and added to cultures of human peripherial blood lymphocytes. Apoptotic index was determined in lymphocytes after treatment with the raw or disinfected concentrates by flow cytometry. Disinfected water concentrates of 100 microl/ml increased the apoptotic ratio of lymphocyte culture. The same amount of raw water concentrate also enhanced apoptosis. Both raw water and disinfected water contain substances that induced a significant rate of apoptosis in lymphocyte cultures.
Major waterborne cryptosporidiosis and giardiasis outbreaks associated with contaminated drinking water have been linked to evidence of suboptimal treatment. Cryptosporidium parvum oocysts are particularly more resistant than Giardia lamblia cysts to removal and inactivation by conventional water treatment (coagulation, sedimentation, filtration and chlorine disinfection); therefore, extensive research has been focused on the optimization of treatment processes and application of new technologies to reduce concentrations of viable/infectious oocysts to a level that prevents disease. The majority of the data on the performance of treatment processes to remove cysts and oocysts from drinking water have been obtained from pilot-tests, with a few studies performed in full-scale conventional water treatment plants. These studies have demonstrated that protozoan cyst removal throughout all stages of the conventional treatment is largely influenced by the effectiveness of coagulation pretreatment, which along with clarification constitutes the first treatment barrier against protozoan breakthrough. Physical removal of waterborne Crytosporidium oocysts and Giardia cysts is ultimately achieved by properly functioning conventional filters, providing that effective pretreatment of the water is applied. Disinfection by chemical or physical methods is finally required to inactivate/remove the infectious life stages of these organisms. The effectiveness of conventional (chlorination) and alternative (chlorine dioxide, ozonation and ultra violet [UV] irradiation) disinfection procedures for inactivation of Cryptosporidium has been the focus of much research due to the recalcitrant nature of waterborne oocysts to disinfectants. This paper provides technical information on conventional and alternative drinking water treatment technologies for removal and inactivation of the protozoan parasites Cryptosporidium and Giardia.
H-1085 Budapest, ¨ Ull˝ oiú 26, Hungary. Tel.: +36 1 266 04 51; fax: +36 1 266 04 51. E-mail address: bszende@korb1
- Corresponding
* Corresponding author at: H-1085 Budapest, ¨ Ull˝ oiú 26, Hungary. Tel.: +36 1 266 04 51; fax: +36 1 266 04 51. E-mail address: bszende@korb1.sote.hu (B. Szende).