Comparative assessment of genotoxicity of mineral water packed in polyethylene terephthalate (PET) and glass bottles

The potential migration of genotoxic compounds into mineral water stored in polyethylene terephthalate (PET) bottles was evaluated by an integrated chemical/biological approach using short-term toxicity/genotoxicity tests and chemical analysis. Six commercial brands of still and carbonated mineral water bottled in PET and in glass were stored at 40 °C for 10 days in a stove according to the standard EEC total migration test (82/711/EEC), or at room temperature in the dark. After treatment, the samples were analysed using gas-chromatography/mass spectrometry (GC/MS) to detect volatile and non-volatile compounds, the Microtox^® test to evaluate potential toxicity of the samples, and three mutagenicity tests - Tradescantia and Allium cepa micronucleus tests and the Comet assay on human leukocytes - to detect their genotoxic activity.GC/MS analysis did not detect phthalates or acetaldehyde in the water samples. The Microtox^® test found no toxic effects. Mutagenicity tests detected genotoxic properties of some samples in both PET and glass bottles. Statistical analyses showed a positive association between mineral content and mutagenicity (micronuclei in A. cepa and DNA damage in human leukocytes). No clear effect of treatment and PET bottle was found. These results suggest the absence of toxic compounds migrating from PET regardless of time and conditions of storage. In conclusion, bottle material and stove treatment were not associated with the genotoxic properties of the water; the genotoxic effects detected in bottled water may be related to the characteristics of the water (minerals and CO₂ content).     

A new approach to evaluating the toxicity and genotoxicity of disinfected drinking water

The aim of this study was to evaluate the formation of toxic and genotoxic compounds in surface drinking waters treated with two widely used disinfectants, sodium hypochlorite (NaClO) and chlorine dioxide (ClO(2)), and a new disinfectant, peracetic acid (PAA). For this purpose a pilot plant was set up to add these biocides continuously to pre-filtered lake water flowing into three different basins. During three seasonal experiments, short-term in vivo tests (with plant, fish and molluscs) and in vitro tests (with bacteria, yeast and human cells) were carried out to evaluate the formation of genotoxic disinfection by-products (DBPs). Gas chromatography/mass spectrometry (GC/MS) was used to identify DBPs produced during the different treatments, microbiological analyses were performed to test the biocidal activity of the disinfectants, and chemical analyses were carried out to evaluate the quality of the water. The pilot drinking water plant under study was useful in studying the toxicity and genotoxicity of disinfected drinking water with this combined chemical/biotoxicological approach. This paper describes the setting up of the pilot plant and sets out/reports the results of the microbiological and chemical analyses.     

Xenobiotic organic compounds in leachates from ten Danish MSW landfills--chemical analysis and toxicity tests

A monitoring program comprising chemical analysis and biological toxicity testing of leachate samples from 10 Danish landfills (six engineered and four uncontrolled) revealed the presence of 55 different xenobiotic organic compounds (XOCs) and 10 degradation products of XOCs. The compounds belong to the following groups: BTEX, C3-benzenes, bicyclo compounds, napthalenes, chlorinated aliphatics, phenols (chloro-, methyl-, dimethyl, nonyl-), pesticides, and phthalates. Concentrations of single XOCs ranged from <0.1 to 2220 microg/L. A pesticide screening including 101 different compounds resulted in detection of 18 pesticides and three degradation products. The findings of degradation products of toluene, phenols, phthalates, pesticides, and nonylphenol ethoxylates show that degradation occurred inside the landfills. In biotests with bacteria and algae it was found that the non-volatile organic compounds were toxic as the samples only needed to be pre-concentrated from 1.3 to 9.4 times to give 50% inhibition of the test organisms. One of the ten samples proved to be genotoxic in the umuC test after 141 times pre-concentration. A major part of the organic chemicals causing toxicity remains unknown and it is recommended to combine chemical analyses and biotests in future monitoring programs.     

Toxicity evaluation of surface water treated with different disinfectants in HepG2 cells

It is well known that water disinfection through chlorination causes the formation of a mixture of disinfection by-products (DBPs), many of which are genotoxic and carcinogenic. To demonstrate the formation of such compounds, a pilot water plant supplied with water from Lake Trasimeno was set up at the waterworks of Castiglione del Lago (PG, Italy). The disinfectants, continuously added to pre-filtered lake water flowing into three different basins, were sodium hypochlorite, chlorine dioxide and peracetic acid, an alternative disinfectant used until now for disinfecting waste waters, but not yet studied for a possible use in drinking water treatment. The aim of this study was to evaluate the formation during the disinfection processes of some toxic compounds that could explain the genotoxic effects of drinking waters. Differently treated waters were concentrated by solid-phase adsorption on silica C(18) columns and toxicity was assessed in a line of human hepatoma cells (HepG2), a metabolically competent cellular line very useful for human risk evaluation. The seasonal variability of the physical-chemical water characteristics (AOX, UV 254 nm, potential formation of THM, pH and temperature) made indispensable experimentation with water samples taken during the various seasons. Autumn waters cause greater toxicity compared to those of other seasons, in particular dilution of the concentrate at 0.5l equivalent of disinfected waters with chlorine dioxide and peracetic acid causes a 55% reduction in cellular vitality while the cellular vitality is over 80% with the all other water concentrates. Moreover it is very interesting underline that non-cytotoxic quantities of the autumnal water concentrates cause, after 2h treatment, a decrease in GSH and a statistically significant increase in oxygen radicals, while after prolonged treatment (24h) cause a GSH increase, without variations in the oxygen radical content. This phenomenon could be interpreted as the cellular adaptation response to an initial oxidative stress.     

Genotoxic response of Austrian groundwater samples treated under standardized UV (254 nm)--disinfection conditions in a combination of three different bioassays

Ground water samples from different geographic areas in Austria, with different amounts of natural and anthropogenic organic compounds were treated with a standardized low pressure UV (254 nm)-irradiation laboratory flow-through system (UV fluence: 800 J/m2). The genotoxic activities of the water samples before and after the UV disinfection were investigated using a combination of three different bioassays which complement each other with regard to their sensitivity detecting different genotoxins. The test battery comprises the Salmonella/microsome assay (Ames test with TA98. TA 100 and TA 102, with and without S9 mix) and two micronucleus tests with the plant Tradescantia (clone #4430) and with primary rat hepatocytes. Overall, the tested Austrian groundwater samples used for human consumption caused only weak genotoxic activities compared to drinking water samples reported from other countries under similar experimental conditions. With the exception of one weak positive result in the Ames test (only in strain TA98 without S9 mix) with an induction factor of 1.9) all samples after UV disinfection were devoid of additional mutagenic and clastogenic activities compared to the samples before UV disinfection.     

Toxicity assessment of organic compounds in drinking water in the Netherlands

In a recent survey of organic compounds present in drinking water of twenty cities in The Netherlands, it was found that only a minor fraction (10%) of the total organic content could be identified. It appeared that drinking water prepared from polluted surface water contains more organic compounds with carcinogenic and mutagenic properties than water prepared from groundwater. The concentration of most of the organic constituents identified was generally below the microgram/litre level.It is not expected that circumstances will occur, that these compounds willbe present in quantities, which are acutely toxic for consumers. On the other hand it cannot be excluded that certain organic compounds, in particular carcinogens and mutagens, may cause chronic toxic effects as a result of life time consumption of such contaminated drinking water.Therefore an epidemiological study was started in The Netherlands in which cancer mortality was related to the raw water source used for drinking water and the level of organic constituents. Preliminary results of the epidemiological study are presented.Furthermore a limited survey was carried out whereby drinking water of six cities was investigated for the presence of organic genotoxic compounds. The results of this survey led to the decision to extend this investigation to 19 cities. Finally, preliminary results regarding the characterization of the organic genotoxic compounds, present in drinking water, will be discussed.     

Tools for monitoring toxicological and genotoxicological changes in a drinking water treatment plant in Northeast Italy

Drinking water quality can be compromised at different stages, from raw water to treated one. This research aimed to evaluate the toxicity and genotoxicity of groundwater contaminated by fluorinated compounds treated in a drinking water treatment plant, through several bioassays. Water samples underwent chemical analyses and were assayed on Daphnia magna, Pseudokirchneriella subcapitata, Allium cepa, human leukocytes and Salmonella typhimurium. Physical–chemical parameters were always within the Italian legislation limits. Water after filtration and disinfection caused slight toxicity in D. magna; the sample after filtration inhibited the proliferation of P. subcapitata. None of the water samples exerted toxicity in A. cepa. All the analysed samples had genotoxic effects on A. cepa and human leucocytes, while only disinfected water caused mutations in S. typhimurium. A battery composed of tests on D. magna, P. subcapitata, S. typhimurium and A. cepa could represent a useful tool to verify the toxicity/genotoxicity through the water treatment stages and to improve drinking water quality management.     

The quality of drinking water prepared from bank-filtered river water in the Netherlands

The quality of raw water and drinking water was analysed at 18 sites in the Rhine delta in an integrated program with hydrological,chemical and toxicological parameters. About 600 different organic compounds have been detected,of which about 200 could be identified,and 400 more have been classified on the basis of their mass spectra. Lipophilic compounds with a log P(octanol/water) greater than 3.2 are adsorbed during the first few meters of the bank infiltration. More hydrophilic compounds are often not adsorbed and not removed by the currently used water purification systems,such as aeration and sand filtration.The presence of organohalogens was demonstrated with surrogate parameters,such as extractable and adsorbable organohalogen. All the samples tested were mutagenic in the Ames test with strain TA98 + S9 mix. Only part of the mutagenic activity was related to compounds originating from Rhine water.     

Seasonal variation in drinking water concentrations of disinfection by-products in IZMIR and associated human health risks

Seasonal variation in concentrations of two different disinfection by-product groups, trihalomethanes (THMs) and haloacetonitriles (HANs), was investigated in tap water samples collected from five sampling points (one groundwater and four surface water sources) in Izmir, Turkey. Estimates of previously published carcinogenic and non-carcinogenic risks through oral exposure to THMs were re-evaluated using a probabilistic approach that took the seasonal concentration variation into account. Chloroform, bromoform, dibromochloromethane and dichloroacetonitrile were the most frequently detected compounds. Among these, chloroform was detected with the highest concentrations ranging from 0.03 to 98.4 microg/L. In tap water, at the groundwater supplied sampling point, brominated species, bromoform and dibromoacetonitrile, were detected at the highest levels most probably due to bromide ion intrusion from seawater. The highest total THM and total HAN concentrations were detected in spring while the lowest in summer and fall. The annual average total THM concentration measured at one of the surface water supplied sampling points exceeded the USEPA's limit of 80 microg/L. While all non-carcinogenic risks due to exposure to THMs in Izmir drinking water were negligible, carcinogenic risk levels associated with bromodichloromethane and dibromochloromethane were higher than one in million.     

PAH content, toxicity and genotoxicity of coastal marine sediments from the Rovinj area, Northern Adriatic, Croatia

Surface marine sediments collected from 8 sampling sites within the Rovinj coastal area, Northern Adriatic, Croatia, were used for determining priority pollutant polycyclic aromatic hydrocarbons (PAHs) and toxic/genotoxic potential of sediment organic extracts. Total PAH concentrations ranged from 32 microg/kg (protected area) to 13.2 mg/kg dry weight (harbor) and showed clear differences between pristine, urban industrial and harbor areas. PAHs distribution revealed their pyrogenic origin with some biogenic influence in harbor. At all sampling sites sediment extracts showed toxic potential that was consistent with the sediment type. No correlation between toxicity measured by Microtox assay and concentrations of individual or total PAHs was found. Noncytotoxic dose of sediment extracts showed no genotoxic potential in bacterial umu-test. DNA damage is positively related to total PAHs at 4 sampling sites (S-1, S-2, S-3, S-6), but the highest DNA damage was not observed at the site with the highest total sediment PAH content (S-5).     

Combinaison d'une cellule d'extraction liquide-liquide en continu et d'un couplage CG-SM en vue de l'analyse des pesticides dans les eauxContinuous composite sampling and analysis of pesticides in water

The occurrence of synthetic organic chemicals in drinking water supplies has prompted the European Economic Community to establish standards for pesticides. Currently, the limit on total pesticides is 500 ng l^?1 with no individual pesticide to exceed 100 ng l^?1. The variability of pesticides, both in concentration and composition, indicates that composite rather than grab samples are desirable for analysis of the water quality. Furthermore, the variability in composition makes a broad spectrum analysis preferable to individual compound analysis so that many compounds can be analysed simultaneously.Although composite broad spectrum samples are desirable from a collection point of view, the occurrence of many pesticides in one sample presents a problem for individual compound quantification and identification. For this reason, gas chromatography (GC) is used to separate the compounds and mass spectrometry (MS) is used to identify and quantify the compounds. Coupled GS-MS avoids interferences which may occur in GC by using a separate method (other than retention time or volume) to identify compounds.This research compared liquid-liquid extraction (LLE) in the batch and continuous mode. The LLE process is accomplished in a continuous mode by mixing the water and solvent in a coil, allowing the water and solvent to separate in a quiescent decantation cell, then recirculating the solvent by a separate distillation cell while the water goes to waste. Tap water was spiked with pesticides at 10, 50 and 100 ng l^?1. Extraction efficiency was compared at each of the three spiking concentrations. The extracts were analysed on GC-MS using a moving needle injection technique to enhance sensitivity. The identification and quantification of compounds were accomplished by MS using the fragmentometry technique which enhance sensitivity of the analysis.The results indicate that continuous LLE will recover an average of 75% (± 14%) of the pesticides in the 10–100 ng l^?1 range recoverable by batch LLE. There was no significant difference in recovery for structurally different pesticides (chlorinated, nitrogenous or phosphoric) as all fell in the 75 ± 14% range. Eighteen pesticides were identified and quantified by the GC-MS in a 25 min analysis.This demonstrates that the continuous LLE technique can be used to automate collection of composite samples if the reduction in extraction efficiency is taken into account. The continuous LLE can handle much larger volumes of water than the batch LLE. Composite samples can be continuously collected over time, a sampling regime not possible with batch LLE. This technique when coupled with GC-MS can be used to identify and quantify pesticides at the ng l^?1 level and can be applied routinely for analysis of pesticides at approximately the same price as individual pesticides analysis.     

Effects of co-exposure to extremely low frequency (50 Hz) magnetic fields and xenobiotics determined in vitro by the alkaline comet assay

In the present study, we used human peripheral blood leukocytes from 4 different donors, to investigate in vitro the possible genotoxic and/or co-genotoxic activity of extremely low frequency magnetic fields (ELF-MF) at 3 mT intensity. Two model mutagens were used to study the possible interaction between ELF-MF and xenobiotics: N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and 4-nitroquinoline N-oxide (4NQO). Primary DNA damage was evaluated by the alkaline single-cell microgel-electrophoresis ("comet") assay. Control cells (leukocytes not exposed to ELF-MF, nor treated with genotoxins) from the different blood donors showed a comparable level of basal DNA damage, whereas the contribution of individual susceptibility toward ELF-MF and the tested genotoxic compounds led to differences in the extent of DNA damage observed following exposure to the genotoxins, both in the presence and in the absence of an applied ELF-MF. A 3 mT ELF-MF alone was unable to cause direct primary DNA damage. In leukocytes exposed to ELF-MF and genotoxins, the extent of MNNG-induced DNA damage increased with exposure duration compared to sham-exposed cells. The opposite was observed in cells treated with 4NQO. In this case the extent of 4NQO-induced DNA damage was somewhat reduced in leukocytes exposed to ELF-MF compared to sham-exposed cells. Moreover, in cells exposed to ELF-MF an increased concentration of GSH was always observed, compared to sham-exposed cells. Since following GSH conjugation the genotoxic pattern of MNNG and 4NQO is quite different, an influence of ELF-MF on the activity of the enzyme involved in the synthesis of GSH leading to different activation/deactivation of the model mutagens used was hypothesized to explain the different trends observed in MNNG and 4NQO genotoxic activity in the presence of an applied ELF-MF. The possibility that ELF-MF might interfere with the genotoxic activity of xenobiotics has important implications, since human populations are likely to be exposed to a variety of genotoxic agents concomitantly with exposure to this type of physical agent.     

Combinaison d'une cellule d'extraction liquide-liquide en continu et d'un couplage CG-SM en vue de l'analyse des pesticides dans les eaux

The occurrence of synthetic organic chemicals in drinking water supplies has prompted the European Economic Community to establish standards for pesticides. Currently, the limit on total pesticides is 500 ng l⁻¹ with no individual pesticide to exceed 100 ng l⁻¹. The variability of pesticides, both in concentration and composition, indicates that composite rather than grab samples are desirable for analysis of the water quality. Furthermore, the variability in composition makes a broad spectrum analysis preferable to individual compound analysis so that many compounds can be analysed simultaneously.Although composite broad spectrum samples are desirable from a collection point of view, the occurrence of many pesticides in one sample presents a problem for individual compound quantification and identification. For this reason, gas chromatography (GC) is used to separate the compounds and mass spectrometry (MS) is used to identify and quantify the compounds. Coupled GS-MS avoids interferences which may occur in GC by using a separate method (other than retention time or volume) to identify compounds.This research compared liquid-liquid extraction (LLE) in the batch and continuous mode. The LLE process is accomplished in a continuous mode by mixing the water and solvent in a coil, allowing the water and solvent to separate in a quiescent decantation cell, then recirculating the solvent by a separate distillation cell while the water goes to waste. Tap water was spiked with pesticides at 10, 50 and 100 ng l⁻¹. Extraction efficiency was compared at each of the three spiking concentrations. The extracts were analysed on GC-MS using a moving needle injection technique to enhance sensitivity. The identification and quantification of compounds were accomplished by MS using the fragmentometry technique which enhance sensitivity of the analysis.The results indicate that continuous LLE will recover an average of 75% (± 14%) of the pesticides in the 10–100 ng l⁻¹ range recoverable by batch LLE. There was no significant difference in recovery for structurally different pesticides (chlorinated, nitrogenous or phosphoric) as all fell in the 75 ± 14% range. Eighteen pesticides were identified and quantified by the GC-MS in a 25 min analysis.This demonstrates that the continuous LLE technique can be used to automate collection of composite samples if the reduction in extraction efficiency is taken into account. The continuous LLE can handle much larger volumes of water than the batch LLE. Composite samples can be continuously collected over time, a sampling regime not possible with batch LLE. This technique when coupled with GC-MS can be used to identify and quantify pesticides at the ng l⁻¹ level and can be applied routinely for analysis of pesticides at approximately the same price as individual pesticides analysis.     

Occurrence, oral exposure and risk assessment of volatile organic compounds in drinking water for Izmir

Concentrations of volatile organic compounds (VOCs) were measured in the drinking water in Province of Izmir, Turkey, and associated health risks due to ingestion of these compounds were investigated using population weighted random samples. A total of 100 houses were visited in different districts of Izmir and drinking water samples were collected from consumers' drinking water source. Questionnaires were administered to one participant in each house to determine demographics and drinking water consumption rates. Oral exposure and risks were estimated for each participant and Izmir population by deterministic and probabilistic approaches, respectively. The four trihalomethane (THM) species (i.e., chloroform, bromodichloromethane, dibromochloromethane, and bromoform), benzene, toluene, p-xylene, and naphthalene were the most frequently detected VOCs with concentrations ranging from below detection limit to 35 microg/l. The risk estimates were found to be less than the values reported in the literature with few exceptions. Noncarcinogenic risks attributable to ingestion of VOCs for Izmir population were negligible, whereas the mean carcinogenic risk estimates for bromodichloromethane and dibromochloromethane were above the de minimis level of one in a million (10(-6)). For all VOCs, the concentrations measured in metropolitan area were greater than those in other districts. All THM species were detected in higher concentrations in tap water, whereas nontap water contained more benzene, toluene, p-xylene, and naphthalene. Therefore, the concentrations of the latter four compounds and associated risks increased with increasing income and education level since bottled water was used in larger proportions within these subgroups. The results of this study showed that oral exposure to drinking water contaminants and associated risks may be higher than the acceptable levels even if the concentrations fall below the standards.     

Comparative temporal ecotoxicological study in a river basin influenced by petrochemical industries

An approach was developed to evaluate ecotoxicological effects in river basins impacted by anthropic industrial discharges. Genotoxicity was the first level of evaluation of the river water, but when cytotoxicity was associated with genotoxic effects, our research group added chronic assays allowing the assessment of the ontogenic cycle in environmental diagnosis. The genotoxicity of river water sampled during two periods was compared using the microscreen phage-induction and Salmonella/microsome assays. The study assessed the ability of these assays to diagnose environmental quality in an area where petrochemical impacts occur. The study was performed at six sampling sites using the Salmonella/microsome assay for 10 sampling periods and the microscreen phage-induction assay for 15 samplings. The percentage of mutagenic activity was higher at the sites sampled in front of the petrochemical complex in both periods, but there were more significant mutagenic responses in the first assessment. However, comparing the percentages of samples with mutagenic and cytotoxic activity observed during the two periods it becomes clear that there are more cytotoxic samples during the second period throughout the area studied. The genotoxic activity analyzed by the microscreen phage-induction assay was constant in the second period. Chronic toxicity studies with the microcrustacean Daphnia magna confirm the toxic effects observed. The mortality of individuals was higher at the site most influenced by the petrochemical complex, followed by the station located upstream from this area, while the formation of ephippial eggs was uniform at all stations. The rise in the toxic potential of the region detected by cytotoxic and chronic toxicity may interfere and probably impair the use of the Salmonella/microsome assay to determine the potential of the area, showing the importance of assay association to evaluate potentially contaminated areas.     

Considerations for improving the accuracy of exposure to disinfection by-products by ingestion in epidemiologic studies

Disinfection by-product (DBP) exposure characterization studies are often based on the analysis of a limited number of samples collected from a distribution system (DS) in which DBP levels are variable over time and space. A compositing technique was developed to simplify the sample collection procedures for integrating over temporal variations in DBPs measured in terms of trihalomethanes (THMs), haloacetic acids (HAAs), and total organic halogen (TOX). Over the course of 5 days analysis, the single composited sample was within 94-100% of the average THM concentration in all grab samples, 92-105% of HAAs, and 130% of the TOX concentration. Additionally, temporal variability factors such as timing of sample collection and the handling of tap water prior to consumption were found to influence DBP levels in consumers' drinking water. Included in our study of home water use are the effects of boiling which removed up to 98% of THMs and point of use (POU) devices which all showed DBP removal but differed depending on the device used. These factors should be taken into consideration in DBP exposure characterization for epidemiologic studies.     

Water mutagenicity and toxicology in Rio Tercero (Cordoba,Argentina)

A study on the water quality from the Rio Tercero River was performed for 14 months. The aim of the work was not only to assess the control of bacteriological, phycological and chemical aspects, but also to measure genotoxicity of drinking water and its relation with the water treatment technique employed. Bacteriological parameters are negative in general, apparently indicating low levels of contaminants. Algae were present in the untreated water, especially several diatoms (Bacillariophyceae) and potentially hepatotoxin-producing cyanobacteria (blue-green algae). The chemical analysis detected arsenic (up to 0.114 mg/l) and vanadium (up to 0.109 mg/l). Water was genotoxic and clastogenic over several biological systems. The use of alternative disinfectants, such as chlorine-dioxide or ozone, and granular activated carbon are recommended.     

Chemical water quality in Thailand and its impacts on the drinking water production in Thailand

In Thailand, surface water and groundwater are the main water sources for tap water and drinking water production. Thirty-six different samples from surface waters from Chao Praya and Mae Klong rivers, tap waters, bottled drinking waters, groundwaters and commercial ice cubes from around the Bangkok area were collected. Water samples were also taken from two waterworks in the Chonburi province. The extensive survey showed that, overall in all water samples investigated, there was only a minor pollution which could be traced back to the analyses performed including amongst others total organic carbon, inorganics and heavy metals, pesticides, organochlorine compounds, volatile organic compounds, surfactants, pharmaceuticals and disinfection by-products. However, whenever organic micropollutants could be detected in surface water, such as, e.g. the herbicide atrazine, they were also present in the tap water produced thereof proving that the present treatment steps are not sufficient for removal of such pollutants. The concentration of disinfection by-products was higher in tap water produced from Chao Praya river than from Mae Klong river. Disinfection by-products were also found in bottled drinking water. Commercial ice cubes contained anionic surfactants and their metabolites at elevated concentrations. The data of this study constitute the first set of homogenous data for the chemical water quality and also aid development of new water quality criteria in Thailand.