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At least 19 recordsLinked to original sources
PubMed1982

Characterization of indicator bacteria in municipal raw water, drinking water, and new main water samples.

Municipal water samples were analyzed by membrane filter (MF) and presence-absence (P-A) tests for pollution indicator bacteria. In four years, 11 514 bacterial cultures were isolated from either raw water, drinking water, or new main water samples submitted to three environmental laboratories. The bacterial species occurring most often in all types of water samples were Escherichia coli (11.6-39.7%), Enterobacter aerogenes (18.1-26.3%), Aeromonas hydrophila (8.8-17.0%), Klebsiella pneumoniae (7.7-10.3%), and Citrobacter freundii (5.9-22.7%). A lactose - lauryl tryptose - tryptone broth was examined as an alternative medium to modified MacConkey broth in the presumptive portion of the P-A test. The intensity of acid and gas production in presumptive positive P-A bottles was compared with the types and frequencies of indicator bacteria shown by confirmatory tests. The results of detecting indicator bacteria following the analysis of 53 130 samples over a 2-year period were arranged by water source (well, lake, river, mixed) and water type (raw or drinking) to determine the influence of these parameters on the recovery of indicator bacteria. A further subdivision of the sample types into raw surface, raw ground, in-plant, plant discharge, reservoir, and distribution samples demonstrated the effect of water treatment practices.

Aeromonas↗
PubMed1997

[Microbiological condition of bottled natural mineral waters, drinking water, as well as water from mineral springs].

We are now in the midst of a critical discussion on the microbiological quality of bottled natural mineral water, springwater, so-called "table water" and drinking water. "Still" waters have high colony counts after long storage, whereas in carbonated bottled products multiplication of oligocarbophilic microorganisms is suppressed by carbon dioxide. Opportunistic species are also found in bottled water. Present knowledge as to whether they are contaminants or part of autochthonous flora is insufficient. Highly colonised foodstuffs and opportunistic species may be hazardous for immunosuppressed patients. Hence, it is claimed that existing legal microbiological criteria for bottled water are inadequate. High colony counts in foodstuffs do not necessarily imply poor microbiological quality a priori. Detection of an opportunist species does not justify classifying a food item as hazardous. Microbiological criteria for bottled water which are laid down in the Directive for Mineral and Table Water of the German Food Legislation Act (LMBG) were established based on recommendations by international microbiologists for the normal not oversensitive consumer. For more sensitive groups of consumers, for example babies, more severe criteria were set up. Immunosuppressed patients are another sensitive group, demanding special hygienic requirements for their surroundings. If the risk of infections for immunosuppressed patients cannot be reduced by other means, it might be useful to establish microbiological criteria for bottled water and of course for other foodstuffs as well. However, such criteria cannot be adequately applied to food for normal consumption, since otherwise many foods would have to be regarded as hazardous and could not be marketed because of legal prescriptions.

Drinking↗
PubMed1976

[Considerations on critics towards conditioned waters (drinking water in general and particularly mineral water) especially from the microbiological point of view].

After having precised what has incited to extend our considerations reported at the International Congress on Microbiology for Mineral Waters to all the conditioned waters, in a "first part" we have examined the drawbacks imputed to the water itself. a) In a first analytical chapter, we have made the schedule and the critical examination of the different reproaches given to conditioned waters on considering successively: 1) Special drawbacks (although these are of an other category than microbiology) which were given, whichever type of supply (loose, at the tap, or splitted up when the water is conditioned), to some categories of waters (carbonated and mineral) because of their nature by the fact that these waters do not show the charactheristics of potability with regard to the legislation and administration. This examination leads to eliminate those reproaches because the consumer knows to which he is exposed, being forewarned: -when he is using mineral water at the cure-resort, by the thermal consultant who is watching over him, -when he is using one or the other of the conditioned waters, -either by the medical practictioner, who should give him the contre-indicates; -either by indicating on the label, if not the contre-indicates (like we would hope that they figure on), at least the composition (which now figures within the EEC).

Food Inspection↗
PubMed1990

[Bacterial regrowth in drinking water. IV. Bacterial flora in fresh and stagnant water in drinking water purification and in the drinking water distribution system].

Six dead end water pipes were installed inside a Zurich drinking water plant and five others over a distance of 12 km along the distribution system and the water was left stagnating in there for 2 weeks. A total of 1508 bacteria from fresh and stagnating water were isolated and identified. Of these, 241 bacterial isolates from the distribution system were examined using the nutrient-tolerance test, i.e. testing the ability to grow in tap water and in media with low and very high nutrient content. In the fresh water of the treatment plant specific bacterial populations were obtained, these occurring particularly after the filters. According to different chlorine dosage and chlorine demand, they were finally washed into the distribution system in varying amounts and compositions. It was shown that in the fresh water of the distribution system the genera of Pseudomonas, Azotobacter and Actinobacteria were each present at a level of approximately 30%. After two weeks stagnation non-fluorescing pseudomonads were dominating in the treatment plant as well as in the fresh water of the distribution system. All isolated Actinobacteria and Azotobacter and almost half of the Pseudomonads proved to be oligotrophic oligocarbotolerants or oligocarbophilic organisms in the nutrient-tolerance test. The other half of the Pseudomonads plus the Flexibacter species were mesotrophic oligocarbotolerants, since they could grow in tap water and in culture media with very high nutrient content. Attention is drawn to the unrecognized danger of recontamination of mesotrophic bacteria growing rapidly in stagnating drinking water, which is used as rinsing water for cleaning food processing equipment.

Acinetobacter↗
PubMed1988

[Bacterial regrowth in drinking water. II. Drinking water distribution systems].

Five chromium steel dead-end water pipes were installed over a distance of 12 km along the Zurich city drinking water distribution system. Cell counts were determined in two series of four samplings in fresh water and stagnating water using three different methods. The colony counts of oligocarbon tolerant bacteria (1:10 diluted plate count agar, 20 degrees C, 14 d) in the fresh water was increasing along the distribution line. Initially there were counts around 1 CFU ml-1 and after 12 km between 120 and 1100 CFU ml-1. Water taken from house tabs showed higher colony counts than water taken after reservoirs. After a stagnating time of 14 d all 40 water samples showed aftergrowth from 10(3) up to 10(4) CFU ml-1. Water from the two sampling locations with the longest distance from the treatment plant showed less regrowth tendency. Epifluorescence microscopy and the INT-method for determining the electron transport system positive bacteria (ETS+) were less useful for monitoring bacterial regrowth. However, in the stagnating water there occurred a significantly higher percentage of ETS+ units as compared to the colony forming units (CFU) with growing distance from the treatment plant.

Bacteria↗
PubMed1993

[Health hazards from metals in drinking water].

Drinking water is essential for man and cannot be replaced. In the public discussion the quality of drinking water is often presented in a one-sided way. This has led to great sensitivity and insecurity with the result that the intake of drinking water is often regarded as deleterious to human health. In this presentation it is attempted to demonstrate by the example of six metals and semi-metals in which way these substances are transmitted into water, how much the consumption of drinking water contributes to the total uptake, and whether a health risk can be derived from this source.

Humans↗
PubMedDate not supplied

Important considerations in the development of public health advisories for arsenic and arsenic-containing compounds in drinking water.

Drinking water contamination by arsenic remains a major public health problem. Acute and chronic arsenic exposure via drinking water has been reported in many countries of the world; especially in Argentina, Bangladesh, India, Mexico, Thailand, and Taiwan, where a large proportion of drinking water (ground water) is contaminated with a high concentration of arsenic. Research has also pointed out significantly higher standardized mortality ratios and cumulative mortality rates for cancers of the bladder, kidney, skin, liver, and colon in many areas of arsenic pollution. General health effects that are associated with arsenic exposure include cardiovascular and peripheral vascular disease, developmental anomalies, neurologic and neurobehavioral disorders, diabetes, hearing loss, portal fibrosis of the liver, lung fibrosis, hematologic disorders (anemia, leukopenia, and eosinophilia), and carcinoma. Although, the clinical manifestations of arsenic poisoning appear similar, the toxicity of arsenic compounds depends largely u[on the chemical species and the form of arsenic involved. On the basis of its high degree of toxicity to humans, and the non-threshold dose-response assumption, a zero level exposure is recommended for arsenic, even though this level is practically non-attainable. In this review, we provide and discuss important information on the physical and chemical properties, production and use, fate and transport, toxicokinetics, systemic and carcinogenic health effects, regulatory and health guidelines, analytical methods, and treatment technologies that are applied to arsenic pollution. Such information is critical in assisting the federal, state and local officials who are responsible for protecting public health in dealing with the problem of drinking water contamination by arsenic and arsenic-containing compounds.

Arsenic↗
PubMed1987

Chemical contamination of California drinking water.

Drinking water contamination by toxic chemicals has become widely recognized as a public health concern since the discovery of 1,2-dibromo-3-chloropropane in California's Central Valley in 1979. Increased monitoring since then has shown that other pesticides and industrial chemicals are present in drinking water. Contaminants of drinking water also include naturally occurring substances such as asbestos and even the by-products of water chlorination. Public water systems, commercially bottled and vended water and mineral water are regulated, and California is also taking measures to prevent water pollution by chemicals through various new laws and programs.

California↗
PubMed2001

[Study on an enhancing agent for removing arsenic from drinking water].

Drinking water contaminated by arsenic for an extended period of time could be detrimental to the health of people. Some preliminary symptoms could be alleviated by drinking water non-contaminated. It is important to develop an arsenic removal agent with a specific property of most efficient, cost-effective and easy for operation. The results showed that the capacity of the agent developed in this study was 10 times higher for arsenic removal than other agent available. The lowest arsenic content of the treated water was 0.05 mg/L. The special function of this agent was arsenic removing without changing other components and the concentrations of other elements in the treated water. The operation and management was simple without adjusting pH of the influent and effluent water. The agent was 5 times cheaper in cost than alumina or activated carbon, because it was a reusable oxidation-catalyst. Therefore, the agent could be widely applied in drinking water plants or used as a purifier at home in the high arsenic areas.

Arsenic↗
PubMedDate not supplied

Relationship of fluoride in drinking water to other drinking water parameters.

Fluoride in drinking water and 32 other drinking water variables were evaluated in an epidemiologic study of 158 municipalities in the State of Iowa. The study included three study groups: two for controlled fluoridation and one for natural fluoride. Previous epidemiologic studies of fluoride in drinking water have rarely addressed other drinking water parameters. The results indicated that controlled fluoridation municipalities were more likely to have initiated other treatment practices such as chlorination. Natural fluoride drinking water concentrations were positively correlated with water source depth, and thereby related to other depth-associated variables such as radium 226, strontium, and nitrogen. Future epidemiologic studies evaluating the safety of fluoride in drinking water should address the potential for confounding by other water variables and treatment processes.

Chlorides↗
PubMed1988

Serological and biochemical characteristics of 416 Yersinia strains from well water and drinking water plants in the Federal Republic of Germany: lack of evidence that these strains are of public health importance.

A total of 416 Yersinia strains from well water and drinking water plants in the Federal Republic of Germany was analysed at the National Reference Centre for Salmonella, Hamburg, in the period 1982 to 1987. Of these, 341 (82%) strains were Y. enterocolitica, 46 (11%) strains were Y. intermedia, 24 (5.8%) strains were Y. frederiksenii, and 5 strains (1.2%) Y. kristensenii. The serogroups O:3, O:9, and O:5,27 which in Central Europe are associated with human disease, were not isolated. Seventy-two strains from treated drinking water were characterized by a newly identified combination of O-antigenic factors, i.e. O:6,30,47, and 130 strains possessed a hitherto unknown O-antigen, O:59. These strains were furthermore associated with a new fimbrial antigen [K3] and a new flagellar antigen [x]. Thus, the majority of Y. enterocolitica strains cultured from drinking water plants was characterized by a rather uniform antigenic pattern which was markedly different from strains isolated from patients. Virulence tests (calcium dependency and autoagglutination at 37 degrees C) were negative in all instances. It is concluded from the results of this study that Yersinia isolates from drinking water plants are of environmental origin without pathogenic importance.

Antigens, Bacterial↗
PubMed2003

Identification of Cryptosporidium spp. oocysts in United Kingdom noncarbonated natural mineral waters and drinking waters by using a modified nested PCR-restriction fragment length polymorphism assay.

We describe a nested PCR-restriction fragment length polymorphism (RFLP) method for detecting low densities of Cryptosporidium spp. oocysts in natural mineral waters and drinking waters. Oocysts were recovered from seeded 1-liter volumes of mineral water by filtration through polycarbonate membranes and from drinking waters by filtration, immunomagnetizable separation, and filter entrapment, followed by direct extraction of DNA. The DNA was released from polycarbonate filter-entrapped oocysts by disruption in lysis buffer by using 15 cycles of freeze-thawing (1 min in liquid nitrogen and 1 min at 65 degrees C), followed by proteinase K digestion. Amplicons were readily detected from two to five intact oocysts on ethidium bromide-stained gels. DNA extracted from Cryptosporidium parvum oocysts, C. muris (RN 66), C. baileyi (Belgium strain, LB 19), human-derived C. meleagridis, C. felis (DNA from oocysts isolated from a cat), and C. andersoni was used to demonstrate species identity by PCR-RFLP after simultaneous digestion with the restriction enzymes DraI and VspI. Discrimination between C. andersoni and C. muris isolates was confirmed by a separate, subsequent digestion with DdeI. Of 14 drinking water samples tested, 12 were found to be positive by microscopy, 8 were found to be positive by direct PCR, and 14 were found to be positive by using a nested PCR. The Cryptosporidium species detected in these finished water samples was C. parvum genotype 1. This method consistently and routinely detected >5 oocysts per sample.

Animals↗
PubMed1980

Mutagenic activity in drinking water.

Drinking water samples concentrated by freeze drying were found to be mutagenic in a mammalian tissue culture assay using Chinese hamster embryonic lung cells (V79). The mutagenicity could be enhanced by the promoter 12-O-tetradecanoyl-phorbol-13-acetate. The water itself was also shown to contain promoting chemicals. The mutation frequency of cells pretreated with low levels of benzo(a)pyrene was increased following subsequent exposure to the concentrated water sample. Approaches to estimate the risk involved in exposure to present drinking water are proposed.

Acetone↗
PubMed1986

[Microbiology of ground water and drinking water].

Groundwater has been considered a safe source for drinking water protected against surface contamination. However, a number of reports about chemical and microbiological contamination have disproved this assumption. Besides hygienical monitoring, little is known about the microbiology of ground- and drinking water. The purpose of this paper is to give a review about the main fields of investigation concerning microbial activity in ground- and drinking-water-action. The hygienical relevant topics are: survival and transport of microorganisms, microbiological degradation of organic pollutants, turn-over of nitrogen compounds, oxidation and reduction of iron and manganese and development of methods for microbiological water examination.

Fresh Water↗
PubMed1983

Protection of mice from whole-body gamma radiation by deuteration of drinking water.

Drinking water made available to mice was changed from ordinary tap water to tap water containing 30 atom% D2O when the animals were 6 to 8 weeks old. Twelve days later, the deuterated mice and an approximately equal number of nondeuterated control mice were subjected to whole-body gamma radiation from a 60Co source. All mice received ordinary tap water after the irradiation. Postirradiation mortality was significantly less in deuterated than in nondeuterated animals. These results may have practical implications for radiotherapy of human malignant tumors.

Animals↗
PubMed1990

Genotoxicity of drinking waters.

Drinking waters in many countries have been shown to contain non-volatile polar mutagenic compounds as well as trihalomethanes. Their nature is uncertain, but one compound, a chlorinated furanone (3-chloro-4-(dichloro-methyl)-5-hydroxy-2(5H)-furanone;MX) seems to be responsible for one third to over one half of the mutagenicity. Its concentration seems to correlate rather well also with the total bacterial mutagenicity. Animal toxicity studies are being used to evaluate the possible carcinogenicity risk of this compound as a first stage in complete risk assessment of the whole complex mixture. Epidemiological risk assessment is also possible, since mutagenicity values can be predicted on the basis of organic material in the raw water and the amount of chlorine used. This information has been collected in Finland retrospectively from waterworks, and will be correlated with the Finnish Cancer Registry data.

Animals↗
PubMed1983

[Induction of microbial growth on the walls of plastic tubes by drinking water].

Drinking water flowing through flexible plastic tubes (PVC) causes the development of a thin film-like coating within 24 h. At this stage microorganisms could either not or rarely be seen. After 48 h the number of microorganisms has become greater. With increasing time of experiment the microbial community becomes more dense until after 72 h it covers the whole surface. Now the microorganisms are embedded in extracellular polymeric substances. The primary film seems to be important for the development of microorganisms in equipment and apparatus.

Bacteria↗