Ground water has traditionally been considered safe for human consumption without treatment. However, it is an increasingly significant cause of human disease. Although ground water accounts for only approximately 20% of the nation's water supply, over 50% of the waterborne disease outbreaks in the United States are due to the consumption of contaminated ground water. It has been estimated that 65% of the cases of illness in these outbreaks are caused by enteric viruses. Little, however, is known about the persistence of viruses in ground water. The purpose of this study was to try to determine the chemical, physical, and biological factors influencing virus survival in ground water. This information will be helpful in developing criteria for determining safe distances between drinking water wells and sources of potential contamination such as septic tanks and waste application sites. Ground water samples were obtained from eleven sites throughout the United States. In addition, twenty samples were collected from the Tucson basin. The water temperature was measured at the time of collection. Several physical and chemical characteristics (including pH, nitrates, turbidity, and hardness) were determined for each sample. Separate polypropylene tubes containing 50 ml of water were inoculated with each of three viruses: poliovirus-1, echovirus-1 and MS-2 coliphage. Duplicate tubes containing water which had been filtered to remove the indigenous bacteria were also inoculated with viruses. The tubes were incubated at the in situ ground water temperature; selected samples were incubated at two additional temperatures. One-ml subsamples were withdrawn at predetermined intervals over a 30-day period and assayed to determine the number of microorganisms remaining. Multiple regression analysis revealed that temperature was the only water characteristic significantly correlated with the decay rates of all three viruses. Bacteria did not have a consistent effect on the decay rate of the viruses. In addition, no significant differences were found among the decay rates of the three viruses, suggesting that MS-2 coliphage may be able to be used as a model of animal virus behavior in the environment.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/191091 |
| Date | January 1984 |
| Creators | Yates, Marylynn Villinski. |
| Contributors | Gerba, Charles P., Sinclair, Norval A., Brickler, Stanley K., Wilson, Lorne G., Kelley, Lee M. |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | English |
| Detected Language | English |
| Type | Dissertation-Reproduction (electronic), text |
| Rights | Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
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