Backcountry water quality tests are good news for campers
Sierra Nevada waters usually free of troublesome bacteria except in high use areas
Data collected by experts from the UC Davis School of Medicine have revealed that except for some heavily used areas, streams and lakes in the high country of the Sierra Nevada are generally clean and fresh.
The good news for campers can be found in a pair of studies published in the latest issue of the quarterly medical journal Wilderness and Environmental Medicine. UC Davis physician Robert Derlet and pathology researcher James Carlson present data gathered from nearly 100 locations throughout the Sierra Nevada during the summer of 2003, including Yosemite, Sequoia and Kings Canyon national parks. Their goal was to analyze wilderness water quality for the presence of harmful bacteria such as E. coli, which is typically an indicator of contamination from human or animal waste.
Running counter to popular belief, the two researchers downplay the risk of picking up Giardia in backcountry drinking water. In the Sierra Nevada, E. coli and other pathogenic bacteria may pose a greater risk than Giardia for causing waterborne illnesses in people.
"Whats impressive is that more than half of our water sampling sites had no water quality problems whatsoever," said Derlet, a professor of emergency medicine at the UC Davis School of Medicine and an avid backpacker with 30 years of experience hiking in Californias high Sierra. "People still should use water filters or purification techniques like boiling drinking water in the backcountry. But our findings also are an indication of the outstanding job done by National Park Service in its wilderness management."
Derlet has spent the past five years on water quality studies in the Sierra Nevada. From his recent sampling sites, only 17 had levels high enough to be directly linked to recreational use or the presence of livestock.
"For these two studies, we looked at nearly100 streams and lakes over the 400-mile long mountain range," observed Derlet, who has given presentations to wilderness rangers about infectious diseases and backcountry medicine."Weve also analyzed water at many more Sierra Nevada lakes and streams this past summer with consistent results. Its not surprising that waterways below roads, popular trails and well-used cattle grazing areas often show the presence of harmful bacteria. However, it will probably take a number of years and some sustained funding to pinpoint the exact causes."
The UC Davis physician says his studies are only a snapshot in time, and that all streams and lakes tested in wilderness areas typically contain a certain amount of naturally occurring aquatic bacteria. Low levels of coliform bacteria actually can be part of the natural environment. If bacteria were not present in the water, it would jeopardize the balance of the aquatic ecosystem, including everything from frogs to fish.
Currently working with renowned Lake Tahoe expert and UC Davis professor Charles Goldman, Derlet has several other water quality findings in the Sierra that he also hopes to research:
- Lakes are typically cleaner than creeks, possibly because the ultraviolet rays of sunlight work better at killing off bacteria in calm waters of a lake than in the tumbling flows of a stream;
- Algae growth in backcountry waterways appears to be getting worse;
- Bacteria readings appear higher at the beginning of spring runoff rather than later in the summer when water levels are lower and water quality is thought to be poorer;
- Valley air pollution could be contributing to water quality problems in the Sierra Nevada.
Carole Gan | EurekAlert!
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
Nano-hologram paves way for integration of 3-D holography into everyday electronics
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...