Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

More Swimmers Means More Pathogens in the Water

04.07.2007
Researchers Recommend Water-Quality Testing Be Conducted at Busiest Times

The levels of potentially harmful waterborne microorganisms in rivers, lakes and other recreational waterways may be highest when the water is most crowded with swimmers. Researchers at the Johns Hopkins Bloomberg School of Public Health completed two studies at the Hammerman beach area along Maryland’s Gunpowder River that linked the number of swimmers using the water with the levels of microsporidian spores and the parasites Cryptosporidium parvum and Giardia lamblia. The studies were made available online in advance of publication in the scientific journals Applied and Environmental Microbiology and Water Research.

Exposure to microorganisms like C. parvum and G. lamblia can cause nausea, vomiting and diarrhea. They can be particularly harmful to people with compromised immunity.

“Our research suggests it would be best to test the water when the beach is active to determine if it is safe for recreational use,” said Thaddeus K. Graczyk, PhD, co-author of both studies and associate professor with the Bloomberg School’s Department of Environmental Health Sciences and Center for Water and Health. According to Graczyk, health officials typically conduct water sampling when there is little human activity.

For both studies, researchers sampled the water at the Hammerman area for 11 weeks during the summer of 2006. Samples were taken on Wednesdays, when beach activity was typically low, and on Saturdays, when activity was usually high. The researchers also counted the number of swimmers in the water at the time the water was sampled.

The concentration of microsporidian spores, C. parvum and G. lamblia were highest during the weekends, when the beach was busiest. Water turbidity was also highest on the weekends. The findings indicate that the swimmers stir up pathogens resting in the sediment.

The Environmental Protection Agency does not require testing for microsporidian spores, C. parvum or G. lamblia in recreational waters, because of the cost and difficulty in measuring these pathogens. Regulations do require that water be tested for E. coli and enterococci as bacterial indicators of fecal contamination.

“Monitoring for E. coli and enterococci may not be reliable in monitoring for waterborne protozoan pathogens,” said Graczyk.

“A quantitative evaluation of the impact of bather density on levels of human-virulent microsporidian spores in recreational water” was written by Thaddeus K. Graczyk, Deirdre Sunderland, Leena Tamanga, Timothy M. Shields, Frances E. Lucy and Patrick Breysse. It is published in Applied and Environmental Microbiology.

“Impact of bathers on levels of Cryptosporidium parvum oocysts and Giardia lamblia cysts in recreational beach waters” was written by Deirdre Sunderland, Thaddeus K. Graczyk, Leena Tamanga and Patrick Breysse. It is published Water Research.

All authors are with the Johns Hopkins Bloomberg School of Public Health, except Lucy, who is with the School of Science Institute of Technology in Sligo, Ireland.

Funding for the research was provided by the Fulbright Senior Specialist Fellowship, Johns Hopkins NIEHS Center for Urban Environmental Health, Johns Hopkins Faculty Research Innovation Fund, Johns Hopkins Center for a Livable Future and the University of the District of Columbia.

Public Affairs media contacts for the Johns Hopkins Bloomberg School of Public Health: Tim Parsons or Kenna Lowe at 410-955-6878 or paffairs@jhsph.edu.

Tim Parsons | EurekAlert!
Further information:
http://www.jhsph.edu

More articles from Ecology, The Environment and Conservation:

nachricht Global threat to primates concerns us all
19.01.2017 | Deutsches Primatenzentrum GmbH - Leibniz-Institut für Primatenforschung

nachricht Reducing household waste with less energy
18.01.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New technology for mass-production of complex molded composite components

23.01.2017 | Process Engineering

Quantum optical sensor for the first time tested in space – with a laser system from Berlin

23.01.2017 | Physics and Astronomy

The interactome of infected neural cells reveals new therapeutic targets for Zika

23.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>