Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Using live fish, new tool a sentinel for environmental contamination

18.08.2008
Researchers have harnessed the sensitivity of days-old fish embryos to create a tool capable of detecting a range of harmful chemicals.

By measuring rates of oxygen use in developing fish, which are sensitive to contaminants and stressful conditions, the technology could reveal the presence of minute levels of toxic substances before they cause more obvious and substantial harm.

It could be used as an early warning system against environmental contamination or even biological weapons, said Purdue University researcher Marshall Porterfield, an associate professor of agricultural and biological engineering.

Respiration, the process wherein animals and other organisms burn oxygen to produce energy, is often the first of a fish's bodily functions affected by contaminants. The technology uses fiber optics to quickly monitor this activity and produce results within minutes, Porterfield said.

"Say you are exposed to the common cold virus," he said. "Before symptoms develop and you become aware of the bug's presence, it has already begun to attack your cells. Similarly, fish and other organisms are affected by contaminants before behavioral changes appear. Our technology detects heretofore undetectable changes to act as an early warning system."

In a study published online last week in the journal Environmental Science and Technology, the system detected the presence of several common pollutants such as the widely-used herbicide atrazine – even at levels near or below those that the U.S. Environmental Protection Agency deems acceptable for drinking water.

"This means the technology could not only help monitor environmental quality but may be used to enforce important water quality standards," said Marisol Sepulveda, lead author and assistant professor of forestry and natural resources at Purdue.

Testing also registered noticeable changes in the respiratory activity of fish embryos when the heavy metal cadmium was present at levels 60 times lower than the EPA limit, she said.

Throughout the study, contaminants did not destroy the eggs of laboratory-raised fathead minnows, a commonly studied fish species. This further demonstrates the tool's ability to discern subtle changes before they become fatal, Sepulveda said.

In the laboratory, researchers first manually positioned a tiny optical electrode, or optrode just outside individual embryos of two-day-old fathead minnows. At 1.5 millimeters in diameter, they were slightly smaller than the head of a pin, said primary author and Purdue doctoral student Brian Sanchez.

A fluorescent substance coated the electrode tip, its optical properties varying predictably with oxygen concentration. This allowed researchers to take quick measurements at locations only micrometers apart, moving the electrode via a computer-driven motor, Sanchez said. These readings then allowed researchers to calculate respiration rates within the eggs, he said.

Using a self-referencing technique Porterfield developed over the last decade, he and the team measured each egg with and without contaminants present. This allowed each embryo to serve as its own control, he said, providing more reliable results.

Porterfield said the technology could be used on other organisms. Study co-author and Purdue researcher Hugo Ochoa-Acuña has begun adjusting it to work with a type of crustacean.

A prototype could be ready to test in the field in four years if improvements continue, said Porterfield, a corresponding author. The technology currently tests immobilized eggs in a laboratory setting but there are plans to make the tool more versatile.

Porterfield also said he thinks the technology could have diverse uses. He imagines it could be conjugated with tumor cells to screen potential cancer drugs or help find new therapeutic targets.

During the study the technology detected four of five common pollutants tested, all known to act upon organisms in different ways: atrazine, cadmium, pentachlorophenol – an antifungal – and cyanide. It didn't register low levels of the insecticide malathion, possibly because fathead minnow embryos require more time to elapse for effects to become evident, Sanchez said.

Toxins can slow respiration by directly impeding it or they may stress the organism and cause it to burn more oxygen to provide energy for fighting the stressor, he said.

The most widely-used analogous technology monitors gill movements and other activities of bluegill fish with electrodes secured to the fish's bodies, Sepulveda said. The Purdue system could be advantageous as it records respiration in a sensitive life-stage and the optical equipment doesn't consume oxygen or require the same degree of calibration, Porterfield said.

The study, funded by Purdue's Center for the Environment and the U.S. Department of Education, was different from Sanchez's other research, which is primarily focused upon finding genes and proteins to serve as biomarkers for contaminant exposure in fish.

"This study was all the more exciting to be a part of due to its potential applications in protecting human health," he said.

Writer: Douglas M. Main, (765) 496-2050, dmain@purdue.edu
Sources: Marshall Porterfield, (765) 494-1190, porterf@purdue.edu
Marisol Sepúlveda, (765) 496-3428, mssepulv@purdue.edu
Brian Sanchez, (765) 494-9591, bcsanche@purdue.edu

Douglas M. Main | EurekAlert!
Further information:
http://www.purdue.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: 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...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

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 Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>