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 Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.

nachricht 100 % Organic Farming in Bhutan – a Realistic Target?
15.06.2018 | Humboldt-Universität zu Berlin

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: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>