 |
|
Research measures movement of nanomaterials in simple model food chain
June 02, 2008New research* shows that while engineered nanomaterials can be transferred up the lowest levels of the food chain from single celled organisms to higher multicelled ones, the amount transferred was relatively low and there was no evidence of the nanomaterials concentrating in the higher level organisms. The preliminary results observed by researchers from the National Institute of Standards and Technology (NIST) suggest that the particular nanomaterials studied may not accumulate in invertebrate food chains.
The same properties that make engineered nanoparticles attractive for numerous applications-biological and environmental stability, small size, solubility in aqueous solutions and lack of toxicity to whole organisms-also raise concerns about their long-term impact on the environment. NIST researchers wanted to determine if nanoparticles could be passed up a model food chain and if so, did the transfer lead to a significant amount of bioaccumulation (the increase in concentration of a substance in an organism over time) and biomagnification (the progressive buildup of a substance in a predator organism after ingesting contaminated prey).
In their study, the NIST team investigated the dietary accumulation, elimination and toxicity of two types of fluorescent quantum dots using a simple, laboratory-based food chain with two microscopic aquatic organisms-Tetrahymena pyriformis, a single-celled ciliate protozoan, and the rotifer Brachionus calyciflorus that preys on it. The process of a material crossing different levels of a food chain from prey to predator is called "trophic transfer."
Quantum dots are nanoparticles engineered to fluoresce strongly at specific wavelengths. They are being studied for a variety of uses including easily detectable tags for medical diagnostics and therapies. Their fluorescence was used to detect the presence of quantum dots in the two microorganisms.
The researchers found that both types of quantum dots were taken in readily by T. pyriformis and that they maintained their fluorescence even after the quantum dot-containing ciliates were ingested by the higher trophic level rotifers. This observation helped establish that the quantum dots were transferred across the food chain as intact nanoparticles and that dietary intake is one way that transfer can occur. The researchers noted that, "Some care should be taken, however, when extrapolating our laboratory-derived results to the natural environment."
"Our findings showed that although trophic transfer of quantum dots did take place in this simple food chain, they did not accumulate in the higher of the two organisms," says lead author David Holbrook. "While this suggests that quantum dots may not pose a significant risk of accumulating in aquatic invertebrate food chains in nature, additional research beyond simple laboratory experiments and a more exact means of quantifying transferred nanoparticles in environmental systems are needed to be certain."
###
* R.D. Holbrook, K.E. Murphy, J.B. Morrow and K.D. Cole. Trophic transfer of nanoparticles in a simplified invertebrate food chain. Nature Nanotechnology, June 2008 (advance online publication).
National Institute of Standards and Technology (NIST)
Quantum dots are nanoparticles engineered to fluoresce strongly at specific wavelengths. They are being studied for a variety of uses including easily detectable tags for medical diagnostics and therapies. Their fluorescence was used to detect the presence of quantum dots in the two microorganisms.
The researchers found that both types of quantum dots were taken in readily by T. pyriformis and that they maintained their fluorescence even after the quantum dot-containing ciliates were ingested by the higher trophic level rotifers. This observation helped establish that the quantum dots were transferred across the food chain as intact nanoparticles and that dietary intake is one way that transfer can occur. The researchers noted that, "Some care should be taken, however, when extrapolating our laboratory-derived results to the natural environment."
"Our findings showed that although trophic transfer of quantum dots did take place in this simple food chain, they did not accumulate in the higher of the two organisms," says lead author David Holbrook. "While this suggests that quantum dots may not pose a significant risk of accumulating in aquatic invertebrate food chains in nature, additional research beyond simple laboratory experiments and a more exact means of quantifying transferred nanoparticles in environmental systems are needed to be certain."
###
* R.D. Holbrook, K.E. Murphy, J.B. Morrow and K.D. Cole. Trophic transfer of nanoparticles in a simplified invertebrate food chain. Nature Nanotechnology, June 2008 (advance online publication).
National Institute of Standards and Technology (NIST)
Food Chain Current Events and Food Chain News RSSWarmer means windier on world's biggest lake
Rising water temperatures are kicking up more powerful winds on Lake Superior, with consequences for currents, biological cycles, pollution and more on the world's largest lake and its smaller brethren.
Pilot study relates phthalate exposure to less-masculine play by boys
A study of 145 preschool children reports, for the first time, that when the concentrations of two common phthalates in mothers' prenatal urine are elevated their sons are less likely to play with male-typical toys and games, such as trucks and play fighting.
Earth's early ocean cooled more than a billion years earlier than thought: Stanford study
The scalding-hot sea that supposedly covered the early Earth may in fact never have existed, according to a new study by Stanford University researchers who analyzed isotope ratios in 3.4 billion-year-old ocean floor rocks.
Skunk's Strategy Not Just Black and White
Predators with experience of skunks avoid them both because of their black-and-white coloration and their distinctive body shape, according to UC Davis wildlife researcher Jennifer Hunter.
Eutrophication affects diversity of algae
Eutrophication of the seas may have an impact on genetic variation in algae, research at the University of Gothenburg shows.
Los Angeles fast-food restaurant ban unlikely to cut obesity, study finds
Restrictions on fast-food chain restaurants in South Los Angeles are not addressing the main differences between neighborhood food environments and are unlikely to improve the diet of residents or reduce obesity, according to a new RAND Corporation study.
A new day dawned fast
In 1980, Luis Alvarez and his collaborators stunned the world with their discovery that an asteroid impact 65 million years ago probably killed off the dinosaurs and much of the the world's living organisms. But ever since, there has been an ongoing debate about how long it took for life to return to the devastated planet and for ecosystems to bounce back.
UT Knoxville and ORNL researchers reveal key to how bacteria clear mercury pollution
Mercury pollution is a persistent problem in the environment. Human activity has lead to increasingly large accumulations of the toxic chemical, especially in waterways, where fish and shellfish tend to act as sponges for the heavy metal.
Air pollutants from abroad a growing concern, says new report
Plumes of harmful air pollutants can be transported across oceans and continents -- from Asia to the United States and from the United States to Europe -- and have a negative impact on air quality far from their original sources, says a new report by the National Research Council.
UAB Research Team Working to Keep Terrapin Turtle Off Endangered Species List
University of Alabama at Birmingham (UAB) researchers exploring strategies for conserving the Diamondback Terrapin along Alabama's Dauphin Island coastline are working to keep the once-celebrated turtle off the endangered species list.
More Food Chain Current Events and Food Chain News Articles
 |
Who Eats What? Food Chains and Food Webs (Let's-Read-and-Find-Out Science, Stage 2) by Patricia Lauber (Author), Holly Keller (Illustrator) An award-winning author and artist explain how every link in a food chain is important because each living thing depends on others for survival. "Clear, simple drawings illustrate the clear, simple text. Informative and intriguing, this basic science book leads children to think about the complex and interdependent web of life on Earth."'BL. Outstanding Science Trade Books for Children 1996 (NSTA/CBC) |
 |
The Magic School Bus Gets Eaten: A Book About Food Chains by Pat Relf (Author), Carolyn Bracken (Illustrator) A class trip to the beach becomes an underwater lesson about food chains when Arnold and Keesha are challenged to discover what a tuna fish sandwich and some smelly green pond scum have in common. |
 |
Food Chain: Encounters Between Mates, Predators and Prey by Michael L. Sand (Editor), Catherine Chalmers (Editor), Gordon Grice (Editor) A fresh look at the laws of nature, in startling, beautiful, and at times unsettling detail. Working with a menagerie of insects and animals she raises in her New York City studio, Catherine Chalmers makes images that ask us to examine the lives we ordinarily overlook. What we find is by turns surprising, humorous, and thought provoking. In the series of photographs that gives the book its title, Chalmers vividly sketches the links between predator and prey, eater and eaten, from plant to insect to amphibian. Against a stark white background, caterpillars eat a tomato, a praying mantis eats a caterpillar, and a frog and a tarantula each eat a praying mantis. Another section, focused on "pinkies" (the pet-trade name for baby mice), shows with chilling clarity that the... |
 |
The Story Goes On by Aileen Fisher (Author), Mique Moriuchi (Illustrator) In this exquisitely illustrated picture book, one of America's foremost poets for young people describes the ongoing cycle of life. A seed sprouts and is quickly devoured by a bug. Then a bright green frog appears and makes a meal of the bug. And the story goes on...from bug to snake to hawk to hunter...until a seed begins to sprout. This wonderful poem deftly deals with a sensitive subject and is inventively illustrated by a prodigiously talented young artist. |
 |
Que Son Las Redes Y Cadenas Alimentarias? / What are Food Chains and Webs? (La Ciencia De Los Seres Vivos/Science of Living Things (Spanish)) (Spanish Edition) by Bobbie Kalman (Author), Jacqueline Langille (Author) This title is intended for ages 6-12. Text is in Spanish. Sunlight does not go very deep into water so seaweed must grow at the surface where its rays can reach them. Starting with the sun, food chains link together plants and animals in various ecosystems to help them survive. This book describes these connections in a clear manner that children will understand. Fascinating diagrams show children: the connection between herbivores, carnivores, scavengers, decomposers, and themselves; concepts such as energy pyramids, photosynthesis, and consumer hierarchies; and, an entertaining food web game. |
 |
Hungry Animals : My First Look at a Food Chain (My First Look at Nature) by Pamela Hickman (Author), Heather Collins (Illustrator) The My First Look At series provides young children with an introduction to the world around them. In Hungry Animals, kids follow the progression of a food chain, from a milkweed pod to a nest of hungry owlets. Colorful, detailed illustrations and fold-over flaps complement the easy-to-read text in this enchanting book. The book suggests ways in which parents and children can explore nature -- without disturbing it. |
 |
Food Chain Friends - Gamma Set by Pint Size Productions The Food Chain Friends are creatures from Daro, a small green planet much like Earth as it was 200 million years ago. Daro teems with wildlife, and its exceptionally social and gracious species flourish in a complex-but, oddly, very friendly-ecosystem. They're friends. They eat each other. They're the Food Chain Friends. It's a complicated relationship. |
 |
Buffy the Vampire Slayer Vol. 7: Food Chain by Doug Petrie (Author), Christopher Golden (Author), Jamie S. Rich (Author), Chynna Clugston-Major (Author), Tom Fassbender (Author), Jim Pascoe (Author), Christian Zanier (Author), Ryan Sook (Author), Jason Minor (Author), Cliff Richards (Author) The largest Buffy collection ever! Food Chain presents such landmarks in Buffy`s comics history as T.V. scribe Doug Petrie`s first comics story, Bad Dog, drawn by the notorious Ryan (The Spectre) Sook; Christian (Rising Stars) Zanier`s first two-part Buffy tale; and Chris Golden and Tom Sniegoski`s first Buffy collaboration, from the 1999 Buffy Annual. Also presented here is the unforgettable Double Cross, Doug Petrie`s epilogue to Buffy`s third season, dealing with the night Angel left Sunnydale once and for all. These stories span three years of Buffy`s history, taking us through the breakup with Angel, and into the college years. |
 |
Food Chains (Straightforward Science) by Peter D. Riley (Author) Introduces the basic science behind food chains and presents experiments to show how they work. |
 |
Forest Food Chains by Bobbie Kalman (Author) Ages 5 to 9 years. This informative book focuses on temperate forest food chains. It looks at the plants, herbivores, carnivores, and omnivores of this habitat and how they get food energy during the various seasons of the year. The book includes information on: forest herbivores, carnivores, and omnivores; how plants make food; animal adaptation in winter; decomposition and the forest floor; dangers to forest food chains and webs. |
| © 2009 BrightSurf.com |