Tiny zebras at your serviceFebruary 03, 2004Before new pesticides can be approved, their environmental impact must be assessed. Due to the complexity of ecological systems, researchers require simple yet representative laboratory models. Among vertebrates, schools of zebra fish are especially suitable. --- Studying the ways substances affect living organisms in their environment is the job of the ecotoxicologist. Particularly with deliberately produced toxic substances such as pesticides, the practical aim of these scientists is developing standardized test procedures that are easy to run, yet capable of providing clear results. Such tests form the basis for developing manufacturer regulations and user information. For pesticides used in or near bodies of water, fish toxicity must be assessed. One aspect that has increasingly gained importance over the past few years relates more to subtle endocrine effects than acute toxicity. Some pesticides are suspected of interfering with vertebrate hormone systems. This can negatively affect the reproductive capacity of fish, disrupting egg development and upsetting the ratio of adult males to females. One species of fish frequently used as a model organism is the zebra fish (Danio rerio). A favorite of aquarium owners, this small, hardy fish is easy to maintain and breeds rapidly. This makes it possible to observe the impact of substances over several generations. Researchers at the Fraunhofer Institute for Molecular Biology and Applied Ecology IME are investigating the effect of new pesticides on the vital parameters of these animals, under realistic exposure conditions. "Our aquariums have artificial sediment beds," emphasizes Dr. Christoph Sch'¤fers, IME department manager. "This is because, in the case of pesticides, we need to know the long-term consequences of short periods of peak exposure. In other words, how quickly are these substances released from the sediment and ingested by the fish? We can observe this by using pesticides that are radioactively marked." These tests provide essential information for protecting natural fish resources, for the fishing industry and finally for human health as well. The IME studies reveal a clearer picture of the potential impact of pesticides than other commonly used methods. The results are much more meaningful because three life stages are examined - egg, larva and mature adult. A reliable indication can be given of the concentration below which a pesticide has no discernable effect. To date, the IME has conducted studies on behalf of several of the world's leading pesticide manufacturers, representing a total contract volume of EUR 700,000. The IME's studies of endocrine effects and on the capacity of sediment to store and release pesticides enjoy high international esteem. | |||||||||||||||||||||
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Related Pesticide Current Events and Pesticide News Articles Persistent pollutant may promote obesity Tributyltin, a ubiquitous pollutant that has a potent effect on gene activity, could be promoting obesity, according to an article in the December issue of BioScience. Pitt Research Finds That Low Concentrations of Pesticides Can Become Toxic Mixture Ten of the world's most popular pesticides can decimate amphibian populations when mixed together even if the concentration of the individual chemicals are within limits considered safe. Pesticide Concentrations Decreasing The widespread use of pesticides across the United States has been in practice for decades, with little knowledge of the long-term effects on the nation's groundwater. Scientists simulate gut reaction to arsenic exposure A simulated gastrointestinal system is helping scientists test contaminated soil for its potential to harm humans. The method is likely to save time and money for people hoping to repurpose land with an industrial past. Common insecticide can decimate tadpole populations The latest findings of a University of Pittsburgh-based project to determine the environmental impact of routine pesticide use suggests that malathion--the most popular insecticide in the United States--can decimate tadpole populations by altering their food chain, according to research published in the Oct. 1 edition of Ecological Applications. Nanoscale silver: No silver lining? Widespread use of nanoscale silver will challenge regulatory agencies to balance important potential benefits against the possibility of significant environmental risk, highlighting the need to identify research priorities concerning this emerging technology, according to a new report released today by the Project on Emerging Nanotechnologies (PEN). Pesticide build-up could lead to poor honey bee health Honey bees industriously bring pollen and nectar to the hive, but along with the bounty comes a wide variety of pesticides, according to Penn State researchers. Rising energy, food prices major threats to wetlands as farmers eye new areas for crops Critical food shortages and growing demand for bio-fuels and hydro-electricity due to high fossil fuel prices rank among the greatest threats today to the preservation of precious wetlands worldwide as farmers and developers look for new areas for agriculture, energy crop plantations and hydro dams. Why eating less can help the environment An estimated 19 percent of total energy used in the USA is taken up in the production and supply of food. Currently, this mostly comes from non-renewable energy sources which are in short supply. Nanotech: A regulatory blueprint for the next administration Nanotechnology will significantly change virtually every facet of the way we live. The next president has the opportunity to shape these changes and to ensure that nanotechnology's benefits will be maximized and its risks identified and controlled. More Pesticide Current Events and Pesticide News Articles |
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