"We continue to learn more about how past agricultural practices are affecting our current environment," says Carl Renshaw, Associate Professor of Earth Sciences at Dartmouth. "Unlike some of the pesticides used today, metals like arsenic and lead in old pesticides do not degrade over time. So the question becomes, where do they end up? As we learn more about what happens to these metals since they were applied, we can make better decisions about how to use our land."
Renshaw and his colleagues studied two New Hampshire apple orchards where the pesticide lead arsenate was once used, and they compared the data to a nearby uncontaminated field. Their research was published in the January-February issue of the Journal of Environmental Quality.
The researchers confirmed earlier findings that, in the former orchards, most of the arsenic and lead remains in the top ten inches of soil. The new study goes further and shows that these toxic metals do not remain in their original mineral form. Instead, they are now part of the fine silt and organic matter in the soil, which is most susceptible to erosion.
"We learned that disturbing this land, for example tilling and replanting, mobilizes the arsenic and lead," says Renshaw. "The remobilized metals were found in sediments in a stream channel that drains the tilled orchard."
Renshaw explains that it’s unclear whether the metals in the sediment are taken up by plants and animals in the stream. The researchers tested the macroinvertebrate residents (midge flies and dragonflies) at the outlet of the contaminated stream, and found that, as of yet, there is no disparity in the levels of arsenic or lead.
"Historic farmlands in New Hampshire and elsewhere are increasingly being developed," says Renshaw. "While the arsenic and lead in the soils of old orchards is essentially immobile as long as the land is not disturbed, our work suggests that the development of these lands can inadvertently mobilize these metals toward bodies of water. Communities in these areas may want to ensure additional precautions are taken to control erosion when old orchard lands are disturbed in order to reduce the potential for contamination of nearby surface waters."
Sue Knapp | EurekAlert!
Raiding the rape field
23.05.2018 | Julius-Maximilians-Universität Würzburg
New technique reveals details of forest fire recovery
17.05.2018 | DOE/Brookhaven National Laboratory
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
23.05.2018 | Life Sciences
23.05.2018 | Life Sciences
23.05.2018 | Physics and Astronomy