Daily News Archive
From August 25, 2006
Nano-Herbicide in the Works
The research will focus on ways to attack a weed’s seed coating, which will prevent them from germinating. This approach will destroy the weed even when it is buried in soil and will prevent them from growing in even the most favorable conditions, say the researchers. The researchers believe this method is more preferable to tilling and manual picking because of the costs incurred with such high-maintenance methods. Due to the incredibly small proportions of nano-scale herbicides, they can easily blend with soil and attack seeds that are buried below the reach of tillers and conventional herbicides.
The researchers say this nanotech approach will reduce the need for convential herbicides, which many weed species have developed resistance to. Tilling as well can have the harmful effect of spreading weeds that will multiply through stem cuttings. However, this does not mean the new technology will be safe. A number of environmental groups, led by the Natural Resources Defense Council, sent comments to EPA on its voluntary nanotechnology program encouraging the agency to develop standards for reviewing nano-pesticides, which are currently unregulated and adverse effects unknown.
Experts say the properties that make engineered nanomaterials exciting for science also present unique regulatory challenges, huge potential impacts on human and environmental integrity, and fears of product liability and litigation. While such new nanotechnologies promise advances in human health and environmental clean-up, almost nothing is known about the risks these nano-sized chemicals may pose to exposed workers, consumers, and wildlife. Animal studies suggest that nanoparticles can trigger a variety of inflammatory and immune responses that would not be predicted by current toxicity models based solely on particle mass and composition. Early research also has highlighted the unique ability of tiny nanoparticles to move from one area of the body to another: from the lungs to the blood stream and beyond, from the GI tract to other organs, and from the nose via olfactory nerves into the brain. A nanoparticle may easily penetrate into a cell, while the bulk form of the same chemical may be unable to enter. When used as a therapeutic device, a nanoparticle may enter a cancerous cell to deliver a cancer-fighting drug, but when it contaminates food, drinking water, or consumer products, the same nanoparticle may also enter healthy cells to cause cancer or other adverse effects.
Just as the minute size of nanomaterials gives them unusual properties of strength and reactivity, environmentalists anticipate that this would give them unpredicted properties of toxicity. Scientists thus anticipate that many otherwise relatively inert and stable chemicals, such as carbon, might pose toxic risk in their nano-scale form. Many unknowns remain, especially regarding the long-term impacts of exposure and the possible effects of nano-engineered materials on the environment and ecosystems. It is also difficult to predict which of these new materials may bioaccumulate and persist in the environment because of their unique physiochemical characteristics that are largely unknown with respect to either environmental or physiological implications.
The combined nano-herbicide research programs between the Tamil Nadu Agricultural University in India and Monterry Tech in Mexico was announced in July of 2006 in a bid to share information and research in the fields of energy, environmental management and agricultural biotechnology. The nano-herbicide project is expected to last five years and has a budget of nearly $240,000.
For more information read the NGO nanotechnology comments to EPA.