(Beyond Pesticides, October 7, 2010) Nanotechnology has played an increasing role in the world of pesticides, particularly in the form of silver nanoparticles for their antibacterial properties; however, as this field grows, scientists and researchers are becoming increasingly concerned with the potential impacts of these particles on public health and the environment. A new study by scientists from Oregon State University (OSU) and the European Union (EU) highlights the major regulatory and educational issues that they believe should be considered before nanoparticles are used in pesticides. The study was published Monday in the International Journal of Occupational and Environmental Health.
â€śUnlike some other applications of nanotechnology, which are further along in development, applications for pesticides are in their infancy,â€ť said Dr. Stacey Harper, PhD, an assistant professor of nanotoxicology at Oregon State University. â€śThere are risks and a lot of uncertainties, however, so we need to understand exactly whatâ€™s going on, what a particular nanoparticle might do, and work to eliminate use of any that do pose dangers.
Some of the potential benefits of nanotechnology that scientists discuss in the report are that it may provide better control and delivery of active ingredients, less environmental drift, formulations that will most effectively reach the desired pest, and perhaps better protection for agricultural workers. â€śIf you could use less pesticide and still accomplish the same goal, thatâ€™s a concept worth pursuing,â€ť said Dr. Harper.
However, she adds that researchers need to be equally realistic about the dangers. Like many other new technologies, all of the big promises that nanotechnology has made still remain to be seen and there are still big unanswered questions about their potentially harmful effects on our health and the environment. OSU labs have tested more than 200 nanomaterials, and while they report that very few posed concern, some were found to be highly toxic.
There is much reason to be cautious, especially since a recent study found that nanosilver can interrupt important cell signaling within male reproductive sperm cells, causing them to stop growing. Previous studies have shown that the particles, which are between one and 100 nanometers in size and smaller than many viruses, can enter the environment through wastewater, where they can accumulate in biosolids at wastewater treatment plants. These biosolids, also known as sewage sludge, are often sold to consumers as fertilizer, despite the fact that they can contain toxic contaminants. Nanosized particles can also be released from impregnated materials via washing or or as a result of sweating, posing unknown adverse effects to humans and water systems.
Some of the concerns that researchers highlight include the potential need for new methodologies from traditional chemical tests in order to fully understand the effects of nano sized particles. They also call for full disclosure from manufacturers on exactly what nanoparticles are involved in their products and what their characteristics are. They also say that special assessments are needed for sensitive populations, such as infants, the elderly or fetal exposure to nanoparticles.
Another issue is to ensure that compounds are tested in the same way humans would be exposed in the real world. Dr. David Stone, PhD, an assistant professor in the OSU Department of Environmental and Molecular Toxicology explains: â€śYou canâ€™t use oral ingestion of a pesticide by a laboratory rat and assume that will tell you what happens when a human inhales the same substance. Exposure of the respiratory tract to nanoparticles is one of our key concerns, and we have to test compounds that way.â€ť
Researchers also say that future regulations need to acknowledge the additional level of uncertainty that will exist for nano-based pesticides with inadequate data and want tests to be done using the commercial form of the pesticides and a health surveillance program as well as other public educational programs should be developed. They conclude that there needs to be a â€ścoordinated effort between governmental, industry, academic and public entities to effectively deal with a revolutionary class of novel pesticides.â€ť
Back in 2007 a broad international coalition of 40 consumer, public health, environmental, and labor organizations, including Beyond Pesticides, released the Principles for the Oversight of Nanotechnologies and Nanomaterials, calling for strong, comprehensive oversight of the new technology and its products. Beyond Pesticides has since advocated for a precautionary course of action in order to prevent unnecessary risks to the public, workers and the environment.
Earlier this year, Canada joined several other countries that have either banned or proposed a ban on nanotechnology in organic recognizing the potential risks that have yet to be addressed. These countries include the United Kingdomâ€™s Soil Association, Biological Farmers of Australia, and Austrian organic certifier Austria Bio Garantie. In the U.S., the National Organic Standards Board (NOSB) heard testimony on the development of a definition and policy on nanotechnology in organic standards earlier this year and the US-based Organic Crop Improvement Association has added a clause in their organic standard to regulate the use of nanotechnology.
Source: Oregon State University