28
Sep
Experts Warn of Nano Resistance, Call for Oversight
(Beyond Pesticides, September 28, 2011) Overuse of antibacterial agents contributes to promoting the development of more powerful bacteria that are resistant to treatment. This, according to a new report released by Friends of the Earth in which leading microbiologists warn that the rapid rise in household antibacterial products containing nanosilver could put public health at risk. The report emphasizes that as the numbers of deaths caused by bacterial resistance to antimicrobials and antibiotics in hospitals continues to rise, as well as increasing allergy incidents, the need to regulatory oversight is urgently needed. 
Dozens of socks, shoe inserts, sports clothing and towels now marketed as ”˜antibacterial’ or ”˜odor controlling’ use nanoparticles of silver to kill the bacteria that cause odor. Since nanosilver can be manufactured as spheres, particles, rods, cubes, wires, film and coatings, it can be embedded into a range of substrates, such as metals, ceramics, polymers, glass and textiles leading to its widespread commercialization. To see a listing of products that contain nanosilver see here. In interviews for this report, entitled, “Nano-silver: Policy Failures Put Public Health at Risk,” published by Friends of the Earth, medical experts warn that using such a powerful antimicrobial in these everyday products is not only unnecessary, but dangerous. Microbiologists from various parts of the world told Friends of the Earth that overuse of nanosilver in consumer products could breed bacterial resistance, undermining its use in hospitals.
According to this report, the overuse of nanosilver can promote resistance. The experts believe that widespread use of nanosilver could promote further resistance to antibiotics and other drugs. Kristen Kulinowski, PhD, a Faculty Fellow in the Department of Chemistry at Rice University and Director for External Affairs for the Center for Biological and Environmental Nanotechnology (CBEN), and currently serving as the Director of the International Council on Nanotechnology (ICON), states: “I think the value to society of the use of nano-silver in a clinical setting is greater than the value to society of its use in a consumer product where there’s no potential health benefit.” The scientists interviewed agree that regulators need to halt the excessive and unnecessary use of powerful antibacterials in everyday products. This is necessary to maintain the effectiveness of antimicrobials and antibiotics for clinical use and to counteract the allergy epidemic.
While the science often has conflicting reports on whether bacteria can develop resistance to silver, it is important to know that nanosilver, because of its size (1-300 nanometers), has the ability to cross many biological barriers at the cellular level, including the blood-brain barrier in animals. This ability to access biological cells in such a way increases the biological and chemical reactivity of nanosilver and can also give rise to novel mechanisms for bacterial resistance.
In addition to bacterial resistance, concern was expressed in the report about the increase in allergic diseases and asthma, as explained by the “Hygiene Hypothesis.” This hypothesis attributes the rise in allergies to the increase in clean, sterile living environments and subsequent decrease in exposure to infectious agents. Nobel laureate Professor Peter Doherty, PhD, also interviewed for the report, agrees that childhood interactions with bacteria are essential to develop strong immune systems in children.
The report also highlights the case of triclosan and possible resistance and cross-resistance issues surrounding its widespread use as an antibacterial agent. Similarly, triclosan has also been linked via the hygiene hypothesis to increased allergies. A 2011 study found that people age 18 and under with higher levels of triclosan in their urine were significantly more likely to report diagnosis of allergies and hay fever. Triclosan, also used in a wide range of consumer products from toothpaste to socks, has been linked to endocrine disruption, adverse fetal development, as well as potential bacterial resistance and cross-resistance to antibiotics. Both nanosilver and triclosan also pose serious environmental fate issues including the destruction native algal populations, accumulation in fish and persistent water contamination. For more on triclosan and Beyond Pesticides’ grassroots campaign to ban triclosan, visit the triclosan program page. Pledge to go triclosan-free today!
Recently, the U.S. Environmental Protection Agency (EPA) announced plans to obtain information on nanoscale materials in pesticide products, while the Food and Drug Administration (FDA) released draft guidelines to industries about when the use of nanomaterials might trigger regulatory interest. Earlier this year, the California’s Department of Toxic Substances Control (DTSC) asked in-state nanotechnology companies and researchers to share how they are keeping tabs on several nano-sized metals, as evidence continues to emerge that these substances may have long-term implications for the environment. Last year, the National Organic Standards Board (NOSB) passed a recommendation directing the USDA National Organic Program (NOP) to prohibit engineered nanomaterials, 1-300 nanometers, from certified organic products as expeditiously as possible. In 2008, the International Center for Technology Assessment (CTA) and a coalition of consumer, health, and environmental groups, including Beyond Pesticides, filed a legal petition with EPA, demanding the agency use its pesticide regulation authority to stop the sale of 250+ consumer products now using nanosilver. EPA agreed that the petition “raises serious issues that potentially affect private and public sector stakeholders.” For more on nanosilver, visit the nanosilver page.
Source: Friends of the Earth
Deborah pisano
September 29th, 2011 at 2:50 am