Don't the nanos smell? And how do they affect nature?
Recently, silver nanoparticles with antibacterial properties have been used in the production of a whole range of goods, ranging from socks and bandages to washing machines. However, despite the growing popularity of such products, experts recommend conducting a detailed analysis of the unintended impact of silver nanoparticles on the environment and human health.
Arizona State University scientists Paul Westerhoff and Troy M. Benn claim that regular washing washes out a significant amount of silver nanoparticles from "antimicrobial" socks. They suggest that after washing socks, these nanoparticles can enter natural reservoirs through the wastewater treatment system and have an adverse effect on aquatic ecosystems, and possibly on humans.
The authors conducted a very simple experiment: they purchased 6 pairs of antibacterial socks containing silver nanoparticles from various manufacturers. Socks were soaked in distilled water at room temperature and containers with socks were swung for an hour, simulating the operation of a washing machine. At the end of the procedure, the water was tested for the content of two types of silver: toxic ionized form and less studied nanoparticles.
It turned out that different socks release silver nanoparticles at different rates, which suggests fundamental differences in the production processes of nanosilver-enriched fabrics. Some types of fabrics release all the silver in the first few washes, while others get rid of the nanoparticles gradually. Some types of material do not release silver at all (the authors of the work checked the presence of nanoparticles in them or limited themselves to the manufacturers' statement that their socks are "nanosilver", not mentioned in the brief message). The authors plan to announce the names of the tested brands of socks at the 235th Annual Congress of the American Chemical Society.
The ingress of a significant amount of nanosilver into natural waters can harm aquatic ecosystems, because in natural conditions it can transform into an ionized soluble form of metal, which disrupts chemical processes important for the vital activity of aquatic microorganisms.
The purpose of the scientists' work was not to identify the toxicity of silver, which a person has been using since ancient times, including for disinfection of water. They hope to draw attention to the problem of studying the effects of nanomaterials on the environment and human health, as well as to the issue of raising people's awareness of the role of nanotechnology in the production of consumer goods.
The authors plan to conduct similar experiments with other materials containing nanoparticles. They hope to identify the moment in the life of each product when nanoparticles are released into the environment, as well as to develop more effective methods for detecting nanoparticles in water and air samples.
Portal "Eternal youth" www.vechnayamolodost.ru based on ScienceDaily materials
10.04.2008