Scientists are calling for a closer examination of the environmental and health implications of nanoparticle silver, which is used for its antibacterial and odour-fighting properties in a range of products including clothing.

The researchers from Arizona State University report that ordinary laundering can wash off substantial amounts of the nanosilver particles from socks impregnated with the material.

And they suggest the particles, intended to prevent foot odor, could travel through a wastewater treatment system and enter natural waterways where they might have unwanted effects on aquatic organisms living in the water and possibly humans too.

"The general public needs to be aware that there are unknown risks associated with the products they buy containing nanomaterials," researchers Paul Westerhoff and Troy M. Benn said.

Their findings were detailed at a meeting of the American Chemical Society (ACS), and are believed to be the first time that anyone has looked at the release of silver from this type of manufactured clothing product.

Silver has been used historically since ancient roman times, though its nanoparticle form has only recently appeared in consumer products.

Beyond socks, nanosilver appears in certain bandages, athletic wear and cleaning products.

The researchers suggest that improved product labeling could help, with clothing labels carrying a list of "ingredients" like nanosilver.