Saturday, May 19, 2007
Smelly feet and the silver bullet
The acid mantle is a protective film and when intact keeps the body from bacterial invasion. Body odour is caused when surface bacteria corynebacterium and micrococcus, breakdown denatured proteins on the skin. Feet harbour billions of micro-organisms and produce over a cup of moisture per day and can provide an ideal breeding ground for odour-causing bacteria. Other chemicals in shoes may also cause body odour in the presence of sweat and perspiration. Eliminating bacteria causing smells is easy for most people by simply washing the skin in warm water (hand hot i.e. 46 degrees Centigrade) with household soap and regularly airing their shoes. Some people however are more prone to smelly feet than others and those folk find simple hygiene is not enough. Treatments for foot doors are varied but there are two main approaches. These involve either trying to stem the flow of sweat via chemicals or physical skin dehydration using charcoal filtered insoles. The second less successful approach is to use skin deodorants that mask the smell. Biotechnology has allowed new fibres to be developed which are then knitted into socks, this clever approach helps wick the skin perspiration and reduced the number of smell causing micro-organisms on the skin. For hundreds of years silver was used to combat infections but scientists were unable to bond silver permanently into thread until the last century. Silver is a soft, white lustrous transition metal with the highest electrical and thermal conductivity of any metal. Silver exhibits both antimicrobial (kills bugs) and anti-odour benefits. Silver has shown itself to be an effective antimicrobial agent. In the laboratory the presence of silver will eliminate 99.9% of bacteria in less than one hour of exposure. Silver’s antimicrobial action (kills bacteria and fungi) is enhanced in the presence of heat. As an anti-odour agent silver easily binds with ammonia compounds and denatured proteins found in the shoes which further reduces the risk of foot odour. For a couple of decades researchers have been trying to reduce peak temperatures inside shoes. This goal became critically important more recently with the Olympic Games in Athens and the FIFA World Cup played in warm and humid conditions. The development of footwear which contained silver elements was introduced to actively regulate temperature through heat transfer. Silver’s thermal conductivity facilitates quick and efficient moisture movement through evaporation. In warm weather, silver-lined footwear addresses evaporation by dissipating the amount of moisture in contact with feet. Now the semi precious metal is being used in the footwear industry for shoes, insoles and socks and some product manufacturers claim their silver products reduce the risk of skin blisters.