By David Liu, PHD

Thursday July 11, 2012 (foodconsumer.org) -- Nanoparticles like titanium dioxide, silicon dioxide, zinc oxide and iron oxide are commonly used in processed food, dietary supplements and personal care products or cosmetics.  The nanoscaled particles can damage cells including DNA leading to mutations and cancer development, according to previous studies.

A new study released in the Sept 2011 issue of Mycobiology suggests silver nanoparticles may be used in crops like pepper to fight disease. The problem is that nanoparticles can be picked up by the plants and after man eats the plant, nanoparticles will find their way to many organs in our bodies.

K. Lampsal pf Kangwon National University in Korea did not address the safety of silver nanoparticles.  But they found the nanoparticles may be used to replace commercial fungicides to fight pepper anthracnose under different culture conditions.

"The application of 100 ppm concentration of silver nanoparticles produced maximum inhibition of the growth of fungal hyphae as well as conidial germination in comparison to the control in vitro," the researchers wrote.

From field studies, the researchers found the inhibition of fungal growth was significantly high when silver nanoparticles were applied prior to disease outbreak on the plants.

The toxic effect of silver nanoparticles was realized by causing a detrimental effect on mycelial growth of colletotrichun species, the researchers reported.

Toxic to fungi, it can be toxic to humans as well.   Although any negative effect has yet to be found associated with this application of silver nanoparticles, it has been known that nanoparticles are toxic to animals and humans.  Some have been known as possible human carcinogens (cancer-causing agents).