New Studies Examine Nanoparticles in Food Chain
According to University of Kentucky researchers, manufactured nanoparticles discharged into waste streams could wind up in agricultural biosolids and thus enter the food chain. Jonathan D. Judy, et al., “Evidence for Biomagnification of Gold Nanoparticles within a Terrestrial Food Chain,” Environmental Science & Technology, December 2010. The study’s authors reportedly used gold nanoparticles to examine the uptake mechanism of tobacco plants and tobacco hookworms, finding that while both organisms absorbed nanoparticles, the hookworm exhibited concentrations 6 to 12 times higher than the plant. “We expected [nanoparticles] to accumulate, but not biomagnify like that,” said University of Kentucky environmental toxicologist Paul Bertsch in describing the process by which substances increase in concentration higher up the food chain.
Meanwhile, a second study has raised questions about how predatory microbes retain nanoparticles. R. Werlin, et al., “Biomagnification of cadmium selenide quantum dots in a simple experimental microbial food chain,” Nature Technology, December 2010. University of California, Santa Barbara, researchers have apparently discovered concentrated levels of cadmium selenide nanoparticles in predatory Tetrahymena thermophila protozoa, which feed on bacteria. “The observed biomagnification from bacterial prey is significant because bacteria are at the base of environmental food webs,” concludes the abstract. See Wired Science, January 5, 2011.
