Ever since Prince Charles' infamous "grey goo" speech, there have been concerns about the safety of nanoparticles in the environment. Adding fuel to the fire, last week researchers in Edinburgh published results in the journal Nature Nanotechnology showing that carbon nanotubes of a certain length could cause damage and inflammation in the lungs, similar to the effects of asbestos.
But all nanoparticles are not the same. Writing in the same journal, scientists from the US National Institute of Standards and Technology studied whether fluorescent nanoparticles, called quantum dots, could build up in a food chain. Quantum dots are being studied for their use in a number of potentially useful application, including medical diagnostic techniques and treatments. This is important information to find out, as pollutants tend to get concentrated as you go up the food chain, and can poison larger predators.
The scientists used a simple food chain of just two aquatic organisms - a predator species and its single-celled prey. The team found that although the prey species took up the quantum dots, and they were passed onto the predators when they ate them, the amount transferred was relatively low, and the dots didn't appear to build up in the predators.
The researchers stress that these are just early results, and shouldn't be extrapolated too much. But it's a promising sign that at least some types of nanoparticles might not be the noxious nightmare that Prince Charles would have us believe.