New research from NIST shows that while engineered nanomaterials can be transferred up the lowest levels of a food chain from single-cell organisms to higher multicelled ones, the amount transferred was relatively low and there was no evidence of the nanomaterials concentrating in the higher level organisms. The study investigated the dietary accumulation, elimination and toxicity of two types of fluorescent quantum dots using a simple, laboratory-based food chain with two microscopic aquatic organisms – Tetrahymena pyriformis and the rotifer Brachionus calyciflorus.
The researchers found that both types of quantum dots were taken in readily by T. pyriformis and that they maintained their fluorescence even after the quantum dot-containing ciliates were ingested by the higher trophic level rotifers. This observation helped establish that the quantum dots were transferred across the food chain as intact nanoparticles and that dietary intake is one way that transfer can occur. However, the study showed that while trophic transfer of quantum dots did take place in this simple food chain, they did not accumulate in the higher of the two organisms.
Keywords: Nanoparticles, Quantum dots, Trophic transfer, Bioaccumulation, Biomagnification
