Biological accumulation of engineered nanomaterials: a review of current knowledge

Abstract

Due to the widespread use of engineered nanomaterials (ENMs) in consumer and industrial products, concerns have been raised over their impacts once released into the ecosystems. While there has been a wealth of studies on the short-term acute toxic effects of ENMs over the past decade, work on the chronic endpoints, such as biological accumulation, has just begun to increase in last 2–3 years. Here, we comprehensively review over 65 papers on the biological accumulation of ENMs under a range of ecologically relevant exposure conditions in water, soil or sediment with the focus on quantitative comparison among these existing studies. We found that daphnid, fish, and earthworm are the most commonly studied ecological receptors. Current evidence suggests that ENM accumulation level is generally low in fish and earthworms with logarithmic bioconcentration concentration factor and biota-sediment accumulation factor ranging from 0.85–3.43 (L kg−1) and −2.21–0.4 (kg kg−1), respectively. ENMs accumulated in organisms at the lower trophic level can transfer to higher trophic level animals with the occurrence of biomagnification varying depending on the specific food chain studied. We conclude the review by identifying the challenges and knowledge gaps and propose paths forward.

Differential Growth of and Nanoscale TiO 2 Accumulation in Tetrahymena thermophila by Direct Feeding versus Trophic Transfer from Pseudomonas aeruginosa

“…This consideration would not have been predicted by the lack of observed toxicity to individual cells. The potential for nanomaterial uptake into organisms and enhanced transfer of nanomaterials in food chains, i.e., bioaccumulation and biomagnification, is also of interest in the ecotoxicology of nanomaterials (15,36). In a prior study, Cd associated with CdSe QDs was biomagnified during trophic transfer from P. aeruginosa to T. thermophila (15), suggesting that bacteria with their bioconcentrated nanomaterials could initiate biomagnification at the base of food webs.…”

Antibacterial activity of silver nanoparticles: A surface science insight

“…Most notably, this study showed also that the surface of macroscopic silver object (such as cutlery or jewellery) could also dissolve and lead to the formation of nanoparticle, contributing to their antibacterial action. Dissolution/reformation of Ag NPs was also observed in presence of humic acid, and may be a phenomenon relevant in environmental conditions [86,87].…”

“…In addition, seasonal variations can cause temperature shift, and oxygen profile in freshwater can vary temporally and spatially [128]. (iii) Environmental systems contain living organisms that can play a role in the distribution and speciation of silver species [87,112]. As such, beyond physical chemistry, a study of the fate of Ag NPs in environmental conditions requires to consider several aspects related to other disciplines, such as hydrology and organisms biology.…”

“…Beyond the adverse effects this could have for the organisms, it impacts the speciation or distribution of silver in the environment in complex ways, and notably as silver species can enter the trophic chains and be spread among a wide variety of organisms [87]. In particular, most micro-organisms (bacteria, micro-algae and fungi) produce extracellular polymeric substances (EPS) [138].…”

纳米材料与农作物之间的相互作用: 食品安全与启示

“…No biomagnification was observed in the above aquatic studies, with bioaccumulation factors (BAFs) ranging from 0.004-0.04 (Hou et al, 2013). However, research more related to agricultural systems points to the possibility of trophic transfer and biomagnification et al, 2010) through the food chain.…”