Researchers:
Maya Al-Sid-Cheikh, Steven J. Rowland, Karen Stevenson, Claude Rouleau, Theodore B. Henry, Richard C. Thompson
Abstract:
Previous studies of uptake and effects of nanoplastics by marine organisms have been conducted at what may be unrealistically high concentrations. This is a consequence of the analytical challenges in tracking plastic particles in organisms at environmentally relevant concentrations and highlights the need for new approaches. Here, we present pulse exposures of ¹⁴C-radiolabeled nanopolystyrene to a commercially important mollusk, Pecten maximus, at what have been predicted to be environmentally relevant concentrations (<15 µg L⁻¹). Uptake was rapid and was greater for 24 nm than for 250 nm particles. After 6 h, autoradiography showed accumulation of 250 nm nanoplastics in the intestine, while 24 nm particles were dispersed throughout the whole-body, possibly indicating some translocation across epithelial membranes. However, depuration was also relatively rapid for both sizes; 24 nm particles were no longer detectable after 14 d, although some 250 nm particles were still detectable after 48 d. Particle size thus apparently influenced the biokinetics and suggests a need for chronic exposure studies. Modelling extrapolations indicated that it could take 300 d of continued environmental exposure for uptake to reach equilibrium in scallop body tissues although the concentrations would still below 2.7 mg g⁻¹. Comparison with previous work in which scallops were exposed to non-plastic (silver) nanomaterials of similar size (20 nm), suggests that nanoparticle composition may also influence the uptake tissue distributions somewhat.
Citation:
Al-Sid-Cheikh M, Rowland SJ, Stevenson K, Rouleau C, Henry TB, Thompson RC. 2018. Uptake, whole-body distribution, and depuration of nanoplastics by the scallop Pecten maximus at environmentally realistic concentrations. Environmental Science & Technology 52:14480-14486.
