Banta, Gary Thomas

Dai, Lina

Forbes, Valery E.

Gilliland, Douglas

Selck, Henriette

English

There has been a lot of concern about the fate and effects of engineered (produced or manufactured) nano-particles (ENPs) due to their rapidly increasing application in different products. Metal ENPs released into the environment, intentionally and accidently, are expected to end up in the aquatic environment via sewage treatment plants, waste handling or aerial deposition. Compared to ‘common metal’, metal ENPs have high reactivity due to their small size which may have implications for bioavailability and thus toxicity in aquatic organisms. Due to the chemical and physiological properties of metals they will sorb to organic matter in the water column and subsequently accumulate in sediments. Thus, metal ENPs may pose a high risk for aquatic organisms, especially for deposit feeders. However, studies of their bioavailability in the aquatic environment are limited, and the toxic mechanisms of metal ENPs in aquatic invertebrates is not yet clear.There is a long history of using gold (Au) in pharmacy and material science. We examined the toxicity of sediment-associated Au in three different forms (nano sized, micro sized and ionic Au). The deposit feeder, Capitella teleta, was exposed to 5 concentrations of sediment-associated Au (for each Au form) during 14 days. Effects were evaluated as worm mortality and growth. In addition, concentrations of Au were measured in exposure systems after 14 days (i.e., worm tissue, sediment, fecal pellets). The following questions will be addressed:-Is Au toxicity related to form?-Does Capitella teleta affect the environmental fate of Au and does the fate depend on metal form? <br/

Roskilde Universitet

RoskildeUniversityUptake and effect of nano-and ionic gold on the polychaete, Capitella teletaDai, Lina; Banta, Gary Thomas; Selck, Henriette; Gilliland, Douglas; Forbes, Valery E.Publication date:2010Document VersionPeer reviewed versionCitation for published version (APA):Dai, L., Banta, G. T., Selck, H., Gilliland, D., & Forbes, V. E. (2010). Uptake and effect of nano-and ionic gold onthe polychaete, Capitella teleta.General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright ownersand it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.            • Users may download and print one copy of any publication from the public portal for the purpose of private study or research.            • You may not further distribute the material or use it for any profit-making activity or commercial gain.            • You may freely distribute the URL identifying the publication in the public portal.Take down policyIf you believe that this document breaches copyright please contact rucforsk@ruc.dk providing details, and we will remove access to thework immediately and investigate your claim.Download date: 02. Dec. 2021Results-Bioavailability•Unit of Nominal conc. is µg Au/g dw sed. ¶ Units are µgAu/worm. NQ: under quantification limit. Bioavailable Au: pooled 10 replicates. Since no data yet on the actual Au conc. in sediment at start and end of the experiment. Therefore, interpretations are based on nominal conc.. Egested Au: pooled 3 replicates data. It was measured in fecal pellets of C.teleta. 1. Accumulation highest from ions which is reflected in the accumulated Au in per worm; 2. NP was egested less than ionic form of Au into fecal pellets.Table 1. Primary bioavailability of Au by C. teleta (n=1) at exposure concentrations based on per worm. Quantification limit=4ng/g dw tissue. Results-Toxicity1.Mortality: no significant mortality was observed (data not shown) as a function of either particle size or exposure concentration.2.Growth: worms from all treatments had positive growth. The concentration-response curves were not monotonic, however, and there were no significant effects of either Au concentration or Au form (i.e., 4nmAuNP, 15nmAuNP, 40nmAuNP and Au3+ ion) on growth rates.Growth of C. teleta after 14 days exposureNominal concentration (µg/g dw sed)                                                                    Particle type & sizeAu3+ ion4nm AuNP15nm AuNP40nm AuNPFinal body volume (mm3 )204680 1 10 50 100Body volume at day 00468Uptake and effect of nano- and ionic gold on the polychaete, Capitella teletaIntroductionThe fate and effects of engineered (produced or manufactured) nano-particles (ENPs, d<100nm) have received a lot of attention due to their rapidly increasing production and application. Compared to metals in conventional forms, metal ENPs may be different in their fate and toxicity in the aquatic environment.① Fate: The smaller particle size and higher reactivity may lead to uneven dispersion and aggregation of ENPs as well as association, flocculation and sedimentation with natural organic matter in the aquatic environment.② Toxicity: We hypothesize that toxicity of metals for deposit feeders to be particle size dependent.However, studies of the bioavailability of metal ENPs in the aquatic environment are limited and their toxic mechanisms in aquatic invertebrates are not yet clearly understood.AimsTo test whether the bioavailability and the toxicity of Au nano-particles are dependent on size.Three different nano-sized Au particles were selected. In addition, the ionic Au3+ form was also tested to gain insights into the uptake and toxicity mechanisms of nano-sized Au.ConclusionsNano Au particles are bioavailable to Capitella teleta, though seemingly less so than Au3+. Neither particle-size dependent nor concentration dependent lethal or sub-lethal effects of Au were observed in the selected concentration range. What’s next...A mass balance budget will be estimated based on the fate and concentrations of Au in different compartments (i.e., fecal pellets  and un-ingested sediment) after 14 days.  Experiment will be optimized in worm tissue rinsing at collection date and Au analytical quantification method.Lina Dai1, Gary T Banta1, Henriette Selck1, Douglas Gilliland2 and Valery E Forbes11 Department of Environmental, Social and Spatial Change, Roskilde University, Universitetsvej 1, DK-4000 Roskilde, Denmark2European Commission, Joint Research Centre, Institute for Health and Consumer Protection,Ispra (VA), ItalyE-mail contact: ldai@ruc.dkMay, 2010     Experimental setup- Mortality and growth were detected on day 14.Capitella teleta4 forms of gold added to sediment (0, 50 and 100µg/g dw sed)14 daysC. teletaFecal pelletsSediment1 mmSize (d. nm)Volume(%)Size distribution of nano-Au by volume4.4 nm14.6 nm 41.3 nmParticle size distributions were measured on a Malvern Zetasizer Nano ZSinstrument. The measured size distributions (intensity and volume basis)show peak maximums at 4.4, 14.6 and 41.3nm (volume basis)-all Au NPs weresynthesized and characterized by JRC.Particle Nominal conc.*BioavailableAu¶AccumulatedAu¶EgestedAu¶Au3+ ion 50 3.2 0.16 1.54nm AuNP 50 3.8 NQ 1.215nm AuNP 50 2.3 0.01 0.640nm AuNP 50 3.5 0.06 0.8Au3+ ion 100 6.7 0.30 3.04nm AuNP 100 6.0 NQ 2.115nm AuNP 100 7.0 NQ 2.340nm AuNP 100 7.0 NQ 1.7

Uptake and effect of nano-and ionic gold on the polychaete, Capitella teleta

https://forskning.ruc.dk/files/48265469/uptake_and_effect_of_ionic_and_nano_gold_on_the_polychaete_Capitella_telets_Lina.pdf

Uptake and effect of nano-and ionic gold on the polychaete, Capitella teleta

Abstract

Similar works

Full text

Available Versions

Roskilde Universitet