Nanoparticle Silver Released into Water from Commercially Available Sock Fabrics

Civil and Environmental Engineering, Arizona State University, Box 5306, Tempe, Arizona 85287-5306, USA.
Environmental Science and Technology (Impact Factor: 5.33). 07/2008; 42(11):4133-9. DOI: 10.1021/es801501j
Source: PubMed


Manufacturers of clothing articles employ nanosilver (n-Ag) as an antimicrobial agent, but the environmental impacts of n-Ag release from commercial products are unknown. The quantity and form of the nanomaterials released from consumer products should be determined to assess the environmental risks of nanotechnology. This paper investigates silver released from commercial clothing (socks) into water, and its fate in wastewater treatment plants (WWTPs). Six types of socks contained up to a maximum of 1360 microg-Ag/g-sock and leached as much as 650 microg of silver in 500 mL of distilled water. Microscopy conducted on sock material and wash water revealed the presence of silver particles from 10 to 500 nm in diameter. Physical separation and ion selective electrode (ISE) analyses suggest that both colloidal and ionic silver leach from the socks. Variable leaching rates among sock types suggests that the sock manufacturing process may control the release of silver. The adsorption of the leached silver to WWTP biomass was used to develop a model which predicts that a typical wastewater treatment facility could treat a high concentration of influent silver. However, the high silver concentration may limitthe disposal of the biosolids as agricultural fertilizer.

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Available from: Paul Westerhoff, Mar 28, 2014
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    • "). Althoughmusselsandoystersdonotbioaccumulatethe anataseformofTiO2NPswhensubjectedtoaspillscenario, theresultsofthisstudycannotbeextrapolatedtoexposure conditionspredictedformostmarineenvironments(i.e.continuousexposuretoconcentrations ,1.0mgL 21 ).Therefore, theexperimentsoutlinedinthepresentstudyshouldbe repeatedatlowerconcentrationsforalongerperiodoftime (.2htodays)todetermineifanymeasurablebioaccumula- tionoccurs.Additionally,thecurrentresearchexamined onlyoneformofonetypeofNP,representingasmallfraction oftheNPsthatarepresentlybeingdeveloped,producedand includedinconsumerproducts.Forexample,nano-Agintextiles(Benn&Westerhoff,2008;Geranioetal.,2009),ZnOin sunscreensandcosmetics(Serponeetal.,2007),andthedeg- "
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    ABSTRACT: Nanoparticles have applications in a diverse range of products including medications, detergents, cosmetics, paint, sunscreen and electronics, with an economic worth projected to reach $2.5 trillion dollars in 2015. Research into the effects of manufactured nanomaterials on the environment, however, has failed to keep pace with the high volume of commercial production. Whereas a number of studies have examined the effects of nanoparticles on aquatic species, little work has focused on the way in which benthic marine species encounter, ingest and depurate these materials. The purpose of this study was to examine the ingestion and depuration of titania nanoparticles (anatase) by the blue mussel ( Mytilus edulis ) and the eastern oyster ( Crassostrea virginica ) during a spill scenario (an acute exposure to elevated concentrations). Bivalves were exposed to nanoparticles either incorporated into marine snow, an environmentally relevant medium for pollutants, or added directly to seawater at a concentration of 4.5 mg L −1 for 2 h. After feeding, the animals were transferred to filtered seawater and allowed to depurate. Faeces and tissues were collected at 0, 6, 24, 72 and 120 h, post-exposure, and analysed for concentrations of titanium by inductively coupled plasma-mass spectrometry. Results indicated that the capture and ingestion of titania nanoparticles by both species was not dependent on the method of delivery (incorporated into marine snow or freely suspended). Additionally, greater than 90% of the titania nanoparticles, on average, were eliminated from the tissues after 6 h, and only trace amounts remained after 72 h. These data demonstrate that mussels and oysters readily ingest titania nanoparticles, but rapidly depurate the material within hours of an acute exposure suggesting that little would be transferred to secondary consumers including humans. Further research is required to determine if other species of suspension-feeders handle titania nanoparticles in a manner similar to bivalves.
    Full-text · Article · Feb 2016 · Journal of the Marine Biological Association of the UK
    • "Indeed, Ag NPs from NP-containing goods are released to the environment in large amounts, where they accumulate in the soil or water reservoirs and affect biota (Benn & Westerhoff 2008; Roh et al., 2009; Kaegi et al., 2010; Gottschalk & Nowack 2011; Quadros and Linsey 2011). The part of metallic Ag NPs that are released from NP-containing products is converted in the soil and sewage sludge to less toxic substances, such as Ag-sulphide NPs (Choi & Hu 2008; Kim et al., 2010; Luther & Rickard 2005). "
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    ABSTRACT: Silver nanoparticles (Ag NPs) are the world's most important nanomaterial and nanotoxicant. The aim of this study was to determine early stages of interactions between Ag nanoparticles and plant cells and investigate their physiological roles. We have shown that addition of Ag NPs to cultivation medium, at levels above 300 mg L(-1) , inhibited Arabidopsis thaliana root elongation and leaf expansion. This also resulted in decreased photosynthetic efficiency and extreme accumulation of Ag in tissues. Acute application of Ag NPs induced transient elevation of [Ca(2+) ]cyt , and accumulation of ROS (partially generated by NADPH oxidase). Whole-cell patch-clamp measurements on root cell protoplasts demonstrated that Ag NPs slightly inhibited plasma membrane K(+) efflux and Ca(2+) influx currents or caused membrane breakdown. However, in excised outside-out patches, Ag NPs activated Gd(3+) -sensitive Ca(2+) influx channels with unitary conductance of approximately 56 pS. Bulk particles did not modify the plasma membrane currents. Tests with electron paramagnetic resonance spectroscopy showed that Ag NPs were not able to catalyse hydroxyl radical generation but they directly oxidised the major plant antioxidant, L-ascorbic acid. Overall, the presented data sheds the light on mechanisms of the impact of nanosilver on plant cells and show that these include induction of classical stress signalling reactions (mediated by [Ca(2+) ]cyt and ROS) and a specific effect on the plasma membrane conductance and the reduced ascorbate. This article is protected by copyright. All rights reserved.
    No preview · Article · Dec 2015 · The Plant Journal
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    • "According to the most recently available data, Ag is reportedly used in 24% (383/ 1,628) identified, commercially available, nanotechnologyenabled products listed in the Project on Emerging Nanotechnologies ( Clothing and personal care products account for the majority of the total AgNP-enabled products, both of which have been shown to leach or contribute AgNPs to wastewater (Benn and Westerhoff, 2008). AgNPs likely accumulate in primary and secondary sludge (Kiser et al., 2010). "
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    ABSTRACT: Physical and chemical transformations and biological responses of silver nanoparticles (AgNPs) in wastewater treatment systems are of particular interest because of the extensive existing and continually growing uses of AgNPs in consumer products. In this study, we investigated the transformation of AgNPs and AgNO3 during thermophilic anaerobic digestion and effects on selection or transfer of antibiotic resistance genes (ARGs). Ag2S-NPs, sulfidation products of both AgNPs and AgNO3, were recovered from raw and digested sludges and were analyzed by analytical transmission electron microscopy (TEM) and X-ray absorption spectroscopy (XAS). TEM and XAS revealed rapid (≤20 min) Ag sulfidation for both Ag treatments. Once transformed, Ag2S-NPs (as individual NPs or an NP aggregate) persisted for the duration of the batch digestion. The digestion process produced Ag2S-NPs that were strongly associated with sludge organics and/or other inorganic precipitates. Ag treatments (up to 1,000 mg Ag/kg) did not have an impact on the performance of thermophilic anaerobic digesters or ARG response, as indicated by quantitative polymerase chain reaction measurements of sul1, tet(W), and tet(O) and also intI1, an indicator of horizontal gene transfer of ARGs. Thus, rapid Ag sulfidation and stabilization with organics effectively sequester Ag and prevent biological interactions with the digester microbial community that could induce horizontal gene transfer or adversely impact digester performance through antimicrobial activity. This finding suggests that sulfide-rich anaerobic environments, such as digesters, likely have a high buffer capacity to mitigate the biological effects of AgNPs.
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