Nanoparticles of WC-Co, WC, Co and Cu of relevance for traffic wear particles – Particle stability and reactivity in synthetic surface water and influence of humic matter
Abstract:Studded tyres made of tungsten carbide cobalt (WC-Co) are in the Northern countries commonly used during the winter time. Tungsten (W)-containing nano- and micron-sized particles have been detected close to busy roads in several European countries. Other typical traffic wear particles consist of copper (Cu). The aims of this study were to investigate particle stability and transformation/dissolution properties of nanoparticles (NPs) of WC-Co compared with NPs of tungsten carbide (WC), cobalt (Co), and Cu. Thei… Show more
“…For the higher particle loading (10 mg L −1 ), an increase in Co release was observed after 4 h in tap water and after 24 h and 1 week in the presence of the eco-corona biomolecules. Observed release rates are in line with previous studies on release rates of Co from WC–Co in surface water, displaying a fast release of most Co during the first 4 h of exposure 21 . Figure 3 Co release investigated by AAS.…”
Section: Resultssupporting
confidence: 90%
“…2 ). Several potential mechanisms may explain the observed protection induced by the eco-corona biomolecules 18 of which three will be discussed below; (i) the eco-corona biomolecules may influence the Co dissolution from the Co- and WC–Co NPs 21 and modulate the released Co ion concentration in solution and hence the toxic response, (ii) biomolecules forming the eco-corona may change the bioavailability of dissolved Co in solution, and (iii) adsorption of eco-corona biomolecules on the NPs may change the surface characteristics and how the particles interact with the zooplankton. The first hypothesis, stating that the dissolution of Co is influenced by the presence of the eco-corona biomolecules, was addressed by assessing differences in the release of Co from Co and WC–Co NPs with and without conditioning in the eco-corona biomolecule solution.…”
Section: Resultsmentioning
confidence: 99%
“…The first hypothesis, stating that the dissolution of Co is influenced by the presence of the eco-corona biomolecules, was addressed by assessing differences in the release of Co from Co and WC–Co NPs with and without conditioning in the eco-corona biomolecule solution. No measurements were performed on released W-ions due to their relatively slow release 21 and low toxicity (EC50 value of approx. 89 mg L −1 for W 6+ 22 ) compared with Co (water quality guideline of 8 µg L −1 Co for chronic exposure in freshwater) 16 .…”
As the use of engineered nanomaterials increases, so does the risk of them spreading to natural ecosystems. Hitherto, knowledge regarding the toxic properties of nanoparticles (NP’s) and their potential interactions with natural bio-organic molecules adsorbed to them, and thereby forming surface coronas, is limited. However, we show here that the toxic effect of NPs of tungsten carbide cobalt (WC–Co) and cobalt (Co) on the crustacean Daphnia magna is postponed in the presence of natural biological degradation products (eco-corona biomolecules). For Daphnia exposed to WC–Co NPs the survival time increased with 20–25% and for Co NPs with 30–47% after mixing the particles with a solution of eco-corona biomolecules before exposure. This suggests that an eco-corona, composed of biomolecules always present in natural ecosystems, reduces the toxic potency of both studied NPs. Further, the eco-coronas did not affect the particle uptake, suggesting that the reduction in toxicity was related to the particle-organism interaction after eco-corona formation. In a broader context, this implies that although the increasing use and production of NPs may constitute a novel, global environmental threat, the acute toxicity and long-term effects of some NPs will, at least under certain conditions, be reduced as they enter natural ecosystems.
“…For the higher particle loading (10 mg L −1 ), an increase in Co release was observed after 4 h in tap water and after 24 h and 1 week in the presence of the eco-corona biomolecules. Observed release rates are in line with previous studies on release rates of Co from WC–Co in surface water, displaying a fast release of most Co during the first 4 h of exposure 21 . Figure 3 Co release investigated by AAS.…”
Section: Resultssupporting
confidence: 90%
“…2 ). Several potential mechanisms may explain the observed protection induced by the eco-corona biomolecules 18 of which three will be discussed below; (i) the eco-corona biomolecules may influence the Co dissolution from the Co- and WC–Co NPs 21 and modulate the released Co ion concentration in solution and hence the toxic response, (ii) biomolecules forming the eco-corona may change the bioavailability of dissolved Co in solution, and (iii) adsorption of eco-corona biomolecules on the NPs may change the surface characteristics and how the particles interact with the zooplankton. The first hypothesis, stating that the dissolution of Co is influenced by the presence of the eco-corona biomolecules, was addressed by assessing differences in the release of Co from Co and WC–Co NPs with and without conditioning in the eco-corona biomolecule solution.…”
Section: Resultsmentioning
confidence: 99%
“…The first hypothesis, stating that the dissolution of Co is influenced by the presence of the eco-corona biomolecules, was addressed by assessing differences in the release of Co from Co and WC–Co NPs with and without conditioning in the eco-corona biomolecule solution. No measurements were performed on released W-ions due to their relatively slow release 21 and low toxicity (EC50 value of approx. 89 mg L −1 for W 6+ 22 ) compared with Co (water quality guideline of 8 µg L −1 Co for chronic exposure in freshwater) 16 .…”
As the use of engineered nanomaterials increases, so does the risk of them spreading to natural ecosystems. Hitherto, knowledge regarding the toxic properties of nanoparticles (NP’s) and their potential interactions with natural bio-organic molecules adsorbed to them, and thereby forming surface coronas, is limited. However, we show here that the toxic effect of NPs of tungsten carbide cobalt (WC–Co) and cobalt (Co) on the crustacean Daphnia magna is postponed in the presence of natural biological degradation products (eco-corona biomolecules). For Daphnia exposed to WC–Co NPs the survival time increased with 20–25% and for Co NPs with 30–47% after mixing the particles with a solution of eco-corona biomolecules before exposure. This suggests that an eco-corona, composed of biomolecules always present in natural ecosystems, reduces the toxic potency of both studied NPs. Further, the eco-coronas did not affect the particle uptake, suggesting that the reduction in toxicity was related to the particle-organism interaction after eco-corona formation. In a broader context, this implies that although the increasing use and production of NPs may constitute a novel, global environmental threat, the acute toxicity and long-term effects of some NPs will, at least under certain conditions, be reduced as they enter natural ecosystems.
“…In Scandinavian countries, especially in the winter, tires with studs are often used for the purposes of obtaining better grip on a road covered by snow or a layer of ice. Containing tungsten carbide, cobalt or copper, such studs may contribute to NP formation at the tyre-road interface [34]. Elements linked to road salt may also be detected in chemical analyses of exhaust particulate.…”
Current ecological trends and resulting legislation like European emissions standards Euro 6d or Best Available Techniques are setting new challenges in the field of environmental protection. Since the problem of emissions of particulate matter from diesel engines was solved by the application of diesel particulate filters (DPFs or FAPs) and due to the global dominance of gasoline fuelled passenger cars, particular concern has been focused on improvement of emissions performance of gasoline vehicles, including hybrids, as well as heavy-duty and non-road vehicles. This paper presents the results of preliminary studies on the chemical and physical properties of gasoline engine-generated particles, including nanoparticles. SEM images were presented which allowed identification of the character of particulate matter and estimates of the dimensions of particles. Moreover, the particles were found to be composed of different elements, including Cu, Si, Na, Ca, Zn and P, pointing to the origination of these particles from the pistons and lubricant additives.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
