Analysis of carbon nanotube levels in organic matter: an inter-laboratory comparison to determine best practice.

Carbon nanotubes (CNTs) are increasingly being used in industrial applications, but their toxicological data in animals and humans are still sparse. To assess the toxicological dose-response of CNTs and to evaluate their pulmonary biopersistence, their quantification in tissues, especially lungs, is crucial. There are currently no reference methods or reference materials for low levels of CNTs in organic matter.

Exposure Assessment Study on Lithium-Ion Battery Fire in Explosion Test Room in Battery Testing Facility.

A lithium-ion battery is a rechargeable battery that uses the reversible reduction of lithium ions to store energy and is the predominant battery type in many industrial and consumer electronics. The lithium-ion batteries are essential to ensure they operate safely. We conducted an exposure assessment five days after a fire in a battery-testing facility.

Nutritional and ameliorative effects of dietary curcumin and its nano-silica and nano-zeolite encapsulated forms on growth, biochemical and fatty acid profile of common carp (Cyprinus carpio).

The present study aimed to examine individual nutritional and ameliorative effects of silica nanoparticles (SiONPs) and natural zeolite nanoparticles (ZeNPs) and their potential role as carriers to alter the bioavailability of curcumin. Common carps (Cyprinus carpio) were fed during 60 days with a control diet, and curcumin, turmeric, SiONPs, curcumin-loaded SiONPs, ZeNPs, and curcumin-loaded ZeNPs each at 1, 50, 6.15, 7.

Biokinetics of subacutely co-inhaled same size gold and silver nanoparticles.

Background: Toxicokinetics of nanomaterials, including studies on the absorption, distribution, metabolism, and elimination of nanomaterials, are essential in assessing their potential health effects. The fate of nanomaterials after inhalation exposure to multiple nanomaterials is not clearly understood.

Methods: Male Sprague-Dawley rats were exposed to similar sizes of silver nanoparticles (AgNPs, 10.

Animal Welfare Considerations When Conducting OECD Test Guideline Inhalation and Toxicokinetic Studies for Nanomaterials.

The OECD test guidelines for animal experiments play an important role in evaluating the chemical hazards. Animal tests performed using OECD guidelines, especially when the good laboratory practice (GLP) principle is applied, reduce the duplication of toxicity testing and ensure the best mutual acceptance of data by the OECD's Mutual Acceptance of Data (MAD). The OECD inhalation toxicity test guidelines 412 (28 days) and 413 (90 days) have been revised.

Health and Environmental Effect of Advanced Materials and Fine Particles.

With the recent development in material sciences, advanced materials have become terms widely used for new materials [...

The Acute and Short-Term Inhalation of Carbon Nanofiber in Sprague-Dawley Rats.

The inhalation toxicity of carbon nanofibers (CNFs) is not clearly known due to relatively few related studies reported. An acute inhalation study and short-term inhalation study (5 days) were therefore conducted using Sprague-Dawley rats. In the acute inhalation study, the rats were grouped and exposed to a fresh air control or to low (0.

Trophic transfer and toxicity of silver nanoparticles along a phytoplankton-zooplankton-fish food chain.

This study evaluated the bioconcentration metrics, organ-specific distribution, and trophic consequences of silver nanoparticles along a Dunaliella salina-Artemia salina-Poecilia reticulata food chain. To this end, accumulation, tissue-specific distribution, bioconcentration and biomagnification factors, and trophic toxicity of AgNPs were quantitatively investigated along di- and tri-trophic food chains. Overall, silver accumulation increased markedly in intestine and liver tissues, carcass, and embryos of guppy fish with rising exposure concentrations and reducing trophic levels.

Exposure Assessment of Silver and Gold Nanoparticles Generated During the Synthesis Process in a South African Research Laboratory.

During the synthesis of engineered nanomaterials (ENMs), various occupational exposures occur, leading to health consequences. To date, there is paucity of studies focused on modeling the deposition of nanoparticles emitted from ENMs synthesis processes. This study aimed to characterise and assess exposure to gold (AuNPs) and silver nanoparticles (AgNPs) during a synthesis process in a research laboratory in South Africa.

On-Site Deployment of an Air-Liquid-Interphase Device to Assess Health Hazard Potency of Airborne Workplace Contaminants: The Case of 3-D Printers.

Biomonitoring of workers is an approach of evaluating workers' exposure to chemicals and particulate matter by measuring biomarkers of parent chemicals, their metabolites, and reaction products in workers' biospecimens. Prerequisites for biological monitoring in the workplace include permission to enter the workplace, approval of the study plan from the IRB (Institutional Review Board), and obtaining consent from workers. Because of the complex legal process involved in biomonitoring, few studies have been conducted so far on biomonitoring of workers' exposures to nanoparticles and other hazards from emerging materials and advanced nanotechnologies.

In silico modeling of the antagonistic effect of mercuric chloride and silver nanoparticles on the mortality rate of zebrafish (Danio rerio) based on response surface methodology.

In this study, in silico modeling was designed to examine the antagonistic effect of mercuric chloride (HgCl) and silver nanoparticles (AgNPs) on the mortality rate of zebrafish (Danio rerio) based on response surface methodology (RSM). Adult zebrafish (Danio rerio) with an average weight of 0.75 ± 0.

Assessment and Mitigation of Exposure of 3-D Printer Emissions.

This study monitored particulates, and volatile organic compounds (VOCs) emitted from 3-D printers using acrylonitrile-butadiene-styrene copolymer (ABS) filaments at a workplace to assess exposure before and after introducing exposure mitigation measures. Air samples were collected in the printing room and adjacent corridor, and real-time measurements of ultrafine and fine particle were also conducted. Extensive physicochemical characterizations of 3-D printer emissions were performed, including real-time (size distribution, number concentration) nanoparticle characterization, size-fractionated mass distribution and concentration, as well as chemical composition for metals by ICP-MS and VOCs by GC-FID, real-time VOC monitors, and proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS).

Dietary supplementation with curcumin nanomicelles, curcumin, and turmeric affects growth performance and silver nanoparticle toxicity in Cyprinus carpio.

An 8-week feeding experiment was conducted to investigate the effects of curcumin nanomicelle, curcumin, and turmeric (Curcuma longa) on growth performances, body composition, fatty acid profile, and biochemical parameters of common carp (Cyprinus carpio), and their ameliorative effects against toxicity of silver nanoparticles (AgNPs). A total of 120 healthy carps were randomly distributed into four equal treatments. Curcumin nanomicelle, curcumin, and turmeric were each added separately to the basal diet.

Quality assurance for nanomaterial inhalation toxicity testing.

The recent revision of OECD inhalation toxicology test guidelines 412 and 413 presents new challenges for both the study director (SD) and quality assurance (QA) personnel when conducting GLP (good laboratory practice) studies. In the case of nanomaterial inhalation exposure studies, GLP has rarely been applied, yet the new revisions are applicable to soluble and insoluble nanomaterials, as well as conventional chemicals. For example, the new guidelines require an additional bronchoalveolar lavage (BAL) fluid assay and lung burden measurement during the post-exposure observation (PEO) period, plus nanomaterial physicochemical characterization before and after nano-aerosol generation when exposing experimental animals.

Evaluation of silver nanowires (AgNWs) toxicity on reproductive success of Daphnia magna over two generations and their teratogenic effect on embryonic development.

This study assessed the reproductive toxicity of silver nanowires (AgNWs) in Daphnia magna over two consecutive generations. An acute immobilization test was conducted according to the ΟECD 202 guidelines. To perform reproductive toxicity tests in both F0 and F1 generations, the animals were exposed to different concentrations of AgNWs (0, 0.

Re-use of health masks after autoclaving.

With the rapid global spread of the new coronavirus and risk of pneumonia from COVID-19 infection, wearing a mask has become an essential defense for all frontline doctors, nurses, and healthcare professionals. Plus, the rise in demand for masks from the general public means the worldwide supply of masks is insufficient, which has led to an increase in the reuse of disposable masks. Therefore, this study compared the impact of autoclaving (steaming) and 70% ethyl alcohol treatment for decontaminating masks, as both methods can easily be used at home.

Lung retention and particokinetics of silver and gold nanoparticles in rats following subacute inhalation co-exposure.

Background: Inhalation exposure to nanomaterials in workplaces can include a mixture of multiple nanoparticles. Such ambient nanoparticles can be of high dissolution or low dissolution in vivo and we wished to determine whether co-exposure to particles with different dissolution rates affects their biokinetics.

Methods And Results: Rats were exposed to biosoluble silver nanoparticles (AgNPs, 10.

Even lobar deposition of poorly soluble gold nanoparticles (AuNPs) is similar to that of soluble silver nanoparticles (AgNPs).

Background: Information on particle deposition, retention, and clearance is important when evaluating the risk of inhaled nanomaterials to human health. The revised Organization Economic Cooperation and Development (OECD) inhalation toxicity test guidelines now require lung burden measurements of nanomaterials after rodent subacute and sub-chronic inhalation exposure (OECD 412, OECD 413) to inform on lung clearance behavior and translocation after exposure and during post-exposure observation (PEO). Lung burden measurements are particularly relevant when the testing chemical is a solid poorly soluble nanomaterial.

Titanium dioxide nanoparticles affect the toxicity of silver nanoparticles in common carp (Cyprinus carpio).

The present study assessed the individual and combined toxicity effects of Ag- and TiO- nanoparticles (NPs) on Ag bioaccumulation, oxidative stress, and gill histopathology in common carp as an aquatic animal model. The 96-h acute toxicity tests showed that TiONPs enhanced the toxicity of AgNPs deducted from the decreased LC in co-exposure to these NPs. Chronic toxicity tests included a 10-day exposure and a 10-day recovery period.

Interference: A Much-Neglected Aspect in High-Throughput Screening of Nanoparticles.

Despite several studies addressing nanoparticle (NP) interference with conventional toxicity assay systems, it appears that researchers still rely heavily on these assays, particularly for high-throughput screening (HTS) applications in order to generate "big" data for predictive toxicity approaches. Moreover, researchers often overlook investigating the different types of interference mechanisms as the type is evidently dependent on the type of assay system implemented. The approaches implemented in the literature appear to be not adequate as it often addresses only one type of interference mechanism with the exclusion of others.

Mode of silver clearance following 28-day inhalation exposure to silver nanoparticles determined from lung burden assessment including post-exposure observation periods.

Recently revised OECD inhalation toxicity testing guidelines require measurements of lung burden immediately after and for periods following exposure for nanomaterials. Lung burden is a function of pulmonary deposition and retention of nanoparticles. Using lung burden studies as per OECD guidelines, it may be possible to assess clearance mechanisms of nanoparticles.

Potential Role of Soluble Metal Impurities in the Acute Lung Inflammogenicity of Multi-Walled Carbon Nanotubes.

Multi-walled carbon nanotubes (MWCNTs) have variable metal impurities, but little is known about the impact of soluble metal impurities on the toxicity of MWCNTs. Here, we evaluated the role of soluble metal impurities to the acute inflammogenic potential of MWCNTs, using five types of high purity MWCNTs (>95%). MWCNTs and their soluble fractions collected at 24 h after incubation in phosphate-buffered saline showed diverse metal impurities with variable concentrations.

28-Day inhalation toxicity study with evaluation of lung deposition and retention of tangled multi-walled carbon nanotubes.

Lung deposition and retention measurements are now required by the newly revised OECD inhalation toxicity testing guidelines 412 and 413 when evaluating the clearance and biopersistence of poorly soluble nanomaterials, such as multi-walled carbon nanotubes (MWCNTs). However, evaluating the lung deposition concentration is challenging with certain nanomaterials, such as carbon-based and iron-based nanomaterials, as it is difficult to differentiate them from endogenous elements. Therefore, the current 28-day inhalation toxicity study investigated the lung retention kinetics of tangled MWCNTs.