Coagulation disorders following an accidental ingestion of cerium dioxide nanoparticles.

Clinically, acute cerium dioxide poisoning or damage is very rare. Here, the investigator reported a case about the patient who accidental ingested cerium dioxide nanoparticles during work shift. The patient recovered well after the treatment with removal of cerium and restoring coagulation factor activity. The author also reviewed relative literatures to discuss the potential mechanism of coagulation disorders following cerium dioxide nanoparticles ingestion. This case is the first report in the world about acute oral poisoning due to cerium dioxide nanoparticles, with the exact exposure concentration.

Effect of nano-sized SiO2 particles on the cognitive function and biochemical response.

Several in vitro studies have convincingly demonstrated that SiO2NPs mediated cytotoxicity, which was dose-, time- and size-dependent. The data on in vivo toxicity of SiO2NPs are even more contradictory. In the present study, we investigated the effects of sub-acute exposure to SiO2-NPs on spatial learning and memory, the biochemical parameters and the histology of organs. Rats were injected intravenously with a single dose of SiO2-NPs (20 mg/kg) during five consecutive days. The analysis of spatial memory in the Morris water maze showed that SiO2-NPs disrupt the cognitive abilities of rats. Moreover, SiO2-NPs could changes the blood counts. However, biochemical markers remained unchanged. Histological examination showed that SiO2-NPs induced pathological changes in rat organs. In this finding NPs were shown to cause granuloma formation and inflammatory cells infiltration in the liver.

The toxicology of ion-shedding zinc oxide nanoparticles.

Zinc oxide nanoparticles (ZnO NPs) are nanomaterials that are widely used in many fields. ZnO NPs are ion-shedding particles, and zinc ions produce important and potent effects that differ from those of other metal or metal oxide NPs. Several studies have reported the toxicological effects of ZnO NPs administered via several different routes, including orally, dermally, by pulmonary absorption, intraperitoneally, and intravenously. Some potential routes for human exposure have produced various toxic effects in animal models. Moreover, several in vitro studies using a range of cell lines have reported the mechanisms underlying ZnO NP toxicity. Zinc ions play a very important role in ZnO NP toxicity, although the effects of the particulate form cannot be excluded. A crucial determinant of toxicity is the solubility of ZnO NPs, which is influenced by various factors, including the pH of the environment in tissues, cells, and organelles. In addition to the inflammatory responses and oxidative stress known to be induced by ZnO NPs, these NPs also exhibit some positive anti-inflammatory, anti-diabetic, and pro-coagulant effects at sub-toxic doses; these effects are probably induced by zinc ions, which are an essential element in cell homeostasis. It is highly likely that there are additional distinct mechanisms at sub-toxic doses and concentrations, which may be concealed or altered by the toxic effects observed at higher levels of ZnO NPs. Furthermore, many signaling pathway molecules associated with necrosis and apoptosis can be activated, leading to cell death. This review presents the status of ZnO NP toxicology and highlights areas requiring further investigation.

Current safety practices in nano-research laboratories in China.

China has become a key player in the global nanotechnology field, however, no surveys have specifically examined safety practices in the Chinese nano-laboratories in depth. This study reports results of a survey of 300 professionals who work in research laboratories that handle nanomaterials in China. We recruited participants at three major nano-research laboratories (which carry out research in diverse fields such as chemistry, material science, and biology) and the nano-chemistry session of the national meeting of the Chinese Chemical Society. Results show that almost all nano-research laboratories surveyed had general safety regulations, whereas less than one third of respondents reported having nanospecific safety rules. General safety measures were in place in most surveyed nano-research laboratories, while nanospecific protective measures existed or were implemented less frequently. Several factors reported from the scientific literature including nanotoxicology knowledge gaps, technical limitations on estimating nano-exposure, and the lack of nano-occupational safety legislation may contribute to the current state of affairs. With these factors in mind and embracing the precautionary principle, we suggest strengthening or providing nanosafety training (including raising risk awareness) and establishing nanosafety guidelines in China, to better protect personnel in the nano-workplace.

Nanotoxicity overview: nano-threat to susceptible populations.

Due to the increasing applications of nanomaterials and nanotechnology, potential danger of nanoparticle exposure has become a critical issue. However, recent nanotoxicity studies have mainly focused on the health risks to healthy adult population. The nanotoxicity effects on susceptible populations (such as pregnant, neonate, diseased, and aged populations) have been overlooked. Due to the alterations in physiological structures and functions in susceptible populations, they often suffer more damage from the same exposure. Thus, it is urgent to understand the effects of nanoparticle exposure on these populations. In order to fill this gap, the potential effects of nanoparticles to pregnant females, neonate, diseased, and aged population, as well as the possible underlying mechanisms are reviewed in this article. Investigations show that responses from susceptible population to nanoparticle exposure are often more severe. Reduced protection mechanism, compromised immunity, and impaired self-repair ability in these susceptible populations may contribute to the aggravated toxicity effects. This review will help minimize adverse effects of nanoparticles to susceptible population in future nanotechnology applications.

How to measure hazards/risks following exposures to nanoscale or pigment-grade titanium dioxide particles.

Due to its multifunctional applications, titanium dioxide particles have widespread use in commerce. The particle-types function as sources of pigment color, in food products, anti-bacterial components, ultraviolet radiation scavengers, catalysts, as well as in cosmetics. Because of its inherent properties in a diverse number of products, exposures may occur via any of the major point-of-entry routes, i.e., inhalation, oral or dermal. Although the majority of TiO2 applications are known to exist in the pigment-grade form, nanoscale forms of TiO2 are also common components in several products. This brief review is designed to identify relevant toxicology and risk-related issues which inform health effects assessments on the various forms of titanium dioxide particles. While there has been an abundance of hazard data generated on titanium dioxide particulates, many of the published reports have limited informational value for assessing health effects due, in large part, to shortcomings in experimental design issues, such as: (1) inadequate material characterization of test samples; (2) questionable relevance of experimental systems employed to simulate human exposures; (3) applications of generally high doses, exclusive focus on acute toxicity endpoints, and a lack of reference benchmark control materials, to afford interpretation of measured results; and/or (4) failure to recognize fundamental differences between hazard and risk concepts. Accordingly, a number of important toxicology issues are identified and integrated herein to provide a more comprehensive assessment of the health risks of different forms of pigment-grade and nanoscale titanium dioxide particles. It is important to note that particle-types of different TiO2 compositions may have variable toxicity potencies, depending upon crystal structure, particle size, particle surface characteristics and surface coatings. In order to develop a more robust health risk evaluation of TiO2 particle exposures, this review focuses on the following issues: (1) Introduction to TiO2 particle chemistry/functionality and importance of robust material characterization of test samples; (2) Implementation of meaningful hazard studies for gauging EHS safety issues ­ pulmonary bioassay data and development of the Nano Risk Framework for developmental nano TiO2 compounds; (3) Epidemiological study findings on titanium dioxide workers ­ the most heavily-exposed populations; (4) Methodologies for setting occupational exposure limits including benchmarking or bridging comparisons; and (5) The importance of particle overload data in the lungs of rats as it relates to gauging the relevance of health effects for humans. A comprehensive evaluation of the existing animal and human health data is a necessary prerequisite for facilitating accurate assessments of human health risks to TiO2 exposures.

Nanoparticles from photocopiers induce oxidative stress and upper respiratory tract inflammation in healthy volunteers.

Photocopiers emit large quantities of nanoparticles (NPs); however, their toxicological properties have not been studied. Here we investigate for the first time early human responses following a day's exposure to NPs from photocopiers. Nine healthy subjects spent 6 h at a busy photocopy centre on 2-3 randomly selected days. Matched nasal lavage and urine samples were collected before and at different time points post-exposure. Nasal lavage samples were analysed for 14 cytokines, inflammatory cells and total protein. Urine samples were analysed for 8-hydroxydeoxyguanosine (8-OH-dG). Exposure assessment was conducted using a suite of instruments. The mean total particle number on exposure days was >5 times higher than background, with size distributions in nanoscale range (peak 30-40 nm). Following exposure, 8-OH-dG and several pro-inflammatory cytokines were elevated 2-10 folds compared with pre-exposure levels and remained elevated for up to 36 h. We conclude that NPs from photocopiers induce upper airway inflammation and oxidative stress.

[Nanoparticles toxicity--selective examples]. / Toksycznosci nanoczastek--wybrane przyklady.

Compared to conventional substances in microscale (molecular diameter expressed in microns), nanoparticles (diameter <100 nm) stands a huge reactive surface is able to interact with biological systems, both in a positive way, and cause toxic effects. Nanomaterials have long been present in everyday life, however, knowledge about the mechanisms of their toxicity, methods to reduce exposure and toxic effects of treatment did not follow the development of nanotechnology and nanomaterials on a large scale. The paper presents selected reports of biotransformation and the toxic effects of selected nanoparticles.

Nanomaterials in humans: identification, characteristics, and potential damage.

Nanomaterials are increasingly being used for commercial purposes. However, concerns about the potential risks of exposure to humans have been raised. We previously reported unusual pulmonary disease and death in a group of patients with occupational exposure to spray paint. However, the nanoparticle and chemical composition of the exposure was not fully described. The present study aimed to isolate and identify the nanoparticles observed in the patients' biopsies and report the potential deleterious effects to human lungs using electron microscopy. Using electron microscopy and energy dispersive x-ray analysis, silica nanoparticles were identified and characterized mainly in macrophages, pulmonary microvessels, vascular endothelial cells, microlymphatic vessels, pleural effusions, and a few in alveolar epithelial cells and pulmonary interstitial tissue (with no microscale particles present). Notably, damage to alveolar epithelial cells, macrophages, vascular endothelial cells, and the blood-gas barrier was observed. Given the well-documented toxicity of microscale silica, it is possible that these silica nanoparticles may have contributed in part to the illness reported in these workers. Such a possibility supports the adoption of controls and prevention strategies to minimize inhalation of nanoparticles by workers, and it highlights the urgent need and the importance of the nanosafety study in humans.