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Current state of knowledge on the health effects of engineered nanomaterials in workers
A systematic review of human studies and epidemiological investigations Objectives: The widespread application of nano-enabled products and the increasing likelihood for workplace exposures make understanding engineered nanomaterial (ENM) effects in exposed workers a public and occupational health priority. The aim of this study was to report on the current state of knowledge on possible adverse effects induced by ENM in humans to determine the toxicological profile of each type of ENM and potential biomarkers for early detection of such effects in workers. Methods: A systematic review of human...
Assessment of nanofibre dustiness by means of vibro-fluidization
Dustiness testing probes for the propensity of a powdery material to release dust particles following agitation. For high aspect-ratio materials like nanotubes, the most important dust fraction is that of potentially carcinogenic fibres(WHO-fibres).Wedeveloped the fluidizer particularly for fibres thatmakes use of vibro-fluidization in order to effectively disentangle single fibres and agglomerates of multi-walled carbon nanotube powders. Counting rules for morphological characterization of collected particles by means of electron microscopywere established, allowing quantifying the WHO-fibre fraction...
WHO Guidelines to Protect Workers from Nanomaterials
The term nanomaterials refers to materials that have at least one dimension (height, width or length) that is smaller than 100 nanometres (10−7 metre), which is about the size of a virus particle. This particular size dimension represents a major characteristic of manufactured nanomaterials (MNMs). The unique properties of MNMs may result in highly desirable behaviour leading to such varying applications as better paints, better drugs and faster electronics. However, for the same reason, MNMs may also present health hazards that differ from those of the substance in bulk form, and may require...
Exposures to nanoparticles and fibers during injection molding and recycling of carbon nanotube reinforced polycarbonate composites
In this study, the characteristics of airborne particles generated during injection molding and grinding processes of carbon nanotube reinforced polycarbonate composites (CNT-PC) were investigated. Particle number concentration, size distribution, and morphology of particles emitted from the processes were determined using real-time particle sizers and transmission electron microscopy. The air samples near the operator's breathing zone were collected on filters and analyzed using scanning electron microscope for particle morphology and respirable fiber count. Processing and grinding during...
IARC Monographs Volume 111: Some Nanomaterials and Some Fibres
This volume of the IARC Monographs contains evaluations of the carcinogenic hazard to humans of fluoro-edenite fibrous amphibole, silicon carbide fibres and whiskers, and carbon nanotubes. None of these agents had been evaluated previously by the Working Group. Source: http://monographs.iarc.fr/ENG/Monographs/vol111/index.php
Carbon Nanotube and Nanofiber Exposure Assessments
An Analysis of 14 Site Visits Recent evidence has suggested the potential for wide-ranging health effects that could result from exposure to carbon nanotubes (CNT) and carbon nanofibers (CNF). In response, the National Institute for Occupational Safety and Health (NIOSH) set a recommended exposure limit (REL) for CNT and CNF: 1 µg m-3 as an 8-h time weighted average (TWA) of elemental carbon (EC) for the respirable size fraction. The purpose of this study was to conduct an industrywide exposure assessment among US CNT and CNF manufacturers and users. Fourteen total sites were visited to assess...
Engineered Nanomaterials
An update on the Toxicology and Work Health Hazards This publication provides updated information about the toxicology and work health hazards of engineered nanomaterials. Safe Work Australia commissioned ToxConsult Pty Ltd to undertake this project. This report updates and builds on the findings of the 2009 report Engineered nanomaterials – a review of the toxicology and health hazards and provides specific information about the health hazards of: •Carbon nanotubes •Titanium dioxide •Zinc oxide •Cerium oxide, and •Silver The report provides suggestions for workplace...
Characterization of exposure to carbon nanotubes in an industrial setting
While production and use of carbon nanotubes (CNTs) is increasing, workers exposure to CNTs is expected to increase as well, with inhalation being potentially the main pathway for uptake. However, there have been few studies reporting results about workers' personal exposure to CNTs. In this study, worker exposure to single-walled CNTs (SWCNTs) during the production of conductive films in a modern up-scaling factory was assessed. Particulate matter concentrations (2.5–10 μm) and concentrations of CO and CO2 were monitored by using real-time instruments. Workers' exposure levels...
Promotion of lung adenocarcinoma following inhalation exposure to multi-walled carbon nanotubes
Engineered carbon nanotubes are currently used in many consumer and industrial products such as paints, sunscreens, cosmetics, toiletries, electronic processes and industrial lubricants. Carbon nanotubes are among the more widely used nanoparticles and come in two major commercial forms, single-walled carbon nanotubes (SWCNT) and the more rigid, multiwalled carbon nanotubes (MWCNT). The low density and small size of these particles makes respiratory exposures likely. Many of the potential health hazards have not been investigated, including their potential for carcinogenicity. We, therefore, utilized...
Occupational Exposure to Carbon Nanotubes and Nanofibers : Current Intelligence Bulletin 65
This NIOSH Current Intelligence Bulletin (1) reviews the animal and other toxicological data relevant to assessing the potential non-malignant adverse respiratory effects of CNT and CNF, (2) provides a quantitative risk assessment based on animal dose-response data, (3) proposes a recommended exposure limit (REL) of 1 μg/m3 elemental carbon as a respirable mass 8-hour time-weighted average (TWA) concentration, and (4) describes strategies for controlling workplace exposures and implementing a medical surveillance program. The NIOSH REL is expected to reduce the risk for pulmonary inflammation...
Occupational Exposure Assessment in Carbon Nanotube and Nanofiber Primary and Secondary Manufacturers: Mobile Direct-Reading Sampling
Research Significance : Toxicological evidence suggests the potential for a wide range of health effects from exposure to carbon nanotubes (CNTs) and carbon nanofibers (CNFs). To date, there has been much focus on the use of direct-reading instruments (DRIs) to assess multiple airborne exposure metrics for potential exposures to CNTs and CNFs due to their ease of use and ability to provide instantaneous results. Still, uncertainty exists in the usefulness and interpretation of the data. To address this gap, air-monitoring was conducted at six sites identified as CNT and CNF manufacturers or users...
New Findings on Lung Tumor Formation in Laboratory Mice Exposed to Multi-Walled Carbon Nanotubes
Earlier today, at the annual meeting of the Society of Toxicology, NIOSH researchers reported preliminary findings from a new laboratory study in which mice were exposed by inhalation to multi-walled carbon nanotubes (MWCNT). The study was designed to investigate whether these tiny particles have potential to initiate or promote cancer. By “initiate,” we mean the ability of a substance to cause mutations in DNA that can lead to tumors. By “promote,” we mean the ability of a substance to cause cells that have already sustained such DNA mutations to then become tumors. It...
Filling the Knowledge Gaps for Safe Nanotechnology in the Workplace
A Progress Report from the NIOSH Nanotechnology Research Center, 2004–2011. This 2012 update presents the program accomplishments of the NTRC from its inception in 2004 through 2011. It includes an analysis of the progress made toward accomplishing the goals and objectives of the NIOSH Strategic Plan for Nanotechnology Research and toward addressing the goals and research needs identified in the U.S. National Nanotechnology Initiative (NNI) Environmental, Health, and Safety (EHS) research strategy. Source : http://osha.europa.eu/en/news/int-filling-the-knowledge-gaps-for-safe-nanotechnology...
Nanotech dangers outlined
It has been known for some time that inhaling tiny fibres made by the nanotechnology industry could cause similar health problems to asbestos. This is borne out by new research by the University of Edinburgh published in Toxicology Sciences. Research on mice, suggests the longer nanofibres are even more dangerous. Some of these fibres are similar in shape to asbestos fibres, which cause lung cancers such as mesothelioma. Nanofibres, which can be made from a range of materials including carbon, are about 1,000 times smaller than the width of a human hair and can reach the lung cavity when inhaled...
Risks and Control of Nanomaterials
Editorial / Trevor Ogden. In this issue we bring together 12 articles on nanomaterials and approaches to risk control. The issue originated with the conference held in April (2011) by the Institut National de Recherche et de Sécurité (INRS) in Nancy, France, on risks associated with nanoparticles and nanomaterials. Topics included measurement and control process design, occupational toxicology, protection, epidemiology, assessment and management of risk of nanoparticles. Source : http://annhyg.oxfordjournals.org/content/56/5/489.full
Safe handling of carbon nanotubes in the workplace
The potential risks from exposure to carbon nanotubes (CNTs) have been highlighted in numerous studies, including a recent review of the toxicology and health hazards associated with nanomaterials commissioned by Safe Work Australia (Toxikos 2009, see Appendix A for a list of references). Therefore, in order to help people work safely with carbon nanotubes, Safe Work Australia commissioned the CSIRO to develop guidance on the safe handling and use of carbon nanotubes. This document provides two approaches to manage the risks: - Risk management with detailed hazard analysis and exposure assessment...
Durability of carbon nanotubes and their potential to cause inflammation
The University of Edinburgh, the Institute of Occupational Medicine (Edinburgh), and the Commonwealth Scientific & Industrial Research Organisation (Australia) have collaborated to determine the durability of carbon nanotubes in simulated biological fluid and subsequent fibre pathogenicity, compared with well-characterised fibre controls. This collaborative project was financially supported under Safe Work Australia's Nanotechnology Work Health and Safety Program. Source : http://www.safeworkaustralia.gov.au/AboutSafeWorkAustralia/WhatWeDo/Publications/Pages/DurabilityCarbonNanotubes.aspx
Developing Workplace Detection and Measurement Techniques for Carbon Nanotubes
The pathways through which carbon nanotubes (CNT) can enter the human body are currently the subject of intensive studies nationally and internationally, as are investigations for determining levels of exposure in the workplace and developing guidelines for the safe use of nanomaterials in the workplace. This report investigates possible approaches for detecting nano-objects that are formed from airborne carbon nanotubes (CNT), while placing special emphasis on the very fine multi-wall carbon nanotubes (MWCNT) that are used for the manufacture of optically transparent CNT sheet electrodes or CNT...
Carbon nanotubes degraded by neutrophil myeloperoxidase induce less pulmonary inflammation
We have shown previously that single-walled carbon nanotubes can be catalytically biodegraded over several weeks by the plant-derived enzyme, horseradish peroxidase1. However, whether peroxidase intermediates generated inside human cells or biofluids are involved in the biodegradation of carbon nanotubes has not been explored. Here, we show that hypochlorite and reactive radical intermediates of the human neutrophil enzyme myeloperoxidase catalyse the biodegradation of single-walled carbon nanotubes in vitro, in neutrophils and to a lesser degree in macrophages. Molecular modelling suggests that...
Des souris sans défense immunitaire après inhalation de nanotubes de carbone
L'inhalation de nanotubes de carbone supprime certaines fonctions immunitaires chez des souris, grâce à des signaux cellulaires transmis depuis les poumons vers la rate, selon des travaux publiés dimanche en ligne par la revue scientifique Nature Nanotechnology. http://hesa.etui-rehs.org/fr/dossiers/rdossier.asp?rd_pk=408&dos_pk=18 Résumé de l'article scientifique: http://www.nature.com/nnano/journal/vaop/ncurrent/abs/nnano.2009.151.html
Inhalation vs. aspiration of single-walled carbon nanotubes in C57BL/6 mice: inflammation, fibrosis, oxidative stress, and mutagenesis
Nanomaterials are frontier technological products used in different manufactured goods. Because of their unique physicochemical, electrical, mechanical, and thermal properties, single-walled carbon nanotubes (SWCNT) are finding numerous applications in electronics, aerospace devices, computers, and chemical, polymer, and pharmaceutical industries. SWCNT are relatively recently discovered members of the carbon allotropes that are similar in structure to fullerenes and graphite. Previously, we (47) have reported that pharyngeal aspiration of purified SWCNT by C57BL/6 mice caused dose-dependent granulomatous...

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