Comparison of dust released from sanding conventional and nanoparticle-doped wall and wood coatings

Introduction of engineered nanoparticles (ENPs) into traditional surface coatings (e.g., paints, lacquers, fillers) may result in new exposures to both workers and consumers and possibly also a new risk to their health. During finishing and renovation, such products may also be a substantial source of exposure to ENPs or aggregates thereof. This study investigates the particle size distributions (5.6 nm–19.8 μm) and the total number of dust particles generated during sanding of ENP-doped paints, lacquers, and fillers as compared to their conventional counterparts. In all products, the dust emissions from sanding were found to consist of five size modes: three modes under 1 μm and two modes around 1 and 2 μm. Corrected for the emission from the sanding machine, the sanding dust, was dominated by 100–300 nm size particles, whereas the mass and surface area spectra were dominated by the micrometer modes. Adding ENPs to the studied products only vaguely affected the geometric mean diameters of the particle modes in the sanding dust when compared to their reference products. However, we observed considerable differences in the number concentrations in the different size modes, but still without revealing a clear effect of ENPs on dust emissions from sanding

Global Ethics and Nanotechnology: A Comparison of the Nanoethics Environments of the EU and China

The following article offers a brief overview of current nanotechnology policy, regulation and ethics in Europe and The People’s Republic of China with the intent of noting (dis)similarities in approach, before focusing on the involvement of the public in science and technology policy (i.e. participatory Technology Assessment). The conclusions of this article are, that (a) in terms of nanosafety as expressed through policy and regulation, China PR and the EU have similar approaches towards, and concerns about, nanotoxicity—the official debate on benefits and risks is not markedly different in the two regions; (b) that there is a similar economic drive behind both regions’ approach to nanodevelopment, the difference being the degree of public concern admitted; and (c) participation in decision-making is fundamentally different in the two regions. Thus in China PR, the focus is on the responsibility of the scientist; in the EU, it is about government accountability to the public. The formulation of a Code of Conduct for scientists in both regions (China PR’s predicted for 2012) reveals both similarity and difference in approach to nanotechnology development. This may change, since individual responsibility alone cannot guide S&T development, and as public participation is increasingly seen globally as integral to governmental decision-making

A Biopersistence Study following Exposure to Chrysotile Asbestos Alone or in Combination with Fine Particles

In designing a study to evaluate the inhalation biopersistence of a chrysotile asbestos that was used as a component of a joint-compound, a feasibility study was initiated to evaluate the short-term biopersistence of the chrysotile alone and of the chrysotile in combination witht the sanded reformulated joint-compound. Two groups of Wistar rats were exposed to either 7RF3 chrysotile (Group 2) or to 7RF3 chrysotile combined with aerosolized sanded joint-compound (Group 3). In addition, a control group was exposed to flltered-air. The chrysotile used in the Ready Mix joint compound is rapidly removed from the lung. The chrysotile alone exposure group had a clearance half-time of fibers L > 20 μm of 2.2 days; in the chrysotile plus sanded exposure group the clearance half-time of fibers L > 20 μm was 2.8 days. However, across all size ranges there was approximately an order of magnitude decrease in the mean number of fibers remaining in the lungs of Group 3 as compared to Group 2 despite similiar aerosol exposures. Histopathological examination showed that the chrysotile exposed lungs had the same appearance as the flltered-air controls. This study uniquely illustrates that additional concurrent exposure to an aerosol of the sanded joint-compound, with large numbers of fine-particles depositing in the lungs, accelerates the recruitment of macrophages, resulting in a tenfold decrease in the number of fibers remaining in the lung. The increased number of macrophages in the chrysotile/sanded joint exposure group was confirmed histologically, with this being the only exposure-related histological finding reported

Role of Surface Area, Primary Particle Size, and Crystal Phase on Titanium Dioxide Nanoparticle Dispersion Properties

Characterizing nanoparticle dispersions and understanding the effect of parameters that alter dispersion properties are important for both environmental applications and toxicity investigations. The role of particle surface area, primary particle size, and crystal phase on TiO2 nanoparticle dispersion properties is reported. Hydrodynamic size, zeta potential, and isoelectric point (IEP) of ten laboratory synthesized TiO2 samples, and one commercial Degussa TiO2 sample (P25) dispersed in different solutions were characterized. Solution ionic strength and pH affect titania dispersion properties. The effect of monovalent (NaCl) and divalent (MgCl2) inert electrolytes on dispersion properties was quantified through their contribution to ionic strength. Increasing titania particle surface area resulted in a decrease in solution pH. At fixed pH, increasing the particle surface area enhanced the collision frequency between particles and led to a higher degree of agglomeration. In addition to the synthesis method, TiO2 isoelectric point was found to be dependent on particle size. As anatase TiO2 primary particle size increased from 6 nm to 104 nm, its IEP decreased from 6.0 to 3.8 that also results in changes in dispersion zeta potential and hydrodynamic size. In contrast to particle size, TiO2 nanoparticle IEP was found to be insensitive to particle crystal structure

Nanotoksikologija za varno in trajnostno nanotehnologijo

Nanotechnology is the term given to those areas of science and engineering where the phenomena take place at nanoscale dimensions. Nanoparticles are particles with <100 nm in one dimension. They have different physical, chemical, electrical and optical properties than those that occur in bulk samples of the same material. Understanding these nanoscale properties and finding ways to engineer new nanomaterials will have a revolutionary impact, from more efficient energy generation and data storage to improved methods for diagnosing and treating diseases. Nanotechnology is poised to become a major factor in the world’s economy and part of our everyday lives in the near future. Hundreds of tonnes of nanoparticles already enter the environment annually, but still very little is known of their interactions with biological systems. Recent studies indicate that some nanoparticles are not completely benign to biological and environmental targets. The challenge for toxicologists is to identify key factors that can be used to predict toxicity, permit targeted screening, and allow material scientists to generate new, safer nanoparticles with this structure-toxicity information in mind. The aim of this paper is to summarize some known facts about nanomaterials and discuss future perspectives, regulatory issues and tasks of the emerging branch of toxicology, that is, nanotoxicology.Nanomateriali izboljćujejo kvaliteto naćega življenja, zato bo njihova uporaba na različnih področjih življenja dramatično narasla. Po nekaterih ocenah bo imela nanotehnologija večji vpliv na družbno kot ga je imela industrijska revolucija. Kot posledica razmaha nanotehnologije se bo povečala poklicna in javna izpostavljenost nanodelcem ter izpostavljenost okolja. Nanodelci, ki nas najbolj zanimajo, so strukture, ki imajo v eni dimenziji manj kot 100 nm, in jih je izdelal človek. Njihove lastnosti se zaradi njihove majhnosti bistveno razlikujejo od lastnosti, ki jih imajo večji delci enake kemijske sestave. Šele v zadnjem času so se začela pojavljati vpraćanja in vzpodbujati raziskave o potencialni nevarnosti nanodelcev. Trenutni rezultati toksikoloćkih ćtudij potrjujejo kvarne učinke nanodelcev in navajajo, da nanodelci najverjetneje delujejo na organizem preko oksidativnega stresa. Študije nakazujejo ćtevilne posebnosti nanodelcev pri interakcijah s celicami, tkivi in organizmi. Najverjetneje je ta trenutek pomembno pridobiti čim več ustreznega znanja za oblikovanje regulative na področju varne proizvodnje in uporabe nanodelcev. Namen prispevka je povzeti že znana dejstva o nanodelcih in predstaviti naloge nove smeri v toksikologiji, nanotoksikologije. V prispevku je povzeta najnovejća regulativa na področju ugotavljanja in zagotavljanja varnosti proizvodov nanotehnologij, navedene so nekatere koristne baze podatkov, razprave ter nacionalne in mednarodne smernice na področju nanotehnologije

In vivo and in vitro proinflammatory effects of particulate air pollution (PM10).

Epidemiologic studies have reported associations between fine particulate air pollution, especially particles less than 10 mm in diameter (PM10), and the development of exacerbations of asthma and chronic obstructive pulmonary disease. However, the mechanism is unknown. We tested our hypothesis that PM10 induces oxidant stress, causing inflammation and injury to airway epithelium. We assessed the effects of intratracheal instillation of PM10 in rat lungs. The influx of inflammatory cells was measured in bronchoalveolar lavage (BAL). Airspace epithelial permeability was assessed as total protein in bronchoalveolar lavage fluid (BALF) in vivo. The oxidant properties of PM10 were determined by their ability to cause changes in reduced glutathione (GSH) and oxidized glutathione (GSSG). We also compared the effects of PM10 with those of fine (CB) and ultrafine (ufCB) carbon black particles. Six hours after intratracheal instillation of PM10, we noted an influx of neutrophils (up to 15% of total BAL cells) in the alveolar space, increased epithelial permeability, an increase in total protein in BALF from 0.39 +/- 0.01 to 0.62 +/- 0.01 mg/ml (mean +/- SEM) and increased lactate dehydrogenase concentrations in BALF. An even greater inflammatory response was observed after intratracheal instillation of ufCB, but not after CB instillation. PM10 had oxidant activity in vivo, as shown by decreased GSH in BALF (from 0.36 +/- 0.05 to 0.25 +/- 0.01 nmol/ml) after instillation. BAL leukocytes from rats treated with PM10 produced greater amounts of nitric oxide, measured as nitrite (control 3.07 +/- 0.33, treated 4.45 +/- 0.23 mM/1 x 10(6) cells) and tumor necrosis factor alpha (control 21.0 +/- 3.1, treated 179.2 +/- 29.4 unit/1 x 10(6) cells) in culture than BAL leukocytes obtained from control animals. These studies provide evidence that PM10 has free radical activity and causes lung inflammation and epithelial injury. These data support our hypothesis concerning the mechanism for the adverse effects of particulate air pollution on patients with airway diseases

Rapid translocation of nanoparticles from the lung airspaces to the body

Nano-size particles show promise for pulmonary drug delivery, yet their behavior after deposition in the lung remains poorly understood. In this study, a series of near-infrared (NIR) fluorescent nanoparticles were systematically varied in chemical composition, shape, size and surface charge, and their biodistribution and elimination were quantified in rat models after lung instillation. We demonstrate that nanoparticles with hydrodynamic diameter (HD) less than ≈34 nm and a noncationic surface charge translocate rapidly from the lung to mediastinal lymph nodes. Nanoparticles of HD < 6 nm can traffic rapidly from the lungs to lymph nodes and the bloodstream, and then be subsequently cleared by the kidneys. We discuss the importance of these findings for drug delivery, air pollution and carcinogenesis