Nanoparticle exposure at nanotechnology workplaces: A review

Risk, associated with nanomaterial use, is determined by exposure and hazard potential of these materials. Both topics cannot be evaluated absolutely independently. Realistic dose concentrations should be tested based on stringent exposure assessments for the corresponding nanomaterial taking into account also the environmental and product matrix. This review focuses on current available information from peer reviewed publications related to airborne nanomaterial exposure. Two approaches to derive realistic exposure values are differentiated and independently presented; those based on workplace measurements and the others based on simulations in laboratories. An assessment of the current available workplace measurement data using a matrix, which is related to nanomaterials and work processes, shows, that data are available on the likelihood of release and possible exposure. Laboratory studies are seen as an important complementary source of information on particle release processes and hence for possible exposure. In both cases, whether workplace measurements or laboratories studies, the issue of background particles is a major problem. From this review, major areas for future activities and focal points are identified

Deagglomeration testing of airborne nanoparticle agglomerates: stability analysis under varied aerodynamic shear and relative humidity conditions

Occupational exposure to nanomaterial aerosols poses potential health risks to workers at nanotechnology workplaces. Understanding the mechanical stability of airborne nanoparticle agglomerates under varied mechanical forces and environmental conditions is important for estimating their emission potential and the released particle size distributions which in consequence alters their transport and human uptake probability. In this study, two aerosolization and deagglomeration systems were used to investigate the potential for deagglomeration of nanopowder aerosols with different surface hydrophilicity under a range of shear forces and relative humidity conditions. Critical orifices were employed to subject airborne agglomerates to the shear forces induced by a pressure drop. Increasing applied pressure drop were found to be associated with decreased mean particle size and increased particle number concentrations. Rising humidity decreased the deagglomeration tendency as expressed by larger modal particle sizes and lower number concentrations compared to dry conditions. Hydrophilic aerosols exhibited higher sensitivities to changes in humidity than hydrophobic particles. However, the test systems themselves also differed in generated particle number concentrations and size distributions, which in turn altered the responses of created aerosols to humidity changes. The results of the present study clearly demonstrate that a) humidity control is essential for dustiness and deagglomeration testing, b) that (industrial) deagglomeration, e.g. for preparation of aerosol suspensions, can be manipulated by subjecting airborne particles to external energies, and c) that the humidity of workplace air may be relevant when assessing occupational exposure to nanomaterial aerosols

Emission measurement and safety assessment for the production process of silicon nanoparticles in a pilot-scale facility

Emission into the workplace was measured for the production process of silicon nanoparticles in a pilot-scale facility at the Institute of Energy and Environmental Technology e.V. (IUTA). The silicon nanoparticles were produced in a hot-wall reactor and consisted of primary particles around 60nm in diameter. We employed real-time aerosol instruments to measure particle number and lung-deposited surface area concentrations and size distribution; airborne particles were also collected for off-line electron microscopic analysis. Emission of silicon nanoparticles was not detected during the processes of synthesis, collection, and bagging. This was attributed to the completely closed production system and other safety measures against particle release which will be discussed briefly. Emission of silicon nanoparticles significantly above the detection limit was only observed during the cleaning process when the production system was open and manually cleaned. The majority of the detected particles was in the size range of 100-400nm and were silicon nanoparticle agglomerates first deposited in the tubing then re-suspended during the cleaning process. Appropriate personal protection equipment is recommended for safety protection of the workers during cleanin

How can nanobiotechnology oversight advance science and industry: examples from environmental, health, and safety studies of nanoparticles (nano-EHS)

Nanotechnology has great potential to transform science and industry in the fields of energy, material, environment, and medicine. At the same time, more concerns are being raised about the occupational health and safety of nanomaterials in the workplace and the implications of nanotechnology on the environment and living systems. Studies on environmental, health, and safety (EHS) issues of nanomaterials have a strong influence on public acceptance of nanotechnology and, eventually, affect its sustainability. Oversight and regulation by government agencies and non-governmental organizations (NGOs) play significant roles in ensuring responsible and environmentally friendly development of nanotechnology. The EHS studies of nanomaterials can provide data and information to help the development of regulations and guidelines. We present research results on three aspects of EHS studies: physico-chemical characterization and measurement of nanomaterials; emission, exposure, and toxicity of nanomaterials; and control and abatement of nanomaterial releases using filtration technology. Measurement of nanoparticle agglomerates using a newly developed instrument, the Universal NanoParticle Analyzer (UNPA), is discussed. Exposure measurement results for silicon nanoparticles in a pilot scale production plant are presented, as well as exposure measurement and toxicity study of carbon nanotubes (CNTs). Filtration studies of nanoparticle agglomerates are also presented as an example of emission control method

Fine and ultrafine particles from indoor sources – Effects on healthy humans in a controlled exposure study and on lung epithelial cells in vitro

In recent years increasing concern has been expressed about the potential adverse health effects of particles from indoor sources. The aims of the EPIA project were: (1) to characterize potentially relevant indoor sources of (ultra)fine particles with respect to their emission levels and composition and (2) to investigate their adverse health effects. We investigated the effects of emissions from candle burning (CB), toasting of bread (TB) and sausage frying (FS) in a randomized, cross-over sham-controlled exposure study in healthy adults as well as in vitro in A549 human lung epithelial cells. Participants were exposed for 2 h to each of these sources at two different exposure levels, and examined before, during and after the exposures at defined time-intervals. We found transient associations between exposures and several respiratory and cardiovascular effects as well as inflammatory changes (e.g. lung function, blood pressure, arterial stiffness, interleukin-8 in nasal lavage/blood). Specific effects were found to depend strongly on the emission source and the selected exposure metric (e.g. size-specific particle mass concentration, size-specific particle number concentration, lung deposited surface area concentration). Evaluation of PM2.5 samples in the A549 cells, revealed an increased interleukin-8 release and DNA strand breakage induction for toasting, whereas candle burning only resulted in DNA damage. The results from our project demonstrate that elevated concentrations from certain indoor emission sources may lead to changes in the lung and cardiovascular systems as well as possibly induce inflammation

Dustiness and deagglomeration testing: interlaboratory comparison of systems for nanoparticle powders

Different types of aerosolization and deagglomeration testing systems exist for studying the properties of nanomaterial powders and their aerosols. However, results are dependent on the specific methods used. In order to have well-characterized aerosols, we require a better understanding of how system parameters and testing conditions influence the properties of the aerosols generated. In the present study, four experimental setups delivering different aerosolization energies were used to test the resultant aerosols of two distinct nanomaterials (hydrophobic and hydrophilic TiO2). The reproducibility of results within each system was good. However, the number concentrations and size distributions of the aerosols created varied across the four systems; for number concentrations, e.g., from 10(3) to 10(6) #/cm(3). Moreover, distinct differences were also observed between the two materials with different surface coatings. The article discusses how system characteristics and other pertinent conditions modify the test results. We propose using air velocity as a suitable proxy for estimating energy input levels in aerosolization systems. The information derived from this work will be especially useful for establishing standard operating procedures for testing nanopowders, as well as for estimating their release rates under different energy input conditions, which is relevant for occupational exposure

Thermal-optical analysis for the measurement of elemental carbon (EC) and organic carbon (OC) in ambient air a literature review

Thermal-optical analysis is currently under consideration by the European standardization body (CEN) as the reference method to quantitatively determine organic carbon (OC) and elemental carbon (EC) in ambient air. This paper presents an overview of the critical parameters related to the thermal-optical analysis including thermal protocols, critical factors and interferences of the methods examined, method inter-comparisons, inter-laboratory exercises, biases and artifacts, and reference materials. The most commonly used thermal protocols include NIOSH-like, IMPROVE_A and EUSAAR_2 protocols either with light transmittance or reflectance correction for charring. All thermal evolution protocols are comparable for total carbon (TC) concentrations but the results vary significantly concerning OC and especially EC concentrations. Thermal protocols with a rather low peak temperature in the inert mode like IMPROVE_A and EUSAAR_2 tend to classify more carbon as EC compared to NIOSH-like protocols, while charring correction based on transmittance usually leads to smaller EC values compared to reflectance. The difference between reflectance and transmittance correction tends to be larger than the difference between different thermal protocols. Nevertheless, thermal protocols seem to correlate better when reflectance is used as charring correction method. The difference between EC values as determined by the different protocols is not only dependent on the optical pyrolysis correction method, but also on the chemical properties of the samples due to different contributions from various sources. The overall conclusion from this literature review is that it is not possible to identify the "best" thermal-optical protocol based on literature data only, although differences attributed to the methods have been quantified when possible.This work was undertaken under Mandate M/503 “Standardisation mandate to CEN, CENELEC and ETSI in support of the implementation of the Ambient Air Quality Legislation”, ENX “Ambient air – Measurement of airborne lemental carbon (EC) and organic carbon (OC) in PM 2.5 deposited on filters”.EUR 1,920 APC fee funded by the EC FP7 Post-Grant Open Access PilotPeer reviewe

Управління загрозами фінансовій безпеці підприємства

Розроблено блок-схему алгоритму управління загрозами фінансовій безпеці підприємства; виділено основні етапи здійснення цього процесу: оцінювання, аналіз та управління. Визначено сутність, зміст, переваги та недоліки застосування методів оцінювання загроз фінансовій безпеці в системі фінансового менеджменту підприємства. Ключові слова: підприємство, фінансова безпека, загрози, оцінювання, аналіз, управління.Составлена блок-схема алгоритма управления угрозами финансовой безопасности предприятия. Выделены основные этапы осуществления данного процесса: оценивание, анализ и управление. Определены сущность, содержание, преимущества и недостатки методов оценивания угроз финансовой безопасности в системе финансового менеджмента предприятия. Ключевые слова: предприятие, финансовая безопасность, угрозы, оценивание, анализ, управление.Enterprise financial security threats management main terms essence and contents were defined on the basis of financial and economic literature analysis and generalization: enterprise financial security threats management is a multistage process, which includes evaluation, management and analysis of enterprise financial security threats management; evaluation of enterprise financial security threats is a process of identification of threats influence on enterprise financial security; analysis of enterprise financial security threats is a process of threats identification, which influence on enterprise financial security. It is established that the majority of modern domestic and foreign scientists consider two groups of enterprise financial security threats estimation: qualitative or subjective (expert, probabilistic (concerning loss, favorable possibilities), consequences analysis) and quantitative or objective (statistical, analytical, rating, expense expediency, analogues, decision tree, normative). Comparative analysis of qualitative and quantitative enterprise financial security threats estimation enables to detect that use either of them has its own advantages and disadvantages. Some methods require using the considerable mass data and at the same time leave out of the account the time factor; others are insufficiently developed for using in the domestic economic conditions. Therefore the choice of the method is made only owing to the purpose of the enterprise financial security threats estimation. It is proved that the methods of the enterprise financial security threats management could be divided into three groups: reduction, maintenance and transmission. Reduction of enterprise financial security threats level provides preventive management and logistical measures implementation as to unfavorable events in financial and economic activities prevention or negative consequences liquidation. As measures, implemented for enterprise financial security threats level maintaining, could be referred the following: getting loans on compensation for losses, which enterprise got as a result of unforeseen, unfavorable events in its financial and economic activities, resumption of output production (goods, works, services) with the help of finance and credit establishments activities, government grants etc. Keywords: enterprise, financial security, threats, evaluation, analysis, management