Indoor Nanoparticle Characterization in Construction Waste Recycling Companies over Time

Building activity is a significant source of atmospheric contamination by ultrafine dust. Cognizant of this fact, those active in the use and recycling of construction materials must be aware of the risks associated with exposure to nanoparticles (NPs) and ultra-fine particles (UFPs), as well as the associated health impacts. This work analyzed NPs and UFPs generated in a small building-material recycling company using high-resolution electron microscopes and X-ray Diffraction. A self-made passive sampler (LSPS) that can obtain particulate samples without physical and morphological changes, especially where there is a suspension of particulate material, was used in this study. A total of 96 particulate samples, using the LSPS for three months in four seasons, were collected during the study. Thus, the dry deposition of the particles, which are considered highly harmful to human health, was found in each of the four seasons of the year. It is suggested that for future research, the toxicological evaluations of the particulates in the construction industry should be investigated through the consideration of measures to control and mitigate the health risks of workers regarding exposure to NPs and UFPs.

Exposure to Ambient Ultra-Fine Particles and Stroke

Stroke is one of the main causes of death attributed to air pollution. Significant research has now shown that urban air pollutants exposure has been established as a source of neuroinflammation and oxidative stress that causes Central Nervous System (CNS) disease. Transition metals, Particulate Matter (PM) including fine particles (PM ≤ 2.5 μm, PM 2.5) and ultra-fine particles (UFPs, PM <0.1 μm, PM 0.1), nitrogen oxide, and ozone are potent or oxidant that capable of producing Reactive Oxygen Species (ROS) can reach the brain and affect CNS health. Numerous biological mechanisms are responsible that are not well understood. Recent studies suggest that changes in the Blood-Brain Barrier (BBB) and or leakage and transmission along the olfactory nerve into the Olfactory Bulb (OB) and microglial activation are the key factors of CNS damage following exposure to air pollution. This preliminary review cites evidence that ambient PM exposure is one of the causes of stroke.

A Hybrid Device for Enhancing Flotation of Fine Particles by Combining Micro-Bubbles with Conventional Bubbles

Flotation in the mining industry is a very significant separation technique. It is known that fine and ultra-fine particles are difficult to float, leading to losses of valuable minerals, mainly due to their low collision efficiency with bubbles. Flotation of fine particles can be enhanced either by increasing the apparent particle size or by decreasing the bubble size. Literature review reveals that electroflotation resulted in higher recoveries of ultrafine particles as compared with dispersed-air flotation, because electrolytic bubbles are smaller in size. To this end, the best practical approach is to combine conventional air bubbles and micro-bubbles from water electrolysis. Therefore, the design, fabrication, and operation of a bench-scale micro-bubble generator through water electrolysis is proposed. Moreover, this electrolysis unit is adapted in a mechanical Denver-type flotation cell. The resulting hybrid flotation device is capable of producing bubbles within a wide range of diameters. The significance of this process is that micro-bubbles, attached tothe surface of fine particles, facilitate the attachment of conventional-sized bubbles and subsequently increase the flotation recovery of particles. Experimental flotation results so far on the hybrid device indicate the enhancement of fine particle recovery by approximately 10% with the addition of micro-bubbles.

Monitoring of Indoor Ultrafine Particulate Matter at the Sites of the Czech Armed Forces

Ultrafine particles and nanoparticles in the air are evaluated as a risk factor for the development of respiratory and other healthsymptoms due to their inhalation from the ambient air. The Czech Army professionals are expected to have frequent presence in apolluted environment and regular exposure to air with increased concentration of airborne pollutants. The report evaluates the presenceof ultra-fine particles (in the range of about 7.6–299.6 nm) in rooms often used by soldiers during their working hours whenthey are not deployed. The purpose is to assess whether the presence of troops in these workplaces is safe and does not pose a riskof adverse health effects in itself. Testing took place in three military rooms (classroom 1, classroom 2 and exercise flight simulatorroom). Seven samples of air were analysed in time by the scanning mobility particle sizer in succession. Mean particle concentrationswere found at 1.79×104, 7.53×103 and 8.39×103 N·cm-3 for the classroom 1, classroom 2 and exercise flight simulator room.Conclusions of the research have shown that particle concentrations in the places of the Czech Army can reach values that borderthe immission limits stated by the World Health Organisation.

Large hemispheric difference in ultrafine aerosol concentrations in the lowermost stratosphere at mid and high latitudes

The details of aerosol processes and size distributions in the stratosphere are important for both heterogeneous chemistry and aerosol-radiation interactions. Using in-situ, global-scale measurements of the size distribution of particles with diameters > 3 nm from the NASA Atmospheric Tomography Mission (ATom), we identify a mode of ultrafine aerosol in the lowermost stratosphere (LMS) at mid and high latitudes. This mode is substantial only in the northern hemisphere (NH), and was observed in all four seasons. We also observe elevated SO2, an important precursor for new particle formation (NPF) and growth, in the NH LMS. We use box modelling and thermodynamic calculations to show that NPF can occur in the LMS conditions observed on ATom. Aircraft emissions are shown as likely sources of this SO2, as well as a potential source of ultrafine particles directly emitted by, or formed in the plume of the engines. These ultra-fine particles have the potential to grow to larger sizes, and to coagulate with larger aerosol, affecting heterogeneous chemistry and aerosol-radiation interactions. Understanding all sources and characteristics of stratospheric aerosol is important in the context of anthropogenic climate change as well as proposals for climate intervention via stratospheric sulphur injection. This analysis not only adds to the, currently sparse, observations of the global impact of aviation, but also introduces another aspect of climate influence, namely a size distribution shift of the background aerosol distribution in the LMS.

Internal Dislocation Density in Deformed GlidCop from X-Ray Line Profile Analysis

Dislocation densities of GLIDCOP®, dispersion-strengthened copper with ultra-fine particles of aluminum oxide, were evaluated by employing the X-ray line profile analysis using the modified Williamson-Hall and modified Warren-Averbach methods. X-ray diffraction profiles for GlidCop samples with compressive strains applied at 200oC were measured with synchrotron radiation. The dislocation densities of GlidCop with compressive strain ranging from 0.6 to 4.3% were in the order of 3.2 × 1014–5.8 × 1014 m-2. The dislocation density increased with increasing the compressive strain within the measured strain range.

Review of composite metal polymers reinforced with nano- and ultra-dispersed particles

The results of studies of the structure, mechanical and tribological properties of composite materials based on polytetrafluoroethylene and simple (Al2O3, Cr2O3, ZrO2) and complex (spinels CoA12O3 and MgAl2O4, and cordierite 2MgO—2Al2O35SiO2) oxide nanopowders are presented; as well as amorphous polyvinyl chloride with heat stabilizers and elastomeric additives. Investigations of thin-layer fluorine-containing coatings with a polymer matrix modified by nano- and ultra-fine particles of diamond-containing graphite by atomic force microscopy are presented.

Translocation of (ultra)fine particles and nanoparticles across the placenta; a systematic review on the evidence of in vitro, ex vivo, and in vivo studies

Fetal development is a crucial window of susceptibility in which exposure may lead to detrimental health outcomes at birth and later in life. The placenta serves as a gatekeeper between mother and fetus. Knowledge regarding the barrier capacity of the placenta for nanoparticles is limited, mostly due to technical obstacles and ethical issues. We systematically summarize and discuss the current evidence and define knowledge gaps concerning the maternal-fetal transport and fetoplacental accumulation of (ultra)fine particles and nanoparticles. We included 73 studies on placental translocation of particles, of which 21 in vitro/ex vivo studies, 50 animal studies, and 2 human studies on transplacental particle transfer. This systematic review shows that (i) (ultra)fine particles and engineered nanoparticles can bypass the placenta and reach fetal units as observed for all the applied models irrespective of the species origin (i.e., rodent, rabbit, or human) or the complexity (i.e., in vitro, ex vivo, or in vivo), (ii) particle size, particle material, dose, particle dissolution, gestational stage of the model, and surface composition influence maternal-fetal translocation, and (iii) no simple, standardized method for nanoparticle detection and/or quantification in biological matrices is available to date. Existing evidence, research gaps, and perspectives of maternal-fetal particle transfer are highlighted.