Visualization of Dust Generation in Outdoor Workplaces Using A Wearable Particle Monitor and Global Navigation Satellite System.

We manufactured a wearable particle monitor (WPM), which is a simple and low-cost dust monitor. We aimed to evaluate the usefulness of the device by using it and location information of a Global Navigation Satellite System (GNSS) to measure dust generation in outdoor workplaces. We used nine WPMs and a particle counter KC-52 to measure in parallel the dust concentration diffusing standard particles in a dust exposure apparatus to evaluate the measurability of the WPM, and visualized dust generation in outdoor workplaces to evaluate its usability.

Combining Indoor Positioning Using Wi-Fi Round Trip Time with Dust Measurement in the Field of Occupational Health.

Monitoring of personal exposure to hazardous substances has garnered increasing attention over the past few years. However, no straightforward and exact indoor positioning technique has been available until the recent discovery of Wi-Fi round trip time (Wi-Fi RTT). In this study, we investigated the possibility of using a combination of Wi-Fi RTT for indoor positioning and a wearable particle monitor (WPM) to observe dust concentration during walking in a simulated factory.

Changes over time in pulmonary inflammatory response in rat lungs after intratracheal instillation of nickel oxide nanoparticles.

Objective: Nickel oxide nanoparticles (NiONPs) are representative metal oxide NPs and are categorized as an insoluble nickel compound. Our previous studies suggested that NiONPs have more pulmonary toxicity than micron-sized NiO because they may dissolve slowly and produce many more Ni ions. We confirmed the hypothesis that the slow dissolution of NiONPs induces a change in inflammatory response over time.

[Design and Evaluation of Miniature Cyclones for Dust Indicators].

Dust indicators based on light scattering photometers are widely used to measure aerosol concentrations in work environments. These concentrations at workplaces in Japan are measured by these dust indicators and calibrated by mass concentration in order to control workers' exposure to dust. The mass concentration in a specific point in a workplace is measured simultaneously with a dust indicator.

Inhalation of titanium dioxide (P25) nanoparticles to rats and changes in surfactant protein (SP-D) levels in bronchoalveolar lavage fluid and serum.

Titanium dioxide (TiO) nanoparticles are typical and widely used nanomaterials, and there are many studies on the inflammatory responses induced by their inhalation. In this study, we conducted a 4-week inhalation exposure study of aerosolized TiO nanoparticles (P25) to male Wistar rats. The mean aerosol concentration measured at each day was 4.

Health Effects of Toner Exposure Among Japanese Toner-Handling Workers: A 10-Year Prospective Cohort Study.

The main objective of this study was to evaluate the risk of the respiratory diseases, i.e. pneumoconiosis, lung fibrosis, granulomatous pneumonitis, lung cancer and bronchial asthma, which have been reported as related to toner exposure.

Usefulness of myeloperoxidase as a biomarker for the ranking of pulmonary toxicity of nanomaterials.

Background: In order to examine whether myeloperoxidase (MPO) can be a useful marker for evaluating the pulmonary toxicity of nanomaterials, we analyzed MPO protein in bronchoalveolar lavage fluid (BALF) samples obtained from previous examinations of a rat model. In those examinations we performed intratracheal instillation exposures (dose: 0.2-1.

Biopersistence of NiO and TiO₂ Nanoparticles Following Intratracheal Instillation and Inhalation.

The hazards of various types of nanoparticles with high functionality have not been fully assessed. We investigated the usefulness of biopersistence as a hazard indicator of nanoparticles by performing inhalation and intratracheal instillation studies and comparing the biopersistence of two nanoparticles with different toxicities: NiO and TiO₂ nanoparticles with high and low toxicity among nanoparticles, respectively. In the 4-week inhalation studies, the average exposure concentrations were 0.

The Effectiveness of Specific Risk Mitigation Techniques Used in the Production and Handling of Manufactured Nanomaterials: A Systematic Review.

Many kinds of manufactured nanomaterials (MNMs) have been developed and used as basic materials of industrial products, and they may pose health risks for workers in not only developed countries but also in developing countries. Few studies have looked at the evidence for effects of controls that mitigate the risk of exposure to MNMs. Therefore, we systematically searched the literature from the year 2000 to 2015.

Assessment of Pulmonary Toxicity Induced by Inhaled Toner with External Additives.

We investigated the harmful effects of exposure to a toner with external additives by a long-term inhalation study using rats, examining pulmonary inflammation, oxidative stress, and histopathological changes in the lung. Wistar rats were exposed to a well-dispersed toner (mean of MMAD: 2.1 m) at three mass concentrations of 1, 4, and 16 mg/m for 22.

Pulmonary responses in rat lungs after intratracheal instillation of 4 crystal forms of titanium dioxide nanoparticles.

Objective: Titanium dioxide nanoparticles are widely used as UV filters in cosmetics and as a photocatalyst. We evaluated pulmonary responses to different crystal forms of TiO nanoparticles.

Methods: We used 4 different TiO samples with similar specific surface areas (anatase, rutile, amorphous, and P25).

Evaluation of Pulmonary Toxicity of Zinc Oxide Nanoparticles Following Inhalation and Intratracheal Instillation.

We conducted inhalation and intratracheal instillation studies of zinc oxide (ZnO) nanoparticles in order to examine their pulmonary toxicity. F344 rats were received intratracheal instillation at 0.2 or 1 mg of ZnO nanoparticles with a primary diameter of 35 nm that were well-dispersed in distilled water.

Comparison of the Pulmonary Oxidative Stress Caused by Intratracheal Instillation and Inhalation of NiO Nanoparticles when Equivalent Amounts of NiO Are Retained in the Lung.

NiO nanoparticles were administered to rat lungs via intratracheal instillation or inhalation. During pulmonary toxicity caused by NiO nanoparticles, the induction of oxidative stress is a major factor. Both intratracheal instillation and inhalation of NiO nanoparticles induced pulmonary oxidative stress.

Long-term retention of pristine multi-walled carbon nanotubes in rat lungs after intratracheal instillation.

As a result of the growing potential industrial and medical applications of multi-walled carbon nanotubes (MWCNTs), people working in or residing near facilities that manufacture them may be exposed to airborne MWCNTs in the future. Because of concerns regarding their toxicity, quantitative data on the long-term clearance of pristine MWCNTs from the lungs are required. We administered pristine MWCNTs well dispersed in 0.

Pulmonary toxicity of well-dispersed cerium oxide nanoparticles following intratracheal instillation and inhalation.

We performed inhalation and intratracheal instillation studies of cerium dioxide (CeO) nanoparticles in order to investigate their pulmonary toxicity, and observed pulmonary inflammation not only in the acute and but also in the chronic phases. In the intratracheal instillation study, F344 rats were exposed to 0.2 mg or 1 mg of CeO nanoparticles.

Comparison of pulmonary inflammatory responses following intratracheal instillation and inhalation of nanoparticles.

In order to examine whether intratracheal instillation studies can be useful for determining the harmful effect of nanoparticles, we performed inhalation and intratracheal instillation studies using samples of the same nanoparticles. Nickel oxide nanoparticles (NiO) and titanium dioxide nanoparticles (TiO2) were used as chemicals with high and low toxicities, respectively. In the intratracheal instillation study, rats were exposed to 0.

Comparison between whole-body inhalation and nose-only inhalation on the deposition and health effects of nanoparticles.

Objectives: We performed the two inhalation exposures, whole-body inhalation and nose-only inhalation, to investigate the pulmonary deposition and health effects of the two inhalation methods.

Methods: In both methods, we exposed rats to the same TiO2 nanoparticles at almost the same exposure concentration for 6 h and compared the deposited amounts of nanoparticles and histopathological changes in the lungs. Rats were exposed to rutile-type TiO2 nanoparticles generated by the spray-dry method for 6 h.

Pulmonary toxicity of well-dispersed titanium dioxide nanoparticles following intratracheal instillation.

In order to investigate the pulmonary toxicity of titanium dioxide (TiO) nanoparticles, we performed an intratracheal instillation study with rats of well-dispersed TiO nanoparticles and examined the pulmonary inflammation and histopathological changes in the lung. Wistar Hannover rats were intratracheally administered 0.2 mg (0.

Analysis of pulmonary surfactant in rat lungs after inhalation of nanomaterials: Fullerenes, nickel oxide and multi-walled carbon nanotubes.

The health risks of inhalation exposure to engineered nanomaterials in the workplace are a major concern in recent years, and hazard assessments of these materials are being conducted. The pulmonary surfactant of lung alveoli is the first biological entity to have contact with airborne nanomaterials in inhaled air. In this study, we retrospectively evaluated the pulmonary surfactant components of rat lungs after a 4-week inhalation exposure to three different nanomaterials: fullerenes, nickel oxide (NiO) nanoparticles and multi-walled carbon nanotubes (MWCNT), with similar levels of average aerosol concentration (0.

[Working environmental control for industrial physicians].

Forty years has passed after the promulgation of the Industrial Safety and Health Law, Japan. In this paper, working environmental control based on the law was overviewed. The working environmental control includes evaluation and engineering controls of hazardous elements in the work environment.

Analysis of pulmonary surfactant in rat lungs after intratracheal instillation of short and long multi-walled carbon nanotubes.

Multi-walled carbon nanotubes (MWCNTs) are interesting new materials, but there is some concern about their harmfulness due to their fibrous nature. To determine the difference in the biological effects of MWCMTs by fiber length, we prepared two MWCNT samples from one bulk sample. One consisted of cut up short fibers (Short; average length=0.

Expression of cytokine-induced neutrophil chemoattractant in rat lungs following an intratracheal instillation of micron-sized nickel oxide nanoparticle agglomerates.

Objective: In our previous study, we reported that the micron-sized nickel oxide nanoparticle agglomerates induced neutrophil infiltration and the gene expression of the cytokine-induced neutrophil chemoattractant (CINC)-2αβ in a rat lung. In this study, we examined the expression of the CINCs family in the lung using the same rat model exposed to micron-sized nickel oxide nanoparticle agglomerates.

Methods: The count median diameter of nickel oxide nanoparticle agglomerates suspended in saline was 1.

[Biological effect of fullerene (C60) to lung by inhalation or instillation].

Fullerene (C60) is a newly generated nanoparticle that has a soccer-ball structure with 60 carbon atoms. Fullerenes are expected to have a multitude of uses, for example as energy device materials or information technology materials. The biological effects of nanoparticles are now being discussed, and there are ongoing animal studies using various nanoparticles.

Analysis of bronchoalveolar lavage fluid adhering to lung surfactant. Experiment on intratracheal instillation of nickel oxide with different diameters.

Nickel oxide with two different particle sizes, micron size (NiO) and submicron size (nNiOm), as well as crystalline silica as a positive control and titanium dioxide as a negative control, were intratracheally instilled in rats and the phospholipid concentration and the protein concentration and surface tension of bronchoalveolar lavage fluid (BALF), which are used in surfactant assessment, were measured to see if they could be effective biomarkers in toxicity assessment. The results showed that the NiO instilled group showed no significant difference compared to the control group throughout the observation period. In contrast, a significant difference was found in the nNiOm instilled group compared to the control group throughout the observation period.