We have previously shown that underground railway particulate matter (PM) is rich in iron and other transition metals across coarse (PM10-2.5), fine (PM2.5), and quasi-ultrafine (PM0.18) fractions and is able to generate reactive oxygen species (ROS). However, there is little knowledge of whether the metal-rich nature of such particles exerts toxic effects in mucus-covered airway epithelial cel...

Toxicological studies have provided evidence of the toxicity of ultrafine particles (UFP), but epidemiological evidence for health effects of ultrafines is limited. No quantitative summary currently exists of concentration-response functions for ultrafine particles that can be used in health impact assessment. The goal was to specify concentration-response functions for ultrafine particles in u...

PM10 is a complex mixture of particles and we have focused here on the ultrafine component, i.e. particles with a diameter of less than 100 nm. In PM10 this fraction is mostly composed of combustion-derived, carbon-centred particles with associated hydrocarbons and metals. Progress in understanding the effects of ultrafine particles in the lungs has been achieved largely through the use of surr...

Underground railway stations are known to have elevated particulate matter (PM) loads compared to ambient air. As these particles are derived from metal-rich sources and transition metals may pose a risk to health by virtue of their ability to catalyze generation of reactive oxygen species (ROS), their potential enrichment in underground environments is a source of concern. Compared to coarse (...

Experiments were carried out in a pilot-scale pulverized coal combustor at the Energy and Environmental Research Center (EERC) burning a Powder River Basin (PRB) subbituminous coal. A scanning mobility particle sizer (SMPS) and an electrical low-pressure impactor (ELPI) were used to measure the particle size distributions (PSDs) in the range of 17 nm to 10 microm at the inlet and outlet of the ...

AIMS The aerosolization and collection of submicrometre and ultrafine virus particles were studied with the objective of developing robust and accurate methodologies to study airborne viruses. METHODS AND RESULTS The collection efficiencies of three sampling devices used to sample airborne biological particles - the All Glass Impinger 30, the SKC BioSampler and a frit bubbler - were evaluated...

To reduce the invasiveness of cryosurgery, a miniaturized cryoprobe is necessary. The authors have developed an ultrafine cryoprobe for realizing low-invasive cryosurgery by local freezing. The objectives of this study are to estimate the heat transfer coefficient and investigate the characteristics of the phase change heat transfer in the ultrafine cryoprobe. This cryoprobe has a double-tube s...

We incorporated ultrafine polymer fibers into calcium phosphate cement (CPC) to improve the resorption rate of CPC with fiber degradation. Different weight percentages of electrospun poly(ε-caprolactone) fibers (0%, 3%, and 7%, named as ultrafine fiber-incorporated CPC0 [UFICPC0], UFICPC3, and UFICPC7) were included into preset CPC specimens for in vitro immersion in lipase phosphate-buffered s...

The current carcinogenicity study with female rats focused on the toxicity and carcinogenicity of intratracheally instilled fine and ultrafine granular dusts. The positive control, crystalline silica, elicited the greatest magnitude and progression of pulmonary inflammatory reactions, fibrosis and the highest incidence of primary lung tumors (39.6%). Addition of poly-2-vinylpyridine-N-oxide dec...

Ultrafine particles (< 0.10 microm in diameter) are present in great number in polluted urban air, thus posing a potential health risk. In this study, the total deposition fraction (TDF) of ultrafine aerosols with a narrow size distribution (number median diameter NMD = 0.04-0.1 microm and geometric standard deviation sigma(g) = approximately 1.3) was measured in a group of young healthy adults...