Pulmonary toxicology studies in rats demonstrate that nanoparticles are more toxic than fine-sized particles of similar chemistry. This study, however, provides evidence to contradict this theory. The aims of the study were (1) to compare the toxicity of synthetic 50 nm nanoquartz I particles versus (mined) Min-U-Sil quartz ( approximately 500 nm); the toxicity of synthetic 12 nm nanoquartz II ...

Introduction: Quartz is one of the most abundant minerals in terrestrial crustal rocks. Viewed in planepolarized light with a petrographic microscope, quartz is clear (i.e., transparent). In cross-polarized light, quartz typically displays gray to white interference colors. Quartz (and other minerals) is deformed and transformed when subjected to strong shock waves, as a consequence of impact e...

OBJECTIVES To review the published literature on respirable quartz exposure and associated disease in agricultural related settings systematically and to describe personal respirable dust and quartz measurements collected on a sandy soil farm in the Free State province of South Africa. METHODS The published studies on exposure to respirable silica and quartz in agriculture and related setting...

The grade of a quartz ore is not a measure of its chemical reactivity. A high grade quartz sample (B) showed low reactivity in sodium silicate production. Structural imperfection usually occurs due to lattice defects in the quartz tetrahedron as a result of several substitutions that happen during mineralization. The random distortion of the quartz tetrahedron that could be affected by various ...

been compiled and analyzed to characterize current occupational expo~urcs to quartz: to determine if the quartz percentages of samples collected for different occupations have changed during the period 1985 through 1992; and to study the intranline variability associated \'vid1 quartz sample percentages of selected occupations. Analysis of the occupational data shows that regardless of the type...

Silica, or silicon dioxide (SiO2), is a group IV metal oxide, which naturally occurs in both crystalline and amorphous forms (i.e. polymorphic; NTP, 2005). The various forms of crystalline silica are: α-quartz, β-quartz, α-tridymite, β-tridymite, α-cristobalite, β-cristobalite, keatite, coesite, stishovite, and moganite (NIOSH, 2002). The most abundant form of silica is α-quartz, and the term q...

Rainfall-induced landslides pose a significant threat to the lives and property of residents in southeast mountainous area. From 5 10 May 2016, Sanming City Fujian Province, China, experienced heavy rainfall event that caused massive landslides, leading loss life property. Using high-resolution satellite imagery, we created detailed inventory triggered by this event, which totaled 2665 across a...