Following the classification of quartz as a human carcinogen by the IARC, many standard-setting committees are currently trying to convert this hazard into their national or EU standards. Since human data to set a safe exposure limit for quartz are limited, we hypothesized that lung burden data on quartz in coal miners' lungs after lifetime exposure could be used to set a non-carcinogenic lung ...

Mesozoic granitic plutons are found throughout the Indochina terrane of eastern Cambodia and southern Vietnam. The rocks range in age from Early Triassic (240 Ma) to Late Cretaceous (80 record distinct tectonomagmatic periods associated with subduction Paleotethys Paleo-Pacific oceans. Samples collected Snoul pluton, composed silicic intermediate dioritic rocks, basalt. quartz diorites magnesia...

iron mineralization of kalate shahin is located 107 km on the ghoochan-neyshaboor road (in khorasan razavi province). subvolcanic intrusive bodies of quartz monzonite to monzonite porphyry intruded the cretacous limestone. sedimentary units of the area in decreasing age include cretaceous limestone and eocene and paleocene-quaternary microconglomerate to sandstone. mineralization in the region ...

Quartz (α-quartz), is the most common crystalline silica polymorph in nature and is the only polymorph found in significant concentrations in coal and coal ash. Since exposure to quartz is liable to cause lung diseases, it is very important to know its concentrations in coal ash and to evaluate its effects on the workers. Inhalation is the most effective route of entry for airborne particles of...

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 ...