An epidemiological investigation was carried out to determine the relationship between silicosis in hardrock miners in Ontario and cumulative exposure to silica (free crystalline silica--alpha quartz) dust. This second report describes a side-by-side air-sampling program used to derive a konimeter/gravimetric silica conversion curve. A total of 2,360 filter samples and 90,000 konimeter samples ...

Lead isotopic ratios of cassiterite, the dominant tin ore, evolve after crystallization through decay of uranium and thorium to lead. We show that the lead isotopic ratios of smelted tin at Rooiberg, South Africa, form an isochron that matches the known geological age of the Rooiberg cassiterite deposits. Since the lead isotopic ratios of several prehistoric tin and bronze artifacts throughout ...

Granite-related uranium ore is an important resource type in China and worldwide. Whether the geochemical theory “U6+ oxidative migration U4+ reductive precipitation” applicable to granite-related mineralization has not been determined. Detailed field petrographic work, as well scanning electron microscopy energy spectrum analysis, are conducted this study analyze relationship between minerals ...

The richest uranium ore bodies ever discovered (Cigar Lake and McArthur River) are presently under development in northeastern Saskatchewan. This subarctic region is also home to several operating uranium mines and aboriginal communities, partly dependent upon caribou for subsistence. Because of concerns over mining impacts and the efficient transfer of airborne radionuclides through the lichen...

The purpose of this study is to assess the response of the aquatic environment (sediment, sea water and mussels Mytilus sp.) on uranium and radium activity and concentration following the decrease of phosphate discharges from a technologically improved transhipment terminal, situated at the CroatianAdriatic coast in the port of Sibenik. The highest U activities (485±16 Bq kg" dry weight) and Ra...