Mining activities, range

The solubility of cobalt is pH-dependent. In acid soils, cobalt is more mobile than in alkaline soils. Annually, approximately 21000 tons of cobalt are transported by rivers to the oceans, and about the same amount is deposited in deep-sea sediments, the Co content of which is in the order of 74 mg kg (Turekian and Wedepohl 1961). The natural transport of cobalt is not significantly affected by mining activities and industrial uses of the element. In uncontaminated samples of fresh water, cobalt concentrations are generally low, ranging from 0.1 to 10 jig L (Forstner and Wittmann... 

Gold miners had a number of arsenic-associated health problems including excess mortality from cancer of the lung, stomach, and respiratory tract. Miners and schoolchildren in the vicinity of gold mining activities had elevated urine arsenic of 25.7 p,g/L (range 2.2-106.0 p-g/L). Of the total population at this location, 20% showed elevated urine arsenic concentrations associated with future adverse health effects arsenic-contaminated drinking water is the probable causative factor of elevated arsenic in urine. 

The examples used cover a range of mining activities both underground and on the surface and are associated with mining operations to extract a range of material including coal, gold, platinum, diamond, copper, iron ore and chrome. 

Agree the boundaries of the study. Clearly, a study encompassing the full range of mine activities would be extraordinarily time consuming, and... 

Rates of nitration in perchloric acid of mesitylene, luphthalene and phenol (57 I-6i-i %), and benzene (57 i-64 4%) have been deter-mined. The activated compounds are considered below ( 2.5). A plot of the logarithms of the second-order rate coefficients for the nitration of benzene against — ( f + log over the range of acidity... 

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