Sources, release and mobility

Contents of REE in massive sulfides from the BMC are strongly controlled by the abundance of and REE concentrations in phosphate minerals, specifically apatite, xenotime and monazite. Strong positive Eu anomalies in apatite, account for the anomalous Eu signatures of exhalative sulfides whereas REE in monazite masses are largely reflective of detrital sources and may mask hydrothermal signatures. Limited release of mobile trace elements (LREE and Eu) during green-schist facies metamorphism has partly modified REE profiles for VMS deposits of the BMC. 

But not only mercury is released by mining. Mn ore mining activities taking place in the Brazilian Amazon basin as open pits (for instance in the Serra do Navio, Amapa State), represent a potential source of associated ferrous metals (such as Ni, Cr, Cu, As). Acid mine drainage contains dissolved and particulate metals in toxic concentrations, affects the pH of streams and mobilizes metals. Moreover, wind dispersal of material from unstable spoil heaps can result in local or regional atmospheric contamination. Despite the likely importance of this source in the environment, it is currently not possible to estimate the quantities of trace... 

Transportation, or mobile sources, account for an estimated release of 34 Mt of hydrocarbons into the atmosphere each year (Merian and Zander, 1982) and urban mnofif as a source of petroleum to the marine environment has been well documented (Eganhouse and Kaplan, 1981 Latimer et al., 1990). In urban atmospheres, the composition of volatile aromatic hydrocarbons has been found by numerous investigators to be similar to that of gasoline, indicating gasoline as a source (Merian and Zander, 1982). The air in rural areas contains benzene at concentrations of... 

Taking into account the kind of sources and the chemistry of technetium, c will be released to the environment as pertcchnetate. Its behavior in the environment attracted much attention during the last two decades due to the long physical half-life of I c and the solubility and mobility of TCO4 in aquatic systems. Considerable effort has been made to understand the long-term biogeochemical behavior of c, its transfer in food chains and the mechanisms controlling its mobility in diverse environments [17]. 

There are four main environmental sources of Hg (PNUMA 2005) (1) natural, (2) anthropogenic releases from mobilizing Hg impurities that exist in raw materials (e.g., fossil fuels and other ores), (3) anthropogenic releases from production processes, and (4) remobilization of Hg from soils, sediments, and water from past anthropogenic releases. Whatever the original source of Hg entry into the environment, the final receptors of such emissions are the atmosphere, aquatic ecosystems, soils, and biota. The biogeochemical cycle of Hg is complex in that several environmental compartments and processes are involved in the cycle. Estimates of Hg emissions to the atmosphere show that natural sources of Hg (median value... 

Natural releases to the atmosphere are geographically variable and superimposed on these are emission to the atmosphere from both stationary and mobile point-sources, of domestic and industrial origin. The routine combustion of fossil fuels for energy production releases significant quantities of CO2 and H2O. In addition, CO2 is released through natural metabolic processes. The increased use of fossil fuels for energy production has increased the total release to the atmosphere of CO2 and there is some... 

The amount of nitrogen deposited in dissolved nitrates is now much larger than NH -N deposition everywhere in Western Europe and eastern North America, where combustion of fossil fuels in stationary and mobile sources releases large amounts of NO. North American maxima, in Pennsylvania and the neighboring northeastern states, are over 20 kg NO3 /ha. Dry NO3 is equal to at least % of the wet input see Warneck (76), pp. 476-483. 

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