World mercury

N. S. Bloom, E. M. Prcstbo, J. S. Tokos, E. von dcr Geest, E. S. Kuhn, Distribution and origins of mercury species in the Pacific northwest atmosphere. Abstract, World Mercury Conference, Hamburg, August 1996. 

Primary. Mercury metal is produced from its ores by standard methods throughout the world. The ore is heated in retorts or furnaces to... 

Spain, which until 1989 was the world s largest producer of mercury, ceased mine production after 1990, although 100 t of mercury were produced in 1991 from stockpiled materials. China, Mexico, and Russia were the largest producers in 1992 (14). 

Dry-battery mercury anodes are pressed compacts of zinc—mercury amalgam. They were first developed and produced during World War II for walkie-talkie communica tion systems. Practically all hearing aids employ this type of battery in the 1990s. 

Manufacture and Processing. Until World War II, phthaUc acid and, later, phthaUc anhydride, were manufactured primarily by Hquid-phase oxidation of suitable feedstocks. The favored method was BASF s oxidation of naphthalene [91-20-3] by sulfuric acid ia the presence of mercury salts to form the anhydride. This process was patented ia 1896. During World War I, a process to make phthaUc anhydride by the oxidation of naphthalene ia the vapor phase over a vanadium and molybdenum oxide catalyst was developed ia the United States (5). Essentially the same process was developed iadependendy ia Germany, with U.S. patents being granted ia 1930 and 1934 (6,7). 

Deposits. Selenium forms natural compounds with 16 other elements. It is a main constituent of 39 mineral species and a minor component of 37 others, chiefly sulfides. The minerals are finely disseminated and do not form a selenium ore. Because there are no deposits that can be worked for selenium recovery alone, there are no mine reserves. Nevertheless, the 1995 world reserves, chiefly in nonferrous metals sulfide deposits, are ca 70,000 metric tons and total resources are ca 130,000 t (24). The principal resources of the world are in the base metal sulfide deposits that are mined primarily for copper, zinc, nickel, and silver, and to a lesser extent, lead and mercury, where selenium recovery is secondary. 

Rotenone is a common insecticide that strongly inhibits the NADH-UQ reductase. Rotenone is obtained from the roots of several species of plants. Tribes in certain parts of the world have made a practice of beating the roots of trees along riverbanks to release rotenone into the water, where it paralyzes fish and makes them easy prey. Ptericidin, Amytal, and other barbiturates, mercurial... 

Reductions in U.S. mercuiy emissions from medical and municipal waste incinerators and other industrial sectors have already occurred. Additional emission reductions from some coal-fired power plants have also already begun as co-benefits from technologies used to control SO2 and NO emissions. These mercury emissions from power plants are, however, expected to be reduced further over the next few decades. Meanwhile, changes in mercuiy emissions in other parts of the world may also affect some U.S. ecosystems. 

In the early 1980s, the world witnessed the sale of the first personal computers. Its transition from the relatively bulky and slow first units to the sleek, speed demons has made the computer truly revolutionary. With each improvement in computers, however, comes the increasing problem of what to do with the ever increasing number of computer e-wastes. The U.S. EPA estimates that nearly 250 million computers will become obsolete in the next five years in the United States alone. Unfortunately, only approximately 10% of these old computers that are retired each year are being recycled. This presents a substantial concern because toxic elements such as lead, cadmium, mercury, barium, chromium, beryllium as well as flame retardant, and phosphor are contained in a typical computer and there would be potential harm if there was a release of these elements into the environment.1... 

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