Pollution mercury

In 1988 diaphragm cells accounted for 76% of all U.S. chlorine production, mercury cells for 17%, membrane cells for 5%, and all other production methods for 2%. Corresponding statistics for Canadian production are diaphragm cells, 81% mercury cells, 15% and membrane cells, 4% (5). for a number of reasons, including concerns over mercury pollution, recent trends are away from mercury cell production toward the more environmentally acceptable membrane cells, which also produce higher quality product and have favorable economics. 

Watras C J, Bloom NS, Hudson RIM, Gherini SA, Munson R, Klaas SA, Morrison KA, Hurley J, Wiener JG, Fitzgerald WF, Mason R, Vandal G, Powell D, Rada R, Rislove L, Winfrey M, Elder J, Krabbenhoft D, Andren AW, Babiarz C, Porcella DB, Huckabee HW. 1994. Sources and fates of mercury and methylmercury in remote temperate lakes. In Watras CJ, Huckabee JW, editors. Mercury pollution — integration and synthesis. Boca Raton (FL) Lewis Publishers, p. 153-177. 

Lee Y-H, Borg GCh, Iverfeldt A, Hultbeig H. 1994. Fluxes and turnover of methyhnercury mercury pools in forest soils. In Watras CJ, Fluckabee JW, editors. Mercury pollution, integration and synthesis. Boca Raton (FL) Lewis Pubhshers, CRC Press, Inc. 

Krabbeiihoft DP, Orem W, Aiken G, Gilmour CG. 2004. Unraveling the complexities of mercury methylation in the Everglades the use of mesocosms to test the effects of new mercury, sulfate, and organic carbon. Proc 7th Int Conf Mercury Pollut, RMZ-MG, 51(l-3) June2004. 

Mernelt T, Krueger R, Pietrock M, Osten R, Steinberg C. 1997. Mercury pollution and macrophage centres in pike Esox Indus) tissues. Environ Sci Pollut Res Int 4 32-36. 

Watras, C.J. and Huckabee, J.W., Eds, Mercury Pollution Integration and Synthesis, Lewis Publishers, Boca Raton, 1994, p. 727. 

Muller AK, Westergaard K, Christensen S, Sorensen SJ (2001) The effect of longterm mercury pollution on the soil microbial community. FEMS Microbiol Ecol 36 11-19... 

Methylmercury in the marine environment may originate from industrial discharges or be synthesised by natural methylation processes. Fish do not themselves methylate inorganic mercury [62,64], but can accumulate methyl mercury from sea water [63]. Methylmercury has been detected in sea water only from Minamata Bay, Japan, an area with a history of gross mercury pollution from industrial discharge. It has been found in some sediments but at very low concentrations, mainly from areas of known mercury pollution. It represents usually less than 1% of the total mercury in the sediment, and frequently less than 0.1% [65-67]. Microorganisms within the sediments are considered to be responsible for the methylation [65,68], and it has been suggested that methylmercury may be released by the sediments to the sea water, either in... 

Mercury levels have been determined in seven fish species (European catfish, northern pike, common carp, rudd, roach, barbell, and bleak) from the three mercury pollution hotspots of the Ebro River basin previously described, namely Sabinanigo, Monzon, and Flix areas and downstream sites (Fig. 1). These species display different diet and habitat and belong to different families siluridae, esoci-dae, and cyprinidae. 

Average THg concentrations increased progressively at Flix, Asco, and Xerta sites and decreased at the irrigation channels of the Delta. This result evidences a mercury pollution transport downstream from the Flix plant until Xerta. Differences found when comparing water conductivity at Flix, Asco, and Xerta sites [48] with... 

Delta irrigation channels (Faria, personal communication) indicate a saline water intrusion in the irrigation channels of the Delta. This saline intrusion may cause a dilution of mercury pollution originated at the chlor-alkali plant, hence resulting in lower average THg concentrations in Delta specimens. 

This area was the most profusely studied in the AQUATERRA project in terms of biological effects in fish populations. Barbel and bleak were the sentinel species selected in this area and an array of histological and biochemical tests were used to monitor the impact due to three major sources of pollution mercury and OCs at Monzon (with a comparison in one of the papers with Flix) and PBDEs in Barbastro [1—4, 37]. Mercury pollution was directly correlated to an increase of MTprotein in the liver of barbel captured downstream Monzon when compared to samples captured upstream (Fig. 3a). However, mRNA quantitative analyses failed to show any differences between downstream and upstream Monzon, neither correlated with MT protein levels. Further studies showed that MT mRNA in liver is a rather weak marker for chronic metal pollution in liver (see below) [4], The presence of degenerative hepatocytes in barbels and bleaks was also linked to mercury poisoning although it can also reflect the impact by other pollutants, like OCs or PBDEs (Fig. 3e). 

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