| Author/Editor | Horvat, Milena; Nolde, Nataša; Fajon, Vesna; Jereb, Vesna; Logar, Martina; Lojen, Sonja; Jaćimović, Radojko; Falnoga, Ingrid; Qu, Liya; Faganeli, Jadran; Drobne, Damjana | |
| Title | Total mercury, methylmercury and selenium in mercury polluted areas in the province Guizhou, China | |
| Type | članek | |
| Source | Sci Total Environ | |
| Vol. and No. | Letnik 304, št. 1-3 | |
| Publication year | 2003 | |
| Volume | str. 231-56 | |
| Language | eng | |
| Abstract | The province of Guizhou in Southwestern China is currently one of the world's most important mercury production areas. Emissions of mercury from the province to the global atmosphere have been estimated to be approximately 12% of the world total anthropogenic emissions. The main objective of this study was to assess the level of contamination with Hg in two geographical areas of Guizhou province. Mercury pollution in the areas concerned originates from met'cury mining and ore processing in the area of Wanshan, while in the area of Quingzhen mercury pollution originates from the chemical industry discharging Hg through wastewaters and emissions to the atmosphere due to coal burning for electricity production. The results of this study confirmed high contamination with Hg in soil, sediments and rice in the Hg mining area in Wanshan. High levels of Hg in soil and rice were also found in the vicinity of the chemical plant in Quingzhen. The concentrations of Hg decreased with distance from the main sources of pollution considerably. The general conclusion is that Hg contamination in Wanshan is geographically more widespread, due to deposition and scavenging of Hg from contaminated air and deposition on land. In Quingzhen Hg contamination of soil is very high close to the chemical plant but the levels reach background concentrations at a distance of several km. Even though the major source of Hg in both areas is inorganic Hg, it was observed that active transformation of inorganic Hg to organic Hg species (MeHg) takes place in water, sediments and soils. The concentration of Hg in rice grains can reach up to 569 micro g/kg of total Hg of which 145 micro g/kg was in MeHg form. The percentage of Hg as MeHg varied from 5 to 83%. The concentrations of selenium can reach up to 16 mg/kg in soil and up to 1 mg/g in rice. (Abstract truncated at 2000 characters). | |
| Descriptors | AIR POLLUTANTS, ENVIRONMENTAL FOOD CONTAMINATION MERCURY METHYLMERCURY COMPOUNDS SELENIUM BIOLOGICAL AVAILABILITY CHEMICAL INDUSTRY CHINA ENVIRONMENTAL MONITORING PUBLIC HEALTH SOIL POLLUTANTS |