8 documents found, page 1 of 1

Flood pulse and spatial dynamics of mercury in sediments in Puruzinho lake, Bra...

The study was conducted in Puruzinho lake (Humaitá, AM) considering seasonal periods of rainy and dry in way to elucidate the flood pulse importance in the deposition, remobilization and distributions of mercury and organic matter in bottom sediments in the Madeira River Basin (Brazilian Amazon). Bottom sediments and soils samples were analyzed for total mercury and organic matter. Mercury concentrations obtain...

Mercury distribution in sediment profiles from lakes of the high pantanal, Mato...

For the distribution of mercury released by the local gold mining. Atmospheric transport is the only pathway of mercury contamination of these remote lakes. Mercury concentrations were higher at the surface of sediments (62 to 80 ug.kg-‘) decreasing to values of 20 to 30 ug.kg-’ in deeper layers. Mercury deposition rate was estimated as 90 to 120 ug Hg.m-*.yr-‘. Although mercury concentrations were much lower t...

Variação sazonal de elementos-traço associados aos sólidos em suspensão no alto...

Natural and anthropogenic factors contribute to the increase in suspension solids production in the Madeira River basin, being trace elements the main substances carried in suspension. Among these elements Hg is one representing greater risk to human health. This study on the high Madeira River basin investigate the seasonal variation of suspended matter and associated trace elements in two contrasting hydrolog...

Degassing de mercúrio em solo de floresta e pastagem em candeia do Jamari

Erosion and leaching are important processes of mercury release from superficial soil. However, experimental studies have shown that mercury emissions by degassing of contaminated and non-contaminated soils play an important role on mercury transfer from soil to air. Therefore, the objective of this work was to estimate the emission of Hg0 from soils under different uses (pasture and forest). And yet, compare t...

Methodologies for sampling, preservation and storage of water samples for mercu...

Knowing the mercury levels of an environment allows a diverse array of biogeochemical studies into the mercury cycle on a local or global scale. Among matrices commonly evaluated, water remains a challenge for research because its mercury levels can be very low, requiring development of complex analytical protocols. Currently, sample preservation methods, protocols that avoid contamination, and analytical techn...

Persistent toxic substances in the Brazilian Amazon: Contamination of man and t...

The organochlorine insecticide DDT was extensively used in Brazil since 1945, both for agricultural purposes and for vector control measures. In 1986 its uses were forbidden in agriculture and in 1997 it was also phased-out in vector controls programs. However, the presence of DDT in urban and forested soils, breast milk and aquatic biota is still common, especially at the Amazon region. The results gathered si...

Erratum: Persistent toxic substances in the Brazilian amazon: Contamination of ...

Analysis of laboratory intercomparison data: a matter of independence

Submitted by Richard Rickes (richard.ribeirorickes@gmail.com) on 2011-10-26T12:47:15Z No. of bitstreams: 1 Analysis of laboratory intercomparison data a matter of independence.pdf: 178564 bytes, checksum: 37b8665c51e99ec89ee7d13be2ba47fc (MD5); Approved for entry into archive by Tatiane Corrêa(tppcorrea@gmail.com) on 2011-11-02T22:48:53Z (GMT) No. of bitstreams: 1 Analysis of laboratory intercomparison data a m...