Mercury fluxes in a natural forested Amazonian catchment (Serra do Navio, Amapá State, Brazil).
Sci Total Environ
; 260(1-3): 201-11, 2000 Oct 09.
Article
em En
| MEDLINE
| ID: mdl-11032128
Mercury (Hg total) fluxes were calculated for rainwater, throughfall and stream water in a small catchment located in the northeastern region of the Brazilian Amazon (Serra do Navio, Amapá State), whose upper part is covered by a natural rainforest and lower part was altered due to deforestation and activities related to manganese mining. The catchment area is 200 km from the nearest gold mining (garimpo). Minimum and maximum Hg concentrations were measured monthly from October 1996 to September 1997 and were 3.5-23.4 ng l(-1) for rainwater, 16.5-82.7 ng l(-1) for throughfall (March-August 1997) and 1.2-6.1 and 4.2-18.8 ng l(-1) for stream water, in natural and disturbed areas, respectively. In the natural area, the inputs were 18.2 microg m 2 year(-1) in rainwater and 72 microg m(-2) year(-1) in throughfall. This enrichment was attributed to dry deposition. The stream output of 2.9 microg m(-2) year(-1) indicates that Hg is being recycled within the forest as other chemical species or is being retained by the soil system, as confirmed by the cumulative Hg burden in the 0-10 cm surface layer, which was 36480 microg m(-2). When the disturbed area of the catchment was included, the stream output was 9.3 microg m(-2), clearly indicating the impact of the deforestation of the lower part of the basin on the release of mercury. The Hg burden in the disturbed area was 7560 microg m(-2) for the 0-10 cm surface layer.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Árvores
/
Poluentes Químicos da Água
/
Água Doce
/
Mercúrio
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
Sci Total Environ
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Holanda