Seasonal variation of methylmercury in sediment cores from the Tagus Estuary (Portugal).
Mar Pollut Bull
; 104(1-2): 162-70, 2016 Mar 15.
Article
em En
| MEDLINE
| ID: mdl-26851871
ABSTRACT
Seasonal and spatial variations of dissolved and particulate methylmercury were evaluated for the first time in sediment cores from the Tagus Estuary. Results showed the highest MeHg concentrations in summer months indicating that the "seasonally" methylation process occurs not only at the topmost layers of the sediments but also in the deeper layers of the sediment column. The proportion of MeHg (up to 92%) in some of our pore water samples was higher than values reported in the literature for other estuaries suggesting that the sedimentary environment in the Tagus tends to favour Hg methylation. This work points to the importance of seasonal variation of the MeHg production in sediment cores. In physically dominated estuaries this enhances seasonal MeHg production in deeper sediments that can have serious ecological impacts due to resuspension or advection processes under extreme events by the increase of MeHg transported to the water column.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Estações do Ano
/
Poluentes Químicos da Água
/
Monitoramento Ambiental
/
Estuários
/
Sedimentos Geológicos
/
Compostos de Metilmercúrio
País/Região como assunto:
Europa
Idioma:
En
Revista:
Mar Pollut Bull
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Portugal