Tracing sources and bioaccumulation of mercury in fish of Lake Baikal--Angara River using Hg isotopic composition.
Environ Sci Technol
; 44(21): 8030-7, 2010 Nov 01.
Article
em En
| MEDLINE
| ID: mdl-20942479
ABSTRACT
This study presents the determination and comparison of isotopic compositions of Hg in sediments, plankton, roach, and perch of two freshwater systems in the Lake Baikal-Angara River aquatic ecosystem the man-made Bratsk Water Reservoir contaminated by Hg from a chlor-alkali factory and the noncontaminated Lake Baikal. Isotopic ratios of biota exhibit both significant mass-independent fractionation (MIF) (Δ(199)Hg from 0.20 to 1.87) and mass-dependent fractionation (MDF) (δ(202)Hg from -0.97 to -0.16), whereas sediments exhibit high MDF (δ(202)Hg from -1.99 to -0.83) but no MIF. δ(15)N and δ(13)C are correlated with methylmercury in organisms from both sites, indicating bioaccumulation and biomagnification through food webs of both regions. Combining this with isotopic composition of samples shows that δ(202)Hg increases with the trophic level of organisms and also with methylmercury in fish from Lake Baikal. This study demonstrates that MIF in fish samples from Bratsk Water Reservoir allow to trace anthropogenic Hg, since fish with the highest levels of Hg in muscle have the same isotopic composition as the sediment in which anthropogenic Hg was deposited. Less contaminated fish do not exhibit this anthropogenic signature accumulating relatively lower Hg amount from the contaminated sediments. This work reveals that Hg isotopic composition can be used to track the contribution of anthropogenic sources in fish from a contaminated lake.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Poluentes Químicos da Água
/
Monitoramento Ambiental
/
Peixes
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Água Doce
/
Isótopos de Mercúrio
Limite:
Animals
Idioma:
En
Revista:
Environ Sci Technol
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
França