Distribution of Total and Methyl Mercury
in a Creek Ecosystem Near Bombay
G.G. PANDIT, R.M. TRIPATlll, S.K. IliA, and T.M. KRISHNAMOORTHY
The Trans Thane Creek Industrial Area (TTCIA) in New Bombay, developed as a chemical zone by the
Maharashtra Industrial Development Corporation (MIDC), houses a large number of major and
small-scale industries which manufacture and store a number of petrochemical, pharmaceuticals, fine
chemicals and pesticide formulations. The creek ecosystem has been monitored three times for total
and methylmercury; once during the pre-and postmonsoon periods of 1994, and once during the
premonsoon period of 1995. The concentration of total mercury was determined by CV AAS using
SnCI, methodology for liberating vapour phase mercury. Reversed phase high performance liquid
chromatography (RP-HPLC) with a UV detector was used for the separation and determination of
methylmercury. The efficacy of the methodology was assessed through analysis of standard reference
material obtained from IAEA (tuna fish, IAEA-350).
The spatial profile of total mercury in creek water depicted a distinct gradient with low
concentration (0.03-0.3 ~lg/I) near the southern side and high concentrations (0.5-4.3 pg/I) towards
north where industries are situated. The postmonsoon values showed only a marginal a decrease in
concentration levels during 1994; however, a significant decrease in the concentrations during
premonsoon in 1995 was observed. The concentrations of total mercury in sediment and biological
species (fish and crabs) varied between (0.3-2.6 ~lg/g) and ( 0.03-2.5 pg/g) dry weight, respectively.
The methylmercury component in sediment was distinctly lower, 5.9-65.5 ng/g (3-8% total Hg),
compared to that in biological samples, 20.4-344.5 ng/g dry weight (33-97% of total Hg).
1
Introduction
Mercury is one of the heavy metals well known for its tOXICity. It is widely
dispersed and usually occurs at trace levels in the natural environment (Adriano
1986). These natural trace levels can only be detected in unpolluted open oceans
(Bloom and Crecelius 1983) and in ambient air in remote areas like the polar
region (Ebinghaus et al. 1994). The background levels are usually exceeded in
coastal regions as a result of industrial inputs (Ebinghaus et al. 1994). Worldwide
natural emissions of mercury are higher and were estimated to be 3500 t/a
(Pacyma and Munch 1991). Mercury exists in several forms in the environment.
Geochemical and environmental studies have shown that ionic mercury can be
converted into highly toxic organomercury compounds (Callister and Winfrey
1986). The Trans Thane Creek Industrial Area (TTCIA) in New Bombay,
developed as a chemical zone by the Maharashtra Industrial Development
Corporation (MIDC), houses a large number of major and small-scale industries
which manufacture and store a number of petrochemical, pharmaceutical, fine
Environmental Science
Mercury Contaminated Sites (ed. by R. Ebinghaus et al.)
© Springer-Verlag Berlin Heidelberg 1999
in a Creek Ecosystem Near Bombay
G.G. PANDIT, R.M. TRIPATlll, S.K. IliA, and T.M. KRISHNAMOORTHY
The Trans Thane Creek Industrial Area (TTCIA) in New Bombay, developed as a chemical zone by the
Maharashtra Industrial Development Corporation (MIDC), houses a large number of major and
small-scale industries which manufacture and store a number of petrochemical, pharmaceuticals, fine
chemicals and pesticide formulations. The creek ecosystem has been monitored three times for total
and methylmercury; once during the pre-and postmonsoon periods of 1994, and once during the
premonsoon period of 1995. The concentration of total mercury was determined by CV AAS using
SnCI, methodology for liberating vapour phase mercury. Reversed phase high performance liquid
chromatography (RP-HPLC) with a UV detector was used for the separation and determination of
methylmercury. The efficacy of the methodology was assessed through analysis of standard reference
material obtained from IAEA (tuna fish, IAEA-350).
The spatial profile of total mercury in creek water depicted a distinct gradient with low
concentration (0.03-0.3 ~lg/I) near the southern side and high concentrations (0.5-4.3 pg/I) towards
north where industries are situated. The postmonsoon values showed only a marginal a decrease in
concentration levels during 1994; however, a significant decrease in the concentrations during
premonsoon in 1995 was observed. The concentrations of total mercury in sediment and biological
species (fish and crabs) varied between (0.3-2.6 ~lg/g) and ( 0.03-2.5 pg/g) dry weight, respectively.
The methylmercury component in sediment was distinctly lower, 5.9-65.5 ng/g (3-8% total Hg),
compared to that in biological samples, 20.4-344.5 ng/g dry weight (33-97% of total Hg).
1
Introduction
Mercury is one of the heavy metals well known for its tOXICity. It is widely
dispersed and usually occurs at trace levels in the natural environment (Adriano
1986). These natural trace levels can only be detected in unpolluted open oceans
(Bloom and Crecelius 1983) and in ambient air in remote areas like the polar
region (Ebinghaus et al. 1994). The background levels are usually exceeded in
coastal regions as a result of industrial inputs (Ebinghaus et al. 1994). Worldwide
natural emissions of mercury are higher and were estimated to be 3500 t/a
(Pacyma and Munch 1991). Mercury exists in several forms in the environment.
Geochemical and environmental studies have shown that ionic mercury can be
converted into highly toxic organomercury compounds (Callister and Winfrey
1986). The Trans Thane Creek Industrial Area (TTCIA) in New Bombay,
developed as a chemical zone by the Maharashtra Industrial Development
Corporation (MIDC), houses a large number of major and small-scale industries
which manufacture and store a number of petrochemical, pharmaceutical, fine
Environmental Science
Mercury Contaminated Sites (ed. by R. Ebinghaus et al.)
© Springer-Verlag Berlin Heidelberg 1999