146
R.T. Vinarao et al.
Fig. 12.3 Concentrations of
(a) Pb, (b) As and (c) Hg in
sediment during monsoon
( 2009) and pre-monsoon
( 2010) seasons
The significantly higher traces detected in the Gulf during the monsoon season
may be brought about by run-off which transports metal contaminants from
surrounding environment as a result of increased sedimentation. The strong water
movement caused by increased run-offs may have also exposed the deposited heavy
metals at the surface of the sea floor making more available during the sample
collection period.
Results in Pb levels in this study are opposite to the study conducted by Ahmad
et al. (2010) in Buriganga River, Bangladesh wherein higher Pb levels (upper limit:
77.13 mg/kg) in sediment samples were detected during the pre-monsoon season.
Heavy metals, either of natural or anthropogenic origin tend to be adsorbed to
silt particles in sediments (Gonzalez et al. 1999; Millward et al. 1999; de Astudillo
R.T. Vinarao et al.
Fig. 12.3 Concentrations of
(a) Pb, (b) As and (c) Hg in
sediment during monsoon
( 2009) and pre-monsoon
( 2010) seasons
The significantly higher traces detected in the Gulf during the monsoon season
may be brought about by run-off which transports metal contaminants from
surrounding environment as a result of increased sedimentation. The strong water
movement caused by increased run-offs may have also exposed the deposited heavy
metals at the surface of the sea floor making more available during the sample
collection period.
Results in Pb levels in this study are opposite to the study conducted by Ahmad
et al. (2010) in Buriganga River, Bangladesh wherein higher Pb levels (upper limit:
77.13 mg/kg) in sediment samples were detected during the pre-monsoon season.
Heavy metals, either of natural or anthropogenic origin tend to be adsorbed to
silt particles in sediments (Gonzalez et al. 1999; Millward et al. 1999; de Astudillo