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Ecological risk assessment of metals contamination in the sediment of the Bamdezh wetland, Iran
Vaezi, A. R.; Karbassi, A. R.; Valavi, Sh. & Ganjali, M. R.
Abstract
Present survey investigates the intensity of
heavy metals pollution (Ca, Fe, Ni, Cd, Pb, Zn, AS, Hg) in
the sediments of Bamdezh wetland, Iran. The main
objective of the study is quantification of heavy metal
pollution intensity in this wetland. Bamdezh wetland is
located in about 40 km northwest of Ahvaz, Iran. This
wetland is a habitat and food source for aquatic ecosystem
and migratory birds, also a significant resource of income
for the locals. Anthropogenic portion of the metals was
determined through five-step chemical sequential extraction.
The results of partition studies revealed the arrangement
of anthropogenic portions for the metals as follows:
Cd (86 %) > Pb (80 %) > Ni (46 %) > Zn (44 %) > Fe
(24 %). The mean enrichment factor values for various
metals were between minimal enrichment and extremely
enrichment. The values obtained from Ipoll index are
indicative of a broad range from unpolluted to moderately
polluted to moderately to strongly polluted. All stations can
be interpreted as a very high degree of contamination using
Cd and high degree of contamination using mCd classification.
PLI ranged from 1.22 at station 3 to 1.55 at station
4. Result of cluster analysis for Zn and LOI shows that
these two elements are related together by high similarity
coefficient. As LOI in the environment is the index of
biological activity, then Zn should have biological origin.
The dendrogram also showed that a part of Ca and Ni is
derived from lithogenous source as they are linked to Fe.
Keywords
Bamdezh wetland; Anthropogenic proportion; Sediment contamination; Metal pollution
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