『Abstract
Contaminations of groundwater by heavy metals due to agricultural
activities are growing recently. The objective of this study was
to evaluate and map regional patterns of heavy metals (Cd, Zn
and Cu) in groundwater on a plain with high agricultural activities.
The study was conducted to investigate the concentration of heavy
metals and distribution in groundwater in regions of Shush Danial
and Andimeshk aquifers in the southern part of Iran. Presently,
groundwater is the only appropriate and widely used source of
drinking water for rural and urban communities in this region.
The region covers an area of 1,100 km2 between the
Dez and Karkhe rivers, which lead to the Persian Gulf. For this
study, the region was divided into four sub-regions A, B, C and
D. Additionally, 168 groundwater samples were collected from 42
water wells during the earlier months of 2004. The flame atomic
absorption spectrometry (AAS-Flame) was used to measure the concentration
of heavy metals in water samples and the Surfer software was used
for determination of the contour map of metal distribution. The
results demonstrated that in all of the samples, Cd and Zn concentrations
were below the EPA MCLG and EPA secondary standard, respectively.
However, the Cu contents of 4.8％ of all samples were higher than
EPA MCL. It is also indicated that the concentrations of metals
were more pronounced at the southern part of the studied region
than at the others. The analysis of fertilizers applied for agricultural
activities at this region also indicated that a great majority
of the above-mentioned heavy metals were discharged into the environment.
Absence of confining layers, proximity to land surface, excess
agricultural activities in the southern part and groundwater flow
direction that is generally from the north to the southern parts
in this area make the southern region of the Shush plain especially
vulnerable to pollution by heavy metals than by other contaminants.
Keywords: Heavy metals; Groundwater pollution; Distribution; Agricultural
activities』
Introduction
Materials and methods
Results and discussion
Conclusion
Acknowledgment
References