Background: Many trace elements are essential to plant, animal, and human health in small doses but they will be toxic in higher doses. Two natural processes and anthropogenic activities can be responsible for importing elements to environment (soil, water and air) which enter the human body by eating, drinking and inhalation. Antimony is a trace element that can contaminate environment in both natural and anthropogenic activities. There is no biologic role in human body for Antimony, but its low concentrations can stimulate metabolism. On the other hand, it is very toxic and can cause degradation in liver, high blood cholesterol and low blood sugar. The WHO guideline value for Antimony in surface and groundwater is 0.02 mg/l.

Materials and Methods: In this study, 30 groundwater samples were collected through Kark Island. Samples were collected in polyethylene bottles (250cc) and transported to the ACME laboratory for analysis, filtered through 0.45 µm filters and acidified to pH=2 with HNO3.

Results: The results of the study indicated that Antimony concentration in 82.76% of the groundwater samples with 71.34 mg/l mean value was higher than the WHO standard limit.

Conclusion: Lack of outcrop geological potential of antimony, lead mines and industries confirm that oil and petrochemical industries can be responsible for contamination. It means atmospheric precipitation resulting from fossil fuel is the only reason for high Antimony concentration in Kark island.