Arsenic in soil, vegetation and water of a contaminated region

ABSTRACT

Arsenic concentrations of surface waters, soils and plants were surveyed in three contaminated villages of Bijar County. Total arsenic in water samples [4.5 to 280 micro g/L] was correlated with electrical conductivity, total dissolved solid, total hardness, alkalinity, chloride, sulphate, bicarbonate, calcium and sodium [p<0.001]. Total arsenic in the soils ranged from 105.4 to 1500 mg/kg. Some of the soil factors play an important role in soil arsenic content and its bioavailability for organisms. In general, the arsenic concentrations in plants were low, especially in the most common wild species. Among 13 plant species, the highest mean arsenic concentration was found in leaves of Mentha Longifolia [79.4 mg/kg]. Arsenic levels in soils and plants were positively correlated, while the ability of the plants to accumulate the element, expressed by their biological accumulation coefficients and arsenic transfer factors, was independent of the soil arsenic concentration. Relationships between the arsenic concentrations in plants, soils and surface water and the environmental aspects of these relationships have been discussed in comparison with literature data. The accumulation of arsenic in environmental samples [soil, sediment, water, plant, etc.] poses a potential risk to human health due to the transfer of this element in aquatic media, their uptake by plants and subsequent introduction into the food chain