This study aims to assess the extent of metal accumulation by plants found in a mining area in Hamedan Province in the central west part of Iran. It also investigates to find suitable plants for phytoextraction and phytostabilization as two phytoremediation strategies. Plants with a high bioconcentration factor (BCF) and low translocation factor (TF) have the potential for phytostabilization while plants with both BCFs and TFs greater than one have the potential to be used for phytoextraction. In this study, shoots and roots of the 12 plant species and the associated soil samples were collected. The collected samples were then analyzed by measurement of total concentrations of trace elements (Pb, Zn, Mn and Fe) using atomic absorption spectrophotometer. Simultaneously, BCF and TF parameters were calculated for each element. Results showed that although samples suitable for phytoextraction of Pb, Zn, Mn and Fe and phytostabilization of Fe were not detected, Scrophularia scoparia was the most suitable for phytostabilization of Pb, Centaurea virgata, Echinophora platyloba and Scariola orientalis had the potential for phytostabilization of Zn and Centaurea virgata and Cirsium congestum were the most efficient in phytostabilization of Mn. Present study showed that native plant species growing on contaminated sites may have the potential for phytoremediation.

Various industrial activities contribute heavy metals to the soil environment directly or indirectly through the release of solid wastes, waste gases, and wastewater. Phytoremediation can be potentially used to remedy metal-contaminated sites. A major step towards the development of phytoremediation of heavy metal-impacted soils is the discovery of the heavy metal hyperaccumulation in plants. This study evaluated the potential of 7 species growing on a contaminated site in an industrial area. Several established criteria to define a hyperaccumulator plant were applied. The case study was represented by an industrial town in the Hamedan province in the central-western part of Iran. This study showed that most of the sampled species were able to grow in heavily metal-contaminated soils and were also able to accumulate extraordinarily high concentrations of some metals such as Pb, Fe, Mn, Cu and Zn. Based on the obtained results and using the most common criteria, Camphorosma monospeliacum for Pb and Fe, and Salsola soda and Circium arvense for Pb can be classified as hyperaccumulators and, therefore, they have suitable potential for the phytoremediation of contaminated soils

The use of phosphate fertilizers is essential in agriculture, because they supply farmland with nutrients for growing plants. However, heavy metals might be included as impurities in natural materials and minerals, so heavy metals can also be present in phosphate fertilizers or other chemical fertilizers. The aim of this work was to assess the heavy metal content and contamination status of agricultural soils in the Hamadan province of Iran used for the cultivation of different crops, including cucumber, potatoes, and sugar beet. Surface soil samples were collected and analyzed to determine the total concentration of specific elements (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn), before the pollution index was calculated for each element. Soils used for the cultivation of the three types of crop were not contaminated with As, Cr, Cu, Pb, or Zn. However, the pollution indices for Cd were 1.1, 4.4, and 3.8 in cucumber, potato, and sugar beet fields, respectively, which indicated moderate, high, and high levels of contamination, respectively. Soils from potato and sugar beet fields were heavily contaminated with Cd, which may have resulted from long-term overuse of phosphate fertilizers.

As a result of human activities such as mining, metal pollution has become one of the most serious environmental problems today. Phytoremediation, an emerging cost-effective, non-intrusive, and aesthetically pleasing technology that uses the remarkable ability of plants to concentrate elements can be potentially used to remediate metal-contaminated sites. The aim of this work was to assess the extent of metal accumulation by plants found in a mining area in Hamedan province with the ultimate goal of finding suitable plants for phytoextraction and phytostabilization (two processes of phytoremediation). To this purpose, shoots and roots of the 12 plant species and the associated soil samples were collected and analyzed by measurement of total concentrations of some elements (Fe, Mn, Zn, and Cu) using atomic absorption spectrophotometer and then biological absorption coefficient, bioconcentration factor, and translocation factor parameters calculated for each element. Our results showed that none of the plants were suitable for phytoextraction and phytostabilization of Fe, Zn, and Cu, while Chenopodium botrys, Stipa barbata, Cousinia bijarensis, Scariola orientalis, Chondrila juncea, and Verbascum speciosum, with a high biological absorption coefficient for Mn, were suitable for phytoextraction of Mn, and C. bijarensis, C. juncea, V. speciosum, S. orientalis, C. botrys, and S. barbata, with a high bioconcentration factor and low translocation factor for Mn, had the potential for the phytostabilization of this element.

Excessive amounts of heavy metals adversely affect plant growth and development. Whereas some regions naturally contain high levels of heavy metals, anthropogenic release of heavy metals into the environment continuously increases soil contamination. Preliminary studies have shown that Chenopodium botrys can grow in some heavy metal contaminated soils and is a high accumulator plant species for Cu and moderately accumulator plant species for Fe, Mn, and Zn, thus, was considered as an important species in this study. Based on that, in this species, we studied the individual effects of heavy metals on the formation, development, and structure of anther and pollen. To achieve this purpose, surrounding area of Hame-Kasi iron and copper mine (Hamedan, Iran) was chosen as a polluted area where the amount of some heavy metals was several times higher than the natural soils. Flowers and young pods were removed from non-polluted and polluted plants, fixed in FAA 70, and subjected to developmental studies. Analysis of anther development in plants from contaminated sites showed general similarities in the pattern of pollen formation with those from non-polluted ones, but also deviation from typical form of major stages of anther and pollen development was seen in plants from polluted ones. Stabilizing of tapetum layer, increasing in tapetum layer numbers, thickening callose wall in the microspore mother cell stage, changing the anther shape, and decreasing the size of anther were the effects of heavy metals. Reduction of pollen number was also seen in the plants collected from polluted area.

The long-term application of phosphate fertilizers on vegetable production fields has raised concerns about the potential health risks of heavy metal contamination of crops grown on contaminated soils in the Hamadan province, western Iran. This study found that long-term fertilizer use led to a growing accumulation of heavy metals in soils. High concentrations of elemental As, Cd, Cr, Cu, Pb, and Zn were found in potatoes sampled from overused phosphate-fertilized soils, which increased the daily intake of metals in food. However, the ingestion of potatoes from soils affected by phosphate fertilizers posed a low health risk when compared with the health risk index of <1 for heavy metals. Nevertheless, heavy metal concentrations should be periodically monitored in vegetables grown in these soils. It would also be beneficial to implement effective remediation technologies to minimize possible impacts on human health.

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Heavy metal (Cu, Cd, Zn) concentration of the muscle, gill, and liver of Otolithes rubber, Pampus argenteus, Parastromateus niger, Scomberomorus commerson, and Onchorynchus mykiss are determined by anodic stripping voltammetry method. The results show that the concentration of Cu, Cd, and Zn varied between 0.44 and not detected, 0.585 and 0.001, and 0.450 and 0.005 μg/g, respectively. It is interesting that in O. mykiss, the mean value of copper concentration was more than other marine organisms of this study, while in P. niger, the mean value of copper was minimum. The results of this study indicate that in the different tissues of fish species (O. rubber, P. argenteus, P. niger, S. commerson, and O. mykiss), the concentrations of Cu, Cd, and Zn were significantly lower than the permissible FAO/WHO levels.