Using Plantago major and Plantago lanceolata in environmental pollution research in an urban area of Southern Poland.

The aim of this study was to perform a complex assessment of changes in the elements of an ecosystem that are caused by environmental pollution in industrial and urban biotopes. The study focused on three sites: a park, a road and the site of the metallurgical plant "Pokój" in the city of Ruda Śląska (Southern Poland), which are each under a different level of anthropogenic load. Soil and plant material samples (Plantago major and Plantago lanceolata leaves) were investigated by performing biochemical, ecophysiological and scanning electron microscopy (SEM) analyses. A significant difference was observed in all of the study samples. The content of Pb, Zn and Cd in the soil samples that had been collected at the site of the metallurgical plant exceeded the permitted limits (Cd > 4 mg kg^-1, Pb > 100 mg kg^-1, Zn > 300 mg kg^-1). The content of Fe, Mn, Pb, Cd and Zn in the plant material was much higher in unwashed samples than in washed samples. The concentrations of potentially toxic elements (PTEs) were below the permitted level in the leaves of Plantago lanceolata for Cd (> 5 mg kg^-1) and in the leaves of Plantago major for Zn (> 100 mg kg^-1). The SEM observations revealed a significant decrease in the stomata pore length (SPL) in the Plantago lanceolata leaves that had been collected at the road site compared with the plants from the park site. The elemental content on the leaf surface was also determined using X-ray microanalysis. The total chlorophyll (Chl) content, ascorbic acid (AA), proline, guaiacol peroxidase (GPX) activity, pH, relative water content (RWC) and air pollution tolerance index (APTI) were evaluated. The APTI for the investigated species ranged from 5.6 to 7.4, which demonstrated that the studied plant species are sensitive to air pollutants.