A study on microbial and chemical pollution of surface waters with special reference to metals, VHO and pesticides.

The Authors of the present study have evaluated the quality of Torrente Savena water, examining the major bacteriological and physical-chemical parameters such as metals, volatile halogenated organocompounds and pesticides, known for their persistence in the environment. The results, obtained from two sampling points, Pianoro (hilly country) and S. Lazzaro di Savena (before Savena’s inflow into the Idice torrent) showed a remarkable worsening of microbiological conditions of the torrent’s terminal segment, below the S. Lazzaro di Savena depurator outflow. Along with the microbiological parameters, also the traditional physical-chemical parameters were increased in this sampling point, with the exception of dissolved oxygen. As to the metals, their concentrations were generally modest, especially in the hilly segment. VHO were not found in Pianoro; although in low concentrations, such compounds were detected four times in S. Lazzaro only. Finally, during the investigation period, chlorinated pesticides were not present in measurable quantities; as to triazine pesticides, only the atrazine was detected in 3 S. Lazzaro samples. A comparison with traditional microbiological and chemical parameters, furnished by a previous similar study, showed a worsening of water pollution in Pianoro; on the contrary, S. Lazzaro water conditions appeared improved.