The Content of Heavy Metals in Bottom Sediments of Selected City Rivers of the Podlasie Province

The purpose of the work was to determine the relationship between the state of the water environment quality of selected rivers (Zn, Cr, Pb, Cd and Cu tests in bottom sediments), and the sources of pollution resulting from the close proximity to the cities, through which they flow. The following rivers were selected for the study: the Biała river flowing through the city of Białystok, the Narew river flowing through the city of Tykocin and the village of Złotoria, the Supraśl river flowing through the village of Michałowo and Gródek as well as the Biała river flowing through the city of Bielsk Podlaski. The sediments were collected four times from the same points in 2016 in the period from July to October. The sediment samples were collected from the points located on rivers before and beyond towns and villages. The contents of the following metals were tested in the bottom sediment samples: Zn, Cr, Pb, Cd and Cu. The analyses were carried out applying the flame absorption spectrometry method. The statistical multivariate CA and FA analyzes were used. The highest contents of Zn, Pb and Cr were recorded in the bottom sediments from the following rivers: Biała (Białystok) and Biała inflow of Orlanka (Bielsk Podlaski), which resulted from the anthropogenic activity. The research also showed the impact of the agricultural activity due to the slightly elevated Cd level.