EN
Dependencies of heavy metal concentrations in organs of Tree Sparrow nestlings (Passer montanus), and growth and histopathological changes of these organs in polluted and control (unpolluted) environments of Białystok (53°06' N, 23°10' E; 300,000 inhabitants, NE Poland) were investigated. The highest concentrations of Fe, Zn, Cu, Cd and Pb were found in the liver and kidneys in both environments. Pb concentrations in the polluted areas were highest in the lung and spleen. Comparatively high amounts of Cu and Cd accumulated in pectoral muscles. In all organs the highest concentrations of Fe and lowest of Cd and Pb were found in polluted areas compared with unpolluted ones. Differences of Zn concentrations in nestling organs from both areas were not significant. Concentrations of investigated elements increased during postembryonal development in all organs in both areas. Interactions between Fe and Zn with Cd and Pb were most commonly noticed in the liver, kidneys and lung. Nestlings from the unpolluted areas reached maximum body mass at about the 12th day of their life and biomass gain was more intensive compared with nestlings from the polluted areas, which reached their maximum body mass just before flight from the nests. They grew slower and body mass gain took place until the time of flight from their nests. Differences in the growth and development of nestlings from both areas can be explained by the concentration of toxic heavy metals in the polluted areas. Histopathological changes of nestlings, mainly in their livers, kidneys and lung, were found in both areas. The level of these changes was more intensive in the polluted areas. This state should be connected with the higher concentration of toxic heavy metals in these areas and also with the heredity of diseases causing histopathological abnormalities.