In order to assess the possibility of using waste from agri-food processing for fertilization, residues in the form of apple pomace, carrot root, onion husks and dried nettle were selected for the tests. The research material came from food plants located in north-eastern Poland. In selected waste, the pH value, dry matter content, organic matter, nitrogen, phosphorus, potassium and carbon were determined. It was found that apple pomace, carrot root and onion husk were acidic and dried nettle was alkaline. The nitrogen content in the tested waste ranged from 0.61 to 2.29%, phosphorus from 0.07 to 0.55%, and potassium from 0.19 to 3.72%. Based on the results obtained, it was found that the examined post-production residues are characterized by good fertilizer properties. However, it should be remembered that fertilizers or soil improvers must meet a number of requirements and above all, they must be safe for the environment.

The research on the content of polycyclic aromatic hydrocarbons (PAHs) in soil and grass ( Lolium perenne L.) was carried out on samples collected in the city of Białystok, in north-eastern Poland. The test samples came from green belts in the vicinity of communication routes, differentiated in terms of the surrounding buildings and infrastructure and characterized by a different car traffic intensity. The highest total concentration of all sixteen PAHs in soil and grass samples was found near a large intersection at Nicholas Copernicus Street, one of the most important communication routes connecting two parts of the city. In the aboveground parts of the studied grass samples, benzo[a]pyrene was the most abundant, its content ranging from 53.8 μg/kg DM up to 91.7 μg/kg DM. On the other hand, in soil samples, much higher benzo[a]pyrene content was found, and the dominance of this compound was observed in almost every measurement location. Based on the obtained results, it was found that car traffic is a significant source of PAH emissions to the urban soil environment and urban greenery. The squares and green belts located along communication routes and intersections are the most exposed to pollution.