The pollution of soil and ground water by heavy metals, sulphur and nitrogen in the Region of Plock Petrochemical Works

In the years 1984-1990 soil and ground water quality was defined in selected allotment gardens of Płock (central Poland) and in a household garden situated in a village about 25 km from the town. In soil, analysis covered the level of accumulation of heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn), and total sulphate sulphur and total nitrogen, and in ground water the metals mentioned above, as well as sulphate sulphur and nitrate nitrogen. These pollutants were accumulated in soil in mostly permissible amounts except for zinc and sulphate sulphur, which occurred in excessive amounts in all gardens. The soil pollution level in analyzed gardens did not decrease proportionally to the increasing distance from the Petrochemical Works. In all gardens an excessive accumulation of sulphate sulphur, iron, lead, cadmium, manganese and copper in ground water was noted, while chromium, nickel and cobalt appeared in nondetectable amounts. The pollution of ground water had some tendency to decrease with increasing distance from the works; however, this evidently applied only to iron.