[en] As a waste product in phosphate fertilizer production, phosphogypsum is characterized by technically enhanced natural radioactivity caused by phosphate rock, a raw material used during the production. Phosphogypsum is deposited at a local pile situated at the borderline of Lonjsko Polje Nature Park. Therefore, constant monitoring of the deposition site environment is necessary. In this investigation, the natural radionuclides (238U, 235U, 232Th, 226Ra and 40K) in the soil, grass and water samples from the surroundings of the deposition site were measured. Soil and grass samples were measured gammaspectrometrically. Ground water samples collected by piezometers were measured alphaspectrometrically after radiochemical separation of 226Ra. The results showed that there was no significant difference between the activity concentrations of natural radionuclides in any of the samples and those measured in samples from other parts of Croatia as well as those from the surroundings of other deposition sites worldwide. However, constant monitoring is necessary to detect possible future changes in the radioactivity levels in the environment.(author)