Abstract. In this paper low background high-resolution gamma spectrometry was used for the determination of the activity concentrations of the natural and man-made radionuclides in topsoil samples collected in the vicinity of a large steel plant in Galati, Romania. Their values (mean ± standard deviation) for ²³⁸U, ²²⁶Ra, ²³²Th, ²³⁵U, ²¹⁰Pb, ⁴⁰K and ¹³⁷Cs were: 38.1 ± 6.2; 35.9 ± 5.4; 35.5 ± 3.0; 1.8 ± 0.4; 47.3 ± 8.6; 504.5 ± 38.9 and 7.2 ± 4.7 Bq·kg^–1, respectively. ⁶⁰Co and ²⁴¹Am had activities below the detection limit: 0.6–1.3 and 2.2–4.7 Bq·kg^–1, respectively. The results indicate inputs of natural radionuclides in the sites close to the slag dump, raw materials transportation facility, ore and coal processing factories, blast furnaces, and iron scrap deposit. The evaluation of the associated radiological impact was performed based on selected hazard parameters: absorbed gamma dose rate, total external gamma dose rate, radium equivalent activity index, external hazard index, representative level index, annual effective dose, excess lifetime cancer risk, and annual gonadal dose.

Key words: Radioactivity, soils, risk, gamma spectrometry, steel industry, Galati, Romania.