Topsoil samples taken on the Khamar-Daban mountains to the north-east of the Baikal Paper and Pulp Complex (BPPC) at a height of about 1200–1500 m above sea level in two areas (Area 1–11 km and Area 2–84 km away) were used for assessment of the regional environmental pollution level by instrumental neutron activation analysis (INAA). Mass fractions using short-lived radionuclides of Al, Ca, Dy, K, Mg, Mn, Na, Ti and V and using long-lived radionuclides of Ag, As, Au, Ba, Br, Ca, Cd, Ce, Co, Cr, Cs, Eu, Fe, Gd, Hf, Hg, La, Lu, Nd, Rb, Sb, Sc, Se, Sm, Sr, Ta, Tb, Th, U, Yb and Zn were measured. The considerable remoteness of Area 2 from BPPC allows to assume it as a checkpoint in BPPC air emission impact assessment (background levels). No statistically valid increase in the contents of all investigated chemical element were found in the topsoil on the Khamar-Daban mountain slopes and tops in Area 1. The comparison of the obtained results with literature data makes it possible to conclude that the average mass fractions of all elements in the Khamar-Daban topsoil are within the range characteristic to non-polluted soils in the territories of former USSR, CIS and across the world.