The paper presents the results of laser granulometry study of atmospheric particles contained in the snow in the northern part of Altaiskiy State Nature Biosphere Reserve collected in winter 2016. The results of the study prove that the north of the Alay nature reserve is relatively safe ecologically. Harmful for living beings microparticels (of no more than 10 μm in size) were in the atmosphere in a limited number and were no more than 19.1%. At the same time the maximal concentration of fine substances was observed in places of a man living, which proves an anthropogenic cause of particles formation.