The effect of industrial air-borne pollution on the stability of the development of Pinus sylvestris L. populations was investigated in the Central district of the Murmansk region. Surveys revealed disturbed growth and development of pine populations progressing towards the Severonickel smelter and Kovdorsky ore-dressing mill. The manifestations are shorter needles, higher asymmetry in needle length and higher fluctuating asymmetry index. The indices can be used for early diagnosis of stress.