The content and toxicity of heavy metals in soils affected by aerial emissions from the Pechenganikel plant

The zoning of the terrestrial ecosystems exposed to the aerial emissions from the Pechenganikel plant (Murmansk oblast) was performed; it was based on the state of the soil cover in 2012. The following parameters were determined: the pH, the contents of heavy metals (HMs) and exchangeable calcium and magnesium, the proportion between the organic and mineral soil components, and the state of the soil micro-biota. Three zones differing in the intensity of the soil pollution were distinguished: the zone of strong pollution (at a distance of 3 km from the source of the emission), the zone of medium pollution (16 km), and the zone of weak pollution (25–30 km to the southwest from the pollution source). In the last ten years, the soil pollution in the zone influenced by aerial emissions from the Pechenganikel plant has remained the same. The amount of bacteria and fungi in the air is directly related to that in the soil. The results obtained point to the bacterial pollution of the atmosphere nearby the industrial center. In the vicinity of the plant, gram-negative bacteria (Gracilicutes) predominate in the air; in remote areas, gram-positive bacteria (Fermicutes) are dominants. In the air nearby the industrial center, potentially pathogenic fungi (Gongronella butleri and Alternaria alternata) were revealed.