Indicators of the permissible content of oil and products of its transformation for podzols of illuvial-ferruginous, sod-podzolic, peat boggy raised soils of the Perm territory are presented. The sampling of the selected soil types was carried out, with which experiments on phytotesting, biotesting of the quality of water extracts with differentiated oil pollution were carried out. The assessment of chronic phytotoxicity was carried out according to the reaction of three species of terrestrial plants: spring wheat, pea sowing, and hybrid spruce. The water extract of contaminated soils was tested on chlorella and daphnia. As a result, quantitative indicators of the permissible concentration of hydrocarbons in soils after reclamation for agricultural and forestry lands were obtained.

The effect of pollution of Albicluvisols/Retisols, Calcaric Leptosols, Luvic Phaeozems, Greyzamic Phaeozems and Folic Fluvisols with oil (Solovatovsky oil field, Perm region) added in amounts of 1, 2, 3 and 5 g oil/kg of soil on the organisms was studied in a model laboratory experiment. Oil addition showed phytotoxic effects on root length in Triticum aestivum L., Lepidium sativum L., Picea obovata Ledeb. and Pinus sylvestris L. in all soils. However, oil contamination of Calcaric Leptosols and Greyzamic Phaeozems led to growth stimulation in Picea obovata seedlings. A remarkable shift in the diversity and number of colony-forming units of heterotrophic and oil-oxidizing bacteria was detected in all soil types. The maximum decrease in biodiversity (45%) was noted for heterotrophic bacteria in Luvic Phaeozems. Aqueous extracts from all oil-contaminated soils had a toxic effect on Chlorella vulgaris Beijer, causing an increase in biomass by more than 30%, but did not show acute toxicity on Daphnia magna Straus. Oil addition in the range of 1–3 g oil/kg soil posed no environmental risk to human health. However, oil addition at 5 g oil/kg of soil led to an increase in the level of carcinogenic risk to children to the threshold values of acceptable risk and ranged from 0.95 × 10–4 for Greyzamic Phaeozems and Folic Fluvisols to 1.098 × 10–4 for Luvic Phaeozems. Our results suggest that the reaction of test organisms to oil pollution depends on the soil type, and their complex application makes it possible to identify the most sensitive factor and assess the dangerous level of pollution.

Responses to contamination of several soil types with crude oil were comparatively analyzed in organisms of different trophic groups. Samples of soddy podzolic, light gray, soddy calcareous, dark gray, and floodplain soils were supplemented with oil in concentration ranges of 1–5 and 100–300 g/kg and tested in the laboratory for the effect on heterotrophic soil bacteria and higher plants (Lepidium sativum, Triticum aestivum, Picea obovata, and Pinus sylvestris). In addition, water extracts from oil-contaminated soils were tested for the effect on Chlorella vulgaris and Daphnia magna. It was found that agricultural plants Lepidium sativum and Triticum aestivum were more tolerant of low-dose oil contamination (1–5 g/kg soil), compared to seedlings of the taiga tree species Picea obovata. The abundance of heterotrophic bacteria increased in soils treated with low oil concentrations (up to 5 g/kg) and decreased when oil concentration reached 100–300 g/kg soil. The entire range of tested oil concentrations caused reduction in the morphological diversity of heterotrophic soil bacteria. Experiments with water extracts from oil-contaminated soils showed that toxicity test with Daphnia magna was insufficiently sensitive and that the response of Chlorella vulgaris microalgae to soil contamination with oil was ambiguous. The floodplain soil proved to be most tolerant to oil contamination, while soddy calcareous and light gray soils were most vulnerable.

Abstract This article is devoted to the study of the content of petroleum products in surface and groundwater in the karst area. The hydrological and hydrochemical features of the Yasyl river, the dynamics of oil content in three hydrological phases in the period from 2016 to 2018 are considered. The time and spatial features of the distribution of petroleum products along the length of the water stream are revealed. The hypotheses of the origin of oil products in a water body were put forward.