Ecological and toxicological assessment of oil-contaminated soils

The intensification of economic growth in modern times contributes to the intensive development of the oil industry, which leads to the accumulation of large amounts of waste that have a negative impact on phytocenoses: growth slows down, chlorosis and a tendency to dehydration are noted, photosynthesis and respiration functions are disrupted, floral diversity and biomass decrease. Environmental pollution with petroleum products, including in the Astrakhan region, is increasing due to the long history of the development of the oil industry. The objects of accumulated environmental damage from past economic activity are particularly environmentally hazardous. These include the Ilyinsky oil fields, which pose a serious threat to the population of the nearby village and the Volga River hydraulic system. The article evaluates the contamination and toxicity of the soils of the Ilyinsky oil fields by phytotesting with the culture of the dicotyledonous cress plant (Lepidium sativum) according to the indicators of early seed development. The methods used were ISS R ISO 18763-2019 and ISS R ISO 22030-2009. Soil samples were tested at three monitoring sites: the beginning, middle and end of the oil fields, and soil from an area uncontaminated with petroleum products with similar characteristics was used as a control. The results of the study indicate high toxicity and contamination of the soil at individual monitoring sites (at the end of the oilfield) according to the minimum indicators of early development of watercress seeds: germination, stem height and root length of seedlings, where the herbicidal effect of oil sludge on the plant is observed. The territory (the beginning of the oil fields) with minimal soil toxicity and low contamination with petroleum products, which had a stimulating effect on the plant, was also noted. The indicators of seed germination and the height of the above-ground part of the watercress test facility at an early stage of development became the most sensitive to oil pollution.