ECOTOXICOLOGICAL ASSESSMENT OF THE INFLUENCE OF FUEL STATIONS ON THE POLLUTION OF URBAN SOILS WITH HEAVY METALS

Abstract

Problem Statement and Purpose. In modern cities, there is a rapid increase in the number of gas stations (gas stations), which are also located in residential areas of cities, causing a high level of local pollution. The growing demand for gas station services leads to the expansion of their network and maximum proximity to consumers. Among the specific features of environmental pollution near gas stations are: a high concentration of pollutants in the surface layer of the atmosphere with subsequent deposition on the soil cover and the surface of plants, the absence of dispersion of pollutants by wind currents, the presence of a significant traffic load and toxic emissions from motor vehicles during refueling, etc. Among pollutants, heavy metals have a particularly negative impact, which, due to participation in various migration cycles, pollute all vital spheres: atmosphere, hydrosphere, pedosphere. The high content of heavy metals negatively affects the main functions of living organisms and human health. Soluble forms of HM are especially toxic. The purpose of this study is to assess the ecological state of urban soils in relation to their contamination by soluble forms of heavy metals within the influence of gas stations in the city of Odessa. Data & Methods. As a methodological basis, the developments presented in the scientific works of A. Antropchenko, I. Rabosh, O. Chaika and others regarding the assessment of the ecological state of the territories in the zone of influence of gas stations were used. When determining the impact of gas stations on soil pollution, the HM used both general scientific methods of research (systemic, analysis, observation) and special ones (laboratory-analytical, comparative-geographical, statistical, cartographic). Results. The conducted studies showed that urban soils within the influence of all gas stations have a significantly higher content of movable forms of HM compared to background values. Thus, the manganese content is 1.3–1.7 levels of the background content; zinc – 7–51; cobalt – 0.6–4; copper – 4–24; cadmium – 0–4; lead – 1.5–14. It was established that by the concentration factor, the most polluted are the soils with the content of zinc, copper, and lead, which is from 100% to 50% of the studied territory. 55% of the studied territory has a dangerous level of soil pollution according to the indicator of total pollution. The priority polluting elements that have the highest level of pollution intensity are zinc (Рj = 121.64) and copper (Рj = 51.01), which according to the scale of assessment of ecological danger of soil pollution belong to the fourth – very dangerous category of pollution, which can significantly influence the increase of the total morbidity of children and adults of the city. The average intensity of contamination of the investigated soils with lead (Рj = 24.92) corresponds to the second level (safe); manganese (Рj = 3.63), cobalt (Рj = 8.22) and cadmium (Рj = 9.46) – the first (permissible level of intensity of soil pollution). The correlation between the intensity of urban soil pollution and the total pollution index is 0.99, which confirms the negative impact of gas station operations on the ecological state of the city’s soil cover. Therefore, the conducted studies indicate a high probability of technogenic influence of gas stations on the soils of the studied territory and a high degree of their contamination with heavy metals, which can cause a negative impact on the health of the urban population. The danger of environmental pollution during gas station operation is currently, in our opinion, underestimated, and the issue of environmental safety of gas station operation requires further study. We believe that in order to increase the ecotoxicological safety of gas stations, it is necessary to conduct constant monitoring studies of the urban environment in order to assess the man-made load on the «soil-plant-human » system.