Assessment of anthropogenic pollution of the aquatic environment based on hematological parameters of hydrobionts

Anthropogenic impact on aquatic ecosystems is one of the key factors of environmental degradation, which necessitates the search for informative and rapid methods for assessing the state of water bodies. One of the promising areas of modern ecotoxicology is the use of hematological indicators of aquatic organisms as sensitive bioindicators of the impact of pollutants of various origins. Our research has shown that the increase in river water pollution caused by the Russian aggression and the accumulation of organic matter leads to an increase in both chemical oxygen demand (COD) and biochemical oxygen demand (BOD). These indicators are used to assess organic pollution of water bodies. The BOD level reached 6.9 mg O2/l (the norm is 6.0 mg O2/l), the COD value ranged from 32.2 to 40.5 mg O2/l, which significantly exceeds the norm. According to the current State Sanitary Rules and Regulations, the permissible COD concentration in drinking water is no more than 0.3 mg O2/l, for surface water – no more than 30 mg/dm³. It was established that the obtained analysis results indicate that the water quality in the studied areas does not meet the established standards. The article also presents the results of the analysis of changes in the cellular composition of the blood of aquatic organisms under the influence of anthropogenic factors. It is shown that an increase in the level of segmented neutrophils usually correlates with the development of acute infections, inflammatory processes and stress conditions caused by toxicants. An increase in the number of eosinophils is associated with parasitic invasions and allergic reactions, and also indicates immune shifts caused by the action of toxic pollutants. Changes in the ratio of cellular elements of the blood of aquatic organisms are an important diagnostic criterion in the study of the quality of the aquatic environment. Express methods, in particular the micronucleus test, demonstrate high efficiency as a tool for rapid diagnosis of genetic predisposition. The main advantage of this approach is the ease of collecting material even in field conditions, small expenditure of time and resources, and the ability to analyze a significant amount of data. This test allows for a detection of erythrocyte amitosis – a pathological condition of red blood cells, when erythrocytes become binucleated or form one or more micronuclei. Erythrocytes are extremely sensitive to the effects of reactive oxygen species, the formation of which is provoked by heavy metals. The proposed approach can be used for express monitoring of aquatic ecosystems, detection of early signs of toxic effects and assessment of the level of anthropogenic load.