ACCUMULATION OF BENZO[A]PYRENE IN PLANTS OF DIFFERENT SPECIES AND ORGANOGENIC HORIZON OF SOILS OF STEPPE PHYTOCENOSIS UNDER TECHNOGENIC POLLUTION

Abstract

The relevance of the research. Despite a significant amount of research of environmental pollution by polyarenes, there is insufficient information on accumulation of polycyclic aromatic hydrocarbons, and in particular the most toxic benzo[a]pyrene, by various types of herbaceous plants, which determines the relevance of research in this direction. The distribution of benzo[a]pyrene over plant organs and organogenic horizons of soils in the Novocherkassk Power Station effect zone was studied. The main aim wasto study the accumulation of benzo[a]pyrene in plants of different species and the organogenic soil horizon of steppe phytocenoses depending on the distance from Novocherkassk Power Station. Objects. In the coverage area of the Novocherkassk Power Station, the samples of the aerial and root parts of plants and the underlying soil horizons of the organogenic layers were taken to a depth of 0–20 cm. For the study on monitoring sites, dominant species of herbaceous plants: ragweed (Ambrosia artemisiifolia L.), Austrian wormwood (Artemisia austriaca Jack.), noble yarrow (Achillea nobilis L), common chicory (Cichorium intybus L.), common tansy (Tanacetum vulgare L.), creeping wheatgrass (Elytrigia repens (L.) Nevski.)were selected.The cereals: oatmeal (Avena fatua), wheat (Triticum aestivum L.), oats (Avena sativa L.), Wallis fescue or fescue (Festuca valesiaca L.), common reed (Phragmites australis L.), meadow bluegrass (Poap retense L.) were studied as well. Methods. The content of benzo[a]pyrene in plants was determined by the standard method RD 52.10.556-95 in a modification that allows removing interfering lipid macrocomponents of plants by saponification (saponification method). When benzo[a]pyrene was determined by the method of saponification, the saponifiable lipid fraction was initially removed in the samples by boiling the plant sample in an alcohol solution of alkali, followed by threefold extraction of benzo[a]pyrene with hexane. The basis for determination of benzo[a]pyrene in soils is the PND 16.1:2:2. 2:3. 39-03 technique. Quantitative determination of benzo[a]pyrene in the extract was carried out by high performance liquid chromatography. The results. Based on cluster analysis, three groups of herbaceous plants were identified by the level of benzo[a]pyrene content: weak, medium, and active accumulation. The maximum levels of benzo[a]pyrene accumulation were found for fescue, and the minimum for ragweed. It was found that the mass fraction of benzo[a]pyrene in soils and plants naturally decreased with distance from the enterprise. Maximum pollution was detected by the transect of the general direction, 1,6 km from the source. The least polluted sites were laid in the eastern direction. A study of polyarenes accumulation in different organs of plants showed that the roots of all the species studied differed the greatest pollution. The mass fraction of benzo[a]pyrene in the organogenic horizon of soils significantly exceeded its content in plants of various species.

Keywords

• benzo[a]pyrene
• coal burning
• herbaceous plants
• soil
• bioaccumulation
• industrial pollution