ИСТИНА

Special Issue "Humics and Living Systems" of the Environmental Research - Elsevier Journal In the Earth ecosystem, photosynthesis and humification function as the coupled anabolic and catabolic processes of organic carbon fixation and liberation, respectively. Photosynthesis is driven by sun energy and leads to production of highly ordered systems of living organic matter, whereas humification is fueled by energy release from breakdown of biomacromolecules, and yields highly disordered systems of non-living organic matter - humic substances - composed of oxidized bioprecursor molecules of predominantly low molecular weight. The living and non-living systems of organic matter interact instantly comprising the ecosystem metabbolism, which sustains environmental health. The reported examples of these interactions range from mediating effects of HS in the polluted ecosystems (Use of Humic susbstances...2005) to the effects of HS on microbial metabolism (Lovley et al., 1996), on plant physiology (Mora et al. 2010), and on human health (Swidsinski et al. 2017). Still, the major problem remains in integrating these scattered pieces of knowledge into holistic view of the role, which humic substances play in environmental and human health. This problem brought about the topic of the Fifth International Conference on Humic Innovative Technologies (HIT) “Humic substances and living systems”, which was organized by the CIS chapter of the International Humic Substances Society on Oct. 19-23, 2019. It took place in the sailing club "Vodnik", located in Moscow Region, Russia (www.humus.ru/hit-2019). The papers presented at the conference formed the basis for this special issue of the Environmental Research. The papers consider both indirect and direct effects of humic substances on living systems. The former include mitigating effects of humic substances in heavy metals and organic xenobiotics. A whole set of papers is developed to evaluating an impact of anthropogenic pollution and different agricultural practices on the quality of soil humic substances. Important conclusions are drawn on the role of these processes for soil organic matter restoration and for environmental health. New tools for studying quality and quantity of humic substances are proposed. Among them is photoacoustic spectroscopy, tritium labeling technique, and others. Another important issue under consideration is a direct impact of humic substances on living cells and organisms including microorganisms, algae, and fungi. The concluding set of papers is devoted to effects of HS on human health. The hot-spot topics, such as immunotoxic, allergogenic, immunotropic properties of HS are discussed. The very promising results for human health application are presented on the example of humic-like oxidized lignin preparation, which was used for the development of the whole family drugs: the mechanisms of action are discussed. The collection of the presented papers provides the state of art on complexity of interactions humic substances and living systems and fosters a deeper view into the impact of humic substances on environmental and human health.