Hygienic approaches to the safety levels identification of microplastics in water

Introduction. The international community’s positioning of microplastics (MP) in water as a new health hazard has determined the relevance and formed the basis of the research objective based on literature data and the results of own sanitary-chemical and sanitary-microbiological experiments to develop a programme of analytical and toxicological studies that will justify the indicators and criteria for assessing the danger of MP as necessary to determine its safe level in water.Material and methods. The research material consisted of 5 mm granules of primary MP made of polystyrene (PS) and polyethylene terephthalate (PET). The granules were ground and the particles divided into fractions of 0–100, 100–250 and 250-500 µm. Publications were searched using the scientific literature databases MedLine/PubMed/PubChem, Scopus, and eLIBRARY. Sanitary-bacteriological and sanitary-chemical methods were used, as well as the TFME-GC-MS method – a combination of solid-phase microextraction and gas chromatography with mass spectrometric detection, laser diffraction (LD) and dynamic image analysis (DIA).Results. Experiments to determine the size and morphology of microplastic particles allowed considering optical methods, including LD and DIA, as promising for determining MP in water. In model water bodies, MP from PS at a concentration of 100 g/L created favourable conditions for the development of microorganisms and stimulated BOD processes. In chlorinated samples with MP, 50 substances were identified, 13 of which are potential products of MP chlorination from PET, some of which have long-term toxic effects. Under the conditions of this experiment, the largest number of substances whose peak area increased after chlorination was observed when treating a sample with an MP concentration of 10 g/L.Limitations. Insufficient representative data from experimental studies on the toxicity and hazard of MP for warm-blooded animals in scientific literature databases.Conclusion. An MP research programme has been developed on the base of the methodology for regulating harmful substances in environmental objects, will make it possible to establish the indicators and criteria for assessing the hazard of MP necessary to determine its safe level in water.Compliance with ethical standards. The trial does not require the submission of the conclusion of the Committee on Biomedical Ethics.Contribution: Tulskaya E.A. – concept and design of the study, gathering material, editing; Sinitsyna O.O. – concept and design of the study, editing; Kalyuzhin A.S., Ryashentseva T.M., Borisova N.A., Sypalov S.A. – gathering material, data analysis; Turbinsky V.V., Trukhina G.M., Pushkareva M.V. – concept and design of the study, editing. All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.Conflict of interest. The authors declare no conflict of interest.Funding. The study had no sponsorship.Received: November 25, 2025 / Accepted: December 2, 2025 / Published: February 10, 2026